Patent GB-234919-A (GB)
Title: Improvements in methods of and apparatus for conforming uppers to lasts
IPC: A43D21/12
Filed: 1924-03-11
Abstract: 234,919. White, A. E., (Goodrich Co., B. F.). March 11, 1924. Lasting and pulling-over.-A machine specially intended for lasting rubber footwear pulls the upper about the last by engagement with the outer face only of the margin of the upper. In the machine described, pneumatic suckers hold the margin of the toe portion and two adhesive covered surfaces hold the margin of the heel portion of a flat sheet of rubber which is to form the upper, the central portion of the sheet being supported by pivoted plates. A last is then forced into the upper and the heel stretchers operated to apply the rear part of the upper to the last, surplus material at the rear being cut away and the two edges overlapped and rolled. The toe portion of the upper is held by suckers 47, 48, 49, Fig. 10, in communication with suction pipes, the side suckers being pivoted at their front ends so that they can move inwards as the last is depressed. Between the suckers and the last is a U-shaped bar carrying a helical spring 58 and an outer rubber tube 59 to act as a roller support for the upper while this is being pulled over the last. The rear parts of the flat sheet are engaged by adhesive surfaces on heel stretchers 73, Fig. 3, which are horizontal at the commencement of operations, and are turned through 90‹ to the position shown to apply the rear parts of the upper to the last. These stretchers are each pivoted to a block 75, Fig. 3, rotatably mounted at the end of an arm 79 rotatably and slidably mounted on a transverse shaft 80, Fig. 9. The arms 79 are swung about and moved along the shaft 80 by cams on a main shaft 38, and the stretchers are turned from vertical to horizontal position by cam-operated plungers 82, Fig. 3, which engage stem plates on the stretchers and lock them in upper receiving position. When in the operation of laying over the heel ends of the upper, springs 86 are allowed to withdraw the plungers, the stretchers are turned to vertical position by springs on their pivots. At the commencement of operations the central part of the upper is supported on plates 62, 63, Fig. 11, which, as the last descends, are turned downwards about their pivots by mechanism operated from the cam shaft. The last is held by suckers 19, Fig. 6, on an arm 18, Fig. 9, raised and lowered by a link 40 connected to a crank on a pinion 41 driven as required by interrupted gears 43 on the cam shaft. To retain the pinion in either of its two positions a pawl 130 engages pins 128, 129 on the pinion, the pawl being freed just before the interrupted gear meshes with the pinion. When one side of the heel part of the upper has been pressed against the last, as shown in Fig. 11, an electricallyheated knife 89 is raised, approached to contact with the upper, as shown, and allowed to fall by its own weight to cut away surplus material. The other side of the heel part of the upper is then wiped to the last, trimmed, and its edge laid over the first edge by appropriate action of the heel stretcher. A seam roller 102 is then operated as was the knife, to press down the joined edges. The knife and roller are operated resiliently, so that they can follow the contour of the heel portion of the last. The suckers 19, Fig. 6, and the chamber 28 are connected to suction pipes having interconnected valves controlled by a single handle. When the last has been depressed to its lowermost position, with the crown of the last resting on a support 16, suction is applied to a chamber 28, Fig. 6, of the last holder. This chamber has perforated side walls which suck the edges of the upper inwards to hug the last. The cam shaft 38 is driven by a pinion which is clutched to a constantly-rotating shaft 109, Fig. 9, when a pedal 111<a> is depressed or a handle 112 is lifted. Normally, the clutch is kept in engagement by a latch which is tripped at the end of the machine's cycle, but the latch may be tripped at any time by either of two pedals 118, 120 at the front and rear, respectively, of the machine.