ep0456867a1_luoi cat rong beo

7/28/2019 EP0456867A1_luoi Cat Rong Beo

1/15

Europaisches PatentamtEuropean Patent OfficeOffice europeen des brevets Publication number: 0 4 5 6 8 6 7 A 1

EUROPEAN PATENT A P P L I C A T I O N

@ Application number: 90109383.1 Date of filing: 17.05.90

int. ci.5: A01D 34/37, A01 D 34 /3 0

@ Date of publication of application: Inventor: Asatsuma, Kinpei21.11.91 Bulletin 91/47 2-12, Ikuta 4-chome, Tama-kuKawasaki-shi, Kanagawa-ken(JP) Designated Contracting States:DE FR GB IT SE 0 Representative: Patentanwalte Griinecker,

Applicant: KOMATSU ZENOAH CO. Kinkeldey, Stockmair & Partner142-1, Sakuragaoka 2-chome Maximilianstrasse 58Higashiyamato-shi Tokyo(JP) W-8000 Munchen 22(DE)

Mowing apparatus.

COooCOi n

Disclosed is a mowing apparatus (101) whichincludes a pair of first and second cutting members(105U,105L) slidably superposed with each other,each of the members including a plurality of alignedcutting teeth (12311,1 23L); mechanism for moving thefirst cutting member (105U) relative to the secondcutting member (105L) reciprocably within a pre-determined range in the direction of the alignedcutting teeth (12311,1 23L) at a substantially uniformspeed; and a drive source for driving the movingmeans. The moving mechanism includes a solenoidactuator having first and second coils (107R.107L)

F I G . 7

and a plunger (109) provided reciprocatingly mov-ably between the first and second coils (107R,107L).The plunger (109) is connected to the first cuttingmember. The moving mechanism further includes aswitch (121) alternately switches the first and secondcoils ON, thereby causing the first and second coils(107U,107L) to become magnetized alternately toattract the plunger (109) alternately so that the firstcutting member (105U) to which the plunger (109) iscoupled is moved at a substantially uniform speed inaccordance with the motion of the plunger (109).

117 |

121

105U

Rank Xerox (UK) Business Services


2/15

1 EP 0 456 867 A1 2

BACKGROUND OF THE INVENTIONField of the Invention

The present invention relates to a mowing ap-paratus with two oscillatable cutting members.Description of the Prior Art

One example of an oscillative mowing appara-tus is illustrated in European Patent Application No.87112105.9 filed by the applicant of the presentinvention. First and second superposed cuttingdisks are used in the mowing apparatus of thatpatent application. The two cutting disks oscillate inopposite directions within a predetermined oscillat-ing range, through a crank mechanism. Specifi-cally, as shown in Figs 1 and 2, a tubular first shaft3 is integrally provided at the center of a firstcutting disk 1U. The first shaft 3 is rotatably pro-vided in a casing 5 through a bearing. Also, asecond shaft 7 is integrally provided at the centerof a second cutting disk 1L, and the second shaft 7is rotatably inserted into the first shaft 3 in the axialdirection. The bases of a first arm 9U and a secondarm 9L are integrally mounted on the first andsecond shafts 3, 7 respectively. The tip of the firstarm 9U is connected to a first link 11U and the tipof the second arm 9L is connected to a second link11L. A cam shaft 13 provided with two circulareccentric cams 15U, 15L is installed in the casing5. The first and second links 11U, 11L are slidablyfitted into the circular eccentric cams 15U, 15L,respectively. The cam shaft 13 is connected to amotive power source through a large gear 17, asmall gear 19, an intermediate shaft 21, a bevelgear 23, a bevel gear 25, and a drive shaft 27.In the above structure, the rotational motion ofthe motive power source is transmitted to the camshaft 13, causing the cam shaft 13 to rotate. Thetwo eccentric cams 15U, 15L rotate as a result ofthe rotational motion of the cam shaft 13, and thefirst and second arms 9U, 9L are reciprocatinglypivoted in opposite directions through the first andsecond links 11U, 11L. Then, the first and secondcutting disks 1U, 1L oscillate reciprocatingly inopposite directions through the pivoting action ofthe arms 9U, 9L, thereby enabling to cut grassbetween the teeth of the upper and lower cuttingdisks as scissors.The conventional mowing apparatus describedabove is highly superior in safety of operation.However, in the conventional mowing apparatus,the relative positional relationship of the teeth ofthe upper and lower cutting disks during the os-cillating action of the cutting disks of this mowingapparatus, as indicated by the solid line "A" in Fig.3, is represented in the form of a sine curve.

