Patent GB-337764-A (GB)
Title: Improvements in or relating to shoe-bottom pressing means
IPC: A43D25/07
Filed: 1929-07-03
Abstract: 337,764. British United Shoe Machinery Co., Ltd., (United Shoe Machinery Corporation). July 3, 1929. Sole-laying.-Relates to machines of the kind described in Specification 185,499, wherein a shoe-bottom pressing pad is dilatable, and consists in means for restricting the dilation of the pad in accordance with the size and shape of the shoe, and means for swinging a jack from outof-the-way position to operative position above a positioned shoe, moving the shoe up to the jack and, thereafter, dilating the pad. A rubber diaphragm 15, Fig, 4, forms the upper side of a pressure chamber communicating with a cylinder 9 in which is a piston 13. The diaphragm rests on a plate 21 supported by springs 31 engaging the outer ends of pairs of levers 25 geared together at their inner, adjacent, ends. Normally, this plate is depressed by an arm 42 having at its end a roll engaging a cam on a slide bar 45, Fig. 3, connected by links and levers to a cam on the main shaft of the machine. To restrict. the dilation of the pad, four sliding plates are provided, a rear plate 47, adjustable for size of shoe by a thumb screw 55, a front plate 49 and two side plates 51, 53, the last three of which are advanced after the shoe is positioned. For this purpose, the side plates are provided with racks 90, 113 gearing with pinions operated by racks on slide bars parallel with the bar 45 and similarly operated by the main cam shaft. The four sliding plates are faced with rubber at their shoe-engaging edges. The jack comprises a lastabutment 139, Fig. 1, pivotally carried by a shaft 133 engaging a socket in a casting housing a pair of sleeves internally screw-threaded to engage screws 137, 139. The sleeves are connected by chain and sprocket gearing, and rotated by a hand-crank and bevel gearing to adjust the vertical position of the abutment 129 for different lasts. The shafts 137, 139 are connected by a heavy curved brace 165, the whole structure pivoting about the screw 137, the brace having an arm 171, Fig. 3, slotted to engage a block on a slide bar operated by the cam shaft. In operative position, the lower end of the screw 139 engages under a fixed plate 125, Fig. 1, to prevent it rising under the thrust of the sole pressing operation. A pressure relief valve 205 is provided, normally closed by a spring 207. To adjust the spring, a nut 212 is formed with helical teeth engaging a pinion which can be rotated by a hand-crank, a pressure gauge 220 being provided to indicate the result of adjustment. Water passing the valve on the upstroke of the piston 13 is stored in a chamber 203. To allow this water to return to the cylinder 9 as the piston descends, the valve is maintained open during the first part of the down stroke by mechanism driven by the cam shaft, a thumb screw 235 determining the point at which the valve closes. The cam shaft is driven by a spurwheel. 234 gearing with a pinion on the shaft of a wormwheel 239 driven by a. worm 241 on the shaft of an electric motor, any suitable onerevolution clutch mechanism operated by a treadle being interposed between the motor and the cam shaft. In operation, a lasted shoe 100 with an unvulcanized rubber sole 200 is positioned on the diaphragm. 15. The treadle is then depressed, with the result that the front plate 49 moves into contact with the front of the shoe and the jack is swung so that its abutment member 129 is located above the top of the last. The plate 21 is pushed upwardly to clamp the shoe. and the side plates 51, 53 closed about the shoe. The piston 13 then forces water into the pressure box to wrap the diaphragm about the lower portion of the shoe and press the sole against the bottom of the shoe. All parts then return to starting position and come to rest, when the work piece may be changed.