shafting, pulleys, belting, etc - forgotten books · introduction this handbook is intended to...
TRANSCRIPT
TH E POWER H AND BO O ! S
The b est l ib rary fo r the engin eer and the man who hopes
to b e one .
Th is book is o ne o f them . They are a l l good — and
they cost
postpaid per volume . (Engli sh pri ce postpaid .)
SOLD SEPARATELY OR IN SETS
BY PROF . AUGUSTUS H . GILL
OF THE MASSACH USETTS INSTITUT E OF TECHNO LOGY
ENGINE ROOM CHEMISTRY
BY HUBERT E. COLLINS
BOILERS ! NOC! S AND ! IN! S
SHAFT GOVERNORS PUMPS
ERECTING WOR! SHAFTING,PULLEYS AND
PIPES AND PIPING BELTING
BY F . E. MATTHEWS
REFRIGERATION. (In Preparat i on . )
H ILL PUBL ISH ING COMPANY
505 PEARL STREET,NEW YOR!
6 BOUVERIE STREET, LONDON, E. C .
THE PO WER HAND BO O ! S
Shaft ing, Pulleys, Be lt ingAND
Ro pe Tran smissio n
COMPILED AND WRITTEN
HUBERT E.
IC’ZO L L INS
Copyr ight, 1 90 8 , BY TH E HIL L PUB L ISH ING COM
All r ights reserved
GENERAL
H ill Publ i shing Compa ny, New York, U.S .A .
INTRODUCTION
THIS handbook i s intended to furn ish the readerwi th pract i ca l he lp for the every-day handl ing ofshaft ing , pul leys and be l t ing . These a re a l l ied in theoperat ion of plant s and i t i s a pret ty genera l ly conceded fact that a l l three a re much neglected by manyoperators .
A close perusa l of these pages wi l l enable t he reade rto determine the best course to pursue i n the mostcommon instances and in various t roubles , and in a ll
art icles t here a re suggest ion s for s im i la r cases whichmay arise .
For instance , the need of be l t d ressing as a preserva t ive , now genera l ly conceded by most authorit ies ,i s ful ly covered in Chapte r XI and the resul t of a testmade by disinterested part ies to find the degree ofefl ic iency of four of t he best known dress ings i s given .
The resul t s a re of importance to a l l bel t use rs .A port ion of the book i s a l so given to rope t rans
mission which i s in more genera l use to-day than everbefore , and in this connect ion some advice i s offeredby experts as to the se lect ion and care of the rope .
Rope spl ices and how to make t hem wi l l a l so proveva luab le to many engineers .The author wishes to make acknowledgment tovarious contributors t o Power whose art icles are used
V
1 9 648 6
vi INTRODUCTION
herein , and to some specia l cont ributors , from whoseart icles smal l port ions have been taken . Acknowl
edgment i s a l so made to Stan ley H . Moore , t he authorof “Mechan ica l Engineering and Machine Shop Pract i ce ! for the sect ion on spl icing .
HUBERI E. COLLINS.
NEW YOR! , November, 1 90 8 .
CONTENTS
SHAFTING HINTSSHAFTING HINTSSHAFTING HINTSTRUING UP LINE SHAFTINGAPPARATUS FOR LEVELING AND LINING SHAFTINGSOME PRACTICAL ! IN! SPRACTICAL METHODS OF LOOSENING PULLEYSSPLICING LEATHER BELTSCARE AND MANAGEMENT OF LEATHER BELTSBELTINo— ITS USE AND ABUSEA COMPARATIVE TEST O F FOUR BELT DRESSINGSBELT CREEPROPE DRIVESA NEw SCHEME IN ROPE TRANSMISSIONH ow To ORDER TRANSMISSION ROPEA BELTING AND PULLEY CHARTSPLICING ROPEWIRE ROPE TRANSMISSIO N
SHAFT I NG H INTS 1
IN t he i nsta l l at ion , maintenance and repai r of shafting , as i n a l l other things , the re i s a right and a wrongway ; and though the wrong way ranges i n i t s defect sfrom matters causing t rivia l inconven ience to ab
'
solutedanger , the right too Often owing to lack of knowledge O r discernment — finds but scan t appreciat ion .
Where , as i s O ften t he case , the end Of a shaft i sjourna led to admit Of the use Of an Odd , smal l-borepi l low block or wal l-box hanger , t he journa led partshould equa l i n length twice the lengt h of the hangerbearing plus the length of the col la r . The hanger canthus readi ly be s l id out of the wal l box , and the necessity of uncoupl ing th is shaft length and removing i tbefore access to the bearing for purposes Of clean ingor repa i r i s done away with .
A plank or board A (Fig . I ) , about i to 73 inch longerthan the distance from the bot tom of the shaft to thefloor , can be used to good advantage a t such t imes tofree the hanger of the shaft ’ s weight , and to preven tthe shaft ’ s springing from its own weight and the pul leysi t may be carrying .
Should i t become necessary to place a pul ley with1 Con tributed to Power by Chas . H errman .
SHAPTING ,PULLEYS , BELTING,
ETC .
ha lf the hub on and hal f off t he journa led part , thi scan readi ly be done by the use Of a sp l i t bush ing, asshown in sect iona l View Of Fig . I.
CCNYERW
FIG . I .
Very often a sma l l -s i zed bearing i s used and the shaftjourna led ofl to act a s a col la r . Of thi s procedure i tcan on ly be sa id that i f done with the idea of making a“good job it s igna l ly fa i l s of i t s Object ; i f Of necessi ty
(a col la r be ing insuffi cien t ) , t hen the shaft i s heavi lyoverloaded and serious t rouble wi l l resu l t , because of i t .I t i s advisab le to center punch , or otherwise mark ,
the ends of both shaft s held by a compression coupl ingclose up against the coupl ing, and both edges of thecoupl ing hub should have a punch mark just oppositeand close to the shaft punch marks . These marks wi l lserve a t a l l t imes to show at a moment ’ s glance anyend or ci rcumferent ia l s l ippage of the shafts with i nthe coupl ing . The same method can be resorted tofor proof of pul ley sl ippage .
When a new l ine of shaft ing is put up , the foot posit ion of each hanger should be clea rly marked out onthei r respect i ve t imbers after the shaft has been brought
SHAFTING HINTS 3
i n to a l inemen t . Hangers can thus be eas i ly put backin to the i r proper pla ce should t imber shrinkage or heavystra in s cause them to sh ift out of l ine . This idea can beappl ied to good advantage on old l ines a l so , but beforemarking out the hanger posit ions the shaft should bet ried and brought in to perfect a l inement .Hangers t hat do not a l low of any vert ica l adjustment
should not be used in old bui ldings that a re l iab le toset t le . Sha ft ing so run pret ty nearly a lways get s outand keeps out of level .In flanged bol t Coupl ings (Fig . I ) no part of the bol t
should project beyond the flanges . And where a bel truns in close proximity to such a coupl ing , spl i t woodcol la rs should be used to cover i n the exposed coupl ingflanges , bol t heads and nuts . Countershafts have beentorn out of place t imes innumerab le by bel t s get t ingcaught and winding up on the mai n l ine .
Whenever possib le a space of 8 to IO i nches shouldbe left between the end Of a shaft l ine and the wa l l .A sol id pul ley or a new coupl ing can thus readi ly beput on by simply uncoupl ing and pushing the twoshaft lengths apart without taking ei ther down . Teninches does not represen t t he ful l scope of pul leysadmissib le , for so long as the pul ley hub does not exceed a 10 - i n ch length the pul ley face (the more readi lyi n proport ion to the la rger pul ley diameter) can beedged i n between the shafts .Fig . 2 i s an i nstance Of bad judgmen t i n locat ing the
bearings . In one case thi s bearing overheated ; t heremedy Is eIther to re-babbit t the old box or replacei t wit h a new one .
4 SHAFTING,PULLEYS
,BELTING
,ETC .
Both pul leys were sol id and the keys— head lessones— had been driven home to stay . The rims ofboth pul leys a lmost touched the wa l l , and the circumferent ia l posi t ion on t he shaft of both these pul leyswas such as to preclude the possibi l i ty (owing to anarm of a being in a di rect l ine with key BI and armof b with key d
l) of using anything but a s ide oflset
key sta rt ing drift .
DAB TO R W YHEN7 045 W !
W FTYOOCTHSR
FIG . 2.
An effort was made to loosen b (which was fa rthestfrom the wal l ) by s ledge-driving i t toward the wa l l ,hoping t hat t he pul ley might move o ff the key . Thekey , as was afte rward found out , not having been oi ledwhen origina l ly driven home had rusted in p lace bad ly ;t hough the pul ley was moved by sledging , t he key ,
secure i n t he pul ley hub , remained there .
Ul t imate ly one of us had to get in to pul ley b, and ,removing cap 5 , hold t he improvised side offset , long ,start ing drift D i n place aga inst B1 a t whi le the otherswung the hand sledge a t a . The en tering end of t hekey , not having been fi le chamfered off, as i t shou ldhave been (see E) , our sta rt ing drift burred i t up ; so ,after having started i t , we had the p leasure of get t ing
6 SHAFTING,PULLEYS
,BELTING
,ETC .
driven shaft (as B) , so as to provide a ready mean sfor shut t ing off the power in cases of emergency .
Figs . 4, 5 and 6 represen t a dangerous mode , muchi n vogue , of driving an overhead floo r . An ext remelys lack be l t connect s t he driving shaft A and t he drivenshaft B; when i t i s desi red to impart mot ion to thedriven shaft t he bel t t ightener C i s let down and bel tcon tact i s thus secured .
FIG . 4. FIG . 5. FIG . 6
Thi s t ightener system is ca l led dangerous advised ly ,for few are the shops employing i t but that some em
ployee has good cause to remember i t . Un l ike a clutchwhere cont rol of the power is posi t i ve , i n stantaneous
and simple — the t ightener cannot be handled , as inemergency cases i t has to be .
I n any but st ra ight up and down drives with t hedriven pul ley equa l to or la rger (diamet rica l ly) t hant he driver
,un less t he be l t have specia l lead ing id lers
t here i s more or less of a constan t bel t con tact with i t sresul tant l iabi l i ty to sta rt the driven shaft up unex
pec tedly . When t he t ightener i s complete ly off, the
SHAPTING HINTS 7
be l t,owing to heat , weight or be l t faul t , may at any
t ime cont inue to cl ing and t ransmit power for a shortspace
,despi te t hi s fact .
These t ighteners a re usua l ly pret ty heavy in fact,
much heavier t han the unfami l ia r imagines when onthe Spur of emergency he grapples t hem , and t roubleresu l t s .Tightener (i n Fig . 5) A i s he ld i n place by two
threaded rods B — as shown by slot a i n A l — andregulated and t ightened by ring-nuts C working a longthe threaded port ion of B . C (of Fig . 4) i s a l so apoor arrangement . Fig . 6 i s t he best Of t hem al l .Apropos of cl utches , great care must be exerci sed
in t ighten ing them up whi le t he shaft ing is in mot ion ,
for i f the least bi t overdone the clutch may start upor , on being locked for t ria l (according to the clutches
’
st ructure ) , cont inue runn ing without possib i l i ty ofre lease unt i l t he main source of power be cut off.
Noth ing can exceed the danger of a clutch on a sprungshaft .Heavi ly loaded shaft ing runs to much bet ter advan
tage when cente r driven than when end driven , andwhat often const i tutes an overload for an end drivei s but a ful l load for a center drive . To i l lust rate ,here i s one case of many : The main shaft end drivenwas so overloaded that i t could be a l ined and
leveled one week and be found out one way or theother , frequent ly both ways , the next week . Beingt i red of the cease less t inkering that the condit ion underwhich that shaft was working necessi ta ted , t he pro
prieto rs were given the ul t imatum : A heavier l ine of
8 SHAFTING,PULLEYS
,BELTING ,
ETC .
shaft ing which wou ld be sure to work , or a t ry of t hecenter drive which , owing to the ext reme severi ty ofth is case , might or might not work .
A center drive , being the cheapest , was decided upon .
Pul ley A_,Fig . 7, which happened to be a sol id ,
setscrew and key-he ld pul ley , was removed from the endof the shaft . The spl i t , t igh t-cl amping-fi t pul ley B,
Fig . 8 , was put in the middle of the shaft length ; t he
'
ENCJN
E NGINE DRIVE N
FIG . 8 .
gas engine was sh ifted to accommodate the new d rive,
and hanger C 1 was put up as a re i nforcement to hangerC and as a prevent ive of shaft springing . Afte r thesechanges the shaft gave no t rouble , so that , as had beenhoped , the torsiona l st ra in t ha t had formerly a l l beenat poin t I must evident ly have been divided up betweenpoint s 2 and 3 .
When a main shaft i s bel ted to the engine and to acountershaft , as shown in Fig . 9 , t he pul ley A I get s a l lt he load of main and countershaft s . In the a rrangement shown in Fig . IO poin t 1 get s A ’
s load and 2 get sB
’
s load and is the bet ter a rrangemen t .
SHAFTING HINTS 9
Where a machine is s i t uated close to one of t hecolumns or t imber upright s of the bui ld ing i t i s ve ry
FIG . 9 . FIG . 1 0 .
customary to carry'
t he be l t sh ifter device Upon thecolumn , as i n Fig . I I . The sudden stoppage of amachine se ldom does any damage
,whereas an unex
BE LT ON TIGHT PUL LEY
IF SHIFTED AGAINST UPRIGHTWILL'SHUT OFF POWER
FIG . 1 1 .
pec ted start ing may cause i rreparable damage andoften even endanger the l imb and l ife of the mach ineoperat ive .
Io SHAFTING, PULLEYS , BELTING , ETC .
To avoid t he possib i l i ty of some pass ing personb rush ing up again st the shift ing leve r and thus start ingt he mach ine , t he t ight and loose pul leys of the countershaft should be so placed that when A i s exposedt ha t i s , away from the column i t s acciden ta l sh ift ingshal l s top the mach ine . Fig I2 makes th is poin t clea r .
Th is arrangement i s often used to save a col lar (a tA) . The O il run s out between the loose pul ley and thebearing , especia l ly i f the lat te r be a spl i t bearing ; t heloose pul ley , i n stead of being tota l ly free when the be l ti s on the t igh t pul ley , acts more or less , i n proport ion tothe end play of the shaft , as a buffer between the t ightpul ley and t he bearing ; fina l ly , the t ight pul ley i sdeprived of the support (which , when under load , i tcan use to good advantage) a nearer proximi ty to thehanger would give i t .The shafts of l ight-working counters should not be
need less ly marred with spott ing or flats for col lar setscrews , nor should cup or poin ted set-screws (whichmar a shaft) be used . I f the col la r be sharply tappedwith a hammer,
'
diamet rica lly opposi te the set-screw,
whi le i t i s being t ightened up , a l l s lack i s taken out ofthe col lar ; and the hold i s such that , without resource
SHAFTING HINTS 1 1
to the same exped ien t when loosen ing the col la r, ascrewdriver wi l l scarce ly avai l against a s lot ted setscrew .
When required to sink the head of a bol t i n to at imber to admit of the t imbers lying snug in or againstsome spot , i f a l lowab le , t he bol t
’ s future turn ing canbe guarded against by cut t ing the hole square to fi tthe bol t head . But where a washer must be used , t heon ly posit ive and pract ica l way to preven t t he bol tfrom turn ing is to drive a nai l (as shown ) i n to A (Fig.
I3 ) far enough for the nai l head to flush B; now bend
3\ ‘7 4SECTIONONm-a:
FIG . 1 3 .
the head down behind the bol t toward o. I t i s eviden tthat if t he bol t t ries to turn i n the d i rect ion of 3 t he na i lend (wood he ld) wi l l prevent i t ; i f toward 4, t he na i lhead wil l be forced against t he wood and catch holdof the bol t head .
Large bel t s of engines , dynamos , motors , e tc . , wheni n need of taking-up a re usua l ly at tended to when theplan t i s shut down ; t hat i s , n ights , Sundays or lega lhol idays . At such t imes power is not to be had ; andif the spl iced part
'
of t he be l t , which must be opened ,
shortened , scraped ,re-cemented and hammered , hap
pens to be rest i ng against t he face of one of the pul leys ,i s up between some beams or down in a pi t , t he chancesof the job , i f done at a l l , being any good are very s l im .
The spl i ced part of a large be l t should be clea rly
1 2 SHAFTING,PULLEYS , BELTING,
ETC .
marked in some permanen t and easi ly recogn i zab leway (a rivet , or where the be l t i s rivet-held at a l l i t sjoint s some Odd a rrangemen t of rivets i s as good a wayas any) . This marking wi l l m in imize t he possib i l i ty ofmistake and enable the engineer to place the be l t sp l i cei n t he posi t ion most favorab le for the be l t-maker ’ staking-up .
I n wire- l acing a bel t , very often , despi te a l l effort sand ca re , t he edges of t he be l t (A ,
B) get out of l ine , asshown in Fig . I4, and make t he bes t of jobs look poor.By securing t he be l t i n proper posi t ion by two sma l lp ieces of wi re passed through and fastened at I
,2 , 3
and 4, Fig . 15, t he lacing can be more conven ien t ly
FIG . 1 4. FIG . 1 5.
accompl ished and the edge project ion is avoided . Whenthe lacing has progressed fa r enough to necessi ta te theremova l of wires c d , the lacing a l ready in p lace wi l lkeep the bel t i n i t s origina l posit ion .
A wire lacing under certa in condit ion s wi l l run ace rta in length of t ime to a day . On expensive ma ~
chinery whose t ime rea l ly i s money it pays to renew thelacing at regula r in te rva l s so as to avoid the loss oft ime occasioned by a sudden giving out of the lace .
Neve r throw a be l t on to a rim-frict ion or other kindof clutch whi le t he shaft i s i n ful l mot ion . Bel t s , whenbeing thrown on
,have a knack , pecu l ia rly thei r own ,
1 4 SHAFTING,PULLEYS
,BELTING
,ETC .
someth ing out of place , or a fold of i t sweeping to thefloor s lams th ings around genera l ly un t i l t he poweris shut off .The remedy is obvious : Reinforce A ,
A ’ by securingB, B
’ to the support ing shaft 5 at c l , oz.