Specifically, in the conventional mowing apparatus,the upper teeth 29U move relatively from onesuperposed state in which the upper teeth 29U aresuperposed on the lower teeth 29L (this state cor-5 responds to the top or the bottom of the sinecurve) to the next superposed state in which theupper teeth 29U are superposed on the adjacentlower teeth 29L (this state corresponds to the bot-tom or the top of the sine curve). Then the upperw teeth 29U move in the reverse direction toward thefirst superposed state and are once again super-posed on the previous lower teeth 29L. At this time,the motion of the upper and lower teeth 29U, 29L,slows down according as the superposed position15 (the top or the bottom of the sine curve) is ap-proached, and the moving speed becomes highestwhen the upper and lower teeth are in alternatepositions (this state corresponds to the middle por-tion of the sine curve). In this case, it is apparent20 that slope of the curve represents moving speed ofthe cutting teeth. Therefore, in the conventionalmowing apparatus, the moving speed of the cuttingteeth when the upper teeth 29U are superposed onthe lower teeth 29L becomes extremely low. Grass25 is being cut by the teeth just before the super-posed states. This means that the grass is beingcut by the relatively low moving speed of thecutting teeth.Accordingly, in the conventional mowing ap-30 paratus, there is a problem that the highest movingspeed of the cutting teeth could not be used in thegrass cutting operation. Further, because the mov-ing speed of the cutting teeth is slow before andafter the teeth reach the superposed position and35 there is no stationary state when the teeth of theupper and lower cutting disks are superposed, theduration of the period when the upper and lowerteeth 29U, 29L are fully superposed (this statecorresponding to the top or bottom of the sine40 curve) is short. For this reason, only a short time isavailable to the cutting disks in the condition wherethere is a wide space between each of the teeth29U and each of the teeth 29L, which is necessaryto receive the grass to be cut between the teeth as

45 much as possible.SUMMARY OF THE INVENTION

A main object of the present invention is toso provide, with due consideration to the problem ofsuch conventional apparatus, a mowing apparatusprovided with two upper and lower oscillating cut-ting members each having a plurality of cuttingteeth wherein, when grass is cut by the teeth55 between the teeth of the cutting members, themoving speed of the cutting teeth is substantiallyuniform.Another object of the present invention is to

2


3/15

3 EP 0 456 867 A1 4

provide a mowing apparatus wherein in order toadequately cut grass, there is a long time intervalin the condition where a wide space occurs be-tween the upper and lower teeth, in which the teethof the upper and lower cutting members are super-posed.These objects are achieved in the present in-vention by the mowing apparatus comprising (1)apair of first and second cutting members slidablysuperposed with each other, each of the membersincluding a plurality of aligned cutting teeth; (2)-means for moving the first cutting member relativeto the second cutting member reciprocably within apredetermined range in the direction of the alignedcutting teeth at a substantially uniform speed; and(3)a drive source for driving the moving means.As a result, the cutting members of the mowing

apparatus can move at a substantially uniformspeed relative to each other, which does not havesubstantially decelerating motion. Accordingly, theteeth of the upper end lower cutting members aresuperposed in such a manner that the movingspeed of the teeth of the cutting members whenthe teeth of the cutting members are about to besuperposed with each other, that is the movingspeed of the teeth in the grass cutting operation isnot reduced. The cutting members therefore pro-vide a superior cutting force.Further, by providing halting means for haltingthe motion of the cutting member when the upperand lower teeth are superposed a long time intervalcan be provided when the upper end lower teethare superposed, in which the space between theteeth is wide. Accordingly, the grass to be cuteasily enters between the teeth, and the amount ofuncut grass becomes small.Furthermore, the operator can change the cy-cle of the motion of the cutting members as re-quired without changing the speed of the motion.Therefore, even when the cycle of the motion ismodified, the cutting force of the cutting teeth ismaintained, and the operator can easily operate themowing apparatus.BRIEF DESCRIPTION OF THE DRAWINGS

