Patent GB-628371-A (GB)
Title: Improvements in or relating to power-operated machines for conforming shoe uppers to the shapes of lasts therein
IPC: A43D13/00
Filed: 1947-09-27
Abstract: 628,371. Lasting-machines. BRITISH UNITED SHOE MACHINERY CO., Ltd. Sept. 27, 1947, No. 26219. Convention date, Sept. 30, 1946. [Class 17 (i)] An electric switch is closed, by presentation of a shoe upper on a last to a lasting machine, to start a cycle of power operations, and is held closed until the end of the the cycle when it is opened automatically. In an illustrative form of machine described for lasting open toe ends of shoes, rearward movement of the toe end of the last, bottom uppermost, against a toe former or toe band 292, Figs. 1, 24, effects the closure of a switch 630 to energise a solenoid 624 and close a sleeve valve 612 to cause development of fluid pressure in a manifold 434 fed by a continuously running pump 422, from a sump 428, which causes a one-revolution clutch 534, through which the machine may be driven through its cycle of operations, to be actuated. Such pressure fluid is supplied from the manifold 434 at appropriate times to various cylinders which control the grippers, wipers and other mechanisms under the control of valves operated by solenoids, switches controlling the energisation of which are controlled by cams 512, 514, 516, rotatable as a unit on a drum 520 through the one-revolution clutch 534, to determine a cycle of operations. A cam 640 on this drum holds the switch 630 closed throughout the cycle. Fluid delivered by the pump when the machine is not operating is permitted to escape through a relief valve 440 to the sump 428 to prevent the fluid pressure in the manifold 434 from rising. At the beginning of the cycle of operations, pressure fluid is supplied from the manifold 434 to a cylinder 82, Figs. 2, 3, through closing of switch 494 by cam 512, to cause slide valve of a valve unit 450 to open. The piston 80 raises the toe rest 66 to clamp the shoe against the rest 2. At the same time, fluid is admitted to cylinder 148 through the same valve to move grippers 100, Fig. 19, outwardly to a position just beyond edge of insole. Cam 514 next closes switch 496 to move sleeve valve in a valve unit 452 to admit fluid to cylinders 104 to close the grippers, the piston 190 being then operated to move the holdown 198 to engage the insole and cause grippers to move up. After this, a cam 516 closes a switch 498 to cause sleeve valve of valve unit 454 to admit fluid to cylinder 268 to move piston upward and cause upwipe by the toe former 292. An arm 282 acts through springs 324 and levers 322 to move bars 318 against the toe former to press it inwardly against upper at sides of toe and urge the former lengthwise of last. Wipers 226 are then operated by piston 266 to press inwardly against the upper. Cam 514 next causes switch 496 to open to cause grippers 100 to release the upper, the grippers being moved upwards out of the way of the wipers by rods 406. The holdown 198 also is raised. The wipers 226 are moved inwards in curved paths with a component of movement lengthwise heelwards of shoe. Before the wiping movement is completed, arm 282 acts on a latch 48 to release lever 30, which is operated by spring 46 to raise sole rest 2 clear of wipers. Clamp members 330 are first moved inwards by wedge members 360 operated yieldingly by piston 266 through bell-crank lever 364 and springs 380. When the wipers have completed their movement, the drum 520 causes switches 494, 498 to open to release fluid from cylinders 82, 268, and the parts operated thereby are returned to starting positions by spring action. The shoe is thus released. The drum 520 is disconnected from its driving shaft 526 by the clutch 534 when it arrives at stopping position, switch 630 is opened, to cause sleeve valve 612 to return to intitial position to cause pressure of fluid to drop, and arms 562, 580 for controlling the clutch are returned to initial position, by a spring 576, ready to be operated by piston 664 to actuate clutch 634 again, when pressure in the manifold is re-developed in response to presentation of next shoe in machine. The machine has grippers 100 which grip the margins of upper at opposite sides of the toe and pull it heightwise. They are constructed and operated substantially as described in Specification 608,176. Wipers 226 then wipe the margin of the upper at the sides of the toe inwards over an insole on a last and the toe former 292 wipes the toe end heightwise of the upper, after it has been-tensioned by the gripper, and holds it as the margin is wiped inwards by the wipers. These are moved bodily towards each other widthwise of the last and each has a plurality of wiping fingers which operate in series lengthwise of the shoe bottom, the rearmost part beginning the wiping action. The toe former 292 has a metal upperengaging member curved to extend around the end of the last and resilient to permit it to be conformed to the last by pressure. It is mounted in a holder 298 which is resilient lengthwise of the last and which is moved, on the insertion of a shoe in the machine by the operator to cause the switch 630 to close. The toe former is controlled by members not connected to it but arranged to be yieldingly forced lengthwise of last against the toe former independently of one another. The machine may be stopped at any time by operating, by a knob 672, a master switch 670 which controls the electric circuits of the solenoids and breaks any which may be closed. Those valves which have been operated are returned to initial position independently of the cams on drum 520, those parts which have been operated being returned to initial position by their controlling springs. The drum 520 turns until it reaches its normal stopping position. The machine may also be stopped when the wipers are at their inner limit, and then caused to complete its cycle of operations, by an auxiliary stop 676 secured to a stop 548 associated with clutch 534.