‘ The yoke xi s a re l iab le and pract ica l means to th is end . St raps aheld by the nuts b hold the yoke secure ly on the support ing shaft c , whi le the pul ley-shaft ends B, B
’ arehe ld in the U of the yoke a t w’ at any desi red distancefrom c by means of the adjustment provided by thenuts b.
SIDEVIEW
FIG . I7.
The end of a hanger bearing was badly worn (Fig .
I7) . The cap could be l ifted out by removing bridgeA , but the shaft i n terfered with the l ift i ng Of the bot tomout , owing to i t s being he ld i n the hanger s l ides . I thad to be removed and we were ca l led upon to put i ti n to shape by re—babbit t ing .
Being a newspaper plan t , money was no object ;the t ime l imit , however , was th ree hours , or hands off.
SHAFTING HINTS 1 5
Open ing the 3 0 -i nch engine bel t and removing thein terfering shaft length was out of the quest ion in soshort a t ime . So the job was done as fol lows : The shaftwas braced against down sag and engine pul l a long thel ine B C by a piece of t imber at A , and aga inst pul l onB D by t imber arrangemen t X ; t imber y
’
s poin ts y‘
TIMBERARRANGEMENT X
and y2 rest ing against the uprigh ts a t I and 2 ,
t imberwedged in between y at y
? and the shaft at 4, thusact ing as the stay a long l ine B D . The nuts andwashers a , 4 were removed ; t he bol t s driven back outof the bracket ; the end of a rope was thrown over theshaft a t b, passed through the pu l ley and t ied to thebracket and hanger which , as one piece , were thens l id endways off the shaft and lowered to the floor .The bearing was cleaned , re—babbit ted and scraped ,everything put back , s tays removed and the shaftrunn ing on t ime with a ha lf-hour to the good .
When desi rable to keep a shaft from turn ing whi lech ipping and filing l
fla ts , spot t ing in se t screws ormoving pu l leys on i t , i t can be done by in sert ing anarrow st rip of cardboard , soft wood or severa l t h icknesses Of paper between the bearing cap and the topof the shaft and then t ighten ing the cap down .
The packing, 1-16 to 3 - 16 i nch th ick and about as
1 6 SHAFTING , PULLEYS , BELTING,ETC .
long as the bearing , must be narrow ; otherwise , asmay be deduced from Fig . 18 (which shows t he rightway) , by the use of a wide st rip in t he cap the shafti s tu rned in to a wedge , endangering the safety of thecap when forced down . At poin t 3 packing does noharm , but at I and 2 t here i s just enough space to a l lowthe shaft diameter to fit exact ly , with no room to spare ,i n to t he cap bore diameter .
SOFT WOOD PAC ! ING
SHAFT DIAMET ERJUST=CAP SPA N
FIG . 1 8 .
As a very l i t t le clamping wi l l do a good dea l ofholding t he clamping need not be overdone . A shaftcan a l so be he ld from turn ing , or t urned as may bedesi red , by holding i t wit h a screw (monkey) wrenchat any flat or keyway
,as shown in sect iona l view
,
Fig . 19 .
When a shaft b reaks i t i s e i ther owing to torsiona lst ra in caused by overload , springing through lack of
SHAFTING HINTS 1 7
hanger support at t he proper inte rva l of shaft length ,the ist ra in of imperfect a l inement or leve l , or a flaw .
An immediate temporary repai r may be effectedby taking some spl i t pul ley that can best be sparedfrom another part of t he shaft and clamping it over thebroken part of the shaft , t hus convert ing it , as i t were ,i nto a compression coupl ing . The longer the pul leyhub the bette r t he hold ; spot t ing t he set-screwst hat i s
,chipping out about fi-in ch holes for the ir a ccom
moda t ion in to t he shaft is a l so a great help .
FIG . 1 9 .
I f when t he shaft breaks i t has not been Sprung bythe sudden dropping of it se lf and the pul leys that wereon i t
,a permanen t repa i r can be effected , afte r correct
ing the cause of the break , by the use of a regula r keyless compression coupl ing .
I f i t has been sprung , a new length comes cheapesti n the wind-up ; and if overload was the origina l causeof the t roub le , on ly a heavie r shaft or a considerablel ighten ing of t he load wi l l prevent a repet i t ion .
I n Fig . 20 A shows how to drive to make bel t weightcount i n securing ext ra contact . I n B t h i s weightcauses a loss of contact . Bearing in mind that B i snot on ly a loss from the normal contact but a l so a lossof the ext ra contact t hat A gives , i t wi l l readi ly be seenhow importan t a power-saving factor the right sort of
1 8 SHAFTING , PULLEYS , BELTING,ETC .
a drive i s —especia l ly on high-speed smal l-pul ley machines , such as dynamos , motors , fans , blowers , etc .
EXAGGERATED FOR
CLEARNESS
FIG . 20 .
A good many elect rica l concerns mount some of thei rstyles of dynamos and motors (especia l ly t he l ightduty
,sma l l si ze ) upon two V—shaped ra i l s , Fig . 2 1
(the bottom of the motor or dynamo base being Vgrooved for the purpose) . The machine
’ s weight and
FIG . 2 1 .
the screws A are counted on to keep i t i n pla ce . I ft he machine be properly mounted on these rai l s , asregards screws A i n re lat ion to i t s drive , t he screwsreinforce the machine ’ s weight in holding i t down anda l so permit a surer adjustment through th is steadyholding of the machine .
SHAFTING HINTS
Fig . 22 shows the machine properly mounted . Thebel t tension and pul l tend to draw B corner of themachine toward the shaft C; and screw B1 i s t here toresis t th i s pul l . Owing to th is res istance and the pul la long l ine D , E tends to l ift and s lew around in E1
di rect ion ; screw E2 i s , however , i n a posi t ion to overcome both these tendencies . I f the screws are bothfront , t here i s noth ing but the machine
’ s weightto keep the back .of i t from t i l t ing up . The absurdi tyof placing the screws a t F and G,
t hough even this i st hought less ly done , needs no demonstra t ion .
FIG . 22.
When putt ing a new be lt on a motor or dynamo ,both the drive r and the driven are often need less lyst ra ined by the use of be l t-c lamps , i n t he at tempt totake as much st retch out of the belt as poss ib le . Onbeing loose ly endlessed i t soon requi res taking up ; andif on ly laced , when the t ime for endlessing comes t hebe lt i s botched by the spl i cing in of the piece which ,owing to the in sufficiency of the origina l be l t length ,must now be added to supply enough bel t to go around ,
plus the spl ice .
20 SHAFTING, PULLEYS , BELTING ,ETC .
The proper mode of procedure i s : P l ace the motoron i t s ra i l s or s l ides 5 i n ches away from i ts nearestpossib le approach to the driven shaft or machine andwire-lace i t (wire-lacing is a very close second to anendless belt ) . Let i t run for a few days , moving themotor back from the driven shaft a s the bel t st retches .When a l l reasonable st retch is out , move the motorback as close to the driven shaft a s possible .
The 5 i nches forward mot ion wi l l gi ve IO i nches ofbe l t ing
,which wi l l be amply sufficient for a good spl ice ;
and,further , the machine wi l l be in posi t ion to a l low of
t ighten ing the be l t up , by simply forcing t he motorback , for probably the be l t
’ s l i fe t ime .
22 SHAFTING,PULLEYS
,BELTING
,ETC .
t ha t the bol t may be he ld by a screwdriver whi le t henut i s t urned wit h a wrench .
Where an ext ra st rong screwdriver must be used,
the use of two blades a t the same t ime in the hack-sawframe wi l l give a slo t of the requis i te width . Wherethe bol t ’ s end p l
‘
OJCCtS beyond the nut and i t i s desi redto t ighten the nut a St i l l son wrench i s O ften , t houghinadvisedly , ca l led Into service . This tends to spoi l t helower threads of t he bo lt and thus preven t s any futureloosen ing , except by the cutt ing off of the project ing end .
FIG . 23 .
As t he a l i nement and leve l of shaft ing depend on thepower of the i r hold , bol t s , lag-bol t s and set-screwsshould , when they are t ightened , be so in fact and notin fancy .
The proper way to use a wrench , especia l ly a screwwrench , so a s to ava i l yourse l f of every ounce of power ,not of your b iceps on ly but of your who le body , i s a sfol lows : P lace your shoulders on a leve l with the Objectto be t ightened , secure the wrench jaws wel l upon i t ,
SHAFTING HINTS 23
grasp the jaws with the left hand and the wrench handlewith the right , holding bot h arms st ra ight and ten se ;swing the upper part of the body to t he right from thehip
,backing the force of your swing up with the ful l
force of your legs , steadying yourse lf the whi le wit hyour left-hand grip on the wrench jaws , which are thecenter of your swing . Severa l such ha lf turns , atthe wind-up ,
wil l cause an extremely hard jam withcomparat ive ease .
I n t ighten ing up a spl i t-pul ley , the expedien t ofhammering the bol t s t ight
,by mean s of an open—ended
bolt-wrench and a smal l s ledge , i s often resorted to .
I f the head of the bol t be l ight ly tapped whi le the nuti s being t ightened
,even a l ight hammering , except
in the ext remest cases,becomes unnecessary .
Spl i t-pul leys are invariab ly bet ter he ld in place bya good clamping fi t t han by set-screws . I t must a l sobe borne in mind that
,for good hold ing , set-screws must
be spotted in to the shaft,and thi s defaces and Often
materia l ly weakens the shaft . Spl i t-pul leys , l ike sol idones , a re l somet imes subject to stoppage , owing toexcessive St rai n . Set-screws , at such t imes , cut a shaftup pret ty badly ; whereas , i f clamped , on ly a few sl ightscratches would resul t .Where packing with paper , cardboard , emery clot h
or t in becomes necessary to secure a good clamping fi t ,care should be taken to put an equa l th ickness of packing in to both ha lves of the pul ley ; otherwise i t wi l lwabble and jump when runn ing .
Emery cloth , on a ccount of i ts grit t iness , i s preferab le for packing where the duty done by the pul ley
24 SHAFTING , PULLEYS , BELTING ,ETC .
i s l ight . When the duty done is ext ra heavy,emery
cloth , despi te i t s gri t t iness , wi l l not do ; t i n or sheeti ron , owing to body , must be used .
The fol lowing i s the most pract i ca l way of packing aspl i t-pul ley to a good clamping fi t , assuming that emerycloth i s to be used :The thickness of the emery cloth to be u sed ,
andwhether to use one or more folds
,can readi ly be ascer
ta ined by ca l ipering the shaft d iamete r and pul leybore , or by t ria l-clamping the pul ley by hand . I n bothof these i n stances , however , due a l lowance must bemade for the compressiveness of the packing used .
I f the packing be too th in , t he pu l ley wi l l not clampst rongly enough ; i f too th ick , the chances of breakingthe lugs when draw ing the bol t s up a re to be appre
hended .
Having determined the proper th ickness of emerycloth to be used , place the pu l ley on the shaft , as showni n Fig . 24. I nto the lower ha l f C, i n space A ,
which i sout of con tact with the shaft , place a sheet of emerywith the emery side toward the hub and the smoothside toward the shaft . The width of the emery shouldbe a l i t t le less than ha l f of t he shaft ’ s ci rcumference ,and i t should be long enough to project about one-ha l fof an inch to an inch on each side of the hub .
Now t u rn t he pul ley on t he shaft so t hat t he posit ionof the ha l ves sha l l become reversed (Fig . C on top ,B on bottom . See that the emery cloth remain s i n i t sprope r posi t ion in ha l f-hub , the smooth side be ingtoward t he shaft ; t he project ing length beyond thepul ley hub wi l l he lp you to do th i s .
SHAFTING HINTS 25
I nto ha lf-hub B (space D ) i nse rt a simi lar s i zed pieceof emery cloth , smooth side toward t he hub and theemery side toward the shaft . Draw up on your bolt s toclamp the pul ley in to posi t ion . Be sure
,however
,
that no emery cloth get s in between the ha lf-hubs orlugs at poin ts I and 2
, Fig . 25, as th is would preven tthei r coming properly together ; t he width of the emerybeing less than ha lf of the shaft
’
s ci rcumference w i llbe a he lp to th is end .
FIG . 24.
I t often happens , m g to downright neglect orunwit t ing neglect
,through the oi l hole or oi le r be ing
blocked up , t hat a loo se pul ley , runn ing un lubricated ,
cuts , heat s , and fina l ly , t hrough heat expansion , se i zes .I t then becomes necessa ry to take the countershaft
26 SHAFTING,PULLEYS
,BELTING
,ETC .
down , force the loose pul ley off and fi le and pol i shshaft up before i t can be put back in to p lace .
FIG . 25.
The fol lowing method avoids the taking down andput t ing back , provides an easy means for loosen ing upthe pul ley that has se i zed , and improvises , as i t were ,a lathe for fi l ing and pol ish ing the shaft .
FIG . 26.
I n Fig . 26, A i s t he loose pul ley tha t has se ized .
SHAFTING HINTS 27
Throw off both the be l t that leads from the main shaftto pul leys A ,
B and the be l t t hat leads to the drivenmachine from the driving pul ley C . Tie , or get somebody to hold , an i ron bar in pul ley A at s ide a , as shownin Fig . 27, over an arm of the pul ley , under t he shaft ,
FIG . 27.
and rest ing against the t imber , ce i l ing, wa l l or floor ,i n such a way as to preven t t he pul ley from turn ing inone di rect ion , as shown in Fig. 27. Now
,w i t h another
bar, of a sufficien t length to give you a good leverage ,take the grip under a pul ley arm and over the shafti n the t ight pul ley B at b, which wi l l enab le you to workagainst the resistance
,of the bar in the loose pul ley A .
°With enough leverage,th i s kind of persuasion w i l l
l oosen the worst of cases . Take the bars out and moveB sufficient ly to the righ t to a l low A to take B’
s formerposi t ion . Secure B by mean s of it s set-screws in i t snew posi t ion and , by means of a piece of cord , fasten
28 SHAFTING,PULLEYS
,BELTING
,ETC .
an arm of A to one of B ’
s . I t Is eviden t that by throwing the main-shaft be l t on to A i t wi l l , th rough A
’
s
cord connect ion with B, which i s screwed to the shaft ,cause the shaft to revolve , t hus enab l ing you to fi leup and pol ish that port ion of i t formerly occupied byA . To preven t the countershaft from side-s l ipping outof hanger-bearing D 1
, get somebody to hold somethingagainst hanger-bearing D2 at E; or fasten a piece ofwire or cord on the counte rshaft a t F and the hangerD1
, so as to prevent s ide-s l ipping whi le not in terferingwith revolut ion .
Fi l ing , pol ish ing, a clean ing out of the oi l hole or
oi le r, and t he taking of proper precaut ion again stfuture fa i lure of l ubricat ion w i l l put everyth ing in tofirst—cl a ss orde r . When the loose pul ley i s , as i t i s bestfor i t to be , fart hest away from the bearing , held in it sp la ce by the t ight pul ley and a col la r , not on ly i s t het igh t pul ley bette r adapted for ca rrying it s load , ow ingto addi t iona l support resu l tan t from its proximityto the bearing , but such mat te rs of sma l l repa i r ascome Up are much simpl ified .
Fig . 28 i n some degree , as ide from the cut t ing up and
FIG . 28 .
heat ing of t he bearings , i l l ust rates the breaking st ra in ,i n addi t ion to the usua l torsiona l st ra in
,which becomes
enhanced in di rect proport ion with the increase ofbreaking st ra in , to which an out-o f-l i ne or ou t-of-leve l
3 0 SHAFTING,PULLEYS
,BELTING
,ETC .
B. Now , i t i s se l f-eviden t , as l i ne C i s s t ra ight and setequidi stant from the shaft end centers G and F
,t hat
i f you set t he ent i re cente r l i ne of the shaft ing at thesame di stance from l ine C, as G and F , you are boundto get your shaft ing into pe rfect a l i nement .I n level ing a l ine of shaft ing t ha t i s a l ready up
,
you can , by the use Of a leve l and perseveran ce , get i tright .P lacing the leve l at A , you are just a s l ike ly to ra ise
the fi rst hanger as to lower the middle one . Lookbefore you jump , even i f compel led to cl imb to the topof the fen ce to do so . When you find a length of shafting out of leve l , t ry the two adjacent lengths beforeact i ng , and your act ion wi l l be the more Inte l l igentfor i t .On except iona l ly long l ines of shaft ing the fol lowing
method , i n which the leve l and a l ine const i tute a checkupon and a guide for each other , can be used to grea tadvantage . St retch a l ine so t hat i t i s exact ly above ,or
,i f more conven ien t , below t he shaft ing to be leveled .
With the level find a length of shaft ing t hat i s leveland adjust your l ine exact ly para l le l wi th thi s length .
Your l ine now , free of contact except a t i t s reta in ingends
,and level owing to i t s para l le l i sm to the level shaft
length,const i tutes a safe b igbt level guide whi le the
leve l i t sel f can serve to verify the accuracy of thefin ished job .
In l in ing , whether for leve l or a l inement , un less theshaft ing l i ne consi st s of the same diamete r of shaft ingthroughout i t s ent i re length , though of necessi ty measuring from the shaft c i rcumference to the l i ne , a lways
SHAFTING HINTS 3 1
base your ca lcu la t ion s on the shaft cen ters . Thefigures in Fig . 29 wil l make th is poin t clea r .The manner of securing the ends of the l ine underdifferen t ci rcumstances must be left to individualIngenul ty . Only be sure that the l ine i s so placed thatt he Shaft ing adjustment shal l not affect i t s origina lposi t ion with reference to the end shaft cen te rs .Coupl ing clutches , those join ing two lengths ofshaft ing in to one at opt ion , wil l fa i l , ut terly or part ia l ly ,if the respect ive shaft s which bear them are out of l ineor leve l wit h each other . Such a condit ion should notbe tolerated on accoun t of the danger en tai led by theinab i l i ty to shut Off the power i n cases of emergency .
As a genera l rule , i t i s most advisable to set a clutchto take as hard a grip as i t can without in terfering withit s re leasing power . Where a clutch grips weakly ,
i t i s subject to undue wear owing to sl ippage , whereasa st rongly regula ted clutch absol ute ly preven ts s l ippage wear .
