Patent GB-523480-A (GB)
Title: Improvements in or relating to machines for conforming shoe uppers to the shape of the sides of lasts
IPC: A43D21/12
Filed: 1939-01-03
Abstract: 523,480. Lasting machines. BRITISH UNITED SHOE MACHINERY CO., Ltd. (United Shoe Machinery Corporation). Jan. 3, 1939, No. 120. {Class 17 (i)] Relates to machines of the kind described in Specification 316,186, [Class 17 (i)], for operating progressively along both sides of a shoe simultaneously, a last with a shoe upper 'thereon being mounted on a jack and carried past the operating instrumentalities. Those pattern cams which require changing most frequently for change of style of shoe are carried on the ends of 'camshafts projecting from the base, 'to facilitate such change. The machine is adapted for operation on both right and left shoes by connections between a pair of pattern cams and the lasting 'devices which connections are interchangeable so that each cam operates on a right shoe with the connections which co-operated with the other cam during an operation on a left shoe, and vice versa. The pattern cams are driven intermittently; a lever 26, Fig. 7, having an eccentric strap at its upper end and pivoted on a link 28 has a roll 32 at its lower end co-operating with slots 38 in a disc 36 normally clutched to a pattern cam shaft 12. The roll also engages a slot 48 in an arm secured to a rock shaft 44 also carrying. an arm having a roll 40 which acts as a detent to hold the disc 36 when the roll is passing from one slot to the next. As the lever 26 rises and falls and oscillates, the roll 32 enters one of the slots 38, turns the shaft 12 one step, and then leaves the slot to pass to the next. The driving mechanism comprises a gear rim 50, Fig. 22, driven continuously by an electric motor through. reducing gearing. The driven member 72 of the clutch splined to the shaft 10 is disengaged from the clutch face of the rim 50 by pairs of rollers 88, 90 brought into line by depressing a treadle connected to a rod 106, Fig. 7. When the clutch is disengaged the member 72 acts as a brake. To engage the clutch a treadle 116 co-operates with a link 112 supported at its rear end by a link 114 and pivoted to a link 110 connected by a lever 108 with the rod 106. The clutch is held closed by a latch 118 engaging a lug on the link 112 to retain it in its raised position. To disengage the clutch at the end of the cycle the pattern cam shaft carries a bell-crank lever 124 urged clockwise by a spring and actuated by an arm 132 from the shaft 44 to engage a lug 130 on the link 112 to free the link from the latch. The mechanism for swinging the lasting units about axes substantially perpendicular to the sole of the shoe comprises connections which may be interchanged for operation on the other shoe of a pair. Each comprises a cam lever 164, Fig. 18, from which a rod 170 extends upwardly pivoted to a link 172 the forward end of which is connected with an adjusting lever 174. In line with each rod 170 is a rod 176, the lower end of which is formed with a head provided on opposite sides with grooves 188 arranged to receive rolls on the pivots of the rods 170 and links 172. Oppositely inclined slots in the levers 174 are engaged by a pin carried by a handle 196 to move 'the rolls simultaneously in opposite directions to change the connections. The outward pressure of the guiding presser feet of the lasting units against the rib of the insole is varied during the cycle by a pattern cam. For controlling the action of the upper 'tensioning grippers, a lever 230, Fig. 15, pivoted to a cam actuated lever 232, is connected at its forward end to the grippers by a cross head 234. The fulcrum 240 of the lever is yieldingly supported against upward movement during the upward movement of the grippers by a spring 246, and positively held against downward movement by a pattern cam 254. A pattern cam 272 provides additional resilient tension to that provided by the spring 246 at certain times in the cycle, a spring 256 providing a yield in this additional mechanism. A latch 288, Fig. 33, connects the jaws to their actuating member so that they remain open during any to and fro movement of the member. The latch is pivoted at the pivot of the gripper jaws and linked to , link 294 urged anti-clockwise by a spring. A stop pin 298 co-operates with an arm of the latch to free this in 'the lowest position of the grippers. An eccentric pin 303 guides the gripper by engagement with the shank 282. A cam plate 305 secured to the wiper carrier imparts a positive swinging movement to the gripping jaws inwardly over the sole edge. The feeding movements of the jack are imparted to the jack frame 304, Fig. 1, by a pattern cam 24 actuating a lever 312 connected by links 320, 314 to a bell-crank lever 316 linked to the jack frame. To vary the individual feeding movements for shoes of different sizes the pivotal connection of the links 314, 320 is connected to a locking rod 322 extending diametrically through the hub of the lever 312. As in the machine described in the prior Specification, the movement of the jack to operative position adjusts the jack feeding mechanism in accordance with the size of the shoe. To permit this adjustment the locking rod is freed while the jack is being so moved. The locking rod 322, Fig. 25, is formed with 'teeth co-operating with teeth on a block 326 urged away from the rod by a spring 330 within a tubular plunger in the hub of the cam lever 312. An arm 340 is connected to the starting treadle to compress the spring 330 and allow a weaker spring 338 to hold the teeth in contact, and thus lock the rod, during the operation on a shoe. The lateral position of the lasting units is adjusted by the movement of the jack to starting position, a cam secured to the lever 316 actuating linkage between itself and the units. When the machine is in operation, an upward pressure is exerted on the jack, to force the shoe against the pressure feet of the lasting units, by a spring 398, Fig. 14, connected to an arm 400 from which a cord leads to a strut 410 supporting the jack frame 304. The tension of the spring is increased during staple driving by a link 422 connected to the lever 26 and a pawl 426 actuating a lever 418 to which the upper end of the spring is secured. An arm 430 releases the pawl quickly just before the start of a shoe feeding movement. A pattern cam 432 removes the shoe from contact with the lasting units prior to the outward movement of the jack, this cam also straightening a toggle 440 linked to a plunger which imparts this outward movement to the jack to facilitate the removal of the finished shoe. Inward movement of the jack, when a new work-piece has been positioned, by the operator, breaks the toggle and allows the jack to rise. The shoe support comprises a cradle 454, Fig. 12, swinging about an axis extending lengthwise of 'the shoe and close to the bottom thereof. A last pin 456 projects from a slide 458 urged to the right by a spring and provided with a lug co-operating with a pawl pivoted to a lever 506 'to move it to the left. The lever 506 is carried by two links 508, 510 and engages a slot in a link 498 actuating an arm 494 resiliently connected to a lever 490 which when moved anticlockwise locks the cradle. This lever is linked to a lever 484 co-operating with a spring plunger in line with the last pin, and is actuated by a link 504 from a crank pin on a pulley 500 oscillated by cords secured to a disc 522 oscillated by a pattern cam 538. When a shoe is finished the last pin is moved to the left and the arm 494 swung to the right, actuating the lever 490 to lock the cradle. When the shoe has been removed and a new work-piece. positioned the spring plunger is depressed by the shoe, unlocking the cradle and lowering the pawl 478 to allow the last pin 'to move the shoe forward to contact the toe gauge 462.