* GB785728 (A)

Description: GB785728 (A) ? 1957-11-06

Improvements in or relating to the magnetic recording and reproduction oftelevisionsignals

Description of GB785728 (A)

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PATENT SPECIFICATION 785728 Date of Application and filing Complete Specification June 21, 1955. No 17920/55. Application made in France on June 24, 1954. Complete Specification Published Nov 6, 1957. Index at Acceptance:-Class 40 ( 3), F( 2 F 3: 2-: 3 A: 3 B: 3 F: SA: 5 B 6 K). International Classification: -H 04 n. COMPLETE SPECIFICATION Improvements int or relatg Esg to the Magnetic Recording and Reproduction of Television Signals We, PHILIPS ELECTRICAL INDUSTRIES LIMITED, of Spencer House, South Place, Finsbury, London, E C 2, a British Company, do hereby declare the invention, for which we pray that a patent may be granted to us, and the method by which it is to

be performed, to be particularly described in and by the following statement: - This invention relates to methods of and means for the magnetic recording and reproduction of television signals. It is known that signals can be recorded on a carrier such as, for example, a magnetic tape passing over a recording head, and that the recorded signals can be accurately reproduced by a reproducing head without the system having to be very complicated, provided that the frequency of the signals does not exceed a practical limit which, in the present state of the art, is approximately 1 Mc /s. The usual television signals have a bandwidth extending from a frequency of a few hundred c /s to several Mc /s, so that it is not practicable to record them with a high standard on a single track. The object of the present invention is to provide a relatively simple method of and means for recording and reproducing television images by means which are readily available For this purpose the high-standard picture is recorded in one or more magnetic record tracks, and the invention uses electro-optical converters, which are available commercially, as distinct from purely electrical converters When a plurality of tracks is used the original picture can be reproduced with a high standard. By the " standard " of a picture is meant, in this specification, the precision of detail, i e. the number of lines per frame and/or the number of frames per second Thus a picture of high standard corresponds to a large bandwidth in the signal by which it is represented. In one respect the invention comprises a method of or means for manufacturing a maglPrice 3 s 6 d l netic record of a television picture, characterized in that signals representing a high-standard picture are applied to one or more electrooptical converters, such as television picture tubes of known construction, and that the image thus produced is scanned by a scanner or scanners, or that the images thus produced are scanned by scanners, in such a way that electric signals corresponding to a reduced standard are generated, the last-mentioned signals being applied to magnetic recording means so as to produce one or more low-standard record tracks. In a further aspect the invention comprises means for reproducing a television signal from a magnetic record which has been manufactured in the above manner in such a way that it comprises a plurality of low-standard record tracks, and is characterized in that a signal derived from each said track is applied to a corresponding electro-optical converter which operates in accordance with the same scanning system that is followed in the scanners used in manufacturing the record.

In order that the invention may be readily carried into effect, embodiments thereof will now be described by way of example with reference to the accompanying diagrammatic drawings, in which:Figure 1 shows' one embodiment of apparatus for carrying out the invention; Figure 2 shows a second embodiment; Figures 3 a and 3 b show a variant of the embodiment represented in Figure 1; Figure 4 shows a line diagram of a television picture according to the French standard; Figure 5 shows diagrammatically apparatus for the commutation of the tubes shown in Figure 3 a with the standard illustrated in Figure 4. In accordance with the invention we propose to effect conversion of the prior standard to one suitable for magnetic recording, that is to say that starting with a given television 1 ) , ' l2 785,728 standard, i e a given number of lines per picture and pictures per second, we convert this standard, which will be referred to herein as "high ", into at least one and preferably a plurality of lower standards, that is to say to a number of lines per picture or a picture frequency or, in general, a product (number of lines per picture)x (picture frequency), which is lower than the standard referred to as " high ". Fundamentally, the sum of the signals in the low standards should correspond to the signals in the high standard; at least the viewer observing the information obtained from the magnetic recording, single or multiple, should not perceive any discontinuities Each signal of lower standard, owing to the lower value of above-mentioned product, has a snaller band-width (preferably at the most equal to 1 Mc /s, as was stated above), and can be recorded without difficulty on a magnetic record-carrier in the conventional manner Let n recordings, for example, be made which, according to one feature of the invention, are advantageously made of a common record-carrier, the N record tracks being adjacent to one another The N signals are subsequently read and their sum yields the high-standard signal. From the further description it will be clear that a single recording instead of N recordings would be sufficient, but primarily the invention aims at converting a high standard into a lower standard by means of at least one cathode-ray tube or other electro-optical converter, on the screen of which the picture of high standard is produced, and at least one pick-up tube scanning this picture with a lower standard. Several embodiments based on the abovementioned principle will now be explained with reference to the accompanying drawings. In the system shown in Figure 1, a picture, produced by a picture tube 1 which is fed with video signals through an amplifier 2, is divided into N parts adjacent to each other; in the drawing n= 4 Each of the i parts is projected by means of a suitable optical system (not shown) on to the photo-cathode of a pick-up tube comprising an iconoscope 3

a, 3 b, 3 c, 3 d or other picture-scanner Since the picture supplied by tube 1 has N lines, it will be obvious that, in order to maintain the same definition, N/n lines per picture scanner are sufficient, the picture frequency remaining unchanged, while the line-scanning in the scanning tubes may be effected N times as slowly. On the other hand the time constant of the phosphors of the picture tube and/or the time constant of the pick-up tubes, for example that of the super-iconoscope type, should be sufficient The video signals, the band-width of which is reduced in the ratio n, are separately recorded in adjacent parallel tracks on a magnetic tape 4 by means of recording heads 5 a, Sb, Sc and 5 d respectively, and these are fed through amplifiers 6 a, 6 b, 6 c and 6 d respectively if necessary. In order to reproduce the complete video signal, the N tracks on the tape 4 are read simultaneously and N partial pictures are repro 70 duced in N picture tubes These pictures, when recombined by optical means, form a complete image on the photo-cathode of a pickup tube scanned according to the high standard The apparatus may be represented by 75 the diagram shown in Figure 1, with the understanding that the signals pass in the direction opposite to that previously described, and that the tubes 3 a, 3 b, 3 c, 3 d on one hand, and the tube 1 on the other, are of the inverse types; 80 the first-mentioned tubes become cathode-ray tubes and the second-mentioned tube an iconoscope, for example. In a second embodiment, shown in Figure 2, a high-standard picture is formed on the lumi 85 nescent screen of tube 1, and is optically projected on to the photo-cathode of a pick-up tube 3 which is scanned with the same number of lines but at a reduced frame-frequency, and consequently a reduced speed of line-scan 90 ning, which are, however, at least high enough for the reproduction of motion, the time constants of the phosphors being chosen accordingly If, for example, the high standard has a picture frequency of 50 per second, a picture 95 frequency of the order of 12 5 per second may be chosen for the low standard. The signals of smaller band-width which are supplied by the pick-up apparatus 3 are recorded on the magnetic tape 4 by usual 100 means, after being amplified if desired in an amplifier 6. The reproduction process is carried out in the reverse sense,-as in the preceding instance. The eye of the viewer does not perceive that 105 the signals are less complete than the original signals. In the embodiment shown in Figure 1 the four partial images may advantageously be interlaced; in this case each of the scanning 110 tubes 3 a-3 d scans a line of the high-definition picture in turn, at a velocity one quarter of that at which the high-definition picture is

formed on the screen of the tube 1 Alternatively a number of initial picture tubes la, 115 lb, 1 c, id, Figure 3 a, equal to the number of pick-up tubes 3 a-3 d may be used A suitable control system 7 permits only one line in four to be traced on the screen of each of the tubes la-id, the lines in each tube being displaced 120 in relation to those of the following tube In this manner, a picture of high definition along a line of low definition in the direction transverse to the lines is reproduced in each of the n tubes la-id, and this picture is scanned 125 with a low standard by the associated pick-up tube 3 a, 3 b, 3 c and 3 d Each pair (la, 3 a)( 1 d, 3 d) may be combined to form an electrooptical unit, and even embodied in a single envelope In reproduction, Figure 3 b, a pick 130 synchronizing signals comprise regularly recurring pulses S, and between these pulses supplementary pulses S, occur, in connection with the interlacing, at the end of each field of type A, but no such pulse occurs at the end of a 70 field of type B the signals S are represented as a function of time, which is shown as increasing from left to right They are applied to the input of an electronic trigger circuit U 1, which supplies two output signals a and b (also 75 represented as functions of time) in conformity with the signals S The signals a go into a circuit D which didferentiates them and consequently supplies the signals e, which alternate in polarity, but signals of only one polarity are 80 retained, the others being suppressed by a rectifier r The positive signals e are applied to a second trigger circuit U 2 which supplies square output pulses c and d of doubled duration Adding-devices M 1, M, M,, M 4 add the 85 pairs of signals (a+c), (b+c), (a+d), and (b+d), respectively The outputs of the adding-devices are rectified by rectifiers rj, r 2, r, r 4, and the resulting pulses are applied to the tubes la, 1 b, lc, Id, Figure 3 a, respectively so 90 as to make these conductive for the successive lines of the high-standard picture These tubes are thus rendered operative regularly and successively until the two half-length pulses are reached; these make paths II and III, Figure 95 5, conductive at the times required by Figure 4 The pulses shown in Figure 5 are numbered 402, 403 and so on, with the same numbers as the corresponding lines The apparatus shown in Figure 5 is represented only diagram 100 matically, and in particular the polarities of the signal S and the design of the trigger circuits, differentiating devices, and rectifiers should be chosen in relation to one another. Various modifications, such as the use of a dif 105 ferent number of tracks, may be made within the scope of the invention. Alternatively, if the recorded picture is only to be reproduced without being transmitted to a distance, it is sufficient to supply the signals 110 derived from the record tracks to an assembly of

suitable electro-optical converters associated with an optical system in order that the corresponding low-standard pictures may be fused into a single high-standard picture observed by 115 the viewer; it is then unnecessary to reproduce the individual low-standard pictures by means of one or more scanners.