SHAFT I NG H INTS 1
ENGINEERS, machin ist s and genera l mechan icsare often ca l led upon to turn the i r hands to a shaft ingjob . We recogn i ze that a l l of t he fol low ing cannotprove new or even suggest ive to most of our readers;st i l l , some of i t for a l l , and , mayhap , a l l for some , maynot come amiss .We al l know that to have bel t ing run right ly on
pul leys loca ted upon para l le l l ines of shaft ing theshaft ing must be in absolute ly correct para l le l . Thesl ightest deviat ion , even to a 1- 16 i nch , often impart sa marring effect , t hrough poorly runn ing be l t s , to anotherwise faul t less job .
Fig . 3 0 shows how to l ine a countershaft as regards
FIG . 3 0 .
para l le l i sm with the driving shaft when the countershaft ’ s end-centers are avai lab ly Si tuated for thusmeasuring . A i s t he countershaft , B the main shaft ,C i s a st ick of proper length about I a} i n ches in thickness
1 Con tributed to Power by Chas . Herrman .
SHAFTING HINTS 3 3
and width , D a heavy nai l - about 20 -penny wi l l do- driven into C fa r enough from it s end E to a l low ofC ’ s rest ing square ly upon the top of the shaft B.
Rest the measuring rod upon the main shaft , keepingthe na i l i n touch with the shaft , so that when the Fend is in contact with the end of the countershaft thest ick sha l l be at righ t angles to the main shaft , and thenmark the exact locat ion a of the countershaft ’ s endcen ter on the st ick . Do the same at the other end of thecountershaft . I f both marks come at the same spot
,
your counter i s para l le l ; if not , space between thesetwo marks wi l l show you how much and wh ich way thecounter is out .I t may on ly be necessary to sh ift one end in or out
a l i t t le ; and then , aga in , i t may be tha t to get into°
line
you wil l have to throw one end a l l t he way in one direct ion and the other a l l or some in the opposi te di rect ion .
But , whichever i t be , do not rest conten t un t i l you haveverified the correctness of your adjustment by a re
measuremen t .The nai l should be Wel l driven in to C, so tha t i ts
posit ion wi l l not readi ly change,and i t should , pre
ferab ly , be s lan t driven (as shown in Fig . as it ~thus
helps to keep the st ick down in con tact wi th the shaft .Where an end-center i s not avai lable or where there
i s no clear space on the main shaft,opposi te a center,
the method shown in Fig . 3 I can genera l ly be used .
Rest C on top of both shafts and at right angles tothe driving shaft B. With D pressed against B, placea square on st ick C, as shown (stock in ful l contact withthe top of the rod , and the tongue running down the
3 4 SHAFTING , PULLEYS , BELTING,ETC .
s ide of i t) . S l ide a long C toward A unt i l t he s ide oft he tongue touches the shaft t he other s ide of A . Nowmark a l ine on the st ick down tongue . Do the sameat t he other end of your coun tershaft and the tworesu l tan t marks wi l l be your pa ra l le l adjustment gu ides .
FIG . 3 1 .
I t often happens tha t a coun te r , or even l ine shaft ,i s end driven from the ext reme end of the main or jackdriving shaft wit h i t s othe r end runn ing beyond t hereach of the driving shaft , as shown in Fig . 3 2 .
FIG . 3 2.
I t i s eviden t tha t nei ther method I nor 2 can herebe appl ied to solve the a l i nemen t problem . If the
SHAFTING HINTS 3 5
driving pul ley B and the driven pul ley A a re both inplace
,the fol low ing method can be used to advantage .
Fasten , or let somebody hold , one end of a l ine againstpul ley B ’
s rim at B‘; ca rry the l ine over to A a t A2;
now sweep the loose A2 end of the l ine toward pul ley Aunt i l t he l ine just touches pul ley B ’
s rim at BZ. When
the l ine so touches and it must just ba re ly touch orthe measurement i s worth less A I and A2 of pul ley Amust be just touched by or (if B and A a re not of a l ikeface width , as in Fig . 3 2) equidistan t from the l ine .
A single , two-hanger—supported length of shaft ingthus l ined is bound to be in pa ra l le l ; but where the soadjusted shaft l ine consist s of two or more coupl ingjoined lengths supported by more than two hangers ,on ly pul ley A ’
s support ing port ion of the shaft betweeni t s immediate Support ing hangers I and 2 i s sure to bel ined ; the rest may be more or less out .To make a perfect job , fix a st ring in para l le l with
shaft length I and 2 , st ret ching a long the en t i re lengthof the adjusted shaft , and a l ine the rest of the Shaftlength to i t .When there are no pul leys in place to go by , or when ,
as occasiona l ly happens,the wabbly mot ion of pul ley
B (when running) i ndicates t ha t , having been ina ccura te ly bored or bushed , or being located on a sprungshaft length
,i t s rim l ine i s not a t right angles to the
shaft l ine , t he method shown in Fig . 3 3 can be re
sorted to .
I nstead of the nai l used in methods I and 2 , use aboard about 8 to I2 i nches long and of a width equa lto considerably more than ha lf of shaft B’
s diameter .
3 6 SHAFTING,PULLEYS
,BELTING
,ETC .
By nai l ing t his board x to the measuring rod c a t anysuitable angle , you wi l l be enabled to reach from theend 4 We l l in to the shaft B, as a t b, and from b’ wel l in toA , as a ’
. By keeping the board x a long i t s ent i re lengthi n ful l contact with the shaft B at both I and 2 ,
theangula r posi t ion of rod C i s bound to be the same inboth instances , and you wi l l t hus (by the use of a square ,as in Fig . 3 1 ) be enabled to a l ine A para l le l with B.
FIG . 3 3 .
I n a l l i n stances of paral le l adjustmen t here ci ted i ti s a ssumed that both t he a l ined and the a l ined-toshafts have been , as to secure accuracy of resul t t heymust be , prope rly leve led before sta rt ing to a l ine .
The above methods apply to cases where the shaft ingi s a l ready in place . Where , however , shaft ing i s beingnewly in sta l led before the work can be proceeded with ,i t i s necessa ry , after dete rmin ing on the locat ion for theshaft ing , to get a l ine on the cei l ing in para l le l with thedriving shaft to which to work to . Mark tha t
, po int A
which you in tend to be the center l ine for the proposedshaft ing upon the ce i l i ng (Fig .
3 8 SHAFTING , PULLEYS , BELTING , ETC .
and , for the better assurance of accuracy , as t o justtouching a t 2 , remove and readj ust t he l ine sepa rate lyeach t ime . I f now a st ra ight l ine from 3 to 5 cut s 4,
your l i ne 5 i s a t right angles to the driving shaft anda l i ne a t right angles to thi s wi l l be para l le l to the shaft .
FIG . 3 5.
The plumb-bob method is so fami l ia r and , where notfami l ia r
,so eas i ly thought out In Its va rious appl ica
t ions , that we deem i t use less to touch upon i t .The st ringers or support ing t imbe rs of drop hangers
shou ld be equa l i n th ickness to about one-fifth Of thehanger drop .
Where the st ringers run with the hangers and crosswise of the shaft
,both feet of a hanger base are bol ted to
the same st ringe r,and th is should be from I } to I%
t imes the w id th of the widest port ion of the hanger base .
As the hanger i s secure ly bol ted to i t s s t ringer , t h i sext ra Width i s i n effect an en la rgement of the hangerbase , and thus enables i t the be t te r to ass i st t he shaft
’
send motion .
Where the st ringers run with the shaft and crosswise of the hangers , the two feet of the hanger base areeach fastened to a sepa rate t imber , and these should
SHAFTING HINTS 3 9
be equa l i n width to t he length of one hanger foot,plus
twice the amount of adjustment (i f there be any) thehanger ’ s support ing bol t s lots wi l l a l low it . In reckoning hanger adjustment , be sure to figure i n the
'
bo lt’
s
diamete r and to bear i n mind that to get the utmostadjustment for the countershaft the bol t s shouldorigina l ly be cen tered in the s lot ; thus a Ifr 1 3-i nchs lot , as i t ca l l s for a. i -i nch bol t , leaves a -i nch play
,
FIG . 3 6.
and th i s p lay , with the bol t i n the cen ter of the s lot ,a l lows of g-i nch adj ustmen t e it he r way . Without th isext ra width addit ion any latera l adjustment of thehanger would resul t i n l eaving a part of the hanger ’ sfeet without st ringer Support . Such jobs look poorly,and often run st i l l more poorly . Fig . 36, i n i t s twoViews , W i l l make the above poin t s clea r.I n the stringing of countershafts whose hangers
have no adjustment i t often happens , despi te a l l care
40 SHAFTING ,PULLEYS
,BELTING
,ETC .
i n the laying out , that they come to 5, i nch out of pa ra lle l . A very common and l ikewise very dangerous pract ice at such t imes i s to subst i tute a smal ler diametersupport ing bol t i nstead of the large r si ze for which thehanger foot i s cored or dri l led , and to make use of theplay so gained for adjustment .That shaft ing so carried does not come down oftener
than i t doe s i s due solely to the foresight of the hangermanufacturers . They , i n figuring the support ing bol t ’ sdiameter as against t he st ra in and load to be susta ined
,
are carefu l to provide an ample safety margin for overload
,thus enabl ing the bol t subst i tuted to just barely
come with in the safety l imit under easy working cond it io ns .
The la rgest-s i zed bol t that a hanger wi l l easi ly admitshould i nvariab ly be used , and for a l inement purposese i ther of the fol lowing s lower but safer methods shouldbe used .
Rebore t he hanger-support ing bol t holes i n thest ringers to a la rge r s i ze , and use the play so gained foradjustmen t . I t i s not advi sable , however , to reborethese holes any la rger t han to one and three-quartert imes the diamete r of the bol t to be used ; and thediameter of the washers to be used on top of t hest ringers should be diamet rica l ly equa l to a t leasttwice the si ze of the rebored holes . That the washersused , under such condi t ions , must be of a good pro
po rt io na te th ickness goes wi thout saying .
When the reboring method cannot be used aswhen the hangers a re ca rried by lag screws , lag—bol ts ,bol t s screwed di rect ly in to support ing i ron gi rders ,
SHAFTING HINTS 4 1
etc .
— it i s eviden t t hat hanger adjustment can besecured by packing down one foot of the hanger base
,
as shown in Fig . 3 7.
HANGER 1
FIG . 3 7.
The piece of packing (necessa ri ly wedge-shaped)between the hanger foot B and the st ringer A t i l t st he bot tom of the hanger forward . The size of t he
Wedge regulates t he amount of adjustment . Wedgeshaped Space D , at foot C, should a l so be packed outso as to avoid throwing undue st ra in upon C ’ s ext remity
‘
c . I f now , t he foot c of the countershaft’ s
other Support ing hanger (No . 2) be simi larly and equal lypacked
,as B of No . I hanger , the shaft wi l l have been
thrown forward at one end and back at the othe r,and
thus in to l ine . The equal divi sion of the adjustingwedge packing between the opposi te feet of the twohangers enables a l imited packing to do considerabl eadjust ing without any undue marring effect ; and ,further
,in sures the shaft ’ s rema i n i ng level , which evi
42 SHAFTING,PULLEYS
,BELTING
,ETC .
dent ly would not be the case if on ly one hanger werepacked down .
After so adjust ing , be sure to get your hangerssquarely crosswi se of the shaft as readjusted
,so t hat
t he hanger bea rings wi l l l ie i n a t rue l ine with the shaftand not bind i t . At a l l t imes be sure to have yourhangers hang or stand plumb up and down ; as , i f thebearings a re not so pivoted as to be hori zon tal ly se lfadjust ing, excess ive frict ion wi l l be the lot of one endof the bearing with not even con tact for the rest of i t .The bearing being se lf-adjust ing
,
a l l ways,square
crossing of the shaft l ine by the hanger l i ne and plumbst i l l remain eminen t ly des i rable for appea rance ’ s sake .
Before a countershaft can be put up on a ce i l ingwhose support ing t imbers a re boarded over
,or in a
modern fi reproof st ructure Whose gi rders and beamsare so bricked and plaste red in as not to show , i t i snecessa ry to posi t ive ly loca te t hose of them whicha re to carry the st ringers .I t i s i n the earnest endeavor to properly locate these
t hat the unaccustomed hand turn s a wood cei l ing intoa sieve and a brick one in to a wreck . To avoid kitchenand house razing effect s , t ry the fol lowing recipe :We wil l a ssume tha t l ine A B
, Fig . 3 8 , l a id out byone Of t he methods previously described , i s t he centerl i ne of the proposed countershaft . The hanger
’
s baselength
,l a te ra l adjustment and individua l foot length
cal l for st ringers 41} i nches wide , placed 5} i nches apart
or I4i! i nches outside (as per sketch ) . The floor posi t ionof the mach ine to be driven , or the driving poin t of themain shaft
,i s so located with reference to the counter
SHAFTING H INTS 43
shaft tha t one of the support ing hangers must go a t orvery nea r C, and the countershaft
’ s length brings theother hanger at or very nea r D .
Now between point s C D and with due reference tothe center l i ne A B, l ay out the posi t ion which yourst ringers are to occupy . I t i s se lf-eviden t tha t byconfin ing your beam prospect ing to t he st ringerspaces E and F , ult imate ly , when the countershaft i si n place
, a ll the cut-up port ion s of the ce i l ing wi l l behidden from view .
FIG . 3 8 .
Genera l ly the necessary support ing beams wil l nota l l be found within t he shaft ’ s length distan ce C D ;i n such cases cont inue your cut t ing in the same para l le ll i ne to A B, as a t E or F , going from C D outward lyunt i l you st rike the sought-for beams . Having locatedbeams , say I and 2 , we find by measurement that theyare 5 feet apa rt , and , a s beams a re genera l ly un iformlyspaced , we may start 4 feet 6 i nches (go 4 feet 6 inchesand not 5 feet , to make sure not to skip beam 3 and
44 SHAFTING , PULLEYS , BELTING , ETC .
t hus make a cut tha t wi l l not be covered by the st ringers) from I to cut outward ly for the locat ion of beam 3 .
Where the bui lding ’ s beams run para l le l to theshaft , Fig. 3 9 , mark the counter
’
s-center l ine A B,and
then mark the spaces a s determined by the countershaft lengt h , floo r posi t ion of the driven machine or t hed riving poin t on the ma i n shaft — to be occupied bythe st ringers C D , and , sta rt ing from the cente r l ineA B, cut outward ly each way to the desi red beamsI a nd 2 .
FIG . 3 9 .
Where the cen te r l ine a s la id out the pos i t ionof t he ce i l ing beams wa s known ) brings i t close to ord i rect ly under a support ing beam , i t i s genera l lyadvisable where possible to step t he counte r back orforward to a cen t ra l posit ion between the beams .Where sha ft ing i s a l ready in place i n a bui ld ing , no
matte r on what floor , va l uable mea su remen ts a s tobeam locat ion can t hus be had from the pla in ly in sightand the reasonably deducible . La cking in-place-shafting to go by
,the wal l s
,col umns and main gi rde rs a lways
clea rly i ndica te t he crosswise or pa ra l le l run of thece i l ing beams to the proposed shaft ing l ine .
46 SHAFTING, PULLEYS , BELTING,ETC .
t hey can be sen t home safe and t rue in the center of thet imber .I t often happens that i n boring for the lag screws
the bit st rikes a na i l and further progress at that poin tseems out of the quest ion . When so si tuated
,take your
bi t out , and runn ing the lag screw up as far as i t wi l l go,by sheer force swing i t th ree or four turns up furtherthan the poin t where your b i t st ruck . Removing thelag and rep lacing the bit , i t wi l l be found that the nai lhas been forced aside and the way is now c lear.
ELEVATION
PLAN
FIG . 42.
Hook bol t s (Fig . 42) or as our across-t he-seacousins ca l l t hem “e lbow bol t s ,
! despi te a ll asse rt ions to the con t ra ry , are an easy , safe and economica lst ringer fastene r or suspending device .
Figs . 43 and 44 i l l ust rate two very common abusesof the hook bol t . I n the one (Fig . i n stead of thebol t proper lying snug up aga inst the beam flange withthe whole of i t s hook rest i ng square ly upon the beam ’ sflange , i t s support ing countershaft i s turned into amenace to l imb and l ife by thi s “chance i t kind of
TING HINTS 47
erect ion . I n the other (Fig . though the bol t sdo l ie snug against the flange , the hook being out ofsight and no means being provided for te l l ing whether
FIG . 43 .
t he hook l ies , as i t should , at righ t angles to the Webof the beam , even if properly placed at insta l la t ion ,t imber shrinkage , vibrat ion or a sl ight turn of the bo lt
when t ightening the nut , al l const i tute dangerousfactors tending to loosen or en t i re ly loosen the boo k
’
s
grip upon the beam flange .
Fig . 43 suggest s i t s own remedy . As to Fig . 44, ascrewdriver s lot (made by a hacksaw) at the nut endof the hook bol t and running in the same di rect ion as
48 SHAPTING ,PULLEYS
,BELTING,
ETC .
the hook,Fig . 45, wil l a t a l l t imes serve to i ndicate t
hook ’ s posi t ion and , a l lowing as i t does of a comb inuse of screwdriver and wrench , i t can be used to pven t the bol t ’ s t urn ing when being t ightened .
Ho o k s
Pl ate
Pl a te
FIG . 45. F IG . 46.
Where two or more hook bolt s a re placed close togethe r on the same beam flange , a pla te , preferablywrought i ron with properly spaced confin ing pins forthe hooks , may be placed be tween the beam flange andthe hooks as in Fig . 46. I ts benefi t s a re obvious andso l ikewise i s the use of a smal l , square , wrought-i ronp late with a bol t hole th rough it s center instead ofhook bol ts .The various styles of beam clamps carried by
,t he
hardware and supply t rade a l l have thei r good poin ts ,and though the C of thei r cost may seem to loom large ,i t i s not a whi t more emphat ic , taken a l l i n a l l , t hanthe W of thei r worth .
TRU ING UP L I NE SHAFT I NG
IT i s a ssumed , for the purposes of th is descript ion ,t hat t he modern style of shaft ing , i ncreasing in diameterby the 5 i nch , i s used , and that a ll pul leys and be l t sare i n p lace . We wil l take a l ine composed of s i zesranging between 3b} and 2 1
73 i n ches . This gives us
four si zes , 3 35, 3 173 , 233 and 2 1
73. i n ches in the l ine .
