Patent GB-732237-A (GB)
Title: Improvements in or relating to machines suitable for attaching heels to shoes
IPC: A43D79/00
Filed: 1952-05-23
Abstract: 732,237. Heel-attaching machines. BRITISH UNITED SHOE MACHINERY CO., Ltd. (United Shoe Machinery Corporation). May 22, 1953 [May 23, 1952], No. 13079/52. Class 17 (1). A machine for attaching a heel to a shoe has a work support for the shoe and heel, fastening drivers arranged to be moved towards the work twice, in the same path and to like extents, during a heel attaching operation, and means to move the work support from a predetermined level towards the path of the drivers, so to position the work that, in the first movement the drivers form holes in the work to receive the fastenings, and then to move the work support back to the pre-determined level, which is such that the drivers in their second movement drive fastenings into the holes and complete the movement with their operative ends more or less level with the tread face of the heel. A preliminary clamping pressure is applied to the work prior to the starting of the machine into. power operation by fluid pressure operated means 24, arid an additional clamping pressure is applied prior to the forming of the holes. In operation a jack 10 bearing the shoe is slid rearwardly to engage the heel end with a back gauge which aligns that portion with a heel base 14 and top lift 16 held against an abutment 18, and treadle 22 is depressed to actuate mechanism 24 to raise the jack and apply moderate clamping pressure. The starting lever 34 is then depressed to trip a one-revolution clutch 35 for driving the main shaft 36 through one complete cycle, during which a heavier clamping pressure is applied, the work is pricked, the fastenings are driven simultaneously through the heel sections into the heel seat, and finally the clamping pressure released. A thinner heel plate 18 is used if the fastenings are to be driven beyond the tread surface. The jack 10 comprises heel and toe posts 44, 46 carried on a slide 48 movable horizontally between loading and operative positions, and the back gauge. The toe post 46 is adjustable heightwise and angularly, post 44 is adjustable heightwise, and the back gauge is adjustable heightwise, laterally, and to and from the heel post. The heel plate 18, supplied in two different thicknesses and three different sizes and provided with fastening receiving passages, is slid into the pressure block 69, which has three corresponding sets of passages 74, and secured by latch 72. The top lift and heel base are supported and positioned by arms 76, 76 and 78, 78 pivoted on eccentric studs 80, 82, springs 84 closing the arms to grip, and links 86, 88 equalizing the movement. Closing movement of arms 78 is limited by engagement of pins 100, 102 on arms 76 with the closed ends of slots 96, 98 in arms 78, and of arms 76 by engagement of a pin 106 on one arm with a slot 104 in plate 18. If no heel base is to be fitted arms 78 are held inoperative (as in Fig. 8) by use of a spring- pressed detent 90 carrying a pin 94 which is received in slot 98. When no heel plate is present arms 76 are held separated by a spring-pressed detent 108 (not shown) in block 69 which engages a shoulder 110 on one arm 76, but when plate 18 is assembled a cam 112 thereon raises detent 108 and permits arms 76 to close. The slots 104 are of different lengths in the various heel plates 18 so as to position the arms automatically for the required heel &c. As plate 18 is removed the arms are opened by the camming action of pin 106 and slot 104, and detent 108 operates. The jack frame 20 movable vertically on bushings 114 has a foot 118 with a sloping surface which seats on a wedge 120, movable horizontally to raise or lower the jack, for pricking or fastening driving respectively. The amount of the final clamping pressure is controlled' by means of a cam 130 turned by arm 132 and acting through a roll 128 to raise a crosshead 124 which supports the jack &c. through a shaft 30 until the final cam 130 turned by arm 132 and acting through a roll 128 to raise a crosshead 124 which supports the jack &c. through a shaft 30 until the final pressure is applied. A spring 135 partially counterbalances the weight of the jack &c. The preliminary clamping pressure is applied by depression of the spring-returned treadle 22 which acts through 138, 140, 142, 144, 146, 148, 150,and valve piston 152 to operate the mechanism 24. In this mechanism oil is drawn from the sump and discharged under pressure through 160 to a valve casing 162. With the piston inoperative the bulk of the oil passes through 166, to a pressure relief valve 168 and through 170 to the sump, while some passes through the valve 162 and 184 to cylinder 186 urging the plunger to the left (Fig. 21) and via 194 to the sump. With the piston in its operative position the oil passes through valves 162 and 214, to move piston 190 and rack bar 192 to the right, rotating gear 198, shaft 200, gear 202 (not shown), 204, 206, and pinion 