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* GB785729 (A)

Description: GB785729 (A) ? 1957-11-06

Improvements in or relating to a door latching mechanism

Description of GB785729 (A)

PATENT SPECIFICATION Inventor: ROLLO MMPLE 7855729 4 @ ' Date of Application and filing Complete Specification: July 1, 1955. No 19082/55. Complete Specification Published: Nov 6, 1957. Index at acceptance:-Class 44, BC 6, BD 5 C. International Classification:-E 05 c. COOMPLEBTE;SPEICIRCATI'ON Improvements in or relating to a Door Latching Mechanisrn We, HANCOCK MANUFACTURING 'COMPANY, a corporation organised under the laws of the State of Michigan, United States of America, of Jackson, Michigan, United States of America, do, hereby declare the invention, for which we pray that a patent may be granted to us, iand the method by which it is to be performed, to be particularly described in and by the following statement: - This invention relates to door latching and locking mechanisms adapted for use on the doors of automotive vehicles where the door is subjected to jarring or vibrations.

It is an object of this invention to provide a latching mechanism which utilizes the principle of a rotary member forming either the bolt or keeper member, and in which a camming action is imparted to the rotary member in its latching direction after its engagement with the other member. According to the invention there is provided 'a latching mechanism, adapted for use on doors of automotive vehicles, having relatively movable bolt and keeper members, one of which is a rotary member, ssaid rotary member having a latching surface engagealble with said other member when rotated in a latching direction, iand means for dogging said rotary member against rotation in an uniatching direction, said means comprising a track adjacent said rotary member and a roller movably positioned on said track, said roller being adapted to wedgingly engage said rotary member when the roller is moved in one direction along said track, to thereby urge said rotary member in its latching direction, the' lines of force passing through the lines of engagement of the roller with the rotary member iand the track forming a greater angle wath respect to a' tangent to the track surface, at it's line of contact with the roller, than the friction angle between the roller and track forms with respect 0 o said tangent, so as to prevent unlatching movement of the rotary member. In order that the invention may be understood, it will now be described with reference to the accompanying drawings in which: lPrice 3 s 6 d l Figure 1 is an elevational view of the rotary keeper mechanism of one form of our invention, showing the take-up means and also fhowing portions of the cooperating bolt mechanism in cross-section. Figure 2 is a side eleivational view of the keeper mechanism of Fig 1, showing the bolt mechanism in dot-dash lines. Figure 3 is ian elevational view of a preferred bolt mechanism adapted to cooperate with the 'keeper mechanism shown in Figs. 1 and 2. Figure 4 is a fragmentary cross-sectional view taken along the line 4-4 of Fig 5 and showing the bolt member in its retracted position, parts being omitted for clarity. Figure '5 is a side elevational view of the bolt mechanism with parts broken away for clarity and showing the locking members. Figure 6 is a fragmentary elevational view taken in cross-section along the line 6-6 of Fig 2:, and showing the principle of operation of the take-up means which cooperates with the rotary member. Figure 7 is a front elevational view of a modified form of our invention which utilizes a rotary bolt member and a stationary keeper member, the view having parts broken away for clarity and showing the bolt mechanism and a portion of the keeper member in crosssection.

Figure '8 is a side elevational view of the bolt mechanism shown in Fig 7, with parts broken away for clarity iand showing the locking members; and Figure 9 ' is a fragmentary cross-sectional view taken along the line 19 9 of Fig '8 and showing the bolt take-up 'and dogging means in its retracted position. The invention is 'adapted to ibe utilized in the door latches of automotive vehicles in which the doors are subject to jarring or vibration The invention uses a rotary member as either the keeper member or the bolt member, land the invention contemplates a dogging means for holding the rotary member against retraction, the same dogging means also being used as 'a take-up means to continuously and progressively urge the rotary member in its latching direction. As exemplified in the embodiment of Figs. 1 6, the invention is embodied in a door latching mechanism of the type having a keeper mechanism including a rotary keeper member in the form of a toothed rotor 21 mounted on the door pillar (not shown) by a mounting plate 22, and a bolt mechanism generally indicated at 23 ' which is secured to the outer edge of the door (also not shown). The keeper mounting plate 22 comprises a flat base portion and a rotor housing 2,4 extending outwardly from one side of the base portion The upper end of the keeper mounting plate is provided with an abutment 25 extending in the same direction as the rotor housing and having an inclined lower surface 26 for cooperation with the upper inclined surface 27 of a bolt housing 28 The rotor housing 24 is of irregular shape and in particular has a curved lower wall 29 which, as will later appear, underlies the track for the dogging and take-up means Wall 29 is contiguous with a rounded rear wall 31 of relatively large curvature 'and a convex front wall 32 of relatively small curvature, and these walls in turn are connected by an inclined upper wall 33 substantially parallel to lower abu Sment surface 26, and which has a rectangular opening 34 for the teeth of rotor 21. The rotor has four circumferentially disposed neeth, is pivotally mounted by a pin 35 within the rotor housing, the pin 35 being disposed a short distance below the inclined upper wall 33 and a relatively large distance above lower wall 29 Pin 35 is supported at one end by a deck plate 36 which extends in spaced parallel relation with keeper mounting plate 22, 'and at its opposite end by the rotor housing 24. The combined dogging and take-up means for rotor 21 ' is a roller 3 i 7 which is disposed within the rotor housing 24 between the rotor and 'a lower track support Roller 37 is of such diameter that when resting upon a track 38, formed as a flange on deck 36 and conorming in contour with lower wall 29, the r Qller wil I engage a tooth 39 shown in Fig 6, when urged toward the upwardly curving p ortion of the track

In other words, the proportions of the parts are such that when roller 37 is urged to the left as shown in Fig 6, the upward slope of track 318 will cause upward movement of the roller, so that engagement with tooth 39 Ghove the roller will occur before engagement with tooth 41 to its left The track curvature is at progressively decreasin distances from the lower surface of tooth 39 going toward the left, and the rotor will thus be camomed in ta continuous fashion in its latching direction as the roller moves long the track. It is important to keep in mind that the roller 37 is free-floating in the sense that it has no fixed pivot, so that its movement will follow the curvature of track 38 without restriction IA curved guide slot 42 is provided hin deck plate 3:6 adjacent the roller, and a pin 43 extends from the roller through slot 70 42, the pin being provided with an enlarged head 44 The width of slot 42 however, is sufficient to allow a free lateral movement of roller 37 during operation of the device. The means for urging roller 37 toward its 75 dogging and take-up position is a wire spring having one end engageable with pin 43 and its opposite end secured to deck plate 36 The ends are urged apart by expandable loop 46 urging pin 43 toward the left end of 80 curved slot 42 as shown in Figure 1 The engagement of spring 45 with pin 43 is such that it permits relative movement of the pin within slot 42 'It will be seen therefore that the action of spring 45 will urge roller 3,7 85 into its left position in which one tooth of rotor 21 is extending upwardly from the rotor housing As seen in Figure 1, when roller 37 is held in this position, it will not prevent counterclockwise rotation of rotor 21 such as 90 occurs when a bolt 47 approaches the upwardly extending tco th from the right In this case, the tooth 41 to the left of the roller 37 will move to the right, urging the roller to the right against the action of spring 45 This 95 action will continue until tooth 41 passes the center line of the roller at which time the roller will engage the opposite side of the tooth and cam, it counterclockwise as the roller moves to the left along inclined track 38 100 The bolt mechanism 23 embodies the bolt 47 which is retractable The bolt mechanism is mounted on a bolt mounting plate which comprises a base 4,8 and a flange 49 which are in substantially normal relation, and a deck 105 secured in spaced parallel relation with base 48 The bolt 417 is pivotally mounted by a pin 51, within bolt housir, 28 which extends outwardly from base 48 The inclined lower surface of the bolt housing has an elongated 110 slot 52 which allows the bolt 4:7 to extend in inclined position therethrough, the bolt being urged by a coil spring 53 into this position The opposite end of the bolt housing 28 is provided with a pivoted safety member 54 115 which is urged upwardly through a slot 55