We wil l first consider the plumb-bob . The a ccom
panying sketch , Fig . 47, i l l ust ra tes a good one .
The bal l i s 15 i nches diamete r , and the large end ofthe tapered stem inch in diamete r, t urned para l le lfor a short distance at t he lower end . The two th insheet—stee l di sks , 1 and 2 i nches i n diamete r , a re dri l ledto fit snugly when pushed on to the —i n ch part of thestem
,and stay there unt i l pul led off. These disks
are turned t rue . This a rrangement of plumb-bob anddisks enables us to dea l wit h five si zes on one l ine , andthere a re not many l ines t hat conta inmore .
Now having our plumb-bob ready , we wi l l st retchthe l ine . The st retchers should be set hori zonta l lyby nai l ing a st rip of wood , say I X 15X 12 i n ches , witha piece a t each end to form a space between i t andthe wal l , or place of locat ion in l ine with the edge of theshaft , as in Fig . 48 . The top of thi s st retcher should
49
50 SHAFTING,PULLEYS , BELTING, ETC .
be low enough to clea r the la rgest pul ley , and highenough to clea r the ha t of your ta l lest man . You
would perhaps find i t conven ien t to go between thespokes of a large pul ley .
FIG . 47.
Now having loca ted your st re tcher , find approxi~
mate ly the posi t ion of your l ine,and drive a na i l a
foot or more below i t i n a vert i ca l l ine , and another nai lanywhere for conven ien t winding . The advantageof th is p l an i s tha t the l ine can be easi ly adjusted as i t
TRUING UP LINE SHAFTING 51
mere ly passes over the st retcher, and is free to respondto movement e i ther way ; then when the fina l adjustment i s made
,and is ready for i t s fina l st retch , i t i s
on ly necessary to pinch the l ine to the na i l with onehand , Whi le the other is a t l iberty to unwind , st ret chand rewind the l ine wi thout fear of i t s sh ift ing.
The l ine be ing adjusted over the st retchers , we wi l lnow proceed to set i t . Begin a t the 21
7g-i n ch end , by
throwing your plumb l ine over t he shaft and set t ingyour l ine at that end , right with the cen ter po in t of yourbob . Having done so
,go to the other or end of
your l ine,and set the l ine so that t he edge of the ba ll
of your bob just touches i t . Now go back to the 2173end and see that t he necessa ry adj ustment did not a l teri t . Having proved thi s
,give your l ine the fina l st retch
and try i f i t i s right at both ends . You now have acen ter l ine (t hough the edge instead of the cen ter of the
52 SHAFTING,PULLEYS , BELTING , ETC .
shaft i s used) t hat may remain up for days if necessarywit hout fea r of d ist urbance .
I t i s be st to go over t he whole l ine first , before disturb ing anything ; so sta rt ing at the first hanger at thezfg -i nch end , t hrow your plumb l ine over the shaft ,and record on the floor i n cha l k beneat h i t whet her i ti s O . ! . or want s to go ei ther way , and how much ;t hen go to t he next hanger , and so on to the end . A
short st udy of the condit ion s enab les one to correctthe faul t s , with a knowledge of t he requi rement s , andconsequent ly i n the least t ime and with t he leastt rouble .
Now suppose we start a t t he 2 17g - i nch end to inspectt he l ine , we use the center poin t of the bob on the l ineso long as we are test ing 2 173 i nches .When we get to the 2}g-i nch part ,! which i s 5; i nch
larger, we use the ha lf diameter of the stem , t he edgeof which should j ust touch t he l i neWhen we come to the 3 fg -in ch part , 1 i nch la rge r
than 2 173 , we use the I- i nch di sk , s l i p i t on to the stem ,
and when i t j ust touches the l i ne wi th i t s edge i t i sO . ! .
The 3 }g-inch, being 15 i nches l arger than t he z17g -i nch ,wil l be right when t he ba l l of t he bob is i n l ight contactwit h t he l ine .
The 2-i nch disk would be suitable for the next si ze ,and other d isks or mod ificat ion s of the bob prope rmight be made to sui t ci rcumstances .Now having st ra igh tened the l i ne , t he next process
i s to leve l i t . As i n some cases your pul leys wi l l betoo close to place your level where you want , make a
APPARATUS FOR LEVEL I NG AND
L I N ING SHAFT I NG
THE first apparatus expla ined i n th i s chapte r wasdesigned by the la te Chas . A . Bauer , and i s a highlyperfected inst rument .For those who have l ined and leve led shaft ing with
an engineer ’ s t ransi t and leve l i t i s unnecessa ry tosay anything of the advantages of that method overthe cruder method s usua l ly employed . I t i s not on lydone much more rapid ly and economica l ly: but thegreate r accuracy with which the work i s done goes onpaying dividends in decreased frict ion and loss of powerand i n lessen ing of wear .The apparatus we now i l l ust rate (Fig . 50 ) has at
t he top a hook , which is passed over the shaft , as ind ica ted ; on the st ra ight port ion of th is hoo k are twos l iding jaws which a re so set that t he shaft wi l l justpass between them . Set into the face of th is hoo k isa commercia l 6- i nch stee l rule which faci l i tates theset t i ng of the jaws , and they are of course so set thatt he tubular port ion of the hook or level ing rod i s centered vert ica l ly under the shaft . Within the outer tube ,which i s about 1 i nch outside d iameter and n icelyjapanned , i s another tube , and inside thi s a thi rd t ube ,
54
LEVELING AND LINING SHAFT ING
FIG . 50 .
56 SHAFTING,PULLEYS
,BELTING
,ETC .
these being arranged 21 la te lescope s l ide , and clampsbeing provided so that the length or distance from theshaft ing to the target may be anything desi red from
4 to about 10 feet . At the lower end of the th ird ori nner tube is a swive l ing head to which the target i sat tached
,and nurled nuts at t h is point give means of
adjust ing the s ight ing poin t of the ta rget to the exacth ight of the t ransi t or leve l s ight ing l i ne .
The target i s a brass p la te 5% i nches diameter , on theface Of which is a recess mi l led for the recept ion of asecond commercia l s tee l ru le , which in thi s case i svert ica l and can be moved vert ica l ly and clamped inany desi red posi t ion with refe rence to a l ine drawn uponthe ta rget . At the cente r of th is sca le i s a very smal lhole t hrough which the l ight of a hand flash lamp mayshine to form the s ight ing point . The s lot t h rough theta rget a t the right of the sca le is provided with a s inglethickness of white cloth , which permi ts enough l ightto pass th rough i t to he lp i n finding the ta rget i n thefield Of t he te lescope .
The Object Of providing a vert ica l adjustment forthe ru le on the ta rget i s so that when passing from onediamete r of shaft ing to another in the same l ine , assomet imes happens
,the sca le can be moved up or down
just ha l f t he d ifference of d iameter and the sight ingpoin t t hus be kept at a constant h ight .The target i s readi ly detached from the rod , and may
then be placed upon the smal l standard (Fig . 51 ) whichhas a t i t s base a V adapted to go over the shaft . Thestandard is tubula r and the wi re (about 3 i n ch diameter)may be adjusted and clamped at the desi red hight . The
LEVELING AND LINING SHAFTING 57
FIG . 51 .
58 SHAFTING,PULLEYS
,BELTING
,ETC .
ta rget fit s over the wire as shown (rea r view of target )for level ing l ines of shaft ing t hat may be near the floor
,
or,w i t h t he target removed , the V and wire form
a sort Of length gage or cal iper wi th which the shaftmay be made para l le l to a l i ne or wire st ret ched at thes ide of i t . Two different lengths of wire are providedfor thi s purpose .
The plumb-bob shown is part of the equipment andis a very superior a rt i cle . A new fea ture i t possessesi s i n having i t s la rge r port ion hexagona l in stead ofround , so when la id down upon a plank or scaffoldingi t wi l l l ie t he re in stead of prompt ly rol l ing off andfa l l ing to the floor . The en t i re apparatus i s , we think ,very wel l designed for i t s purpose .
TOOL FO R LEVELING SHAFTING
The in st rument shown i n Fig . 52 i s a good one for usei n leve l ing up shaft ing . I t can be made to fi t severa ls izes of shaft , o r a l l t he si zes ord inari ly found in a factory .
When the inst rument i s placed on any piece of shaftand leveled up with the at tached leve l , the plumbl ine wi l l hang exact ly the same distance from theshaft cen ter every t ime . I n th is case the distanceof l i ne from center i s 6 i nches .A handy apparat us for use i n leve l ing up long l ines
of shaft can be made as fol lows .Take two pieces of fini shed materia l , fasten together
as i n Fig . 53 and cut out as shown at A and B i n Fig.
54. The open ing A i s made so that the piece can behung over the shaft
,and the Open ing B i s made for
the recept ion of a wooden st ra ight-edge .
LEVELING AND LINING SHAFTING 59
LEVEL
m os em f : x'
FIG . 53 . FIG . 54.
60 SHAFTING , PULLEYS , BELTING , ETC .
Make the st ra ight—edge out of 13-i nch stuff.
sure t hat the edges are para l le l , the width just enonle ss than the width of open ing B, Fig . 55, to enter
FIG . 55.
and t he length 6 or 8 fee t , to sui t conven ience . U
the appara tus wi th a leve l , as i n Fig . 55, taking cat ha t the suspension pieces a re a lways on the same sishaft .
62 SHAFTING,PULLEYS, BELTING,
ETC .
set-screw made t ight and the pul ley i s now runningwithout any apparent tendency to t rave l from i t sproper posi t ion . I t wi l l be seen that the posi t ion of theset-screw as i ndicated by the l ine at A i s a poor oneand ca lculated to gi ve p lenty of t rouble at the mostinopportune t ime .
Not long ago a cast- i ron pul ley had to move a long acountershaft i n order to make room for a pul ley ofanother diameter . The pul ley had not been on theshaft long, so i t was thought tha t l i t t le work would berequi red to move it . A heavy bar was placed againstt he hub and a s ledge hammer was used to st rike thebar . After an hour and a .
ha lf of heavy work the pul leywas not moved over 1 i n ch (i t had to be moved 16
i nches) , so i t was suggested that a Bunsen burner beat tached to a gas pipe by means of a hose and placedbeneath the hub . The plan was immediate ly adopted .
The burner was p laced beneath the hub , the gas l i tand a l lowed to hea t t he hub . Afte r about twenty-fiveminutes i t was found tha t a b low from the bar was sufficien t to move the pul ley . The pul ley was moved the16 i n ches in side of twenty minutes .
FIG . 57.
A very handy arrangement for moving pul leys i sa bol t and nut . Fig . 57 shows the bol t and nut with
SOME PRACTICAL ! IN ! S 63
a piece of pipe attached . A piece of pipe can be cut tosuit t he distance between the nut and hub of one pul leywhi le the bolt head is against the other hub . The nuti s screwed back upon the bol t as far as possib le . A
washer is then placed against t he nut , and a piece ofpipe cut to suit . Of course , the pipe must be largeenough in diameter to fit ove r the bol t . I f we screwback upon the nut , a powerful st ra in can be broughtto bea r between the hubs and in a ll probabi l i ty thepul ley wi l l move .
FIG . 58 .
I n taking down sol id pul leys from main or countershaft ing i t somet imes happens that a hanger must beremoved to permit the pu l ley to be taken off. A first
rate plan is to make a couple of long bol t s hooked atthe end as shown in Fig 58 ; pass the hook around theShaft and the threaded end through a hole i n thestringer . By screwing up the nut as shown , the shaft
64 SHAFTING , PULLEYS , BELTING,ETC .
and remain ing pul leys can be kept in posit ion, obvia t i
the use of tackle , not to ment ion the labor requi redhoist back the shaft in to posi t ion . The appl icat iof thi s con t rivan ce is especia l ly va l uable where heacone pul leys are requi red to be lowered or changeI t wi l l be seen that if We employ a pipe thread we wbe enabled to sui t a lmost any condit ion Of lengt h thmay arise between the shaft and st ringer.
PRACT ICAL METHODS OF LOOSEN ING
PULLEYS
WHEN a sol id pul ley i s to be removed from a pieceof shaft for any reason , i t i s not good pol icy to usesledge hammers on t he spokes or hub to do it . Casti ron in pul leys i s too l iable to break or crack underrepeated blows .I n Fig . 59 one ready method is i l lust rated by which
the pul ley may be removed . When a place betweentwo wa lls can be found tha t wi l l admit of this a rrangement , proceed as shown to force the shaft t hroughthe pul ley , subst i tut ing longer piece s of pipe as theshaft i s forced through farther.I n one case where a large pul ley was stuck on a 7-i nch
shaft and it s remova l was imperat ive,the shaft was
sawed off (with la rge hack-saws) close up to the pul leyhub and two ! ~ inch holes were dri l led into the shaftpara l le l to it s axis , as shown in Fig . 60 . These holeswere dri l led so that they were 90 degrees apart andcame with in 1
16“ i n ch of the hub of the pul ley . The
hub was 14 i nches th rough and these holes were 8 i n chesdeep ; but that was enough to loosen up the shaftso that when the pul ley was laid over on beams with
65
66 SHAFTING,PULLEYS, BELTING , ETC .
METHODS OF LOOSENING PULLEYS 67
t he shaft hanging through , a sledge hammer appl iedon the Shaft end soo n drove i t out .Another way to remove a pul ley i s shown in Fig . 61 ,
where a ram is used . The ram is another piece ofO ld shaft . To prevent i t s damaging the pul ley huband a lso to have i t s force appl ied most advantageously ,i t should be used i n a di rect l i ne with the di rect ionof remova l . TO do th is , the method shown in Fig . 61
is se lf-explanatory .
FIG. 60 .
Another good method of removing an obdura tepul ley i s i l l ust rated in Fig . 62 ,
where the bol t s W, Wmust have long th reads and the work is done by pul l ingup on the nuts A , A . This method can be used on lywhen the end of the shaft can be reached and used asshown . I n using this method , care must be exerci sed
68 SHAFTING , PULLEYS , BELTING, ETC .
70 SHAFTING , PULLEYS , BELTING ,ETC .
i n t he pul l ing up on the bol t s W,W, keeping the st ra in
equal ly divided between the two by pul l ing a l i t t lea t a t ime on each .
I f t he pul ley comes ext ra hard , i t can be assi stedwhen the st ra in i s on the bol t s by st riking at X witha s ledge .
A: good device for removing motor and generatorpul leys that a re nea r the shaft end is shown in Fig . 63 .
The arms Z , Z a re adj ustable to take hold of hub orarms , and t he screw appl ied to the shaft center wi l l do
the rest .To run a pul ley off a shaft without i njury to the
hands , use a monkey wrench on the rim of each pul ley ,as shown in Fig . 64. One pul ley on the shaft can beselected for a hold-back ; one monkey wrench therewi l l hold t he shaft from turn ing , while t he other wi l lt urn a round the shaft t he pu l ley which i t is i ntendedto remove .
METHODS OF LOOSENING PULLEYS 71
FIG . 63 .
FIG . 64.
SPL IC ING LEATHER BELTS l
THE fi rst th ing is the tool s for the different kinds ofwork . These may be usua l ly changed somewhat tosui t t he taste of the use r , but i n the main the styleand kind here in shown in a ttached drawings cannotbe very much improved upon .
Figs . 65 and 66 show a spl i ce opener for heavy be l ts .I t i s made of - i nch tool stee l wit h the poin t spread outabout 2 i nches wide and wel l tempered
,afte r which i t
i s ground to a good sharp edge , and then an oi l stonerun over the edge unt i l i t has been du l led so that i t wi l lnot cut . The right kind of an edge can on ly be securedby t rying ; i t i s one of the tool s t hat i s very hard toget j ust right . You wi l l not ice that the manner inwhich t his spl i t te r i s bui l t may seem to be rather toomuch work to bestow on such a simple tool , but thereasons for so doing are as fol lows : i n open ing a 36i n ch be l t an old spl ice opene r that was driven in tothe handle l ike an ordinary fi le was used and thehandle spl i t ; that sharp poin t came back through thehandle
,and when i t fina l ly stopped i t had gone about
2 i nches in to the pa lm of the opera tor’ s hand . Some
is-inch hexagon stee l was turned down 6 i nches , just1 Con tributed to Power by Wa lter E. D ixon ,
M . E.
72
SPLICING LEATHER BELTS 73
74 SHAFTING,PULLEYS
,BELTING
,ETC .
enough to round i t up ; t hen a sol id brass washer wasturned out 1} i nches In diameter and 1 i nch thick
,
a hole bored through i t that was a driving fi t on thepiece of stee l and was driven down to the shoulde r .Washers were cut out of old pieces of bel t and put onwith a l ibe ra l coat of glue on both s ides ; when thehandle was fi l led
,a stee l washer which was 5 i nch
thick was screwed down hard on the leather washers,
and when i t had dried wel l t he whole was turned downto si ze shown in the sketch . Two of these tool s weremade ,
°
one for bel t s up to 18 i n ches , and another thatwi l l reach th rough a 4o -i n ch be l t . The tool shown in
FIG . 67.
Fig . 67 i s an ordinary heavy screwdrive r wi th the poin trounded n ice ly , and i t i s used to ra ise the th in poin tsthat the la rger tool wi l l somet imes tear .Fig . 68 shows a handle made a lmost l ike the one in
FIG . 68 .
Fig . 65, with the except ion tha t the brass washerreferred to in Fig . 65 i s here turned down to inch ,commencing 5 i n ch from the la rge end , which i s 1 i n chin diamete r . The lea the r washers a re s l ipped on overt he smal l part un t i l i t i s fi l led , and then a washer i sscrewed on the smal l end and the whole t urned as shown
SPL IC ING LEATHER BELTS 75
i n the sketch . A hole that wi l l tap out i nch is boredi n the large end of the brass cente r , and then tool smade with threaded ends on them that wi l l fi t i n to i t .These tool s a re made of g-i n ch tool stee l wit h scrapingends
,as shown . These scrapers a re used on ly for
removing glue that i s too hard and too thick to beremoved by the scraper shown i n Fig . 69 .