These and other objects, features, and advan-tages of the present invention will become moreapparent from the following description of the pre-ferred embodiments token in conjunction with theaccompanying drawings, in which:Fig. 1 is a sectional plan view of the main partsof a conventional mowing apparatus;Fig. 2 is a sectional elevation of the same con-ventional mowing apparatus;Fig. 3 is a graph showing the relative position ofthe upper and lower moving cutting teeth versus

time for the conventional mowing apparatus and

for the mowing apparatus of the present inven-tion;Fig. 4 is a sectional side elevation of a firstembodiment of the mowing apparatus of the5 present invention;Fig. 5 is a sectional plan view taken along theline V-V of Fig. 4;Fig. 6 is a sectional elevation view taken alongthe line VI-VI in Fig. 5;

w Fig. 7 is a configuration diagram of a control unitof the first embodiment of the mowing apparatusof the present invention;Fig. 8 is a circuit drawing of the first embodi-ment of the mowing apparatus of the present15 invention;Fig. 9 is a sectional elevation of a second em-bodiment of the mowing apparatus of the

present invention; andFig. 10 is a sectional plan view taken along the20 line X-X of fig. 9.

DETAILED DESCRIPTION OF THE PREFERREDEMBODIMENTS25 Now referring to the drawings, preferred em-bodiments according to the present invention willbe explained.Figs. 4 and 5 show a mowing apparatus 101 asa first embodiment of the mowing apparatus of the30 present invention.Namely, a pair of first cutting member 105Uand second cutting member 105L are installed on

the front (the left side in Figs. 4 and 5) of a body103 of the mowing apparatus 101. Various types of35 hydraulic or electrical actuators can be used asmeans for moving the first cutting member 105U inthe lateral direction at a substantially uniformspeed. However, in this embodiment, a solenoidmechanism comprising a coil 107 and a plunger40 109 is used as the moving means. A hollow opera-tion rod 111 is mounted on the body 103 andextending to the upper rear. A handle 113 and acontrol unit 115 for the solenoid mechanism aremounted at the rear portion of the operation rod

45 111. The solenoid mechanism in the body 103 andthe control unit 115 are electrically connected by awiring system (not shown in the drawing) runningthrough the hollow operation rod 111. The controlunit 115 is provided with an adjusting knob 117 for

so adjusting moving cycle of the first cutting member105U. A main switch 121 for the control unit 115 ismounted on a grip 119 provided on the handle 113.A more detailed explanation will now be givenwith reference to Figs. 4 to 6. The first and second55 cutting members 105U and 105L of the mowingapparatus 101 are provided with a plurality of teeth123U, 123L arranged at a uniform spacing in astraight line. The first cutting member 105U is

3


4/15

5 EP 0 456 867 A1 6

secured by a screw 127 to the front of a first plate125U in such a way that the teeth 123U are locatedon the front side of the apparatus. The secondcutting member 105L is secured by a screw 129 tothe front of a second plate 125L. The first plate125U is provided with a channel 133U, which ex-tends laterally, parallel to the teeth 123 of thecutting members 105, and is also provided with aprojection 131U. The second plate 125L is pro-vided with a channel 133L, which extends laterally,parallel to the teeth 123 of the cutting members105, and is also provided with a projection 131 L.The projection 131 U is slidably guided in the lateraldirection in the channel 133L and the projection131 L is slidably guided in the relative lateral direc-tion in the channel 133U. Accordingly, the firstplate 125U can slide in the direction of the alignedteeth 123 of the cutting members 105 (the lateraldirection) relative to the second plate 125L.A bracket 135 is integrally provided at the rearcenter portion of the first plate 125U, extending tothe rear. The rear end of the bracket 135 is con-nected to moving means. In this embodiment of thepresent invention, the solenoid mechanism com-prising a pair of coils 107R, 107L and one plunger109 which moves between the coils 107R, 107L isused. The plunger 109 of the solenoid mechanismis mounted on the rear end of the bracket 135 by apin 137 at the central portion of the plunger 109,and runs in the direction of the aligned teeth 123 ofthe cutting members 105. The first and secondcoils 107R, 107L are secured to the second plate125L, parallel to the line of the teeth 123 of thecutting members 105 and the two ends of theplunger 109 are inserted into the first and secondcoils 107R, 107L, respectively.In accordance with this structure, when a cur-rent flows in the first coil 107R, the first coil 107Ris magnetized, and the plunger 109 is attracted intothe first coil 107R at a substantially uniform speed,then abuts a stopper (not shown in the drawing)included in the first coil 107R without deceleratingmotion to be halted its motion while the currentflows in the first coil 107R. The current in the firstcoil 107R is then cut, and then a current flows inthe second coil 107L and the second coil 107L isthen magnetized, so that the plunger 109 is at-tracted forward the second coil 107L at substan-tially uniform speed, then stopped by a stopperincluded in the second coil 107L. Accordingly,when a current is caused to flow in the first andsecond coils 107R, 107L alternately, the plunger109 is reciprocatingly attracted to the coils 107R,107L at a substantially uniform speed, and halted.The first cutting member 105U is also moved in thedirection of the line of the teeth 123 at an substan-tially uniform speed, and halted. The reciprocatingstroke of the plunger is approximately adjusted to