in the bolt housing by a coil spring 56 surrounding pivot pin 57 The safety member 54 has an extension 518 extending in the opposite direction from its bolt portion, and-this 120 extension is provided with oppositely disposed Transverse lugs 59 and 61, respectively. it will be noted from Figs 1 and 3 that the bolt 47 and safety member 54 have engaging surfaces '62 and 63 respectively which 125 are inclined in substantially parallel relatien, but that the pivot points of these two elements are at opposite ends of their engaging surface, so that leftward movement of the bolt housing in Fig 1 between the rotor housing 24 and 130 1785 jy 29 lug i 61 on the extension 58 of safety member 54 As is best seen in Fig 4, the clockwise undogging movement of lever 74 will cause safety member 54 to 'be rotated counterclockwise and within the elongated slot 55 on, the 70 tipper surface of the bolt housing, therefore allowing the bolt mechanism to pass the abutment 25 Upon release of the retracting lever, spring 56 will urge the safety member back into its projected position 1 t will be noted 75 that the safety member is retractable independently of the retracting lever 74 when it strikes the abutment 2 f 5 ' during closing movement of the door, lug 61 momentarily leaving its engagement with arm 87 during this move 80 ment. The 'bolt mechanism is, also provided with means for undogging the bolt from a remote operator such as an inside door handle As shown best in Fig 5, this means comprises a 85 bell crank 88 pivotally, mounted on flange 49 and having one arm '89 extending downwardly for connection 'to a remote operator link '91 The upper arm 92 of the bell crank is disposed above 90 the outer end of an arm 93 which is part of retracting lever 74, land which extends through a slot 94 in flange 49 Upon counterclockwise rotation' of bell crank 088 as shown in 'Fig 5, 'arm 93 will be depressed causing 95 clockwise rotation of the retracting lever to yndog the bolt and retract the safety mem'ber as described above. Locking means are also provided for preventing unlatching of the bolt by the member 100 85, and this means comprises 'a locking member 95 pivotally mounted above the bolt housing by a pin 96 As is shown in Fig 4, locking member 195 has a locking arm 97 with an outer locking surface 98 ' which, when the lock 105 ing member is in its clockwise or loclking position, is disposed in abuting relation with the upper portion 991 of the flange on the rollback '83 This disposition of the locking member willfl thus prevent clockwise rotation 110 of rollback; 83 and therefore will not permit unlatching of the door by the member 85. Locking member 9 '5 is controlled by a slide 101 mounted for vertical reciprocating movement on flange 4,9 'by 'a retaining pin 102 115 disposed within an elongated slot 103 on the slide 1 An ear 104 at the

upper end of the slide projects through an opening 105 on control arm 106 of ithe locking member, so that the vertical position of the slide controls the 120 rotational position of the locking member An over-center spring 1061 is provided for holding the slide in either its upper or lower position. The position of slide 1101 may 'be controlled by a' push rod 107 which extends upwardly 125 to the inside gamish molding of the automotive vehicle and is connected to 'a lateral arm 108 of slide 101 The lock may also be controlled by a rotary member 109 preferably operated by an outside key-actuator (not 130 the abutment 25 will cause safety member 54 to be retracted by the abutment, and will cause the rounded lower edge of 'bolt 4 i 7 'to engage the inclined keeper surface 3,3 and ride therealong, engaging and rotating the upwardly extending tooth of rotor 21 This leftward movement will lift the entire bolt mechanism (the bolt 47 being dogged against retraction by mechanism later described), so that in its final latched position the upper surface 27 of the bolt housing will be wedged against lower surface 216 of the abutment 25 Upon release of the bolt dogging mechanism and rightward movement of the bolt housing in Fig 1, bolt 47 will be cammed upwardly into retracted position by the dogged rotor 21, and as will 'be seen later, the simultaneous positive retraction of safety member 54, will allow the bolt housing to be withdrawn from between members 24 and 25. The dogging mechanism for preventing the retracting movement of bolt 47 comprises a dog '65 pivoted 'by pin '66 between the mounting plate base 48 and deck 50 Dog 65 is provided with a toe '68 which is movable into obstructing relation above an extension 69 at the outer end of bolt 47 The latter extension is disposed behind base 48, the base being provided with an arcuate notch or recess 71 for allowing the bolt to extend therethrough and pivot between its dogged and retracted positions The dog '65 ' is further provided with an extrusion '72 'engageable 'by a spring 73 to urge the dog counterclockwise as shown in Figs 3 and 4 The dog is operable 'by a retracting lever 74, also pivotally mounted on pin 66, land which has a laterally extending toe 75 engageable with an arm 76 on' dog 65. Toe 75 is engageable by an arm 7 i 7 of:a pivoted bell crank 78, adjacent the outer edge of the base, the opposite arm 79 of the bell crank 78 having a lateral toe 811 engageable by arm '82 of rollback '83 The flanged upper end 8,4 of the rollback is actuable by a member 85 which may be, for example, an outside door operator Bell crank 78 is constantly urged in 'a clockwise direction by spring '8:6, thus urging the member 85 into inoperative position and holding arm 77 of the bell crank away from toe 75 Upon rightward movement of member 85 as shown in 'Fig 4, the clockwise rotation of rollback 83 and the

subsequent counterclockwise rotation of bell crank 78 will cause retracting lever 74 ' to move clockwise, and the engagement of toe 75 with arm 76 will cause simultaneous clockwise movement of dog '65, retracting toe 618 from obstructing position above bolt extension 69, allowing the bolt to be rotated into retracted position by engagement with the rotor 21. Means are also provided for positively retracting the safety member 54 simultaneously with the undogging of bolt 47 when the door is unlatched This means is an arm 8,7 on retracting lever 74 which is engageable with 795 j 729 shown) and having spaced arms 111 ' and 112 in lost-motion engagement with toe 113 at the lower end of the slide When the locking member is in its icounterclock-wise or unlocking position as shown in, Fig 4, it will be out of obstructing relation with the movement of rollback 83 It will 'be observed that even when the locking member 95 is in its locking position as shown in 'Fig 3, opening of the door by the remote operator is still not prevented, since there is no obstruction to the clockwise rotation of retracting lever 74. Means are provided for automatically unlocking the rollback 83 upon operation of the remote operator, or merely upon closing of the door This means comprises lug 59 on the extension 5 '8 of safety member 54, which faces a cam surface 114 at the outer end of locking member arm 106 As is best seen in Figs. 3 and 4, when the locking member is in its clocklwise, or locking position, counterclockwise rotation of safety member 54 will cause lug 59 to engage cam surface 114 thus camming the locking member into its counterclockwise or unlocking position The counterclockwise rotation of safety member 54 may be caused by either of two events-namely, the actuation of the retracting lever 74 by the remote operator, or the engagement of surface 63 of the safety member with abutment 25 during closing movement of the door If either of these events occurs, the simultaneous movement of lug 5,9 will automatically move the locking member into unlocking position, thus preventing accidental or inadvertent locking of the door. The cooperation of the various elements described above may perhaps best be shown by a description of the series of events that take place during a complete closing and opening operation Starting from an initial condition in which the door is open, the keeper mechanism will be in a position approximately as shown in Fig 1, but with the roller 37 in its full leftward position, engaging teeth 39 and 41, on both sides of it The reason for this position is of course that the absence of bolt 47 means there is no force preventing rotor 21 from being urged counterclockwise as far as possible under the influence of the roller Upon movement of the bolt housing 28 into the space between the