Figs . 69 , 69a and 69b show views of the on ly tool
FIG . 69 . FIG . 69 a . FIG . 69 b .
t hat i s hard ly worth being referred to a s a lea ther-cutt ing tool . I t i s made of a th in piece of stee l , about 18gage
,or any old hand-saw wi l l make the very best
scrapers tha t can be secured . They should be about
4 i nches square , perhaps a l i t t le smal le r , and fixed in ahardwood handle (usual ly of hard maple) , s imply bysawing about 25 i nches into the handle and then
-drivingthe blade in . The saw cut should be just a t rifle th innerthan the piece of stee l . Should they get loose from use
,
a piece of paper folded over the back of the b lade andforced back in to the handle with the b lade wi l l usua l lyt ighten i t a l l right .This i s the tool that wi l l ordinari ly worry the novice
more than al l the rest to keep in proper condit ion .
Fig . 70 shows an exaggerated view of how the blade
76 SHAFTING,PULLEYS
,BELTING
,ETC .
Should look when properly fin ished . I t should behooked considerab ly .
FIG . 70 .
Fig . 71 shows a smal l stee l for sharpen ing the scraperafte r i t i s turned
,and it should be absolute ly smooth .
FIG . 71 .
Fig. 72 shows the equipment for turn ing the edgeof t he scrapers . A la rge th ree-cornered fi le , about 12
FIG . 72.
i n ches l ong , which has a ll the teeth ground carefu l lyoff of i t and then n ice ly pol i shed , i s fastened to a pieceof good clean be l t leather by means of the staplesshown .
78 SHAFTING , PULLEYS , BELTING , ETC .
the handle too fast . An ordina ry blade can be tu rnedin about fifty st rokes across the fi le . The edge turnedover should be at least 1
13 i nch long and should be
wel l hooked , as i s shown in Fig . 73 .
FIG . 74.
I t i s wel l to keep on hand about six of these scrape rs ,and as they get too dul l to cut lea the r use them on glue .
With one good scrape r that i s not too sharp a l l the gluecan be cleaned off of both poin t s of a 36—in ch be l t infrom five to ten minutes . When the edge gets a t rifledul l , use the smal l stee l on both s ides of the edge ; firstwet the stee l wi th the l ips , i t makes a much bet ter edge .
For the benefit of beginne rs who may at tempt to spl icea be l t for the fi rst t ime , do not use a glue tha t wi l l nota l low you to remove the clamps and put on the ful lload in forty-five minutes a fte r the glue has beenappl ied and wel l rubbed down . The t ime given hereappl ies on ly to clean be l t s t ha t a re absolute ly freefrom a l l oi l s , and does not incl ude old oi l-soaked lea therthat no glue wi l l eve r dry on .
Fig . 75 shows the equipmen t necessa ry to do a good ,
quick job on a bel t , and most of them are requi redto be done quickly and wel l . With such an outfi t andha lf—dozen sharp scrape rs a join t in a 36- i n ch be l t can
SPLICING LEATHER BELTS 79
be made and run again in four hours afte r t he engine i s
stopped .This includes a l l t he t ime consumed in put
t ing on and taking off the clamps , etc .
FIG . 75.
The top of the pla t form , 76d , i s le ve l wit h the bottomof t he be l t and is he ld in posit ion by the hooks , 76b ,
which are shown in Figs . 75 and 76. These hooks s l ip
over the 2x4—i n ch pieces t ha t project outside the pla tform to which they are at tached , and should be madeof three-quarte r i ron and not too lo ng, or some diffi
cul ty may be expe rienced i n get t ing them on the two
by-fours .
The rods should be long enough to take care of thelongest poss ible spl ice and st i l l gi ve plen ty of room towork
.There should be about 25 fee t between the
80 SHAFTING, PULLEYS , BELTING ,ETC .
i ns ide ends of the threads and the t hreaded end shoube 3 fee t long . This wi l l make the rod 8 feet 6 i nclong, and i t wi l l be none too long at that . For instai n removing the glue from the spl ice , i f t he lastpoin t i s very close to the clamp , t here wi l l be gdifficul ty in clean ing i t and a l so i n fi t t ing the leatherafte r the be l t has been shortened . What i s meant by
FIG . 77.
the head end spl ice i s t he one that i s on the pul leyfi rst—t he a rrows in Figs . 77 and 78 wil l make th isclea r : they indica te the d i rect ion in which the be l tshould run ; therefore that end of the piece of leather
t hat is on the pul ley fi rst is the head end (or fi rst end)and the end tha t leaves the pul ley last i s the la st end .
I f t he two be l t s shown in the sketch were reversed,
t he poin t s would be turned up by everything thattouched them ; whereas , runn ing in the di rect ion thatt hey do , everything tha t touches them has a tendencyto rub them down .
We wil l suppose tha t t he be l t shown in Fig . 75 hada “fi rst end ! poin t that Opened on t he top of the bel ti nstead of the bot tom as this one does (see left-hand éndof bel t between the clamps , .on the lower s ide) ; onecan easi ly see how hard i t would be to work if t he clampwere nea r the poin t . There should a lways be enough
SPLICING LEATHER BELTS 8 1
room between the clamps to a l low the spl ice r to takethe last end (which i s a lways the forked end) , carryi t ent i re ly over the clamp toward the left i n Fig . 75,
lay i t down on that part of the be l t that i s outside theclamp and sl ip an ext ra spl icing board under i t . Fastenthe two be l t s and spl icing board a l l togethe r by meansof a couple of 8-i nch hand-screws (of which every be l tspl ice r should have at least s ix or eight) ; t hen cleanand Shape i t to sui t the othe r. end . I t can be passedback over
'
t he clamp from t ime to t ime and t ried for afi t .
3 R Ha rd M ap l e
FIG . 79 .
The prope r mode of procedure i n spl icing a bel t onthe pul leys i s as fol lows : Decide on where the bel t i sto be opened , and always open i t i n the worst placein the be l t for that i s t he place you certa in ly want tofix . Pay no at tent ion whatever to any former spl icingplace that may be in the be l t , but take i t apart a t anyplace where you are sure repa i rs a re actua l ly necessa ry .
Fi rst put i n the most conven ien t place possible thepoin t t hat you have decided to open and then put the
8 2 SHAFTING,PULLEYS
,BELTING
, ETC .
clamps i n posi t ion . I f you are sure that i t i s going torequire very hard pul l ing to get i t as t ight as you wish
,
take a damp cloth , moisten the inside of the clampsand then sprinkle powdered res in on both upper andlower c lamp . Put the fi rst end clamp on fi rst
,as
th is i s a lways the easiest poin t to clean and fit ; decidehow much you wi l l have to take out , or as near aspossib le , measure off t h i s amount on the be l t and placethe clamp this d istance plus about 10 i nches from the“fi rst end poin t . This ext ra 10 i nches wi l l giveyou plenty of room to clean the glue off and a lso toshorten up the be l t the right amount for a l l t he shortening must be done on the “first end poin t on accountof the ease with which the new scarf can be made .
Should you t ry to shorten up from the “ last endpoin t , by referring to Fig . 78 , you can easi ly see theamount of work you would be in for . There would betwo thin ends to scarf, and outside ends at that ; whereas ifyou shorten up from the “first end ! you make on lyone thin end and that one in the inside of the be l t .The first clamp , with the center mark of the clampcoinciding with the cen ter of the be l t , should be veryt ight ; for should i t s l ip when the load is put on , i t wi l lve ry probably s l ip in the middle of the be l t and maynot s l ip on the edges a t a l l . Should yo u glue i t i n thiscondit ion , the chances a re very much in favor of theoutside edges giving away on a heavy load , due to themiddle being too long . Afte r t he first clamp is inposi t ion and t ightened , put on the second one andleave the bol t s loose , so that i t can be sl ipped easi ly .
Then put the bel t rods in posi t ion with just a “ful l
SPLICING LEATHER BELTS 8 3
nut on each end and t ighten the clamp . Tighten therods enough to take most of the load , then get the largespl i t te r shown in Figs . 65 and 66 and open the join t .The place to commence is be tween X X i n Fig . 75 ;
t h i s incl ined poin t i s about 4 i n ches long and must beOpened at both ends of the spl ice before the m iddle istouched .
The tool should be entered at 0 , i n Fig . 78 , andworked gradua l ly toward A ; when the poin t i s ra i sedto A clea r across t he be l t , open on down to C . Afte rboth ends of the spl ice have been opened up in th is way ,proceed to Open the middle , which is now an easy ta sk ,there being no th in stock tha t a separat ing tool wi l lpass th rough easi ly . Afte r the belt i s en t i re ly apartt ighten up on the rods unt i l t he bel t i s t he prope rtension and hang the hooks (76b , Fig . 75) on the be l trods . Throw the two ends of the be l t back over theclamp and put the spl icing board i n posi t ion . Afte rt hi s i s i n place , t hrow the two ends of the be l t back onthe board and proceed to lay off t he scarfs . To doth is , fi rst take a square and get the two th in poin t sperfect ly square , then put the first end poin t i nbetween them . Thi s i s shown very clea rly in Fig . 77,
the shaded end being the last end . Of course the firstend poin t at C
,Fig . 77, wil l have to be cut off before
the be l t wi l l l ie down properly ; the amount to cu t Offof th is end wi l l be just as much as you have shortenedt he distance between the clamps . Afte r the poin t hasbeen cut to the right length , take the square and makea mark across t he be l t , using the end Of the thin poin tas your measure for length ; then withou t moving the
84 SHAFTING, PULLEYS , BELTING, ETC .
be l t make a mark on the edge of the be l t,showing just
where t he lower t hin poin t came on the bottom.
Throw the last end ! over the left-hand clamp out ofthe way and sca rf down the top of the “fi rst end !
point , le t t ing the sca rf be about 4 i nches long . Be
ca refu l not to gouge a hole i n the be l t where the scarfi s s ta rted , but t ry to make the incl ined plane from X
to X perfect ; try to keep the whole surface of t hisi ncl ine t rue and s t ra ight . Afte r the short 4—in ch sca rfi s fin ished , clean the glue Off of t he inside of the
“fi rst
end !
; l ap up to where i t en te rs t he“ l ast end then
turn i t over by bringing i t over t he right—hand clamp,
place a sca rfing board under i t and make t he scarfshown a t T, Fig . 75. Now clean a l l gl ue off t he lastend ! lap and take a sharp scrape r l ike t he one shownin Fig . 69 or 69b , place a piece of glass under t hepoin t s t ha t have been previous ly squared up
,and
sca rf them down to a kn ife-edge .
Afte r t he th in poin t s a re properly sca rfed ,lay the
whole spl i ce back on the spl i cing board j ust as i t wi l lbe when i t i s glued , and do any fi t t ing that may benecessa ry . Be very ca reful to ge t i t thin enough , or i twi l l make a hammering noise when going over the pulleys . When sca rfing down the th in poin ts wi th thescrape rs
,be sure t hat they are very sharp ; i f not ,
t hey wil l tea r the poin t off when i t gets down to anedge ; a l so give the blade a drawing mot ion in orderto faci l i ta te cut t ing . I t may seem to the novice thatto use a piece of glass to scarf on , when one i s usi ng atool wit h a ra zor edge , i s a t rifle inconsi stent , but i t i snot so in the least ; i f the b lade i s he ld we l l back a t the
86 SHAFTING , PULLEYS , BELTING , ETC .
has been appl ied (and rubbed for about two minutes) ,have an assistant ra i se the poin t up unt i l you can seet he glue breaking a l l across the whole width of the bel t .Then have a second brush ready and repea t the formerprocess , with the except ion that you need not applyt he glue to both sides of the leather as i n the first case ;for if you wi l l keep the brush down in t he fork betweent he two laps you wil l give both sides a coat , and inaddit ion to the t ime saved by using t his method youwi l l get t he join t closed -whi le the glue i s hot . As fastas you go across t he be l t wit h the brush
,have the
assi stant rol l t he be l t together after you ; when youhave used a l l t he glue out of the brush
,the join t i s
closed and ready to rub . You wil l keep the glue muchhot te r by immediate ly closing the spl ice after thebrush
,and there i s nothing el se so importan t as using
hot glue ; as soon as i t commences to get sh iny on thesurface the th ing i s a l l off and i t wi l l not hold anything .
You cannot do any quick work with water in yourgl ue that i s , . un less i t i s old and has been heated upseve ra l t imes . If th i s i s the case , i t wi l l have to bethinned with water . The proper consi stency i s aboutt ha t of a very heavy grade of cyl inde r oi l ; i f i t i s t oothin
,i t wi l l not dry in any reasonab le t ime and i t wi l l
a l so cause pockets i n t he spl ice by open ing up afte r thejoin t ha s been rubbed
,and the a i r i n t he pocket s wi l l
open the whole Spl i ce . I n important work never use aglue t hat wi l l not st ick so t ight ly between every ap
pl i ca t ion be l t that afte r rubbing down you can give i ta good
,hard pul l without i t s open ing up . I n a l l state
ments rega rding the t ime necessa ry for the joi nt to dry ,
SPLICING LEATHER BELTS 8 7
t he bel t s a re considered absolute ly clean , dry and freefrom al l oi l s .The most di sagreeable port ion of the bel t repai rer ’ s
work i s the spl icing and repai ring of O i l-soaked bel t s .I t i s a wel l -known fact t hat t he act ion of oi l and t hatof glue are in direct Opposit ion to each other : t he oi lprevents st icking and the glue st icks , i f i t has a chance .
Such being the case , the first th ing to do is to e l iminatethe oi l complete ly
,and the efficiency of your join t wi l l
be in di rect proport ion to your success in get t ing ridof t he oi l . To this end secure a large gasol ine blowtorch
,such as painte rs use to burn off old pain t . I f
you are not used to i t , be very carefu l ; at a l l event s ,have a bucket of d ry sand to use i n case of t rouble .
j ust throw the sand on the fi re and the fire wi l l go outthat i s , i f you can get the sand i n the right place .
The torch is to be used afte r t he spl ice has been a l lcompleted except the thin pomts . The flame wil l burnthem if finished , so leave them tole rably th ick un t i lafter the O i l has been removed ; then finish them asdi rected before . When the scarfs have been made andthe old glue has been removed , turn the flame (whichshould be an a lmost invis ible b lue if the torch is working properly) direct ly on the leather and move i tover a l l the surface of the spl i ce unt i l the leather hasbecome thoroughly heated ; never a l low the flameto remain di rected a t any poin t long enough to makethe oi l i n the leather boi l . I f you do
,the be l t i s burned .
Cont i nue to move the flame over the surface of the be l tunt i l the leather i s so hot that t he hand can scarce lybe he ld on i t . With one of the scrapers shown i n Figs .
88 SHAFTING,PULLEYS
,BELTING
, ETC .
69 and 69b (69b preferred) scrape the O i l off as thehea t rai ses i t up . Turn the cut t ing edge of the scraperup and wipe the oi l off afte r every st roke ; keep thescraping process going right on afte r the torch ; nevera l low the leathe r to cool off unt i l you can get prac t ica l ly no o i l and the leather begins to turn brown .
“
Byheat ing the leathe r and bringing the oi l to the su rfaceyou do j ust what the glue does when you put i t on anoi l-soaked be l t wit hout removing t he oi l . By means oft he heat con tained in i t , i t brings up a l l t he oi l nea rthe su rface to which i t i s appl ied and in consequencedoes not take any hold on the leather .I t wi l l take two men with a l l t he necessary tool s and
appl ian ces at least s ix hours of good hard work toremove the o i l from a wel l-soaked 36—inch bel t thati s , to remove i t to an exten t sufficien t to warrant t hegluing of i t .I n ca se of overflows in which the whee l pit s are l iab le
to be fi l led with water , pour cyl inder O i l on a l l be l t st hat a re l iab le to get wet and then remove them frompul leys if they wi l l be covered for more than twentyfour hours , clean them wit h gasol ine and t hey wil l befound to be a l l right and dry .
Hold a c lean piece of waste against a ll bel t s a t leasttwice every twenty hours , and wipe them c lean .
90 SHAFTING,PULLEYS
,BELTING
, ETC .
for the best , and i t i s a l so eviden t that no maker i sgoing to say that he makes inferior goods ; so thereforewe must read the qua l i ty by What i s i n sight
,and in
the judging of leather t hat i s a l ready made up,t he
proposi t ion resolves i t se lf i nto a very hard one .
The two principa l th ings left for an opin ion to beba sed upon as to qua l i ty are the re lat ion the piecest hat const i tute the laps bear to the hide from whichthey were cut . They should , i n be l t s runn ing from18 to 36 i n ches , be cut from the cente r of the h ides , orshould be what i s known a s cen ter stock . Of coursea l l be l t s should be cen te r stock , but where t hey arevery narrow or so wide that one hide wi l l not be wideenough to make a lap , then there i s a lways a lot ofnarrow stock worked in t hat cannot a lways be st rict lycen ter . The next thing to look out for i s brands thatare so deep tha t they dest roy the l i fe of the leathe r andwi l l cause i t to brea k afte r be ing used . Then look outfor the length of lap . If th i s i s too long , you wi l l knowt hat i t runs i nto the neck , for about a l l t hat i t i s possibleto get ou t of average hides and st i l l leave nothing intha t i s not fi rst cla ss i s 54 or 56 i nches . Ordinari ly ,
you can tel l i f a lap is cen te r stock by the marks tha trun down eit her side of the back bone ; t hey wi l l beusual ly a l i t t le darke r than the rest of the be l t . Thesemarks or st reaks should be in the center of the be l t .The principa l object ion to neck leather is t hat i t i sl iable to st retch excessi ve ly
,and on th is account i t wi l l
put too much load on the piece immediate ly oppositei t i n a double-ply be l t ; for the poin t of one side i s i n themiddle of the lap on . the other side . Next look out for
MANAGEMENT O F LEATHER BELTS 9 1
holes,which wi l l usua l ly be found so n ice ly plugged
as to escape detect ion un less subjected to t he most carefu l examinat ion .