the moving range of the first cutting member rela-tive to the second cutting member so that the firstcutting member is immediately halted when theteeth of the first and second cutting members5 reach in the superposed condition.A rear-projecting stopper 139 is integrally pro-vided on the rear side portions of both the rightand left ends of the first plate 125U. A positioningmember 141 is mounted on the second plate 125Lw with a screw 142 inside of the each of the stoppers139. The left positioning member 141 is secured inthe position where it abuts the left stopper 139 ofthe first plate 125U when the teeth 123U of the firstcutting member 105U are exactly superposed on75 the teeth 123L of the second cutting member 105L.The right positioning member 141 is secured in theposition where the right stopper 139 of the firstplate 125U abuts the right positioning member 141when the teeth 123U of the first cutting member20 105U are exactly superposed on the adjacent teeth123L of the second cutting member 105L. Thepositioning members 141 are each provided withan elastic body 143 as shock absorbing member(which is consisted of rubber, in this embodiment)25 at the abuted portion thereof.In the above construction, when the stoppers139abut the positioning members 141 the motionof the first cutting member 105L is halted exactly.Therefore, the range of the reciprocal motion of the30 cutting member 105U when the current flows al-ternately through the first and second coils 107R,107L, is reliably restricted by the stoppers 139 andthe positioning members 141 between the two po-sitions at which the upper teeth 123U and the lower35 teeth 123L of the cutting members 105U, 105L areoverlapped with each other, respectively.In addition, a bracket 145 is provided on theupper part of the rear side of each of the stoppers139, projecting rearwardly. Also, an outward-projec-40 ting bracket 147 is provided on each of the posi-tioning members 141. As shown in Fig. 4, biasingmeans is mounted between the brackets 145 and147. In this embodiment, a spring 149, each end ofwhich is connected to each of the brackets 145,

45 147, is used as the biasing means. The spring 149pull the bracket 145 and the bracket 147 togetherso that the first and second cutting members 105U,105L are pressed together, thereby preventing thefirst cutting member 105U from floating.50 A cover 151 which covers the first plate 125Uis secured to the second plate 125L by screws153. Accordingly, it is possible to prevent the mov-ing means of the cutting members 105 from beingdamaged by twigs, rocks and the like.55 A boss 155, on which the hollow operation rod111 is mounted, is integrally formed at the rearcenter of the second plate 125L. The control unit115 is provided on the rear end of the operation

4


5/15

7 EP 0 456 867 A1 8

rod 111. The control unit 115 is electrically con-nected to the coils 107R, 107L in the body 103which pass through the operation rod 111. Themain switch 121 of the control unit 115 is providedon the grip 119 of the handle 113 installed on theoperation rod 111.The configuration of the control unit 115 isshown in Fig. 7. Fig. 8 is a circuit diagram for 'thecontrol unit 115. The control unit 115 in a unit

