Patent GB-806067-A (GB)
Title: Improvements in or relating to machines suitable for use in the manufacture of shoes
IPC: A43D87/00
Filed: 1956-01-06
Abstract: 806,067. Boot making machines. BRITISH UNITED SHOE MACHINERY CO. Ltd, and MURPHY, B. J. M. Jan. 4, 1957 [Jan. 6, 1956], No. 506/56. Class 17(1) A machine for operating around a shoe bottom member lying against the bottom of a last has a rotary tool 8, and a. last supporting jack 10 movable, by the operators relatively to the tool to cause the latter to act around the bottom member, the jack including a pair of clamping members 12, 14 which are actuated by fluid operated means. to clamp the last and shoe bottom, when' an operator actuable member 50 is operated. The fluid operated means includes a piston and cylinder device such that pressure is first built up by a low pressure piston 88 to close the clamping members and then a high pressure piston 126 is caused to move with the low pressure piston to exert an increased clamping pressure. The piston and cylinder device is mounted so that it may yield bodily when pressure in the device, corresponding to the pressure exerted on the last and shoe bottom member, reaches a given value. A machine for bevelling and trimming the heel end of an insole is described. Piston housing 20 is pivoted on horizontal pins in the limbs 26 of lever 28 which is held downwardly by springs 44, and is adjustable about its pivot 30 by means of screws 48 to adjust the position of the housing relative to piston 88. Treadle 50, pivoted at 52 and urged upwardly by spring 78 to engage an adjustable screw 82, is locked, when depressed, by engagement of notched plate 66 with catch plate 56, .and is released by depression of the second treadle plate 74. When the treadle is depressed, raising piston 88, fluid flows, from reservoir 144 via port 150, recess 154, channel 152, port 156, and non-return valve 158 to the space above the piston, and as the latter rises the fluid is forced through: bores in plunger 118 and piston 126 to pipe 16 connected to-the clamp operating cylinder- 180. On continued movement of the treadle, valve 110 carried by piston 88 engages, seals, and raises plunger 118, so that against spring -138, piston 126 rises with piston 88 and causes an increase in the clamping pressure. Lever 28 remains in lowermost position until the pressure in the piston and cylinder device reaches a given value and overcomes springs 44, when the lever rises about pivot 30, thecylinder and pistons then rising so that the clamping pressure is constant. Ultimately, the treadle is latched. In the event of fluid leakage, springs 44 pull the housing downwardly relatively to the pistons, and so maintain the pressure when operating with a large last, so that clamp 14 engages the last well before piston 88 engages plunger 118 and the pressure above piston 88 increases, spring 98, which is adjustable by means of screw 94, is overcome, and valve 110 on plug 102 descends, and fluid escapes via 104, and 162 to channel 152. Raising of treadle 50 releases the pressure. Jack 10 is pivoted to pivoted arms so that it is movable slightly to the left and right, may be swung bodily forwardly and rearwardly, and may be moved vertically, and is partially supported by spring balance means 172, 176. A non-rotatable spindle 20 slidable in cylinder 180, which is supported by jack 10, carries a piston 206 and a return spring 210, and rotatable as a unit thereon is a sleeve 212, last centralizing spring 196, clamp plate 220, and resilient last engaging pad 222. The stationary clamp 12 has a freely rotatable resilient pad 238 and clamp plate 236. Shield 242 and the rotary toothed cutter 240, for trimming, are mounted on shaft 6, and interspersed at intervals with the teeth are tip-hardened cutting elements 244, for bevelling and for dispersing the fragments, mounted individually on a carrier 246 rotatable with shaft 6. When the insole is thick it forces elements 244 rightwards (Fig. 5) against spring 248. The clover-leaf shaped last guide 254 which also acts as cutter guard is adjustable along an inclined axis transversely of the machine, and is adjustable to and from the cutter. The guide is secured by a spring pin in the desired one of three positions such that the desired segment is associated with the cutter to suit the size of the cutter which diminishes with wear.,