Patent GB-363623-A (GB)
Title: Improvements in or relating to boot or shoe sole pressing machines or to pads suitable for such machines
IPC: A43D25/06
Filed: 1930-08-19
Abstract: 363,623. Boot - making machines. UNITED SHOE MACHINERY CORPORATION, 140, Federal Street, Boston, U.S.A. -(Assignees of Ballard, M. H. ; Beverly. Massachusetts, U.S.A.) Aug. 19, 1930, No. 24747. Convention date, Aug. 27, 1929. [Class 17 (i).] Sole-laying.-Relates to sole-pressing machines of the kind described in Specification 339,739, [Class 17 (i), Boots and shoes, Apparatus for making &c.], and consists in automatic mechanism for holding a movable pressure-applying member of a fluid-containing pad having walls of distortable material in pressure applying position, improved means for distorting the pad, means for varying the preliminary pressure applied to the toe and heel ends, respectively, of the last, improved means for moving the sole gauge members to and from their operative positions, and means for maintaining a uniform pressure per unit area, for soles of differing sizes. The pad, Fig. 8, comprises a waterfilled rubber vessel 34 in a casing 42. The top wall of the vessel has a reinforcing layer 40 of duck, and a metal plate 148 vulcanized into the wall at its heel end. A masking plate 146 is provided at the toe end, and is adjustable for size of shoe. The bottom of the casing comprises a pivoted door 44 carrying a roll 48 co-operating with a cam surface 50 formed as a curved wedge rotatable about a central pivot. The ends of the casing have lugs 76, 82 which engage under abutments on the table 20, Fig. 9, of the machine as the box is positioned. The operative position of the box is determined by stops at the rear and a lever 94, Fig. 2 (not shown), provided at one end with an adjustable stop engaged by the rear of the box and at its other end with a roll which presses the box up to its abutment 80 as the box is pushed rearwardly into position. The box carries yokes 104, 106 each having a plunger formed with rack teeth and urged upwardly by a spring, pawls 122 holding the plungers in the positions to which they have been depressed. The yoke 104 is slidable lengthwise of the box, and its plunger carries the toe pad 114. The yoke 106 is pivoted, and can be swung between limits determined by stops 128, 130. A pair of levers 164, 166 co-operate with the plungers, these being pivoted at 162, Fig. 3, to a fixed bracket, the pivot also carrying an arm 184 connected by a link 186 with a treadle 188. The arms 164, 166 are loosely connected by a bar 180, Fig. 9, and the lever 184 carries a block 192 adjustable along the bar 180 to vary the proportion of pressure exerted on the two arms, a hand-wheel 200 turning a shaft having thereon a coarse thread engaging the block. To ensure uniform pressure per unit area of sole the link 186 is connected to the treadle 188 by a roll 206, Fig. 4, on the link engaging a cam slot formed in the treadle, the lower end of the link being guided by a link 209. The slot is so formed that during the descent of the treadle to cause the arms to engage with the plungers the leverage is small, the leverage increases for further movement and then decreases. The total pressure applied to a small shoe is, thus, less than that applied to a large shoe. The pressure applied by the treadle is about 20 lbs. per square inch. A final pressure of about 60 lbs. is applied by a plunger 86 engaging the door 44. The lower end of this plunger is actuated by a lever 210 connected by a link 214 with an intermediate portion of an arm 216 of a bell-crank lever, the other arm of which carries a shoe 258 engaging an eccentric 256 on the main shaft 248 of the machine. The arm 216 supports a rod 228 encircled by a spring 234 supporting a heavy weight 236. When the shoe has been positioned and the preliminary pressure applied by the treadle 188, a clutch-operating handle 238 is depressed to cause the main shaft to perform one revolution. As the eccentric 256 rotates, the weight 236 is allowed to act on the plunger 86 to deform the pad and exert the full pressure on the shoe bottom. The eccentric also engages an arm on a rock shaft 262 carrying an arm 276 linked to a lever 280, Fig. 3, to which is pivoted a finger 286, which engages a pin 292, Fig. 9, to turn the cam 50 and hold the door 44 in pressure-applying position when the plunger 86 descends. The door 44 is grooved to allow the rubber underwall of the pad to distort and allow sufficient rise of the door to enable the cam to make a considerable movement. Yield in the operative movement of the finger 286 is allowed by a spring plunger 270, Fig. 4, between the arm 276 and the rock shaft. The gauging mechanism for the ends of the shoe is advanced to operative position and retracted to inoperative position by cables 328, 346, Fig. 3, respectively, a pair of cables being provided at each side of the machine for the separate gauge mechanisms. The cable 328 is secured to a weighted arm 340 pivoted on the shaft 248 and the cable 346 to an arm 362 secured to a transverse rock shaft 190. To retain the gauges in normal out-ofthe-way position, the arm 362 carries a latch 368, Fig. 5, on a pivot 370, Fig. 3, which latch normally engages a fixed stop 372. The pivot 370 carries a main treadle 376 and a supplementary treadle 386, the former being restrained by a link 380 having lost-motion engagement with a fixed pin 384. The supplementary treadle is connected by a spring 390 with the latch. By depressing both treadles and then allowing his foot to rise, the operator releases the latch and allows the weight to advance the gauges to operative position. As the machine starts, a link 402 having lost-motion connection with an arm 404 on the rock shaft 262 returns the arm 362, and therefore the gauge mechanisms, to normal position, the slot in the link 380 allowing yield of the treadle 376 in case the operator's foot is under it. The heel end positioning mechanism is of the kind described in Specification 366,122.