casing comprises a rotary switch 157 which servesas the switching means for the solenoid mecha-nism, a motor 159 which serves as means forcyclically repeating the switching of the rotaryswitch, and a variable resistance device 161 forchanging the rotation speed of the motor 159. Abattery 163 is also contained in the unit casing as adrive source for the moving means. The rotaryswitch 157 can be electrically connected to orisolated from the coils 107R, 107L and the battery163.In detail, the rotary switch 157 includes a pairof bank connection terminals 165R, 165L and awiper 167. The connection terminals 165R, 165Lore electrically connected to the coils 107R, 107Lof the solenoid. The wiper 167 is electrically con-nected to the battery 163. The wiper 167 of therotary switch is coupled to the motor 159 via alarge gear 169 and a small gear 171 so that thewiper 167 is rotated according to the rotation of themotor 159. As the motor 159 rotates, the wiper 167rotates and is alternately connected to the connec-tion terminals 165R and 165L. As a result, the firstand second coils 107R, 107L of the solenoid arealternately magnetized.The motor 159 is electrically connected to thebattery 163 through the variable resistance device161. In this embodiment of the present invention,as the variable resistance device 161, a circuitcontaining two resistances R1, R2 is utilized. Spe-cifically, the resistances R1, R2 in the device 161are connected in series, and one end of the seriesis connected to the motor 159. Three connectionterminals T1 , T2, and T3 are provided, one at eachend of the resistance R1-R2 series, and one be-tween the resistances R1 and R2. Three switchesS1 , S2, and S3 are provided for selectively switch-ing the three connection terminals T1 , T2, and T3.Each of the switches S1 , S2, S3 can be selectivelyswitched by means of the adjusting knob 117 andis connected to the buttery 163 through the mainswitch 121 mounted on the grip 119. Three dif-ferent circuit resistance values for the variable re-sistance device 161 can be obtained by switchingthe connected switch using the adjusting knob 117;this results in three different currents being appliedto the motor 159 through the device 161. Accord-ingly, the motor 159 can be switched to threedifferent rotational speeds resulting in three switch-

ing cycles for the rotary switch 157.The operation of this embodiment will now beexplained, based on the foregoing configuration.When the operator throws the main switch 121 the5 motor 159 rotates at the speed set by the adjust-ment knob 117. The wiper 167 of the rotary switch157 rotates with the rotation of the motor 159, andis alternately connected to the first and secondcoils 107R, 107L based on the specified switchingw cycle set on the connection terminals 165R, 165L.The first and second coils 107R, 107L are mag-netized alternately as the current passes throughthem. When the first coil 107R is magnetized, theplunger 109 is attracted into the first coil 107R and75 the first cutting member 105U moves toward thefirst coil 107R in response. The motion of the firstcutting member 105U is immediately halted withoutdecelerating motion at the point where the leftstopper 139 of the first plate 125U encounters the

20 left positioning member 141. Then, when the sec-ond coil 107L is magnetized, the plunger 109 isdrawn into the second coil 107L and the first cut-ting member 105U moves toward the second coil107L in response. The motion of the first cutting25 member 105U is abruptly halted without decelerat-ing motion at the point where the right stopper 139of the first plate 125U encounters the right position-ing member 141. When the first cutting member105U moves toward the first coil 107R and then

30 toward the second coil 107L in accordance with thealternate magnetizing of the coils, reciprocatingmotion of the cutting members is obtained byrepeating the moves to the first and second coils107R, 107L and the halts at the points where the

35 teeth 123U of the first cutting member 105U aresuperposed on the teeth 123L of the second cut-ting member 105L. This movement is representedby the dotted line on the graph of FIG. 3.The first cutting member 105U halts imme-40 diately when the stoppers 139R, 139L encounterthe positioning members 141R, 141L. Prior to thehalt the member is moving without substantiallydecelerating motion at a substantially uniformspeed. In short, the movement of the teeth 123U,45 123L at the point where the teeth 123U are super-posed on the teeth 123L, that is, where the teeth123U, 123L are cutting the grass, is at a substan-tially uniform speed which is not reduced. As aresult, the first and second cutting members 105U,so 105L provide a superior cutting force. In addition,because the motion of the first cutting member105U is not reduced, the upper teeth 123U can besuperposed on the lower teeth 123L for a long timeinterval. Accordingly, the grass can easily enter55 between the teeth 123U, 123L to be cut. Thereforethe amount of uncut grass is small. The operatorcan change the cycle of the action simply by