32 with shaft 30 to apply preliminary pressure. The fluid adjacent piston 188 is exhausted through 184, valve parts (not shown), and 222 to the sump. Starting lever 34, which is then depressed to start a cycle of operations is connected through 242, 244, 246 (not shown), 248, to a one revolution clutch 35. Premature starting is prevented by means of a shaft 252 (not shown) which is connected to arm 244 and must pass through a hole in arm 148, which it can do only when treadle 22 is fully depressed, Shaft 252 is also immobilised if slide 42 is not fully retracted, a slide 262 (not shown) being held through 270, 272, 'eccentric stud 273, and roll 274 by the part 534 of the retracted slide 42 so as to permit movement of shaft 252, but being moved by spring if slide 42 is not retracted so as to prevent movement of shaft 252 and operation of lever 34. Cam 278 on the main shaft 36 now acts through 284, 280, 292, toggle 286, 288, and 290 to raise shaft 30 and the jack &c. to provide the heavy clamping pressure, the degree of which is determined by the setting of cam 130 which adjusts the inital spacing between 290 and bearing 126, and finally collapses the toggle. Concurrently wedge 120 is moved to raise the jack &c. by cam 294 acting through 296, ball crank 298 which is bifurcated and has a slot 302 along which blocks 304 are adjustable, bell crank 306 bifurcated, and slotted at 310 with blocks 312 on the same shaft 314 as blocks 304, adjustable eccentric stud 316, and link 318 pivoted to the wedge. This raising of the jack which controls the depth of pricking is regulated by adjusting the position of shaft 314 along slots 302, 310, by means of hand wheel 336, screw 334 and blocks 330, 332, through eccentric 328, 326, and 324, pointer 338 and scale 340 indicating the adjustment. The change in level of the heel seat due to the adjustment of cam 130, and consequent variation of the clamping pressure, may be compensated for by adjustment of arm 342. The driver head 38 comprises a block 344 with drivers 346, and a plate 350 with a cam surface 352 slidable in a recess in plate 348. Two middle drivers 354 at the breast end are carried by a block 356 slidable vertically in 344, 348. During pricking drivers 354 are above drivers 346, as required by the arched shape of the heel seat, but before the driving stroke plate 350 is moved forwardly by a shoe 358 so that block 356 is forced downwardly to bring the driver ends level. Plate 350 is later returned by spring 360. Shoe 358 is operated through 548, 550, 554 by lever 556 which is swung by lever 536, and returned by spring 558. Three sizes of driver head are supplied. A cross-head 368, to which the driver head is attached, is fixed to vertically sliding rods 376 which carry a cross head 378. Pairs of cams 396 on shaft 36 acting through bell cranks 392, 388 &c. extend and collapse toggles 380, 382 to impart two strokes to the drivers for each revolution of the cams. The string feeding device 40 comprises pawl blocks 402, 404, the latter being movable with plunger 414 which is reciprocated vertically through lever 416 fulcrummed on the pivoted link 418, and a link 424 adjustably pivoted at 422, 420, and notched to receive a stud 426 secured to the jack frame 20. Spring 430 normally holds the link 424 against stud 426, but the link may be detached therefrom and held by latch 434 for test operations. The strings are fed from reels 458 through 460, 455. Pins 436 &c. in the pawl blocks carry toothed pawls 438 swung to engage the strings extending through passages in the blocks by springs 442. The strings are carried down with block 402 but during the upstroke are released by 402 and gripped by 404, thus feeding the required length which is controlled by adjustment of stud 422 along slot 420. The strings to be driven by drivers 354 are made shorter by means of vertically adjustable cams 453 (not shown) which hold the breast pawls in block 402 out of engagement with the strings until the block has gone through part of its downstroke. The string passes through a switch box 412 comprising insulating plates 465, 466, a conductor 470 with a contact 472 for each string, and pivoted elbows 476 each having a passage for a string and a contact 480 connected by a compression spring 482 to a conductor 484, the conductors being connected to a lamp 461. If a string is exhausted the elbow will be swung to bring 480 and 472 into contact to complete the circuit to the lamp, operating switch 674, and lock a rod 463 which prevents operation of lever 34 to start the machine. The strings leaving block 404 enter aligned passages 487 in frame 406 and support 486. The loader slide 42 movable in slideways 490 has sets of passages 493, and a transfer assembly is used to ensure the use of that set of passages which corresponds with the driver head. The strings pass from 487 through splayed passages 500 in a transfer block 498 to aligned passages 502 in a transfer plate 496, and shear plate 488 arranged according to the design of the driver head. Similar pas