rotor housing and the abutineent 25, the surface 63 of safety member 54 will first engage the abutment and will be retracted thereby, the spring 56 projecting the safety member behind the abutment to hold the bolt mechanism from subsequent opening movement If the locking member 95 is in its locking position, the retraction of the safety member will also cause unlocking movement of this member As the bolt mechanism rides upwardly and inwardly on housing wall 33, the end 64 of the bolt will engage the right side of the upwardly projecting tooth on rotor 21 as shown in Fig 1 This will cause the rotor to turn counterclockwise, moving roller 37 downwardly and to the right along track 38 against the action of spring 45. When tooth 41 passes the center line of the roller, the spring 45 will cause the roller to be 70 forced rapidly to the left along the track, engaging the underside of tooth 41, now tooth 39, as it moves This action will be rather abrupt since there is initially no obstruction to the counterclockiwise movement of the rotor 75 When the new upwardly projecting tooth reaches the underside of the bolt, the counterclockwise movement of the rotor will be temporarily stopped. The subsequent cooperation' of the roller and 80 rotor is best seen in the progressive studies shown in Fig 6 In this figure, three progressive positions of the roller, rotor and bolt are shown, the first position being shown in solid lines, the second in dot-dash lines, and 85 the third position in double-dot-dash lines It will be seen that in all positions the roller 37 will wedgingly engage the rotor to effectively dog it against clockwise or unlatching movement, since the lines of force passing through 90 the lines of engagement of the roller with the tooth 39 and the track are always at a sufficiently steep angle relative to the track so that the frictional forces will prevent the roller from slipping out of position In other words, 95 at any position of the roller, those lines of force will form a greater angle with respect to a tangent to the track surface at its line of contact with the roller than the friction angle between the roller and track will form 100 with respect to this same tangent When the door is initially closed, the bolt 47 may not be moved leftward as far as possible, and its position will therefore prevent full entering movement of the roller 37 under the tooth -105 39, these parts remaining in their solid lineposition of Fig 6 Upon subsequent vibration, jarring, or other forces tending to further move the bolt leftward and relieve the pressure on' the roller, the roller will immediately be 110 forced by spring 45 along the track, the contour of which will force the rotor counterclockwise into the dot-dash position Still further vibration will again permit the roller to be forced along the track, until the bolt is finally 115 held in its double-dot-dash position It is important to observe that this take-up

action is entirely continuous, and since the arrangement of parts is such that the roller does not normally engage tooth 41, the take-up will not 120 be limited to a predetermined final bolt position. When it is desired to open the door, actuaion of either the member '85 or the remote operator link 91 will cause retracting lever 74 125 to rotate dog '65 into retracted position, so that when the bolt housing is manually forced rightward as shown in Fig 1, the bolt 47 will ride over the projecting tooth on rotor 21 and will be forced downwardly into pro 130 785,7219 action 'of roller 128, the latter is provided with a transversely extending pin 135 to which is connected one arm 1,36 of a retracting lever 137 This retracting lever is movably secured for pivotal and translatory movement to base 70 12,1 by a pin 138 which is disposed within a slightly elongated slot 13 '9 in the retracting lever The positioning of slot 139 is such that movement of the retracting lever in the axial direction of arm 136 is permitted to a slight 75 degree Flange 122 is provided with an elongated slot 140 through which extends a rolltack 141 The rollback is slidably mounted directly behind base 121 by means of a pin and washer 142 disposed within an elongated 80 slot 143 in the lower portion of the rollback. The rollback extends across the open inner side of bolt housing 123, and has an 'arcuate slot 144 within which extends the roller pin 135, thereby affording a lost-motion connec 85 tion between the rollback and the roller A coil spring 145 is engageable with arm 13,6 of the retracting lever 'so as ito urge the latter clockwise as shown in Fig 7, thereby urging pin against the left end of arcuate slot 144 90 This action in turn will urge the rollback 141 to the left, so that pin 142 will be disposed at the right hand end of slot 1143 A guide 146 is provided on base 121 adjacent the opposite end of 'the rollback member to main 95 tain its reciprocating movement. It will be seen therefore that the spring will normally urge roller 128 to the left end of track 134, and therefore into engagement with tooth 14,7 of the rotor 127 During 100 this movement the upward curvature of track 134 will cause the roller to move upwardly against tooth 147 to urge the rotor into its counterclockwise 'or keeper-engaging position. This upward movement of the roller will not 105 be restricted either 'by the retracting lever 13,7 or the rollback 141 The retracting lever will float with the roller because of its slightly elongated mounting hole 139, and rollback 141 will be allowed slight pivotal movement about 110 pin 142 due to the play existing in guide 14 '6. The roller will thus be allowed free take-up action in its engagement with the rotor 127, similar 'to the take-up action described with the relation to the previous embodiment How 115 ever, upon rightward movement of rollback 141 due to engagement with its flange 148 by

outside door operator 149, the pin 135 and therefore the roller will be moved rightwardly and out of obstructing relation with the rotor, the 120 Length of slot 143 being such that sufficient retracting movement is allowed Release of operator 149 will immediately allow spring to return the roller to its dogging position. It will be noted that during operation 'of the 125 roller by the rollback 141, the pin 135 will always remain;at the left end of arcuate slot 144. Means are provided for retracting roller 128 by a remote operator such as an inside door 130 jected position again after it leaves the rotor. In this connection, it should be noted that the bolt will be immediately re-dogged when it returns to projected position Should the operator release the door handle before bolt 4)7 leaves the rotor, the rounded;end of 'bolt extension 169 will cam the toe 68 out of obstructing relation as it moves down, and the toe will ride over the extension Wand move into dogging position above it Upon departure of the bolt from its contact with rotor 21 the latter will be left in the same position as previously described, ready for another closing operation As described previously, operation of either door member 85 or the remote operator will also retract safety member 54, allowing the bolt housing to pass freely 'between the keeper housing 24 and the abutment 25. Figs 7 to 9 illustrate an embodiment of the invention which is generally similar to the first embodiment, but which utilizes a rotary bolt mechanism generally indicated at 115 rather than a rotary keeper mechanism, the take-up principles being therefore embodied in, the bolt mechanism rather than the keeper mechanism The bolt mechanism cooperates with a keeper generally indicated at 116 which is of a conventional stationary type, and which in the illustrated embodiment comprises' a safety member 1117 pivotally mounted in the keeper housing, a striker surface 118 behind the safety finger, and an inclined main keeper surface 11; 9 behind the striker surface The bolt mechanism comprises a mounting plate having a base 121 and a flange 122 in substantially normal relation, with a bolt housing 123 and an inclined abutment 124 extending outwardly in spaced relation from the flange 121 The abutment 124 has an inclined lower surface 125 adapted to slide along the inclined upper surface 1216 of the keeper when the door is clsed, to thereby wedge the keeper between the abutment and rotary member mounted near the upper end of the 'bolt housing The rotary member is 'a multi-toothed rotor 127 similar in design to that described in the keeper mechanism of the previous embodiment, and comprises a single set of teeth adapted to alSO ternately project upwardly for engagement with the keeper, and to cooperate with a takeup, roller 12 '8 For this purpose the rotor is supported for

rotational movement by a pivot pin 1219 held between outer wall 131 of the bolt housing and a deck 132 extending in parallel relation with wall 131 within the upper portion of the bolt housing The upper surface of the housing is provided with an elongated opening 133 which allows the rotor teeth to pass therethrough The lower wall 134 of the housing is curved upwardly and to the left as shown in 'Fig 7 to provide an inclined track similar in, function to the track 3 '8 of the previous embodiment. In order to control the dogging and take-up 7 f 555729 6 785,729 handle I For this purpose the retracting lever 137 is provided with an arm 151 which cooperates with one arm 152 of a bell crank 153 pivotally mounted on flange 122 The opposite arm 154 of the bell crank is adapted to be pivotally connected to a link 155 leading from the remote operator (not shown) Upon leftward movement of link 155 as seen in Fig 8, the bell crank 153 will be rocked clockwise, rotating lever 137 counterclockwise as seen in Fig 7 This movement will cause pin and therefore roller 128 to move to the right end of arcuate slot 144 and out of obstructing relation with the rotor 127 It will be observed that during this action the roller will also 'be allowed relatively unrestricted movement as it follows track 134, due to the free-floating mounting of the lever 13,7 and the rollback 141. Locking means are also provided in this embodiment for preventing movement of rollback 141 This locking means comprises a locking lever 156 pivotally mounted on flange 122 in the same location as bell crank 153. A finger 15,7 on the locking lever extends through a slot 158 in flange 122 and is adapted to be moved in front of slot 140 so as to lie in obstructing relation with locking surface 159 of the rollback, thereby preventing undogging movement of the latter This obstructing position of finger 15,7 occurs when the locking lever 156 is in its counterclock-wise or locking position as shown in dot-dash lines in Fig 8 However, when the locking lever is in its clockwise position shown by the full lines in Fig 8, the finger 157 is lowered and moved leftward sufficiently to clear the undogging path of the rollback The locking lever is movable into its locking position by operation of the remote operator in a direction opposite its normal door-opening direction, that is by rotation of bell crank 153 counterclockwise in Fig 8 The remote operator in this case could be one of the type which is biased to a neutral position and movable out of its neutral position in opposite directions. For this purpose the locking lever is provided with a small lip 160 which extends laterally above the upper edge of arm 152 of the bell crank It will be seen therefore that counterclockwise rotation of the bell crank will cause its upper edge to abut lip 160, moving the locking lever counterclockwise The locking lever may also be moved