changing a switch as required without changing the

5


6/15

9 EP 0 456 867 A1 10

speed of the motion of the first cutting member105U. Accordingly, even when the cycle of theaction is modified, the cutting force of the cuttingteeth 105U, 105L is maintained, and the operatorcan easily operate the mowing apparatus.Fig. 9 and Fig. 10 show a second embodimentof the present invention. In this embodiment, amowing apparatus 201 comprises a pair of ring-shaped first and second cutting disks 205U, 205Lon a body 203. A plurality of teeth 223U, 223L areprovided and disposed around the circular outerperiphery of the first and second cutting disks205U, 205L. The first cutting disk 205U is super-posed on the second cutting disk 205L. The firstcutting disk 205U is installed at the outer peripheryof a ring-shaped first plate 225U; and the secondcutting disk 205L is installed at the outer peripheryof a saucer-shaped second plate 225L. A shaft 231is integrally provided in the center portion of theupper surface of the second plate 225L, extendingupward perpendicularly. A support member 235 isprovided extending across the diameter of the firstplate 225U, and a hole 237 is provided in thesupport member 235. At the hole 237 the supportmember 235 is rotatably supported to the shaft 231on the second plate 225L through a bearing (notshown in the drawings). Two groups of solenoidmechanism assemblies are mounted on the secondplate 225L. In detail, the support member 235 isprovided with two guide channels 281, 281' extend-ing radially. The guide channels 281, 281' aresymmetrically positioned relative to the center ofthe hole 237. Two sliders 283, 283' is provided insuch a manner that sliders may be slidable in theguide channel 281, 281' and horizontally rotatable,respectively. The plungers 209, 209' of the sole-noids are mounted on the sliders 283, 283', re-spectively. The two groups of first and second coils207R, 207L and 207R', 207L' are secured to thesecond plate 225L. The two first coils 207R and207R', and the two second coils 207L and 207L',respectively, are symmetrically positioned relativeto the centers of the hole 237. The two groups offirst and second coils 207R, 207L and 207R', 207L'are provided with alternate current flows same asthe first embodiment in a manner allowing thecorresponding coils in the two groups to be si-multaneously powered at any particular time.In this structure, when the current flowsthrough the first coils 207R, 207R', the first coils207R, 207R' are magnetized in the same manneras in the first embodiment and the plungers 209,209' are attracted into the first coils 207R, 207R' ata substantially uniform speed. Accordingly, thesliders 283, 283', on which the plungers 209, 209'are mounted, slide along the guide channels 281,281'. The first plate 225U centered around theshaft 231 is pivoted at a substantially uniform

speed in the clockwise direction in FIG. 10, thenhalted when the plunger 209, 209' abut on stoppersincluded in the first coils 207R. When the current tothe first coils 207R, 207R' is cut and current is5 supplied to the second coils 207L, 207L', the sec-ond coils 207L, 207L' are magnetized and theplungers 209, 209' are drawn into the second coils207L, 207L'. The sliders 283, 283' slide along theguide channels 281, 281'. The first plate 225U isw pivoted in the opposite direction, that is, the coun-terclockwise direction. Accordingly, when the cur-rent flows alternately through the first and secondcoils 207R, 207R', 207L, 207L', the sliders 283,283' move reciprocatingly along the guide channels15 281, 281', and the first plate 225U pivots at asubstantially uniform speed and reciprocatingly os-cillates.In this embodiment, as in the first embodiment,a pair of stoppers can be provided integrally on the20 first plate and a pair of positioning members whichencounter the stoppers can be provided on thesecond plate. Each positioning member can besecured in a position so that the motion of thecutting disks is halted when the positioning mem-25 ber is encountered by the stopper on the platewhen the teeth of the first cutting disk are exactlyoverlapped the teeth of the second cutting disk. Anelastic body can be mounted as a shock absorbingmember on the part of the positioning member30 encountered by the stopper. With this configura-tion, when a current flows alternately in the firstand second coils 207R, 207L and 207R', 207L*, themotion in the oscillating action of the first cuttingdisk 205U is reliably halted by the stopper and the35 positioning means when the upper and lower teeth223U, 223L of the cutting disks are superposed.A cover 251 which covers the first plate 225Uis secured with two nuts 253 to the upper end ofthe shaft 231 of the second plate 225L. In addition,40 a spring 249 of an initially corned disk spring or thelike is installed between the hole 237 of the shaft231 and the nut 253 as biasing means. The firstplate 225U is pressed toward the second plate225L by the spring 249 so that the first cutting disk