Next in importance is to buy a bel t that has a l readybeen fi l led with some good waterproof dressing . I t i squi te l ike ly that to buy a be l t t hat has been fi l led meansto buy one that perhaps has some bad leather i n i t thatwould be seen in a dry oak tan be l t , and a l so that t headhesive power of the fi l led be l t i s not qui te equa l tothe dry O
’
ne but the points that the fi l led one possessesover the one not fi l led are , first and main ly , i t i s fi l ledwhen you buy i t with a preparat ion t hat does noti njure the leather i n the least ,
! and the prepa rat ionyou wi l l fi l l i t with , for i t wi l l be fi l led , wi l l be engineoi l and water , a combinat ion that wi l l ru in any be l tmade and a lso get i t i n six months in to a condit ionthat wi l l make a pe rmanent repa i r wit h glue impossib le ,for machine oi l and moisture are st rangers to gl ue andwi l l ever be . More good bel t s are ruined by beingsoaked with engine o i l unt i l t he points come loose andthen pul led out of shape than from any other cause . Ofcourse you may be able to keep a main engine be l t t hatruns through a damp whee l pi t and basement
,and
through a long damp tunne l to a main driven pul leythat has two big boxes that a re j ust as close to thepul ley as a first-class machine designer could put them ,
and never get a drop of oi l or water on i t . But th i s i snot l ike ly .
One very common cause of t rouble with engine be l tsi s the fact that such bel t s usual ly run under the floo r ,where there i s considerable moisture . Then the oi l
92 SHAFTING,PULLEYS
,BELTING
,ETC .
table under the average large Corl iss engine wi l l leaka round dash-pot s and rocker-arm shafts , and some oi lwi l l fly from the eccent ric o il cups , get in to the wheel ,run around the rim and get to the be l t ; i f t he bel t i snot fi l led a very few drops of oi l wi l l make a la rge spoton i t . Then , i f an engine does not run the wholetwenty-four hours , whi le i t i s off, watch . A few dropsof water from a leaky va lve stem whose bonnet dra in i ss topped up , as i t wi l l somet imes be , has a way of get t ingt hrough the floor and fa l l ing on to the be l t and runn ingdown the i ncl ined inside of i t unt i l i t fina l ly comesto the flywheel , which , with the assi stance of i t s crowning face , very kind ly makes a n ice pocket for said waterand proceeds to drink i t up . Resul t : t he glue i sloosened and the be l t may come apart in consequence .
Should t here chance to be a poin t j ust a t the bottomof thi s pocket , i t wi l l get t he glue soft enough to s l ipbut may not open up , which is much worse t han if i td id open up for i t may sl ip away from the shoulderof t he spl ice for ha l f an inch , and when the enginei s put to work it may close down by runn ing under thewhee l and st ick . I f i t does , the resu l t i s that at novery distant day you wil l find a break at that part icula rplace , right across the face of the be l t . The reason ist hat t he load was a l l taken Off t he inside ha l f of thebe l t by poin t s l ipping , thereby making the inside of thebe l t too long and put t ing a ll t he load on the outside .
The outside wi l l cont inue to do al l t he work unt i l i tst retches enough to bring t he inside back into serviceagain . During thi s week or month you have beenpul l ing your load wi th a single bel t , not a double one ,
94 SHAFTING, PULLEYS , BELTING,ETC .
each edge of the st rip of t in , which should be longenough to reach beyond any possib le leak through thefloor or oi l table , a piece of 5-i nch pipe , and put the t inover the ridge pole wi th a piece of smal l pipe on ei therside . Ordinari ly the be l t goes out past t he cyl inder ;i f i t run s through a bricked-up runway on i t s routeto the main driven pul ley , j ust fasten the two piecesof 5—i nch pipe to e i ther wal l a nd have t he ridge about 6i nches higher than t he outs ide ones . Then every dropof oi l or water that comes through the floor wi l l fa l lon to the roof and run down to the wa l l s and be ca rrieddown to the floor of the pi t and have no chance totouch the bel t .One of the most difficul t t hings i n the operat ion of
la rge stat ion s where a la rge number of bel t s a re used i sto keep them thoroughly clean and free from moistureand machine oi l , the lat te r especia l ly . One very hardproblem that confront s a l l designers of machinery i st he prevent ion of oi l leakage from boxes . I n severa lplant s with as many as six dynamos of the same kindand the same design , at least four of the six have leakedoi l every t ime they were run . The others did not leakas a usua l th ing , and a l l were equipped wit h the mostmodern methods of holding oi l .Now we come to the bui ld ing of the be l t , and we wi l l
not ice on ly such poin ts as interest t he engineer or buyer .The fi rst t h ing i s to see that t he laps a re of uniformthickness , so that t he bel t wi l l run quiet ly ; and itshould be absol ute ly st ra ight when unrol led on t he floor .I f i t has a long, graceful curve in i t , l ook out ; for i t wi l lnot run st ra ight on the pul leys unt i l i t has st retched
MANAGEMENT OF LEATHER BELTS 95
st raight,and by that t ime one of i t s edges may be
ruined by coming in contact with the floor or someother Obstacle . Next not ice how long the leather i sfrom which i t is made . I t should not show more than
52 i nches , and then there wi l l be 4 i n ches h idden bythe poin t that i s out of sight . Then see t hat t he joint sare broken properly . For instance , find the center ofany piece of leather on one s ide of the bel t , and thenlook on the opposite side and see if the join t i s righ tunder your center mark . I t should be by al l means
,
for right here l ies the most important th ing about theconst ruct ion of leather bel t s . A bel t whose laps area ll the same length , and which has a ll i t s joint s b rokencorrect ly , wi l l put the same load on the glue throughout , and that i s what must be done in order to gett he best resu l t s . See Fig . 80 . Here we have a be l t
FIG . 8 0 .
t hat i s 36 inches in width and a double p ly . Nowsuppose t he re is a draft of 9360 pounds on t his be l t ,t hat from point A to poin t B i s 26 i n ches , and thatt he poin ts a re 4 i n ches long . Now we have 26 i n chesp lus 4 in ches p lus 4 i n ches t imes 36 i n ches for thenumber of square inches in t he glued join t . Thise qua ls 1224 square in ches ; the tota l pul l on the be ltdivided by 1224 wi l l e qua l t he load on each squareinch of glued join t , and wi l l e qua l i n this Case
96 SHAFTING , PULLEYS , BELTING, ETC .
pounds . Now instead of assuming distan ce A —Bi n Fig . 80 to be 26 in ches , le t the lower join t get outof step wit h the upper ones , and condit ions get vdiffe ren t . We wil l suppose that t he dimensions agiven in Fig . 8 1 , as was the case with a new bel t thwas measured less t han one month before the observat ion was made and we have the fol lowing : j oin t A B
i s now on ly 10 i nches , and we have 10 i nches p lus 4i nches p lus 4 i n ches t imes 36 i n ches which equa l s 648square in ches , and the lead on the join t i s nowpounds . You wi l l readi ly perceive what a n important
FIG . 8 1 .
part in the l ife of the be l t , and the l ife of everythingaround the be l t as fa r a s t hat goes , t he proper breakingof the upper and lower join ts i s . Of course the be l tmaker wi l l te l l you that h is glue i s j ust as st rong as theleather i tse lf
,and he is about right a s long as you keep
t he be l t free from O i l and water ; but when the be l t becomes fi l led with oi l t he glue rots and loses i t s st rengt hmuch faste r t han does the leathe r .No good be lt needs any post s a long the sides to make
i t run st ra igh t and stay on the pul leys . I f the pul leysa re in l ine and the bel t st
'
ra ight , i t wi ll run st ra ight .All be lt s should be made to run perfect ly st ra ight onpul leys
,fi rst on account of the loca l advert isement
tha t i t gives to the man who has charge of them ;
9 8 SHAFTING,PULLEYS
,BELTING
, ETC .
dry . You wil l find that the naphtha wi l l not affect theleathe r nor the cement in the cente r of the be l t , but mayopen the join t s a t t he edges ; i n which case the oldcement should be scraped off and the edges recemented.Your bel t man wil l know how to do this . The bel t wi l lnow be somewhat ha rd , and should be t reated with are l iab le be l t dressing before being replaced on thepul leys .
BELT I NG , ITS USE AND ABUSE l
THERE is no class of appl iances so l i t t le understoodby the ordinary steam engineer and steam use r a s be l t s ,which may be seen by the quant i ty of be l t ing sold an
nua lly . Where one can poin t to a be l t t hat has been incont inuous use for twenty yea rs , you can find hundredsthat do not last one-fourth as long . Why? Not a lwaysbecause the buyer has t ried to get someth ing for nothing
,but as a ru le , when they do , t hey get noth ing for
someth ing .
The average be l t i s a poor one , and the averagebuyer wi l l not find i t out t i l l he has used i t for somet ime . I f you weigh the be l t dea le r up as a man whois t rying to rob you , beat h im down in price , then geth im to give from 5 to 40 per cen t . Off, he wi l l en te ra protest , and , afte r some explanat ion , wil l come tosome terms with you . Have you gained anyth ing byyour cleverness? Wel l
,hardly . Be l t dea lers and
makers, l ike a lmost a l l other dea lers in suppl ies , a imto get nothing but first-class goods ; but second andthi rd , and even fourth-class goods , are made , and youget the qua l i ty you pay for . I n the second place , bel t swear out quickly because they do not get proper care .
1 Co n tributed to Power by Wm . H . McBarnes .
99
IOO SHAPTING , PULLEYS , BELTING , ETC .
To let a be l t run one moment after i t gets too slackis bad pract ice , for i t i s apt to s l ip and burn a l l thestaying qua l i t ies out of i t . Another good reason , whyit should not be run s lack is t hat t he engineer or beltman , to save work , would be tempted to put on a dressing or , worse yet , put on res in to make i t pul l , and , i nthe language of Rex , t he man who wi l l put resin onhis bel t s i s e i ther a fool or a knave ,
! for i t i s sure tospoi l h is bel t if cont inued for any length of t ime .
I n an emergency , as when some unforeseen substancehas found it s way to thebel t , i t may be necessary , tokeep from shut t ing down between hours
,to use some
of the so -ca l led dressi ng . We know . from experiencethat engineers wi l l go to a lmost any ext reme to get outof a t ight p lace — ci rcumstances somet imes make i tnecessary to keep a bel t runn ing when i t should notbut t h is shou ld not be a l lowed to any extent . To a l lowa bel t to run too t ight is j ust a s bad , for i t wi l l makeshort l ife for the be l t , hot boxes and scored shaft ing .
There i s not one in twenty who takes the t ime or canspl ice a be l t properly ; i t i s general ly done in a hurry ,
any way to make i t hold together, with the understanding that i t cannot ta l k ; but i t does . How often we seeboards nai led up or rims tacked on to keep bel t s fromgett ing off t he pul leys . All of th is i s good for the be ltdea lers .This i s not a l l the faul t of the engineer or the bel t
manufacturer . Often be l t s a re made uneven , and soonget out of shape
,even with the best Of care . We some
t imes find a bel t t hat ordinari ly runs easy on the pu l leysand does i t s work with ease sudden ly i ncl ined to run
A COMPARAT IVE TEST OF FOUR BELT
DRESS INGS 1
DURING j anuary , 190 5, a comparat ive test of theworking efficiency of four be l t dressings and preservat i ves wasmade by T . Farmer, j r . ,
and the wri te r . Thetest was made on the regula r be l t-test ing machine ofS ib ley Co l lege , Cornel l Un iversi ty , a ful l descript ion ofwhich appea red on pages 70 5-70 7 of V0 ] . 12 , Tram .
A . S . M . E. This machine tests the bel t under actua lrunning condit ions
,though our be l t s were in somewhat
bet te r t han average condi t ion . The four be l t s werenew 4
-inch Alexander NO . 1 oak-tanned single-ply ,
and were 3 0 feet long . Part icula r ca re was taken tokeep them free from oi l and di rt . The bel t s were firsttested as rece ived from the manufactu re r , after whicheach bel t was t reated with one of the dressings andagain tested .
The dressings were two semi-sol ids , designated No . 1
and No . 2 ; a bar , No . 3 ,and nea tsfoo t O i l , No . 4.
As the first th ree are proprietary a rt icles , i t was nott hought best to give thei r names , though any onefami l ia r with the act ion s of bel t dressings wi l l readi lyrecogni ze No . I from i t s pecul ia r curve . In applying
Con tr ibuted to Power by Wi ll iam Evans .
TEST OF FOUR BELT DRESSINGS 1 0 3
t he dressings,we fol lowed direct ion s careful ly , and in
the case of Nos . 2 and 3 exceeded them . The bel t wasgi ven a five-hour run , during which two or three appl icat ion s of the dressing were given , and then i t was setaside in a warm place to a l low it to absorb the appl ieddressing . After thus “soaking for at least forty-e ighthours
,t he be l t was again run , t h i s t ime for three hours ,
with one more appl icat ion of the dressing . As No . 3was a bar of st icky dressing, i t wi l l readi ly be seen thatthi s precaut ion was not rea l ly necessary . NO . 4,
t he
nea tsfoo t oi l , was not appl ied during the last run , aswe were afra id of get t ing too much oi l i n t he be l t . As
t hi s oi l i s so extensive ly used by engineers for dressingbe lt s
,specia l ca re was taken to get t he best possib le
resul t s wit h i t .
Neat sfoo t O i l Be l t
FIG . 8 2.
I n Fig . 82 ,t he resu l t of the test with the nea t sfoo t
oi l i s shown graphica l ly . This curve i s plat ted to showthe relat ion between in i t ia l tension per inch of widthand horse-power per inch of width . One reason for thedrop in horse-power in t he t reated be l t i s that t he sl ip
1 0 4 SHAFTING, PULLEYS, BELTING, ETC .
was materia l ly increased ; i n t he lowest tension at whichany power at a l l was t ransmit ted
,about 1 5 pounds
per i nch of width , t he s l ip ran up as high as 25 per cent .
Summat ion Shee t
FIG . 8 3 .
I n Fig . 83 , which shows t he comparat ive va lue of thefour dressings , the h ighest horse-power del ivered to thebe l t was taken as t he standard . The horse-powerdel ivered by the be l t was divided by th is standard ,
and the resu l t , expressed in percentage , was used as t hepercentage of avai lable horse-power t ransmit ted . Thiscomparison shows t he great superiori ty of dressing No .
1 at a l l t imes,and especial ly at low tensions . I n look
ing a t th is chart , i t i s wel l to remember that No . 3 i s ast i cky dressing.
As t he t ime of the test was so short , we were unableto determine the ul t imate effect of the dressings on theleather of the bel t s . We could on ly approximate thi sby a chem i ca l test and a close examinat ion of the bel t sat t he end of each test . The chemica l ana lysi s showed
BELT CREEP
THE quest ion of the minimum amount of sl ip of a be l ti n t ransmit t ing power from one pul ley to anotherreduces it se l f to a qest io n of creep , for i t i s possib le tohave be l t s la rge enough so t hat wit h proper tensionst here wi l l be no regula r s l ip . With a difference i n tension on the two sides and of e last ici ty in t he be l t
,creep
,
however,i s bound to take pla ce . What doe s i t amoun t
to and what a l lowance should be made fo r i t ? asksProf. Wm . W . Bi rd of the Worceste r Polytechn icI nst i t ute i n h i s paper under the above t i t le .
FIG . 84.
I n Fig . 84 let A be the driver and B the dri ven , TIt he tension i n the t ight side of the be l t and T2 i n theslack side
,t he pul leys and bel t runn ing in the di rect ion
i ndicated . One inch of s lack be l t goes on to thepu l ley B at 0 ; at or before t he point p i t fee l s the effectof increased tension and st retches to 1 5 i nches .
1 0 6
BELT CREEP 1 0 7
I t now trave l s from p to m and goes on to pul ley Awhi le st retched . At or before reach ing the poin t n
,
as the ten sion decreases , i t cont ract s to one inch andso completes t he cycle .
With a l ight load the be l t creeps ahead of the pul leyB at or near the point I f t he load i s heavy , t he creepworks towards t he poin t 0 and the bel t may sl ip ; th i sa l so takes place when the be l t tension s are too l ighteven with smal l loads .The poi n t may be easi ly appreciated by imagin ing
the bel t to be of e last i c rubber . Professor Bi rd givesformulas for ca lcu lat ing t he creep , and test s made at thePolytechn ic to determine the modulus of e last icity.
He concludes that t he an swer to h is open ing quest ioni s that for the common leathe r be l t runn ing under ordinary condit ions the creep shou ld not exceed one percent . Whi le t hi s i s somet imes ca l led legit imate s l ip ,i t i s an actua l loss of power and cannot be avoided bybel t t ighteners or patent pul ley coverings .The smoot h or fin ished side should go next to t hepul ley because the actua l area of contact i s greater t hanwhen the rough side i s i n contact ; consequent ly , t headhesion due to frict ion i s greate r . Moreover , t hesmooth side has less tensi le st rength t han t he rough side ,so that any wear on that side wi l l weaken t he be lt lesst han wear o n t he other side would .
ROPE DR IVES 1
THERE seems to be considerable difference i n Opin ionregarding the various ways of applying rope to t hesheaves i n rope driving , viz. , mul t ip le or separate-ropesystem , con tinuous-wrap or single-rope system with therope from one of the grooves runn ing on a t rave l ingtake-up device , cont inuous-wrap or Si ngle-rope systemwith the take-up working di rect ly on a l l t he wraps .
FIG . 8 5.
The mul t ip le or separate-rope system on a horizonta ldrive where the distance between centers i s greatenough so
°
tha t t he weight of the rope wi l l give therequi red ten sion
,having the t ight or pul l ing part on
the lower side and the sheaves of the same diameter , asi n Fig . 85, should be very sat isfactory , as old or worn
1 Con tributed to Power by R . Ho yt .
1 0 8
1 1 0 SHAFTING,PULLEYS
,BELTING
, ETC .
Consequent ly the proport ionate pi tch diameter on therope on the drive r and driven sheave wi l l be changed .
The act ion wi l l depend upon whether the large or thesmal l sheave is the drive r . I f t he drive r i s t he larger
,
and of course assuming that the s lack or large rope i sweaker than the combined t ight or sma l le r ones
,t hen
i t wi l l have less st ra in on the pul l i ng side ; but if t hedriver i s smal le r , t hen the new or la rge rope wi l l havegreate r st ra in on the pul l ing side . Whether the driveri s la rger or smal le r , a la rge or slack rope affect s theact ion Oppositely to a smal l or t ight rope . Fig . 87shows how the act ion is reversed from Fig . 86.