into either of its positions by a forked lever 161 pivotally sup-. ported on flange 122 and adapted to have a lost-motion connection with -an arm 162 on the locking lever Forked lever 1161 may be actuated by a key mechanism (not shown), and the 'locking lever is held-in either of its positions by an over-center spring 163 connected to an arm 164 on the locking lever It will be noted that even when the locking lever is in its locking position, retraction of the roller 128 by the remote operator will still be permitted, since the rotational movement of retracting lever 1317 will not be prevented. Means are also provided for automatically unlocking the outside rollback either when the remote operator is actuated to unlatch the bolt, 70 or when the door is closed This means comprises a kick-off toe 165 on the locking lever disposed immediately under arm 151 of the retracting lever, as shown in Fig 8 Upon counterclockwise rotational movement of the 75 retracting lever as seen in Fig 7, either due to actuation of the remote operator or by clockwise rotation of rotor 127 due to closing of the door, arm 151 will engage toe 165, thus rotating the locking lever into its un 80 locking position, in which position it will be held by over-center spring 163. The cooperation of the various elements described in the embodiment of Figs 7 to 9 may perhaps best 'be illustrated by a descrip 85 tion of the sequence of events which occur during a normal closing and opening of the door Starting from an initial condition in which the door is open, the bolt mechanism will be in a position substantially shown in 90 Fig 7, the roller 128 however being urged fully to the left so as to engage tooth 147 above it and tooth 166 to its left Upon movement of the bolt mechanism to the right, safety member 117 of the keeper will first engage 95 the upwardly projecting tooth on the rotor and will be retracted until it passes over the tooth and falls 'into position behind it This will prevent subsequent opening movement of the door, since the dogging position of roller 1218 100 under tooth 147 will prevent clockwise rotation of the rotor Further rlghtward movement of the bolt mechanism will cause lower abutment surface 125 to ride up on keeper surface 126, and will further cause striker surface 118 to 105 engage the upwardly projecting tooth 127 The subsequent counterclockwise force on the rotor will cause roller 128 to be moved rightward against the action of spring 1145, undogging lever 137 rocking counterclockwise at the same 110 time During this movement, pin 135 will. move within arcuate slot 144 on the rollback, the latter remaining stationary When tooth 166 passes the center-line of roller 128, the latter will be forced leftwvardly by spring 145 115 under the tooth, which then becomes tooth 147 The subsequent rapid counterclockwise rotation of the rotor will terminate when the next upwardly projecting

tooth abuts keeper surface 119 From then on, the take-up action 120 of roller 128 will be similar to that described for the previous embodiment, any jarring or vibration serving to wedge the roller further under tooth 147 to thereby rotate the rotor further counterclockwise 125 When it is desired to open the door, the roller 128 will be moved rightwardly either by the rollback 1,41 or by the retracting lever 137 operated by the remote operator, the retraction of the roller allowing the rotor 127 130 7 $ 85,729 4 Mechanism according to caim 3, wherein said retracting means comprises a retracting lever and a pin-and-slot connection for supporting said lever, said connection allowing pivotal and translatory movement of said lever during movement of said roller along said track. Mechanism according to claim 4, comprising a rollback having a lost-motion connection with said roller for moving the roller from its dogging to its undogging position independently of said retracting lever. 6 Mechanism according te claim 5, wherein said lost-motion connection comprises an arcuate slot in said rollback, said roller having a pin extending through said slot and normally urged against one end thereof 'by said spring means, Said retracting lever being connected to said pin, whereby the retracting lever is adapted to move said pin along said slot. 7 Mechanism according to claims 5 or 6, comprising locking means for preventing movement of said rollback into its undogging position, said locking means comprising,a locking lever movable between locking and unlocking positions, said lever when it is in locking position having a portion in obstructing relation with said rollback. 8 Mechanism according to 'claim 7, wherein a portion of said retracting lever is engageable with said locking lever during its retracting movement, whereby said locking lever is moved from its locking to its unlocking position. 9 Mechanism according to claim 2, wherein said multi-toothed rotor forms said keeper member, said bolt member being normally prevented from retracting by a dog which is releasable to allow such retraction when the bolt member is moved in an unlatching direction, and where an abutment is provided in spaced relation with said rotor, and a safety member is engageable with said abutment, a retracting lever being provided for simultaneously retracting said bolt member and said safety member. A latching mechanism constructed and adapted ito operate substantially as described and shown in the accompanying drawings. STEVENS, LANGNER, PIARRY & ROLLINSION, Chartered Patent Agents, Agents for the Applicants. to rotate freely The bolt mechanism may then be moved leftwardly, the

rotor spinning clockwise as it allows first the keeper surface 1,19 and then the safety member 1117 to pass thereover. While it will be apparent that the preferred embodiments of the invention herein disclosed are well calculated ito fulfil the object above stated, it will 'be appreciated that the invention is susceptible to modification, variation aand change without departing from the scope of the subjoined claims.

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* GB785730 (A)

Description: GB785730 (A) ? 1957-11-06

Improvements in buttons

Description of GB785730 (A)

COMPLETE SPECIFICATION Improvements in Buttons I, HERBERT ARTHUR GLEIM, 'Crown Court, Newbury, Berkshire, 'British, do hereby de-. dare the invention, for which I pray that a patent may be granted to me, and the method by which it is to be performed, to be partica- larly described in and by the following statement: The invention consists in a button corn- prising a cap made of aluminium, Bakelite, (Registered Trade Mark) or brass, or the like, with edges turned down ninety degrees, fitted on to a head of moulded rubber, polythene, polyvinyl chloride or other plastic compounds, provided with a shank and thin base. In the accompanying drawing Fig. 1 is a plan view of a support showing a bead 1, base 2 and sewing holes 3. Fig. 2 is a plan view of a cap showing edges 4 turned 'down ninety degrees. Fig. 3 is an elevation of

the support showing the head 1, shank 5 and base 2. Fig. 4 is an elevation of the cap showing domed top 6 and wall 7, the edge of which is turned down ninety degrees. A button is assembled by pressing the cap over the head. The base can be circular, crescent shaped, square, or any suitable shape and can be wider or narrower than the head. The top of the cap and the top of the head of the support can be domed or fiat. There is no need to sew the button on to a garment, as the buttonhole on the garment is made smaller than the base, ibut if preferred it can be sewn on through the holes provided in the base. What I claim is: - 1. A button comprising a support of moulded rubber, polythene, polyvinyl chloride, or ether plastic compounds, consisting of a head, shank andi thin base, the head fitted into a cap made of aluminium, Bakelite (Registered Trade Mark) or brass, with edges turned down ninety degrees, and the base provided with two or more sewing holes. 2. A button comprising a support and cap substantially as herein described! and illustrated by the accompanying drawing. PROVISIONAL SPECIFICATION Improvements in Buttons I, HERBERT ARTHUR GLEAM, 'Crown Court, Newbury, Berkshire, British, do hereby de- clare this invention to be described in the following statement: A cap made of aluminium, Bakelite (Regis- tered Trade Mark) or brass, with edges turned down ninety degrees, is fitted on to a head of moulded rubber, or other suitable material, provided with a shank and thin disc as a base. To fasten the button on a garment, the 'base is pulled through a buttonhole and lies fiat against the inside of the garment, so that the button is held in place without having to be sewn on.

* GB785731 (A)

Description: GB785731 (A) ? 1957-11-06

Improvements in or relating to resinous compositions and fire resistantlaminates prepared therefrom

Description of GB785731 (A)