45 205U does not float.An operation rod 211 is installed at the uppercenter portion of the cover 251. A control unit 215is provided on the operation rod 211 in the savemanner as in the first embodiment. The construc-50 tion of the control unit 215 is identical to that of thefirst embodiment excepting for the configuration forpossessing the two groups of coils 207R, 207L and207R' 207L', so further explanation is omitted.In the construction outlined above, when the55 operator throws the main switch 121 , the motor 159rotates and the rotary switch 157 is switched basedon the specified switching cycle. The two groups ofcoils 207R, 207L and 207R*, 207L' are alternately

6


7/15

11 EP 0 456 867 A1 12

magnetized as the current flows through each al-ternately. The plungers 209, 209' are reciprocallyattracted into the first and second coil 207R, 207Land 207R', 207L' at a substantially uniform speed,according to the specified switching cycle, andthen stop. Accordingly, the sliders 283, 283' slidereciprocatingly in the guide channels 281, 281' andthe support member 215 pivots reciprocatingly at asubstantially uniform speed. The first plate 225Uand the first cutting disk 205U move at a substan-tially uniform speed and stop, then repeat the mo-tion cycle, providing oscillating action,In the above embodiments, an actuator op-erated by a solenoid mechanism is used as themoving means. However, a hydraulic activatingmechanism operated by oil or air can also be used.In such a case a solenoid valve may be used tocontrol the direction of the hydraulic fluid. Thissolenoid valve is switched by the rotary switch.

In addition, the solenoid mechanism may beprovided with one coil and an elastic tension mem-ber instead of two coils. Also, magnets can beused instead of the plungers or coils.An electronic circuit using transistors, thyris-tors, timers, and the like can be used as a switch-ing means for the moving means.Further, instead of one of the two cutting disksbeing fixed it is, of course, also possible to use aconfiguration wherein both cutting disks move re-ciprocatingly in opposite directions.The present invention can also be applied toan attachment for a construction machine or anindustrial machinery.It must be understood that the invention is inno way limited to the above embodiments and thatmany changes may be brought about therein with-out departing from the scope of the invention asdefined by the appended claims.Claims1. A mowing apparatus comprising:a pair of first and second cutting membersslidably superposed with each other, each ofthe disks including a plurality of aligned cuttingteeth;

means for moving the first cutting memberrelative to the second cutting member re-ciprocably within a predetermined range in thedirection of the aligned cutting teeth at a sub-stantially uniform speed; anda drive source for driving the movingmeans.

2. The mowing apparatus of Claim 1, whereineach of the aligned cutting teeth of the firstand second cutting members are arranged in astraight line at uniform intervals, the first cut-

ting member is reciprocally movable at thesubstantially uniform speed in the direction ofthe aligned cutting teeth, and the second cut-ting member is fixed.5 3. The mowing apparatus of Claim 2, wherein themoving means comprises an actuator drivenby the energy supplied from the drive source,and the actuator having an actuating rod which

w is provided reciprocatingly movably within apredetermined stroke and connected to thefirst cutting member.4. The mowing apparatus of Claim 3, further15 comprising switching means provided betweenthe drive source and the moving means forenabling the reciprocal motion of the movableactuating rod of the actuator.

20 5. The mowing apparatus of Claim 4, wherein theactuator comprises a solenoid mechanism.6. The mowing apparatus of Claim 5, wherein thesolenoid mechanism comprises first and sec-

25 ond coils and a plunger provided reciprocatin-gly movably between the first and secondcoils, the plunger is connected to the firstcutting member, and the switching means al-ternately switches the first and second coils30 ON, thereby causing the first and second coilsto become magnetized alternately to attract theplunger alternately so that the first cuttingmember to which the plunger is connected ismoved reciprocally at the substantially uniform35 speed in accordance with the motion of theplunger.

7. The mowing apparatus of Claim 2, wherein theswitching means is constituted so as to be40 switched in a predetermined uniform cycle.8. The mowing apparatus of Claim 7, wherein theswitching means comprises a rotary switchand a motor which is coupled to the rotary45 switch so that the rotary switch is switched inaccordance with the rotation of the motor,

whereby the first cutting member repeats itsmotions in the predetermined uniform cycle.so 9. The mowing apparatus of Claim 7, wherein themotor of the switching means is capable ofmodifying rotation cycle thereof.

