Patent GB-721767-A (GB)
Title: Improvements in or relating to machines for applying pressure to shoe bottoms
IPC: A43D25/10
Filed: 1952-02-26
Abstract: 721,767. Shoe-bottom presses. BRITISH UNITED SHOE MACHINERY CO., Ltd. (United Shoe Machinery Corporation). Feb. 25, 1953 [Feb. 26, 1952], No. 4950/52. Class 17 (1). A shoe bottom pressing machine comprises a turret 54 rotatable about a vertical axis, a plurality of fluid operated shoe bottom pressing units mounted on the turret, a cylinder with a piston connectible with the turret to impart stepwise rotation thereto, and means which admits a relatively high pressure to one end of the cylinder to rotate the turret and a continual lower pressure to the opposite end of the cylinder to cushion the movement of the piston under the high pressure, and to return the piston on the conclusion of a stepwise movement of the turret. One of a series of projecting studs on the turret is engaged by a means connected with the piston to move the turret, the means and stud being disengaged on the completion of a stepwise movement. A first pump applies pressure to one pressing unit, a second pump applies pressure to the other units, and means operated by the pressure to the one unit by the first pump causes the second pump to be connected to this unit. The pressure fluid is provided by two pumps, PI, P2 driven by a motor M and connected to a common relief valve R2 set for high pressures (400-800 lbs./sq. in.), P1, delivering a large volume of oil at varying pressures, applies pressure to the unit at the loading station, while P2, delivering a small constant volume at high pressure, maintains the pressure in the units. A line from P1 to the check valve 364 leads through control valves to the cylinder of the unit at the loading station, or at other setting of the control valves, when pressure on the shoe at the loading position is satisfactory to a relief valve R4 (250 lbs.) to the cylinder for indexing the turret. Beyond the common relief valve R2 is a relief valve R3 to supply low pressure (150lbs.) for cushioning &c. as described above. A shaft to which the turret 54 is secured has four vertical ducts 56 each communicating with the bottom of one of four pressure-applying cylinders 60, and, through a member 62, with a stationary valve 64 having three longitudinal bores 80, 82, 84, all closed at the top and 82 and 84 slugged at the bottom. Exhaust bore 80 connects through 66 and 86 with the sump and through 106 with the duct 56 approaching the loading station, bore 84 passes oil from 88 through 56, 90 for the loading station, and bore 82 receives a small quantity of oil at high pressure from pipe 92 which passes through 94 to a peripheral groove 96 communicating with the remaining three ducts 56. Oil seals 98, 100 and drain holes 102, 104 are provided. The shoe and sole are placed right side up on the pad of the unit at the loading station, and abutments 160, 148 one for the crown of the last and one for the forepart of the shoe are operated vertically to press on the shoe. Each abutment is connected to one of a pair of levers 120, 122 which are pivoted on shaft 124 and engaged by the rounded ends of a dumbell lever 118 pivoted on the piston of one of the shoe-pressing cylinders 60. Each dumbell 118 may have arms of different lengths. The ends of arms 120, 122 rests on arms 130, 134 slidable on rods 126 supporting shaft 124. The abutments are adjustably spaced by means of links 172, 174, connected to a lever 170 which is turned by a handwheel 164. Arms 130, 134, and the abutments are returned by springs 176. One or other of the abutments may be arranged to descend first by adjustment of springs 180, 182 acting on arms 130, 134. Rolls 196 are carried by four arms 194 on member 62 about which an arm 204 is rotatable, and when the latter is swung an inclined flange 214 on a spring-pressed member 208 engages a roll 196 depressing member 208 until the roll can enter a cup 218 in the member, whereupon spring 212 returns member 208 upwards and the arm 204 will turn the turret. Arm 204 is connected for movement with the piston rod 222 of the indexing cylinder 226 which is pivoted at 228 and supplied with low pressure through 233, 232, and high pressure through 246, 248, 250. When no pressure is applied through 232 spring 252 (not shown) moves valve 244 (not shown) to close 248 and prevent the application of high pressure. Exhaust of the high pressure is controlled by valve 260 in turn controlled by spring 267 and latch 272. The piston 290 of a low pressure cylinder 292 presses a pivoted lever 286 to engage a cam edge 288 with a roll 196, and through link 296 controls a rotary cam 300. At the beginning of a movement, with the parts as in Fig. 8, the next roll 196 engages cam 288 and moves lever 286 as in Fig. 9, when the roll reaches the drop 303 on cam 288, lever 286 returns, cam 300 engages the flange 214 to release the stud, and roll 304 on lever 286 causes the latch 272 to be tripped, exhausting the high pressure from 226, the low pressure returning the piston and arm 204. During the first half of the turret rotating stroke low pressure fluid escapes easily from 226 through 237, 234, and piston 224 moves fast, but the escape is gradually checked as the piston covers groove 237 and the only escape is through a narrow slit 318 in the piston which gets gradually less deep and fades out, so that at the end of the stroke escape ceases and the piston stops. Operation of the machine is controlled by a sequence control valve A, sequence valve B, pressurizing valve C, pressure releasing valve D, and indexing valve E. Fig. 12 is a flow chart showing the valves &c. in the idle position of the machine, and further figures are given showing the position at other stages of the operation. Valve C is depressed by treadle 384 through 388, 396, 360 to apply pressure. If required, e.g. if a shoe is misplaced, pressure may be released at the loading station by depressing treadle 408 to partially push down valve D through 414, 420, 422, and to return valve C. Valve D is fully depressed, to exhaust 366 leading to the loading station, 332 leading to the three cylinders 60 under pressure, and 406 leading to the indexing cylinder 226 by depression of knob 432 through 434, 438, 442, 444, and is held by a latch 448. Depression of treadle 408 releases latch 448 and allows spring 446 to raise valve D. When pressure application to the shoe is satisfactory the turret is indexed by pulling forward handle 467 which through 468 depresses valve E. Relief valve R2 is adjusted by handwheel 320. Specification 479,480 is referred to.