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COMPLETE SPECIFICATION Improvements in or relating to Resinous Compositions and Fire Resistant Laminates prepared therefrom we, WESTEGHOUSE ELECTRIC INTER NATIONAL COMPANY of 40 Wall Street, New York 5, State of New York, United States of America, a Corporation organized and existing under the laws of the State of Delaware, in said United States of America, do hereby declare the invention, for which we pray that a patent may be granted to us, and the method by which it is to be performed, to be particularly described in and by the following statement: - This invention relates to resinous compositions and fire-resistant laminates prepared therefrom. It has been desirable to have available, particularly in the electrical industry, resinous laminates that are highly fire resistant while possessing good electrical resistance proper- ties, both when dry and when subjected to humidification, as well as high strength. Resinous laminates of this type in the forms of plates, .tubes, channels, angles and other forms are particularly desirable for use in switchgear, switchboards, tap changers and similar electrical appanaltus that may be subjected to electrical arcs due to opening of electrical contacts. The art has produced a considerable number of laminates wherein expedients, such as incorporation of fireproofing agents, have been made use of. In most cases, however, these added fireproofing agents, such, for example, as chlorinated materials, have reduced the strength of the laminates or the electrical resistance

properties, and consequently, satisfactory results have not been obtained. Certain fire-resistant resms, such as melamine formaldehyde resins, are not only substantially more expensive than phenolic resins, but when applied to cellulosic fibrous materials, their moisture resistance is poor. The dielectric strength of melamines is not as high as that of other cheaper laminates, and thick sections, that is those of over one-quarter of an inch (6 mm) thickness, tend to crack badly on aging, particularly at temperatures of 100 C or more. For example, a melamine formaldehyde laminate l-f inches (38 mm.) thick had cracked badly when heated to 100 C. for one day. In testing the fire resistance of laminates, a test has been employed that is a slight modification as advocated by Gale, Stewart and Alters, in the ASTM Bulletin, page 23. December 1944, of Method 2023.1 of Federal Specification LP406b. The test equipment comprises a ventilated box approximately 18 inches (45 cm) square in cross section and about 3 feet (91 cm) high with an opening at the top in which there is disposed a constant-speed exhaust fan to withdraw gases from the box. At the bottom of the box is located a four-jawed chuck adapted to. hold in a vertical position laminate specimens having dimensions of l inch by 9 inch by 5 inches in length (13 mm by 13 mm by 127 mm). A heating coil of 1 inch diameter (25 mm) and 2 inches long (51 mm) and composed of nickel-chromium alloy is located coaxially about the specimen held in the chuck. Above the top turn of this heating coil are disposed two automobile spark plugs with their ignition electrode tips approximately 1/10 of an inch (2.5 mm) away from two opposite sides of the laminate sample to be tested. In testing a sample of the laminate, a rod of the sample machined to dimensions of -f inch by - inch by 5 inches in length (13 mm by 13 mm by 127 mm) is inserted in the chuck, and the heating coil is energized with 55 amperes of electrical current and the spark plugs are energized with electrical current so that an electrical arc plays across the ignition electrodes continuously. The " ignition time" is the elapsed time from the start of energy sation of the coil and the arcing of the spark plugs until a flame appears upon the sample. Once a flame appears upon the sample, the flow of current to. the spark plugs is vermin ated, but ,the heating coil is energized for 30 seconds longer at which time the current to the coil is also turned off and timing is begun from the moment the current to the coil is terminated until the flame is extinguished, this ame period being designated as the "burning time" of the sample. It will be apparent that both the " ignition time" and burning time" are factors of

considerable value in selecting fire resistant laminates. The chief object of this invention is to provide thermoset laminates comprising a fibrous sheet material impregnated with a thermoset reaction product of phenol, Idicyandiamide and formaldehyde, which laminates have a-high fire resistance, good electrical insulating properties and high physical strength. According to the invention, highly fireresistant ,thermoses resinous laminates may be prepared from a resinous product derived by reacting phenol, dicyandiamide and formaldehyde in the proportions of 1 mole of the phenol, from 0.S to 2 moles of dicyandiamide and from 0.9 to 1.5 moles of formaldehyde for each mole of the total phenol and dicyandiamide. Water is present, being usually furnished as a part of aqueous formaldehyde solution (37% to 40%), and amounting to at least 10% of the weight of the reactants, and ordinarily should not exceed the weight of the reactants. The mixture is reacted in the presence of an alkali catalyst for at least -t- hour, and preferably by refluxing from I to 2 hours, and then is vacuum dehydrated at a temperature not exceeding 100 C. until substantially all of the water is removed, a volatile solvent then being added to produce an impregnating varnish. The varnish may include a small prop or tion for example, of from 2% to 10% by weight of finely divided refractory solids such as silica, aluminium oxide, or antimony oxide to impant better flames resistance. The impregnating varnish is applied to fibrous sheet materials and particularly cellu10 Sic fibrous materials, such as graft paper, alpha paper and cotton cloth. Exceptional flame resistant properties and high strengths are obtained using such cellulosic materials. However, other fibrous materials may be used, such as glass cloth, glass mat, asbestos cloth, nylon cloth and other synthetic fabrics or a mixture of two or more fibrous materials, such for example as a cloth woven from a mixture of nylon and cotton. The fibrous sheet material is dipped in the varnish one or more times until it has picked up resin solids in an amount of from 0.7 to 2 times the weight of the dry fibrous material and the varnish impregnated fibrous material is passed ;through an oven or other dryer after each dip to rb move the volatile solvent. During drying, it is desirable to heat the fibrous material treated with the varnish composition at a temperature of from 110 C to 150 C. in order to remove the solvent therefrom promptly and to advance the cure of the resin well into the " B " stage. The heat treatment of the applied phenol-dicyandiamide-formaldehyde resin at this stage is conducted so that the resulting treated fabric has a " greenness" of from 0.5 to 10%. The "greenness" is determined by placing a small piece of the resin treated sheet material in a hot press at a temperature nf 175 C. and a pressure of 1,000 pounds per square inch (70 kg/cm2) for 5

minutes, and then measuring the amount of resin that is forced out of the sample, that is, the resin that extends beyond the fibrous sheet material proper, and from this determining the proportion of the exuded resin to the total amount of the resin in the sample. A greenness of 10% is desired for the making of certain products, such as ;tubes whlich require a considerable flow of resin between Iaminations in order that the laminations bond adequately. On the other hand, however, a greenness of about 0.5 % is essential for the purpose of making thick laminates, for example, laminates of 9 inch (13 mm) thickness and greater, since a material of low greenness evolves less exothermic heat and consequently thicker pieces can be moulded without heat damage. For preparing laminates of thicknesses of around 1/8 inch (3 mm), a greeness of from 16, to 3% is adequate. The sheet fibrous material, with the applied B" ') stage phenol-dicyandiamide - formalde- hyde resinous reaction product thereon, may be moulded into laminates, tubes and other members by superimposing a plurality of layers of the treated sheet material and compressing them at pressures of from 150 to 5,000 pounds per square inch (10.5 to 350 kg/ cam2) at temperatures of from 135 C. to 165 . In preparing the varnish impregnating composition from the resinous reaction product, particularly good results have been secured by using as a solvent a mixture of ethanol and water wherein the ethanol comprised from 20% to 80% by weight of the mixture. The varnish impregnating composition may comprise from 30% to 60% by weight of the thermosettable resinous product and from 70% to 40% % by weight of the volatile solvent however, acetone may be employed alone or in admixture with the alcohol, or a water and alcohol mixture. Other solvents and solvent mixtures may be employed, as desired. Exceptionally well impregnated cellulosic sheet fibrous material has been obtained by employing water-alcohol mixtures as the solvent. By employing solvents mixtures containing 50soh or more by weight of water, the balance being ethanol, particularly thorough impregnation of paper and cotton fabrics has been secured. The ollowing examples are illustrative of the practice of the invention. EXAMPLE I Into la steam heated reaction kettle there were introduced the following: phenol 2750 parts by weight dicyandiamide 2100 formaldehyde (37%) 4620 ammonia (28%) 166 The ammonia and the formaldehyde were admixed before being introduced into the kettle with the remainder of the ingredients, the total

mixture having a pH of approxiriIwly 8.5. The mixture was slowly heated, and at 80 Ci an exothermic reaction took place that carried the temperature to approximately 95 C. Additional heat was then supplied in order to cause the reaction mixture to reflux. The mixture was refluxed for 90 minutes and then dehydrated under a vacuum of 28 inches (715 mm) of mercury, an!d the temperature gradually increased to approximately 75 C. during dehydration. At 'this point, substanti,ally all the water had been removed. To the hot reaction product there was added 2000 parts by weight of 95% ethanol, and the resulting;thick varnish was cooled to room temperatune. The resinous reaction product was then further diluted with a mixture comprising 50% by weight of ethanol and 50% by weight of water to produce la solution comprising approximately 53 % by weight of resin solids. The viscosity of the composition was approximately 250 centipoises. The resulting varnish of 'this Example I was employed to impregnate the following sheet fibrous materials: (1) 10 mil (0.25 mm) thick alpha paper, the impregnated paper containing 101% of its weight of the resin solids at a greenness of 0.5,%. (2) 5 mil (0.13 mm) thick kraft paper, the treated paper containing 98% of its weight of resin solids, the greenness being 0.8i'?/o. (3) 621 ounce (240 grams per square meter) bleached cambric, the resin solids being equal to the weight of the cambric, the greenness being 0.5i%. Laminates were prepared from each of these three impregnated materials by superimposing a sufficient number of laminationi to produce consolidated members of various thicknesses of up to 1/2 inch (13 mm). The superimposed layers were consolidated at 1,000 pounds per square inch (70 kg/cm2) with the temperature of the press platens slowly rising Ito a final temperature of 165"C. The following table sets forth the ignition time and burning time in seconds of the laminates, and includes a standard XXX-grade phenolic laminate prepared from alpha cellulose paper for comparison purposes. TABLE I EIRE-RESISTANCES OF LAMINATES Laminate Ignition time, sec. Burning time, sec. I Alpha paper-based 199 79