For clea rness we wi l l exaggerate the differences indiameter in the sketches and figure the speeds t hatt he different si ze ropes would produce . We wi l l takeA as normal , B 1 i nch farther out of the groove , produc ing a difference in diameter of 2 i nches ; C 1 i nchdeeper in the groove , producing a difference in diameterof 2 i nches . I n Fig . 8 5 assume for the normal diameterof driver and driven 40 i nches , 42 i nches for B and
3 8 i nches for C , wi t h a speed of 20 0 revolut ions perminute for t he driver . Ei t her A ,
B or C wi l l give20 0 revolut ions per minute for the driven sheave ,omitt ing s l ippage , of course . In Fig . 86 say the normaldiameter of the driver for rope A i s 60 i nches and of thedri ven 30 i nches , a speed of the driver of 20 0 revol ut ion sper minute wi l l give the driven sheave a speed of 40 0revolut ion s per minute ; B,
with the driver 62 i nchesand the driven sheave 3 2 i nches diameter , wil l givet he lat te r a velocity of 3 875 revolut ions per minute .
With C t he driver i s 58 i nches , t he driven 28 i nches , and
ROPE DRIVES I I I
the speed given the la t te r 4 145 revolut ions per minute .
In Fig . 87, t he norma l diameter of the driving sheavebe ing 3 0 i nches and the driven 60 i nches , a speed of thedriver of 20 0 revolut ions per minute wi l l give a speedof t he driven member of 10 0 revolut ions per minute .
With B, i f the driver i s 3 2 and the driven 62 i nches ,the driven sheave wi l l have a speed of 10 3 5
75 revol ut ions
per minute ; C , with the driver 28 i nches and the drivensheave 58 i nches , wi l l give the lat te r a speed of 9655revolut ions per minute . So i t wi l l be readi ly seen whateffect a la rge or a smal l rope would have .
There are some who cla im that slack ropes wil l t ransmi t more power owing to more wrap on the sheaves ,whi le others cla im that t ight ropes a re bette r . I f adrive with a l l t he ropes slack gave t rouble by the ropess l ipping , t he first remedy t ried would be t ighten ing theropes . But i f t he condit ion s were l ike Fig . 87, i t wouldnot be part icu la rly harmfu l to have some of the ropes
FIG . 88 .
longer than others ; i n fact , i t might be wel l , as t helonger ropes would not make a complete ci rcui t asquickly as the shorte r ones ; consequent ly the posi t ionof the spl ices would be cont inua l ly changing . However ,i t seems more natura l to have about t he same pul l onall t he ropes , tha t i s , not have them as Shown in Fig . 88 .
1 1 2 SHAFTING, PULLEYS, BELTING , ETC .
I n conclusion for t he system,i t should be noted t
i t has no means of t ighten ing the ropes except byspl icing ; i t i s not as wel l adapted to various cont ions as the other forms ; i t i s the cheapest forminsta l l and in some cases should give exce l len t satfact ion .
With the cont inuous-wrap system having the ropefrom one of the grooves pass over a t ravel ing take-up ,
t he lat te r has a tendency to produce an unequa l st ra inin the rope . I n taking up , or le tt ing out , the rope muste i ther s l ide around the grooves , or the st rands havingthe greatest pul l wi l l Wedge themse l ves deeper into thegrooves , producing a smal ler pitch diameter than theones having less pul l , making a different ia l act ion onthe ropes . I t i s t herefore probable that i t i s the different ia l act ion that takes Up or let s out the ropes , t hetake-up mere ly act ing in a sense as an automaticadjustable id le r . I n t ighten ing , when the rope st retchesor dries out , or even in runn ing normal , t he greatestpul l wi l l be near the take-up , but if the drive i s exposedto moisture , and the rope shortens , i t wi l l be fa rthestfrom the take-up , depending proport ionate ly on thenumber of grooves the take-up cont rol s ; so i n largedrives i t i s best to have more than one take-up .
I f one should use an unyielda’
b le substance , as , forexperiment , a pla i n wi re on two drums wrapped anumber of t imes around and a l so over a take-up , andthe drums were moved together or apa rt , he would findthat the wi re would have to sl ide around the drum ;but , of course , with a rope in a groove i t i s differen t .The rope wi l l y ie ld some . I t wi l l a l so go deeper i nto
1 1 4 SHAFTING , PULLEYS , BELTING , ETC .
t he greater the wearing angle . I t must bebered that the foregoing appl ies to ordinary Si
drives as shown i n the sketches ; where the drivcompl icated , i t may be necessa ry to make otherlowances.
A NEW SCHEME IN ROPE TRANS
M I SS ION 1
THE use of man i la rope for t ransmit t ing power i sbecoming so common as to a t t ract no comment , and i tpossesses so many advantages in i t s own field over anyother method of conveying power tha t some object ionsrea l ly exist i ng are overlooked . When a rope drive i si n sta l led according to modern pract i ce , i t i s genera l ly sosuccessfu l and furn ishes such an agreeab le and smoothrunn ing drive that any possible object ion is s i lenced bythe many good qual i t ies i t evident lyhas . But , as amatte r of fact , t he American cont inuous method ofinsta l l i ng a rope drive has a few serious drawbacks .Were i t possible to in sta l l a drive of say th i rty ropes
i n such a manner that each one of the ropes had exact lythe same st ra i n on i t t hat each other rope had , and thi sunder varying condit ions of speed and load , i t i s eviden tt hat the t h i rty ropes would work exact ly as a bel t ofproper width to carry the load would , that t he ropeswould be runn ing with exact ly the same tension clea racross t he width of the drive , l i ke the bel t . But according to the best authorit ie s on rope t ransmission , th i side a l condit ion is impossib le to obtain .
1 Con tributed to Power by Geo . F. Willis.
1 1 6 SHAFTING,PULLEYS
,BELTING
,ETC .
I t i s given as desi rab le , by writers on rope t ransmission problems , to use a take-up sheave for everytwelve ropes , whi le ten is considered even bet te r .The best resul t s have been secured by us ing a take-upsheave for not more than eight ropes . But i n any casethe evi l of different ia l driving st i l l exist s .I n t ruth , the on ly drive in which perfect condit ions
can exist , according to present pract ice , i s one usingbut a single rope .
I t i s eviden t that when the load comes on the ropes ,t he ent i re number of ropes in use are on ly able toul t imate ly reach t he same tension from the e last ici tyof the ropes themse lves , as s l ipping in the grooves ra re lyoccurs . But t here i s a cont inued and uneven st ra inon the ropes unt i l t he load becomes divided betweenthem
,and where ropes are used to drive a varying load ,
t h i s st ra i n must and does reduce t he l ife of t he ropesmateria l ly .
Many rope t ransmissions have been unsa t i sfactorybecause of t his , and when these drives have been sobadly designed as to use one take-up sheave for moret han ten ropes , they are apt to be more expensive andt roublesome than could have been ant icipated .
One rope drive i s known where t hi rty ropes are used ,
wit h on ly one take-up sheave . I t has been a source ofcont inua l t rouble and expense , and has been replacedby the Engl ish system of mul t iple ropes . The inheren tt roubles of th is system have made the changed driveeven worse than the origina l . I t wi l l now be replacedby the system here i l l ust ra ted .
I n Fig . 89 i s shown a plan view of t he t ighteners for
1 1 8 SHAFTING,PULLEYS
,BELTING ,
ETC .
t hese two idle r sheaves should we igh , in cl uding theframe holding them .
These sheaves and the frame are mounted di rect ly
Upon the ropes , on the s lack side of course , and justas a t ightener i s mounted on a bel t . The first ropepasses a round the thi rty-two-groove sheave , on upover the single-groove sheave , and back under themul t iple-groove sheave again , and is t hus crossed over .
I t i s eviden t t hat a rope threaded on th is drivewould , by the t ime i t had run ten minutes or so , haveevery st rand in exact ly the same tension every otherst rand was in , and that the ropes would remain in th iscondit ion in spi te of variat ion of load and speed , aslong as they lasted .
The in i t ia l expense , in cl uding the erect ion , wouldprobably be no more than tha t for the necessary six
A NEW SCHEME IN ROPE TRANSMISSION 1 1 9
or eight single-groove idlers , with the i r shafts andboxes , t racks , etc . , which would be necessa ry according
FIG . 9 1 .
to establ ished pract ice . The room taken up wouldeviden t ly be much less .I n Fig . 92 an assembled drive of th is characte r i s
1 2o SHAFTING, PULLEYS , BELTING ,ETC .
shown . I n Fig . 93 i s shown a reve rse drive , common insawmi l l p ract ice , where the two sheaves describedwould prefe rab ly be mounted on a ca r , with the prope rweigh t to give t he desi red tens ion .
1 Groo ve Idler
32Groo ve 1
FIG . 9 2.
I n a recen t des ign is shown a cyl inder with about6 feet of piston t rave l , provided with a reducingva lve ,so t hat t he steam pressure would rema in constan t atabout 40 pounds . The cyl inde r i s bol ted to the mi l l
1 0m “ !
frame,whi le t he piston rod i s connected to the ca r
ca rrying t he t ightener sheaves . The cyl inde r i s of theproper area
,when furn ished with steam at 40 pounds
HOW TO ORDER TRANSM I SS ION ROPE 1
IT is probab le that more differen t and erroneousterms a re used by purchasing agent s and engineerswhen writ ing orders for t ransmission rope than are usedto describe any other art icle needed about a mi l l .A knowledge of how to order clea rly just t he kindof rope wanted would prevent delays and expense tomany plant s . Manufacturers of t ransmission ropeconstant ly receive orders so pecul ia r in thei r wordingthat they da re not venture an immediate shipment ,but must first resort to the ma i l s , te legraph or te lephoneto find out what i s rea l ly desi red , and , of course , t hesemistakes , fol lowing the law of
“the genera l cussednessof th ings , usua l ly occur afte r a breakdown at thevery t ime when every minute
’
s de lay means a considerable sum ofmoney lost .There a re in thi s count ry two manufacture rs of
cordage who make a specia l ty of t ransmission rope ,and the names under which thei r rope is sold a re fa i rlywel l known to a l l users of rope drives . I n addit ion tothese two concerns , t here are , perhaps , t h ree or fou rothe r cordage mi l l s which make th is grade of rope tosome exten t . From th is comparat ive ly smal l source
1 Con tributed to Power by F. S. Greene .
HOW TO ORDER TRANSMISSION ROPE 1 23
many differen t brands have sprung which , rech ri stened ,
find thei r way to the market under a va riety of names,
both poet ic and classic . These many names lead tofrequent de lays i n ordering . The man who does thespl icing at t he mi l l has , at one t ime or another , heardof a rope glorying in the possess ion of some fancy t i t le .
I t i s more than probable that some sa lesman has toldhim most wonderfu l stories of what thi s part icula r ropecan do ; consequent ly when the t ime comes for a newrope , the , spl icer goes to the office and asks that somany feet of such and such a rope be ordered . Thepurchasing agent makes out the order , using th is name ,and sends i t to t he manufacturer , who in a l l probab i lity has neve r hea rd of the rope and knows for a factt hat i t i s not the brand under which any of his fel lowmanufacturers a re se l l ing rope . Before the orde r canbe fi l led , two or more le t te rs or te legrams must besent and rece ived .
I t frequent ly occurs t hat manufacturers rece iveorders specifying brands which never had existencea t a l l , so fa r as t hei r knowledge goes . One fi rm recent lyfound in the same mai l request s for “Fern
,
! “
Juno ,and Elephan t t ransmission rope , t hough no suchbrands have ever been on the market .
Another famil ia r mistake i s t he ordering of a certa incolor yarn i n the rope , as if t h i s decorat ion possessedsome pecul ia r virtue . These colored yarns are simplya quest ion of dye , and the rope in a l l probabi l i ty wouldbe better and st ronger were they left out .Then again , we find pecul ia r wording as to thel ubricat ion of a rope . Some people in si st t hat t he rope
1 24 SHAFTING , PULLEYS , BELTING ,ETC .
sha l l be ta l low in la id others ca l l for an absolute lydry ! rope or for a “water-la id ! rope . All t ransmissionrope
,to be of any se rvi ce what soever ,must be lubricated
and such a t h ing as a “dry ! t ran smission rope or awater-la id one , whateve r t hat term might mean ,would be of but sma l l se rvice to the user . Each manufacturer has h i s own method or formula for lubricat ing,and i f t h i s be a plumbago or graphi te-la id rope , and hei s a sked for an old-fash ioned ta l low-la id rope , he cannotfi l l orders d i rect ly from stock .
I t i s unnecessa ry to name the number of st rands ,un less you wish a t hree or s ix-st rand rope
,for a four
st rand t ransmission rope is a lways sen t , un less otherwise specified . It i s a l so unnecessa ry to say anythingabout t he core , as the rope is a lways suppl ied with one ,and genera l ly i t is l ubricated . Frequen t ly five-st randrope i s ordered . This i s very confusing , as there i ssuch a thing as a five-st rand rope , but i t i s very rare lymade . Ordering a five-st rand rope i s usua l ly broughtabout through the e rror of considering the core as afift h st rand .
I t i s bet te r , though not necessa ry , to order by thediameter in stead of the ci rcumference , as t ran smissionrope is made and usua l ly sold upon diameter spec ificat ion .
By far t he most frequen t specificat ion s rece ived ca l lfor “ long-fiber, four-st rand rope wit h core , and havingdone this , t he purchaser considers he has named a l lnecessary requi rement s . At t he present price of man i lahemp , which varies from 7 cent s per pound for t hepoorer grades to 125 cent s per pound for the best , he
SHAFTING,PULLEYS
,BELTING ,
ETC .
FIG . 94.
FIG . 95.
HOW TO ORDER TRANSMISSION ROPE
known In t he t rade as Superior 2ds , whi le the fiberto the right of the cut is Z ebu .
! Fig . 96 shows
FIG . 96.
a more distant view of the same two heads of hemp ,and the reade r wi l l see that in bot h the fiber i s exceed
1 28 SHAFTING, PULLEYS , BELTING ,
ETC .
i ng long , and if anything , t hat of the Supe rior 2ds’
i s longer than in t he Z ebu . A t ransmission rope madefrom the lat te r , however , wil l cost t he manufactu rerfrom 3 5 to 4 cents more per pound t han if he had usedSuperior 2ds , and wil l out las t two rope s made fromthe longer t hough coarser fiber .The reader, i f he has perused th is chapte r to the pres
ent poin t , i s doubt less now asking himself :“How shal l
I word my order when I want a first-class drivingrope ?
! The safe st road to fol low is to write to somemanufacturer or firm whom you know to be re l iab le
,
and ask for so many feet of t hei r t ransmission rope ,giving the name , i f you are certa in on t hat point , and ,of course , being sure to ment ion the diamete r. I ncase you do not know the name of hi s rope , word yourorder a s simply and briefly a s possib le ; for exampleOne thousand feet 15 i nches d iameter fi rst qua l i tyman i la t ransmission rope , and if t he concern to whichyou write i s a reputab le one , you wil l rece ive a fourst rand rope , made from Z ebu man i la hemp , put together with proper twist and l ay for t he servicerequi red .
1 3 0 SHAFTING , PULLEYS , BELTING ,ETC .
0 200 0 0 .
4 11 10 72 0 .
FIG . 97.
A BELTING AND PULLEY CHART 1 3 1
by ca rrying the space to t he revolut ion sca le on sca leB,and proceeding in the same way .
Example : D iamete r of pul leys 12 and 36 i nchesand speed of L 50 0 , what is speed of 5 ? P lace point sof divide rs on 12 and 36. Now , i f di viders a re ra i sedand one point placed on 50 0 and the ot her above i ton scale A ,
i t wi l l come beyond the top of t he sca le .
Hence go to sca le B, placing lower poin t on revolut ionsca le at 50 0 and the ot her point above , which wi l l fa l lupon 150 0 ,
’
t he answer .RULE 2 . Pulley D iameters . When the speed of
both pul leys and the diamete r of one i s given , to finddiameter of the other : P lace point s of divide rs on t hetwo Speeds on sca le A or revolut ion sca le B. Thenplace one poin t of di viders on gi ven diamete r and theothe r above i t to find diameter of L, or be low it fordiameter of S . The figure t hus i ndicated i s the requi red diameter .Example : Speeds 180 and 450 and diamete r of
smal ler pul ley 20 . What must be diameter of L?P lace point s of dividers on 180 and 450 on sca le A .
Then place one point on 20 (t he given diameter) . Theother point fa l l s a t 50 , the requi red diameter of L .
I f t he point fa l l s between two graduat ions i n anyproblem , the resul t can be close ly j udged by the re lat ive posi t ion .
The othe r and more labor-saving use for t hi s charti s i t s appl i cat ion to be l t ing problems . I t i s general lyconceded that there i s no subject of more genera l i n te rest in pract ica l mechan ics and none on which there i s agreater difference of opin ion than t he proper a l lowance
1 3 2 SHAFTING,PULLEYS
,BELT ING
,ETC .
to be made i n the se lect ion of be l t s i zes for given re
quirement s . The genera l formula for the horse-powert ransmitted by be l t i ng i s
in which HP horse-power,
W width of bel t in inches , S speed of bel t i nfeet per minute , and C constan t .The proper va lues of thi s constant , or the feet per
minute that each i nch of width must run to t ransmi ta horse-power , under ce rta i n condit ions , i s t he poin ti n quest ion .
On the right-hand side of l ine A on the chart is aseries of l ines represent ing diffe rent va lues for th i sconstan t . The lower one , marked 4, represent s 40 0feet be l t Speed per minute , t he next above i s for 50 0 ,
and so on . Again st some of these va lues a re sugges
t ions a s to bel t s often recommended in connect ion wi tht hese constants . For i nstance , 2 to 6 S suggest s t heconstan t 1 10 0 to be used for 2 to 6—i nch s ingle leatherbel t
, 10 0 0 for 65 to 10 -i nch Si ngle , 60 0 for 2 to 6-i nchdouble
,etc .