10. The mowing apparatus of Claim 9, wherein the55 modification of the rotation cycle of the motoris performed by an electric circuit which iselectrically connected between the motor andthe drive source, in which the resistance value7


8/15

13 EP 0 456 867 A1 14

of the circuit can be selectively modified.11. The mowing apparatus of Claim 1, wherein themoving means further comprises means forstationary halting the motion of the cuttingmember immediately when the teeth of the twocutting members reach in the superposed con-dition.

the first cutting member is provided with aradial guide channel, and the actuating rod isslidably fitted to the guide channel to rotate thefirst cutting member in accordance with the5 reciprocal motion of the actuating rod.20. The mowing apparatus of Claim 17, whereinthe actuator comprises a solenoid mechanism.

12. The mowing apparatus of Claim 3, wherein the wstroke of the actuating rod is approximatelyadjusted to the moving range of the first cut-ting member relative to the second cuttingmember so that the first cutting member isimmediately halted when the teeth of the first 75and second cutting members reach in thesuperposed condition.13. The mowing apparatus of Claim 11, whereinthe moving means further comprises: 20a stopper integrally provided on the firstcutting member; anda positioning member provided on the sec-ond cutting member having a part which abutsthe stopper. 2514. The mowing apparatus of Claim 13, whereinthe positioning member has a part which abutsthe stopper, and an elastic body is provided onthe part of the positioning member or on the 30stopper.15. The mowing apparatus of Claim 1, furthercomprising means for biasing one of the firstand second cutting members toward the other 35cutting member.16. The mowing apparatus of Claim 15, whereinthe biasing means comprises a spring for bias-ing the first cutting member against the second 40cutting member in such a manner that the firstand second cutting members are pressed to-gether.17. The mowing apparatus of Claim 1, wherein 45each of the first and second cutting membershas a circular outer periphery, the alignedteeth are arranged along the circular periphery,and the cutting members are constituted sothat the first cutting member oscillates relative 50to the second cutting member.18. The mowing apparatus of Claim 17, whereinthe moving means comprises at least one ac-tuator having a reciprocatingly movable actuat- 55ing rod connected to the first cutting member.19. The mowing apparatus of Claim 17, wherein

8


9/15

EP 0 456 867 A1

F I G . lP R I O R A R T

9


10/15


11/15

EP 0 456 867 A1

11


12/15


13/15


14/15

EP 0 456 867 A1

F I G r . 9

F I G . 1 0

2 0 7 R 231

14


15/15

JEuropeanPatent Office E U R O P E A N S E A R C H

R E P O R TApplication Number

EP 90 10 9383DOCUMENTS CONSIDERED TO BE R E L E V A N T

Category Citation of document with indication, where appropriate,of relevant passages Relevantto claim CLASSIFICATIONOr THEAPPLICATION(Int. CI.5)X.Y.A

X,Y,A

X,A

Y,A

D,Y

FR-A-2 267 690 (WOLF-GERATE)'the whole document *

US-A-4 107 906 (COUSINO)*column 3, line 29 - column 5, line 5; figures 1-3, 5, 6 *

US-A-3 513 917 (STOBER)*column 2, line 34 - column 4, line 39 **column 5, lines 6 -66; figures 1-8, 15, 16 *DE-A-1 482 805 (LICENTIA PATENT-VERWALTUNGS)*the whole document *

EP-A-0 257 566 (KOMATSU ZENOAH)*column 4, lines 1-12; figures 3, 4 *

The present search report has been drawn up for all claims

1-7,15-18,20,8,9,13I- 4,7,II- 13,14,8I- 4,7,II- 13,9

14-16,2,3,5-7,11,13,2017,18,20

A 01 D34/37A 01 D34/30

TECHNICALFIELDSSEARCHED(Int. CI.5)A 01 D

Place of searchThe Hague

Date of completion of search18 January 91

ExaminerWILLIAMS M.J.

CATEGORYOFCITEDDOCUMENTSX: particularly relevant if taken aloneY: particularly relevant if combined with anotherdocument of the same catagoryA: technological background0: non-written disclosureP: intermediate documentT: theory or principle underlying the invention

E: earlier patent document, but published on, or afterthe filing dateD: document cited in the applicationL: document cited for other reasons&: member of the same patent family, correspondingdocument

ep0456867a1_luoi cat rong beo

Documents