Kraft paper-based 245 95 Cambric cloth-based 154 137 XXX Phenolic 145 437 It will be apparent 'that the first three laminates are considerably superior in ignition time and very much better in burning time to the standard XXX phenolic laminate. The dielectric properties of the laminates used in Table I were then determined, both in the as-neceived condition and after humidification and water immersion, and these data are set forth in Table II. TABLE II DIELECTRIC PROPERTIES Laminate Test Conditions (1) 100 Tan 8 Dielectric Constant 60 cy 1 Kcy 1 Mcy 60 cy 1 Kcy 1 Mcy Alpha-base A 1.09 1.44 2.19 4.89 4.78 4.51 C-96/23/96 4.55 4.12 4.28 6.22 5.86 4.90 D-24/23 4.60 3.60 3.14 5.67 5.59 5.15 Kraft-base A 1.18 1.44 2.17 4.79 4.68 4.34 S96/23/96 6.47 4.43 4.60 6.48 6.02 4.93 D-24/23 8.30 4.37 4.26 6.14 5.89 5.15 Cambric-base A 1.93 1.75 2.57 4.97 4.81 4.49 ;96/23/96 14.6 6.19 5.23 6.45 5.63 4.64 D-24/23 17.0 6.53 4.22 6.59 5.65 4.75 XXX Phenolic A 1.35 1.15 3.31 5.27 5.16 4.67 D-24/23 14.3 6.7 5.18 6.80 5.80 4.82 (1) Condition "A" Tested as received Condition "6/23/96" After 96 hours at 23 C. and 96% relative humidity Condition "D-24/23" Tested after 24 hours immersion in distilled water at 23 C. The physical properties of the laminates were also determined, and these data are set forth in Table III. TABLE III MECHANICAL PROPERTIES (ASTM) Bond Tensile Flexural Compressive Laminate Strength Strength Strength Strength ibs Kg psi Kg/cm2 psi Kg/cm2 psi Kg/cm2 Alpha-based 785 356 14483 1020 25613 1800 61253 4320 Fraft-based 1200 545 19174 1350 33618 2370 54577 3850 Cambric-based 1105 500 16684 1175 32658 2300 51682 3640 XXX Phenolic 1042 472 11000 775 13000 915 36000 2540 Laminates made from kraft paper treated with the resin of Example I to a 120% resin ,content, exhibited tensile strengths of 22,800 psi (1605 Kg/cm2), flexunal strength of 28,050 psi (1975 Kg/cm2), compressive strength of

51,320 psi (3620 Kg/cm2), and izod impact of 2.2 ft lbs. per inch (0.121 Kgm per an) width flatwise, (XXX grade phenolic having an izod impact of 1.4 ft. lbs. per -inch (0.077 Kgm/cm) width flatwise). EXAMPLE II The procedure of Example I was employed in reacting the following: phenol 560 pounds = 254 Kg dicyandiamide 500 pounds = 227 Kg formaldehyde (37%) 1160 pounds = 526 Kg ammonia (28 %) 3 gallons = 11.35 liters The mixture was dehydrated under a vacuum of 27 inches (685 mm) of mercury and a final temperature of 70"C. The resulting reaction product was then dissolved in a solvent mixture comprising 90 gallons (340 liters) of 95% ethanol and 35 gallons (132 liters) of water. The resulting varnish had a viscosity of approximately 250 centipoises and between 52 and 55, /O by weight of recoverable resin solids. I'he setting time of the varnish was approximately 16 minutes at 153 C. In order to prepare laminates for use In electrical insulatmg applications from phenolic and similar resins, it has been regarded as necessary to employ a purified cotton fabric. Such purified cotton fabric is prepared from what is known in the trade as *i grey-goods". The grey goods are treated with solvents and the like to remove naturally present waxes and the like. However, we have employed 3 ounce (110 gnams per square meter) grey cotton fabric which has not been treated to remove waxes and other naturally present impurities, and impregnated the fabric with the varnish composition of this Example II to provide thereon an amount of resin solids equal to the weight of the cotton fabric. The greenness of the fabric varied from 1 to 3, /O for different batches thereof. Laminates of a thickness of 1/16 inch (1.6 mm) and 1/8 inch (3.2 mm) were molded from this treated cotton fabric employing, however, a top sheet of the same cotton fabric containing the resin in an amount equal to 1SOiP/o to the weight of the fabric. Such laminates were consolidated in a hot press at 1,500 pounds per square inch (106 Kg/cm2) at 155to, and were tested for their electrical properties. The water absorption of the 1/16 inch (1.6 mm) laminate after immersion in water for 24 hours at 25 C was 1.05%, while the 1/8 inch (3.2 mm) laminate absorbed only 0.6771o/o Bleached cotton fabric made into similar laminates absorbed 75 /O more water than did the grey-goods

base laminate of this example. The dielectric strength of the grey goods laminates was 522 volts per mil (206 KV/cm) thickness for the 1/16 inch (1.6 mm.) laminate and 372 volts per mil (146 KV/cm) thickness for the 1/8 inch (3.2 mm) laminate. These dielectric strength values are excellent and equal to those of the best phenolic laminates available. It will be understood that the resinous compositions of this invention may be prepared by substituting Icresol for a part or all of the phenol. Furthermore, the phenol, dicyandiamide and formaldehyde may be reacted with other alkali catalysts than ammonia Suitable alkali catalysts are sodium hydroxide, sodium carbotiate, disodium phosphate, calcium oxide and barium oxide. The catalysts may be employed in an amount of up to 5,pro based on the weight of the phenol. The laminates of this invention have been applied with considerable success to circuit interrupters. Thus, arc barriers, splitters, channels and tubes land insulating supports for conductors, as well as the covers, bases and other structural parts not necessarily subject to full voltage of the conductors, have been prepared from the laminates of this invention. The laminates withstood arcs between the contacts of such circuit interrupters with no burning, or where in exceptional cases, flames did break out they extinguished themselves promptly on termination of the arc. Fuse tubes and other fuse elements may be advantageously made from the laminates. Switchboards and cubicles, containing electrical members subject to consideoable heating from red hot resistors and other over-heated conductors and to occasional arcing, may be fabricated from the laminates of this invention to advantage. It will be apparent that laminated members have been produced that can be used to great advantage with successful flame retardation in the vicinity of hot electrical conductors and arcing members. Jackets for bus bars are other insulating applications for the insulating members of this invention. It will be appreciated that the resinous members may be employed for nonelectrical uses, especially near flames or hot objects. What we claim is : - 1. A process for preparing fire-resistant thermoset resinous laminates, comprising impregnating a sheet fibrous material with a solution of a thermosettable resinous product derived by reacting one mole of a phenol, from 0.8 to 2.0 moles of dicyandiamide, and from 0.9 to 1.5 moles of formaldehyde for each mole of the total phenol and dicyandiamide in the presence of water and an alkali catalyst, the mixture being refluxed for at least 9 hour and then vacuum dehydrated at a temperature not exceeding 100 C., the resulting reaction product being dissolved in a volatile solvent to provide the said impregnating

solution, the resin impregnated ;sheet fibrous material being heated to drive off the solvent and to advance the cure of the resin to the " B " stage where its greenness is from 0.5% to 10:%, the fibrous sheet carrying from 0.7 to 2 times its weight of the resin after drying, superimposing a plurality of layers of the resin treated fibrous sheet and moulding the superimposed layers lat a pressure of from 150 to 5,000 pounds per square inch (10.5 to 350 Ilg/cm2) at temperatures of from 135"C to 165 C. 2. A process as claimed ia claim 1, wherein the alkali catalyst is used in an amount of up to 51% based on the weight of the phenol. 3. A process as claimed in claim 1 or 2, wherein the volatile solvent comprises a mixture of ethanol and water in the proportions of from 2QP/o to 80% by weight of ethanol. 4. A process as claimed in claim 3, wherein the impregnating solution comprises from 30iP/o to 60.% by weight of the thermosettable resinous product and from 70% to 40i% by weight of the volatile solvent. 5. A process as claimed in claim 3, wherein the sheet fibrous material comprises cellulose. 6. A process as claimed in any of the claims 1 to 4, wherein the sheet fibrous material is

* GB785733 (A)

Description: GB785733 (A) ? 1957-11-06

Method of moulding tires

Description of GB785733 (A)