These suggest ion s pract ica l ly agree with the adviceof the Geo . V. Cresson Company
’ s cata log and thededuct ions of ! ent ’ s HandbookMore power may be t ransmit ted than t hese sugges
t ions wi l l a l low,by increasing the tension , but thi s i s
accompan ied by the disadvantage of requi ring ext raat tent ion and undue pressure upon bearings .The use of the chart for horse-power and width of
be l t ing i s expla ined by the fol lowing ru les :
1 3 4 SHAFTING,PULLEYS , BELTING, ETC .
width of be l t ing when size and speed of pul ley and thehorse-power are gi ven : P la ce one poin t of dividerson sca le B upon the horse-power and the other pointUpon the revol ut ions . Next t ransfe r t h i s space to scaleA by rai sing the dividers , ca rrying them square acrossand placing the poin t that was on revolut ions Upon theconstan t . Then holding the other point stat ionary
,
ra ise t he poin t t hat was on the constan t and opendivide rs un t i l t h i s point fa l l s Upon the given diameter .Now l ift t he d ividers and carry the lower point downto bottom of l ine (t he poin t The Upper point wi l lnow indicate the requi red width of be l t .Note .
— '
If, i n finding width of be l t , there i s doubtabout the prope r constant to take , a medium va lue ,say 6,
may be assumed and a hasty “cut and t ry !
wi l l show in what classificat ion t he requi red bel t wi l lcome .
Example : What widt h of bel t for 10 0 horse-powerwith 4o-i nch pul ley at 50 0 revolut ions ?P lace poin t of dividers on sca le B upon 10 0 on horse
power sca le and the other upon 50 0 on the revolut ionsca le . Then ca rry the space to sca le A with lowerpoin t on constan t 5. Then rest ing divide rs Uponuppe r poin t open them unt i l lower poin t i s a t 40 (diameter) . Fina l ly ,
ra i se dividers and place lower poin t '
at bot tom of l ine . Upper poin t i s now at 95, i ndicat ingthe nearest even widt h 10 as the answer .A l i t t le pract ice wi l l make one famil ia r with these
rules , and i t wi l l be seen t ha t in the be l t ing rules t hefour mot ions perform twomult ipl icat ions and a division .
SPL ICING ROPE
THE sp l ici ng of a t ran smi ssion rope i s an importan tmat te r ; t he poin ts on which the success of the spl ice ,and inciden tal ly the d rive , depend being the lengthof the spl ice
,which in tu rn depends Upon the di amete r
of the rope and which i s given in the t ab le (Fig . 97a ) ;
DATA RELATIVE To MANILA TRANSMISSION ROPE AND SHEAVES
L ENGTH o r SP L IC EIN FE E T
1 3 6 SHAFTING,PULLEYS
,BELTING
,ETC .
the di amete r of the sp l i ce , which shou ld be the sameas the diamete r of t he rope ; t he secu ring of the endsof the st rands of the spl ice , which must be so fastenedthat they wi l l not wear or whip out or cause the ove rlying st rands to wear unduly ; and the workmansh ipof the spl i ce , which shou ld be t he best i t i s possib le tosecu re . When spl icing an old and a new piece ofrope , the new piece shou ld be thoroughly st re tched ,
for, a t best , i t i s an exceedingly diffi cul t task onaccoun t of the st re tch and diffe rence i n di amete r ofthe rope .
The i l l us t rat ion s and i n st ruct ion s for making standard rope spl ice s a re taken , by the courte sy of t heAmerican M anufactu ring Company , from thei r Bl ueBook of Rope Transmi ssion .
!
The re are many diffe ren t spl ice s now i n use , but theone that expe rience has p roved best i s what i s knownas the Engl i sh t ran smi ssion spl ice . In describ ing thi swe take for ou r example a fou r-st rand rope
,15 i nches
i n d iamete r,as spl iced on sheaves i n t he mul t iple
system . The rope i s fi rs t p l aced around sheaves , and ,wi th a t ackle , st re tched and hau led taut ; t he endsshould pass e ach othe r from six to seven fee t , the passing poin t be ing marked wi th twine on e ach rope .
The rope i s then sl ipped from the sheave s and al lowedto rest on Shafts , to give sufficien t s l ack for makingthe spl ice . o
Un l ay the st rands i n pai rs as far back as the twinesM, M ’
, crotch the fou r pai rs of st rands t hus opened
(Fig . core s having been d rawn out togethe r onthe Uppe r Side . Then , having removed marking
SHAFTING, PULLEYS, BELTING,ETC .
Shown in Fig . 99 . The pai r of st rands 6 and 8 arenow separated , and 8 un l aid four fee t back to B
,a
di stance of s ix fee t from cen te r,s t rand 6 being left a t
A . The pai r of st rands 1 and 3 having been separated ,
3 i s left at A ,as compan ion for 6, s t rand
“
1 being carefu l ly l aid in pl ace of st rand 8 un ti l t hey mee t at poin t
SPLICING ROPE 1 3 9
B. The two pai rs of st rands 2—4 and 5—7 are nowseparated and l aid i n the same manne r, eve ry carebeing taken
,whi le thus putt ing the rope togethe r,
that original twist and l ay of s t rand i s main tained .
The prot ruding cores are now cut off so that the ends ,when pushed back in rope , but t together .The rope now appears as Shown in Fig . 10 0 , and
afte r the eight st rands have been cut to conven ien tworking lengths (about two fee t) , t he companionst rands are ready to be fastened togethe r and“ tucked thi s Opera tIOn 15 described for st rands 2
and 7, the method being iden t ical for the othe r th reepai rs . Un l ay 2 and 7 for about twe lve to fourteeninches
,divide each st rand in half by removing i t s
cover yarn s (see Fig . whip wi th twine the endsof i n te rior yarn s 2 ’ and then , le aving cove r 2 , re l ay2’ unt i l near 7 and here joi n wi th simple knot 2 ’
and Fig . 10 2 . D ivide cove r yarn s 7, and pass 2’
th rough them , con t i nuing on through the rope underthe two adj acen t st rands , avoiding t he core , t huslocking Fig . 10 3 . In no even t pa ss 2
’over these or
any other strands . H alf-st rand 7’ must now be taken
care of ; at the right of t he knot made with 2 ’ and2’ i s s l ight ly rai sed with a marl i n spike
,and 7
’ passedor tucked around i t two or three t imes
,t hese two
half- st rands forming i n thi s way a whole st rand .
Half- st rand 7’ i s tucked unt i l cove r 2 i s reached
,
whose yarns are divided and 7’ passed through them
and drawn unde r the two adj acen t st rands,forming
agai n the lock . The st rand ends at both locks arenow cut off
, le aving about two inches , so that the
SHAFTING, PULLEYS, BELTING,
SHAFTING,PULLEYS
,BELTING
,ETC .
yarn s may d raw sl igh t ly wi thou t un locking . Thi scomple te s the joi ni ng of one pai r of st rands , Fig . 10 4.
The th ree remai ning pai rs of st rands are joined i n thesame manner.
FIG . 1 0 4 .
Afte r the rope has been i n se rvice a few days , t hep roject ing ends at locks wear away , and if tucks havebeen carefu l ly made , and the original twi st of yarnsprese rved , t he diamete r of the rope wi l l not be increased , nor can the spl ice be located when the ropei s i n motion .
XVI I I
W IRE ROPE TRANSM I SS ION 1
WIRE ropes are extens ive ly and successful ly usedi n t he hori zonta l and incl ined t ransmission of greatpower of un l imi ted amount , t he advantages over hemprope be l t ing being : driving at very long distances ,comparat ive ly smal l loss t hrough s l ipping and thepossibi l i ty of driving in the open ai r .Vert ica l t ransmission of power , on account of the
weight of the rope , i s excluded .
Formerly the materia l used in the manufactureof t he wi res was best charcoa l i ron , but now almostexclusive ly tough crucible-stee l wi res a re used , as stee lwi re ropes are st ronger , do not st retch as much , and la stlonger than i ron ropes .The wi re ropes consist of six st rands of from Six to
twenty wires each , and the st rands to form the ropeare woven in the Opposi te di rect ion to the WIres In t hest rand . I n the center of each st rand and in the cen te rof the rope a cotton core i s placed . These cores are ofthe greatest importance
,for by reducing the frict ion
of the wi res against each othe r , they serve to increaset he l i fet ime of the rope , which , according to the St rain
1 Con tributed to Power by C . Bo ysen ,M
_. E.
I43
1 44 SHAFTING , PULLEYS , BELTING , ETC .
on the rope and the Si ze of the sma l lest pul ley,i s from
one to t hree yea rs .To prevent rust ing , t he wire ropes rece ive a coat
of boi led l i nseed oi l , or a hot mixture consi st i ng ofthree pa rt s of drip oi l and one part of resi n i s appl ied
.
This lat te r mixt ure a t t he same t ime improves t he adhesio n between the rope and the l in ing placed i n thebot tom of the pu l leys , t hus reducing t he loss caused bys l ipping of t he rope . Wire ropes used for t he t ransmission of power should neve r be ga l van i zed .
The ends of t he rope a re spl i ced together,from 10
to 20 feet being necessa ry for a good spl ice ; great careshould be taken t hat t he spl ice i s made by experiencedmen , and tha t t he rope i s made long enough . A ropest ret ches constan t ly from the t ime when placed on thepul leys
,t he more so when placed on the pul leys t ight ly .
Therefore i t has to be made long enough to t ran smitpower without undue ten sion , and for t h is reason thedistance between the two pul leys has to be long enoughand the working st ra i n pe r squa re inch of sect ion lowenough to a l low sufficien t deflect ion in the rope . As
a guidance to t he amount of deflect ion necessa ry , bei t sa id t hat even in a short drive the deflect ion of therope
,when not runn ing , should not be less t han 2 feet ;
and for a di stance of 40 0 feet between pul ley cen ters ,t he deflect ion of the rope when running should be 5 feeti n t he driving rope and 10 feet in the driven rope .
Ei t he r the top or the bot tom rope may be the drivingone
,t he former being preferab le ; but the ropes should
never be crossed .
Powe r can be t ransmited to a d i stan ce of 60 0 0 feet
1 46 SHAFTING , PULLEYS , BELTING ,ETC .
t he rope . Leather i s the best l in ing and la st s aboutt hree years . Ei t her old be l t leather , wel l saturatedwith oi l , or new leather , boi led i n fish oi l , can be taken .
I t i s cut i n pieces of the same si ze as t he dovetai ledpart of t he groove , and then p laced on and pressed together i n t he lat te r . The pressing is done by meansof a piece of wood . The last remain ing smal l space int he groove is fi l led with soft rubber . I f the l in ing hasto consi st of rubber , t h i s i s softened and hammeredin to t he groove . For wood l in ing , t h in blocks of therequi red si ze are p laced into the groove through a holeprovided i n t he bot tom of t he rim . This s lot i s closedby a plate and fastened to the bottom of the rim bymeans of screws after a l l b locks have been inserted .
The l in ing has to be turned absolute ly t rue , for whichreason t he fi l l ing i s done whi le the pul ley i s st i l l i n t helathe .
Pul leys Up to 3 feet i n diameter are bui l t with casti ron arms ; whereas la rge r pul leys have wrought-i rona rms made of round iron , cast in the rim and boss .Pul leys under 8 feet 6 i nches in d iamete r a re made inone piece
,i f for other reasons i t i s not necessary to have
them in ha lves .Guide pul leys a re used for long ropes , especia l ly
i f t here i s not sufficien t h igh t above the ground . Theguide pul leys are of the same const ruct ion as the mainpul leys
,and for the driving rope they are a l so made of
the same diamete r . The diameter of the guide pul leysfor the driven rope can be made from 20 to 25 per cent .
smal ler .The breaking st rength of unannea led wires per square
WIRE ROPE TRANSMISSION 1 47
i nch of sect ion and according to thickness and qua l i tyis : For i ron wires from to pounds
,
and for stee l wires from to pounds .For thinner wires a higher va lue i s taken than for th ickones .The diameter of the wires used for making ropes for
t ran smit t ing power i s from to inch , and onaccount of the st iffness , no wires above the lat ter si zeshould be used . A rope consi st ing of a greater numberof thin wi res , besides be ing st ronger i s more pl iableand last s longer than a rope of the same area consi st ingof a less number of thicker wires .
1 50 INDEX
Be lts,c leaning
keeping c leanleather
,care and management
Spl ic ingmain l inetaking-UpB ird
,Pro f . Wm . W .
B lue Boo k of Rope Transmiss io nBoard fo r use in l in ing co untershaftBo i led l inseed o i l in w ire ropeBo lt and nut fo r mo ving pul leysfo r hanger
,Size
Bo lt,prevent ing turning
Boysen,C .
,M . E
B rands,effect o n leather
B reaking strain o n Shaftstrength o f unannealed w i resBunsen burner
,use in mo v ing pul ley
Bushing, spl it
Center d rive for heav i ly loaded shaftsto ckChart
,be lt ing and pul ley
C lean ing belt ingC lutch
,rim-frict io n
,arrangemen t
C lutches,co upl ing
O O O O O O O O O O O O O O O O O O O O O
0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0
0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0
0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0
O O O O O O O O O O O O O O O O O O O O O
O O O O O O O O O O O O O O O O O O O
0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0
O O O O O O O O O O O O O O O O O O O O O
0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0
O O O O O O O O O O O O O O O O O O O O O
0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0
0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0
O O O O O O O O O O O O O O O O O O O O O
O O O O O O O O O O O O O O O O O O O O O
0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0
0
O O O O O O O O O O O O O O O O O O O O O
0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0
t ightening whi le shaft ing is in mo t io nCo l l ars
,spl it wo od
Compass saw,use in lo cat ing beams
Co ntact,extra
,securing
Co nt inuo us-wrap system o f ro pe d rive
O O O O O O O O O O O O O O O O O O O O O
O O O O O O O O O O O O O O O O O
-wrap System w ith d i rect—act ing t ightenerCo re co tto n
,o f w i re ro pe
0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0
INDEX 1 51
PAGECo untershaft, l in ing 3 2, 3 3 , 3 5, 3 6, 3 7
Co up l ings, flanged bo lt 3
Cresso n Co .,G eo . V .
, cata log
Deflect io n of ropeD iameter o f spl iceropeo f w ires fo r transmissio n ropeD iameters
,pu l ley
D ifferent ial act io n on ropes . 1 0 9 , 1 1 2,1 1 6
D isks fo r p lumb-b o bD istance o f power transm issio n by w ire ropeD ixo n
,Wa lter E.
,M . E .
Dress ing,waterpro o f
,fo r belts
Driving an o verhead flo o r
E lbow bo ltsEmery c lo th fo r packingEnd drive compared w ith center d riveEng l ish transm issio n spl iceEvans
,Wil l iam
Farmer,T .
, Ir .
Fastening strands of spl iceFiber
,rope
Fi l led be l tsFlanged bo l t co up l ings
Gaso l ine b low to rch,u se in gett ing o i l out o f belt
G luing a jo int
I52 INDEX
Greene,F . S .
Guide pul leys
Hanger adjustment,securing
bearing,repairing worn end
po sit io ns,marks
Hanger,remo ving to take o ff pul ley
Sl id ing o ut o f wal l b o xHangers
,cro ssw ise o f shaft
Hangers no t al low ing vert ical adjustmen tHeads of hempHempHerrman , Chas . 1 , 2 1 ,
Ho lman , A . G .,M . E .
Hoo k bo ltsHo rse-power transmitted by be lt ing I3 2, 1
Hoy t , R .
Jo ints in leather be ltJo urnaled end o f shaft
,proper length
! avanagh,Wm .
! en t ’ s Handbook! inks, pract ical
Lap s o f leather be l t,length
of leather be lt,thickness
Leather bel ts,care and managemen t
se lect io n
1 54 INDEX
Po in t s l ippingPower transm issio n by w i re ro pes
,d istance
Pract ical kinksPu l ley and belt ing chartd iametersl in ing
,w ire rope transm issio n . f
Shafts ho ld ing arrangemen t and adjust ing co n trivancespeedPul ley
,cast- i ro n , mo v ing
d riving,locat io n
loo seseized , loosen ingPu l leys fo r w i re ro pe tran smissio nPu l leys, guideloosen ingmo vingremo ving
Ro pe, cored iameterd ifferent ial act io n
lubricat io nSpl ic ing
transm issio nnew schemeo rdering
Ropes,s lack .
t ight .
Rust ing of w i re rope, prevent ing
1 24
1 1 2,1 1 6
1 0 8
1 24
1 23
1 3 5
1 24
1 3 5
1 1 5
1 22
1 1 1
1 1 1
1 44
INDEX 1 55
PAGE
Scrapers fo r remo ving glueScrapers
,turning edge
Seiz ing o f pul leySeparate—rope systemSet-screws
,use .
Shaft,breaking strain
causes o f breakingprevent ing turningrepairing breakjournaled o ff to act as co l larlength o f journaled part o f endShaft l ine
,space between end and wal l
Shaft ing,apparatus fo r l evel ing and l in ing
hin tslevel ingl ine
,turning Up
l iningtest ing al inemen t and l eve lShafts o f l ight-wo rking co unters , marringSheaves
S izes of belts
S lack ropes .
S l ip of belt,legit imate
Space between end o f shaft l ine and wa llSpeed
,pul ley
Spl ice, d iameterEngl ish transm issio nfastening strandsl engthSp l ice o pener fo r heavy be l tsSpl ice
,w ire rope
wo rkmanshipSpliced part o f belt
,marking
1 56 INDEX
Spl ic ing be lt on the pul leysboard
ro peSpl it bushingSplit-pul ley
,t ighten ing
Split wood co l larsS tee l fo r sharpening scraperSt il lso n wrench
,use
S trands o f ro peStretchers
,posit io n
S tringers, lo cat ing beams to carryStringers of d ro p hangers
,thickness
Superio r 2ds hempSway ing o f rope
,preven t ing
Take-up fo r rope d rive-Up sheave fo r rope d rive
Test ing al inement and level o f shaft ingTight ropesTightener
,automat ic
,fo r rope d rive
Tightener fo r 3 1 -ro pe d rivesystem
,dangero us
Tightening ro pesTimbers of boarded-o ver cei l ing
,lo cat ing
Tin fo r packing .
Too l fo r l evel ing shaft ingToo ls fo r spl ic ing leather be l tsTransm issio n ro perope
, o rderingTransmissio n
,w ire rope
rope,deflect io n o f rope
Travel ing take-up fo r rope d riveTucking strands