Patent GB-907691-A (GB)
Title: Improvements in or relating to mechanisms for use in handling shoes for the operation of shoemaking machines thereon
IPC: A43D117/00
Filed: 1957-11-05
Abstract: 907,691. Shoe-making machines. BRITISH UNITED SHOE MACHINERY CO. Ltd. (United Shoe Machinery Corporation). Nov. 4, 1958 [Nov. 5, 1957], No. 34410/57. Class 17 (1). In a mechanism for transferring a shoe-carrying pallet 34 from a carrying apparatus 30 to the holder 58 of a power-operated machine 40 for operating on the shoe, a transfer device engages the pallet at a first position adjacent the carrying apparatus, a gate in the carrying apparatus is opened, the transfer device moves through the gate to a second position adjacent the holder, the pallet is deposited on the holder, clamped thereto, and released from the transfer device, which returns to the first position and initiates an operating cycle of the machine, then the transfer device returns to the second position, re-engages the pallet, and returns to the first position, where the pallet is deposited on the carrying apparatus and released from the transfer device. The machine shown is a heeltrimming machine of known type and has a cutter 60 and a table 56 movable horizontally on a frame casting 54 which is movable vertically on a pivoted base casting 52. A plunger 94 which is normally raised by a spring 116 is moved downwardly to clamp the pallet against the base-plate 80 of the holder by operation of piston 108 (not shown) in cylinder 110, pins 114 on the base-plate engaging the heel. The abutment member 96 on the end of plunger 94 has a transverse groove 118 (not shown) which receives the end of a sensing rod 152 which protrudes from the pallet when a last is mounted thereon, and bevelled side faces to engage inclined surfaces 142 on the pallet. Each pallet comprises a base 130 with wheels 134 which run in grooved rails 32, and is propelled by lugs 38 of a driving belt 36. Lugs 144 on the pallet arrest the last by engaging a positioning- plate 146 thereon. A spring-pressed bail 160 pivoted to the pallet carries a drive finger 162, and a deflecting-plate 164. At the holdback station the bail is pivoted to disengage finger 162 from a lug 38 when plate 164 engages a camming surface of a spring-held bar 170, and the drive is later reconnected to move the pallet to the transfer station by energization of solenoid S1 which withdraws bar 170. During the passage of the pallet to the transfer station, rod 152 actuates a switch M1 which de-energizes solenoid S1 so that rod 170 returns to hold back the next pallet, and a feeler arm 206 is swung by the heel of the shoe a distance related to the size of the shoe, and this movement is imparted by Bowden cable 216 to set a control mechanism associated with the transfer device. As the pallet arrives at the transfer station stud 234 acts via cam surface 226 to close the normally open switch M2. This energizes solenoid S2 which first swings a release lever 252 to depress plate 164 and so release the pallet from the drive, and then swings a pallet aligning arm 246 to engage wheels 134 and so centre the pallet, At the close of its movement armature 268 of solenoid S2 closes switch M3 (not shown) to initiate a transfer movement. The transfer device comprises a carriage 306 which is moved up and down guideways 302 by means of a piston 374 (not shown) in cylinder 376 which acts via rack 366, pinion 360, larger gear 358, and rack 352 which is connected to the carriage by a spring 386 and by slot 348, pin 346, and arm 344. Lever 314, 316 pivoted to the carriage has a roll 326 engaged in a cam track 318, and a pin-and-slot connection 340, 338 with a pallet gripping device 334, 336 slidable vertically in the carriage. As rack 352 and carriage 306 move down the cam track 313 lever 314, 316 is swung to raise the device 334, 336 above on obstruction on the heel trimming machine and then lower it again, then the carriage is arrested with roll 326 opposite portion 324 of the track. With continued movement of racks 366, 352 pin 346 moves down slot 348, compressing spring 382 and releasing spring 384 so that lever 314, 316 is free to swing and the device 334, 336 with the shoe falls by gravity till the heel H engages base-plate 80 of the holder. Reverse movement of piston 374 returns carriage 306. Movement of the carriage (in both directions) is terminated by resilient stops, the position of stop 406 which limits the movement towards the trimming-machine being adjusted in accordance with the size of the heel by feeler arm 206 via cable 216, and locked in position by a toothed plunger 444 (not shown) controlled by a solenoid S4 which is energized when switch M1 is closed. The pallet gripping device has two pairs of interconnected gripping arms 502, 504 with gripping surfaces 506 which are normally withdrawn by springs 530 but the closing of switch M3 causes movement of piston 522 in cylinder 524 which acts via bellcrank 514 to swing arms 502, 504 outwardly to grip the sides of a dovetail guideway 140 in the upper surface of the pallet. A switch M15, which is provided to prevent operation of the gripping device when there is no pallet in position, is actuated by a cam surface on the pallet. When the pallet is gripped an extension of bell-crank 514 closes a switch M6 to energize solenoid S5 which causes piston 606 (not shown) of cylinder 608 to move and open gates 590, 592 in rail 32. As the gates reach open position, switch M7 is closed, energizing solenoid S6 (not shown) which causes piston 374 to move the carriage 306 through the gate to the second position adjacent holder 58. As the carriage completes its movement switch M8 is closed, energizing solenoid S7 to cause piston 108 to operate the clamping plunger 94. Switch PS1 (not shown) is then opened, de-energizing solenoid S3 (not shown) so that the pallet gripping device is released. Switch M6 is thus opened, de-energizing solenoid S6 so that the carriage returns to the first position, a projection thereon opening switch M9 which deenergizes solenoid S5 causing gates 590, 592 to close again opening switch M7. At the completion of this movement switch M10 is closed and initiates an automatic cycle of operation of the trimming-machine. A switch M11 is then opened and certain circuits are transferred, and at the end of the operation switch M11 is closed and the circuits restored. Then, in sequence, S5 is energized to open the gates, S8 (not shown) is energized to move the carriage 306 to the second position, S3 is energized to grip the pallet, M6 closed to de-energize S7 to release clamp 94, collar 696 closes switch M12 to return the carrier and the shoe to the first position, and S5 is de-energized to close the gates and close switch M10, de-energizing S3 so that arms 502, 504 release the pallet. If, however, there is congestion on the runway beyond the transfer station, a switch M5 is held closed by a pallet and prevents release of the gripping device, and thus prevents movement from the transfer station until M5 is opened. A finger 710 (not shown), which engages finger 162 when arms 502, 504 are in gripping position, then rises, permitting finger 162 to engage a lug 38 to move the pallet from the transfer station. A stud 234 on the pallet engaging a cam surface 716 of an arm 714 (not shown) momentarily closes a switch M4 to energize solenoid S1 which retracts bar 170 to release the next pallet. The known electrical control system of the trimming machine is combined with the electrical control system of the transfer device, and an additional mechanical control linkage is added. The movements of table 56, casting 54, and casting 52 are controlled by respective solenoids. Movement of the transfer mechanism cannot take place until switches M13, M14 are closed by outward movement of table 56, downward movement of casting 54, and movement of casting 52 to the level position. Separate motors for the cutter drive, the pump, and the blower have individual starting switches, but may be started or stopped simultaneously. The cutter motor may be stopped by opening a switch which also causes the shoe holder to retract the shoe from the cutter. Closing of one manually-operated switch permits operation of the trimming-machine independently of the transfer device, the clamping operation being effected through another manually-operated switch. The electrical and hydraulic circuits are illustrated. Specifications 863,464, 863,465, and U.S.A. Specification 2,644,968 are referred to.