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PATENT SPECIFICATION 785,733 Date of Application and filing Complete Specification: July 20, 1955. No 20986/55. Application made in United States of America on Feb 23, 1955. Complete Specification Published: Nov 6, 1957. Index at acceptance:-Class 87 ( 2), A 1 R 3 CX. International Classification:-B 29 d. COMPLETE SPECIFICATION Method of Moulding Tires We, THE GOODYEAR TIRE & RUBBER COMPANY, a Corporation organized under the Laws of the State of Ohio, United States of America, with offices at 1144, East Market Street, Akron, Ohio, United States of America, do hereby declare the invention, for which we pray that a patent may be granted to us, and the method by which it is to be performed, to be particularly described in and by the following statement:- This invention relates to an improved method for moulding tires. In the manufacture of tires by molding "green " unvulcanized rubber tires in a tire mold many difficulties have been encountered. These have been caused to a great extent by the trapping of air in the mold between the surface of the mold and the rubber and by the tendency of the cured rubber to adhere to the surfaces of the tire mold, particularly to facing surfaces between projections in the mold since the rubber must slide over these surfaces when the tire is removed from the mold In attempts to surmount the problems of trapped air and adhesion of the cured rubber to the mold surfaces many things have been tried Molds have been plated with various metals, and have been provided with polished surfaces and with matte surfaces in attempts to eliminate these difficulties In addition to plating and polishing the mold surfaces, the methods which have been most used to overcome trapping of air and sticking of the rubber to the mold are the methods in which a mold dope is coated on the mold surface or a dust is applied to the surface of the rubber tire prior to the insertion of the tire in the mold for the curing operation. The use of mold dopes and dusting powders introduces foreign materials which contact the faces of the tread or side-wall splices and frequently cause splice separation in the cured tires To alleviate the troubles of splice separation, it is customary practice to paint the splice faces with rubber cement lPrice 3/6 l before they are brought

into contact with each other This reduces the frequency of defective splices, but it causes contamination of the molds due to adherence of the cement to the mold surfaces and it adds an additional step 50 to the process of manufacturing tires Mold dopes and dusts also contaminate the mold surfaces so that cleaning must be frequent in order that satisfactory surface finishes on the cured goods can be obtained and in order to 55 insure completely filling of the mold and transfer of the design to the cured article. Solid grains from these mold dopes and dusts become imbedded in a tread or side-wall of a tire and provide a point for initiation of flex 60 cracks. As an alternative to the use of mold dopes and dusts as release agents, attempts have been made to eliminate sticking of the cured rubber by coating the surfaces of a tire mold 65 with a thin coating of " Teflon " (Registered Trade Mark), a tetrafluoroethylene polymer. " Teflon " is a high softening point, insoluble organic polymeric material which is highly resistant to decomposition which can 70 withstand long exposure to elevated temperatures Coatings with " Teflon," however, have not been satisfactory because " Teflon " forms a frangible film that flakes off when abraded or when struck a blow, 75 leaving imperfections in the coated mold surface In addition to these difficulties with " Teflon," it is necessary, in order to obtain a smooth continuous film of this material, to heat it at a temperature in the range of about 80 650 TF to 750 TF, at which temperature range the tire molds now in use (which generally consist of mated pairs of steel outer sections containing aluminum inserts fitted into these outer sections for the purpose of molding a 85 tread pattern in a tire) undergo distortion due to the difference in thermal expansion of the aluminium insert and the steel or iron outer band When the temperature of the composite mold is returned to normal, after being 90 785,733 heated to a temperature in the range of 700 F, stresses are set up which amplify the distortion caused by the differences in the thermal expansion of the two metals Consequently, " Teflon " coated molds have not proved satisfactory for the manufacture of tires. In addition to the difficulties caused by the adhesion of the cured rubber to the mold, defects, known in the art as "i light spots " and rounded tread segments caused by the rubber stock incompletely filling the mold, frequently occur These defects are thought to be due to pockets of air being trapped between the rubber and the mold surface. "Light spots" are unsightly and must be treated to improve surface appearance and salability Rounded tread segments are frequently major defects in a tire and cause down-grading to " imperfect " or second " grade of a tire that would otherwise be a first quality tire. It is an object of this invention to provide an improved method for

making tires. Another object of this invention is to eliminate the necessity of using a mold dope or dusting powder as a release agent for cured tires and thus avoid separation of the tire at the splice A still further object is to avoid contamination of the surface of the tire and the resultant tendency toward cracking on flexing It is another object to provide a method for making tires whereby the production of " light spots " in a tire is substantially reduced Another object is to provide a tire of better appearance than tires made by conventional methods Other objects will appear as the description of the invention proceeds. According to this invention a molded cured tire is made in a tire mold coated on its inner surfaces with a coating of polytrifluoromonochloroethylene By the use of such a mold, the use of mold dopes and dusts is not necessary and sticking of the cured tire to the mold surfaces is substantially eliminated. The practice of the invention is illustrated by the following example A regular production tire mold having tire tread-producing projections and consisting of a mated pair of steel sections containing aluminium inserts as a tread design-forming pattern was cleaned on its inner surfaces, including the aluminium inserts, by heating at 480 TF to remove traces of oils and organic matter that might contaminate the mold, and then by sandblasting to provide a fresh metal surface The inner surfaces, including the aluminium inserts, were then coated with a dispersion of polytrifluromonochloroethylene by spraying with a 25 % dispersion of polytrifluromonochloroethylene in a xylene-diisobutyl ketone solvent mixture The solvent was removed by evaporation and the polytrifluromonochloroethylene was fused into a continuous coating on the mold by placing the mold in an oven, heating the mold to 480 WF and then baking at 480 TF for three hours after the mold had attained this temperature. A conventional, " green," unvulcanized 70 pneumatic tire was placed in the coated mold prepared as above and cured under the usual conditions of pressure and temperature On opening the mold the rubber surfaces were readily released from the tire mold The tire 75 was free from " light spots". The process of the invention has been illustrated with respect to a pneumatic rubber tire Tires made according to the method of this invention can be solid or pneumatic and 80 can be made of various types of rubber including natural rubber, GR-S, cold GR-S. butadiene-acrylonitrile rubbers, neoprene. butyl, and the polyester rubbers such as the rubber-like materials made from polyesters 85 modified with polyisocyanates. The invention has been illustrated wxith particular reference to

coating a tire mold with a dispersion of polytrifluoromonochloroethylene in a xylene-diisobutyl ketone solvent 90 mixture Other solvents or solvent mixtures can also be used Polytrifluoromonochloroethylene can be used as the only film-forming ingredient, but this polymer can be modified by suitable compounding, if desired For 95 example, the polymer can be compounded or blended with phenol aldehyde resins, such as phenol formaldehyde resins, or with epoxy resins, such as epichlorohydrindiphenylolpropane resins or other similar materials 100 The epoxy resin-modified polytrifluoromonochloroethylene dispersions have been found to produce very satisfactory results These may be obtained under the designation of Fluoro blends as sold by Permolite, Inc 105 Other types of tire molds can be used, including all-steel molds into which the tire pattern is incorporated by engraving or otherwise. A coating of 0 003 inch thickness has been 110 found to be satisfactory and to stand up under production molding conditions The coating can be applied in a thicker or thinner film if desired However, if the coating is too thick, some adjustment in mold dimen 115 sions may be necessary to compensate for the the thickness of the coating, and if it is too thin, it will not be serviceable under the rough usage encountered in the manufacture of tires 120 The coating can be applied in several layers, all from a dispersion of the same composition, or the coating can be applied as layers of different composition using the compounded dispersions A preferred coating is 125 made by applying to the metal a base coat of a dispersion relatively rich in an epoxy resin or a phenolformaldehyde resin and correspondingly poor in polytrifluoromonochloroethylene, and an outer coat of a dispersion 130 A_ 785,733 that contains little or no epoxy or phenolformaldehyde resin and is rich in the polytrifluoromonochloroethylene resin. The exact reason why polytrifluoromonochloroethylene provides such an excellent surface for the molding of tires is not known. However, inspection of the surface of the film coating shows that the polytrifluoromonochloroethylene film has a glossy, uneven surface It is believed that any air or other gas trapped in the mold, when it is put under pressure, meanders its way about and around the irregularities in the film surface until it escapes from the mold Thus the trapping of air or other gasses is eliminated The glossy surface minimizes adhesion of the rubber to the film. This invention has been found to offer many advantages in the production of tires, some of which are as follows: cured tires are readily released from the tire molds and are of generally better appearance than are tires made by conventional methods; cleaning of the molds need be done less frequently than is now the case with

regular uncoated molds; the necessity for applying a mold dope or dust as a releasing agent before each molding operation is eliminated; tread and side-wall splice separation due to contamination of splice interfaces from mold dusting materials is eliminated; any trapped air flows out of the coated mold more readily than it does out of an uncoated mold and " light spots " and rounded tread buttons or projections are eliminated; painting of side-wall and tread splices with rubber cement prior to curing is eliminated; and no solid grains of dusting materials are incorporated in the side-walls or tread of a tire; and these points of initiation of flex crack are not present in a tire cured 40 in the coated mold.

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