Patent GB-757563-A (GB)
Title: Improvements in or relating to machines for operating on parts of, or for, shoes
IPC: A43D87/00
Filed: 1954-05-21
Abstract: 757,563. Fluid-pressure presses. BRITISH UNITED SHOE MACHINERY CO., Ltd., (United Shoe Machinery Corporation). May 20, 1955 [May 21, 1954, No. 14929/54. Class 122(3) [Also in Group VIII] A machine for operating upon parts of, or for, shoes (see Group VIII), comprises fluid-pressure operated means for causing a clamp and a work support to clamp a workpiece between them, an operatoractuatable member for causing the clamp and work support to apply a light clamping pressure on the workpiece, and a starting member operable by the operator to cause, firstly increase of the pressure exerted on the workpiece. and secondly the starting of the operation of a tool on the workpiece, the construction and arrangement being such that operation of the starting member by the operator is prevented until the operator-actuatable member has first been operated. In the machine shown, a sole is clamped on a pattern 3 by clamp 110 and trimmed by a cam-influenced knife 7 which is carried around the periphery of the pattern by the rotation of a table 8. The table 8 is driven by mechanism which is operated by depressing a spring influenced handle 75 pivotally mounted on a stub shaft 76. When the driving mechanism is to be operated, the handle 75 is depressed until an arm 102 passes under and into engagement with the lower side of a latch arm 103 which is held against a stop 104 by a spring 105 interposed between the stop and an arm 106. The arm 106 lies in the path of a cam 107 adjustably secured to the table 8. The clamp 110 is secured to a fluid pressure head 112 comprising a small cylinder 130 and a large cylinder 120 in which pistons 132, 146 are slidable respectively. When a treadle 114 is depressed, compressed air is supplied through a valve 116 to the upper end of the cylinder 130 causing the piston 132 to be lowered against spring action and the clamp 110 to be brought under a relatively light pressure into engagement with the sole on the pattern 3. The handle 75 is prevented from being operated until the treadle 114 has been operated owing to the provision of a stop 160 which normally overlies a screw 161 threaded into a projection 162 integral with the lever 97. This stop extends from a spring-pressed plunger 163, Fig. 5, slidable within a casing 164 to which compressed air is supplied. After the treadle 114 has been lowered. the stop 160 is retracted out of the path of the screw 161. The first part of the downward movement of the handle 75 operates to set up the final clamping pressure before the knife-carrying mechanism is engaged. To this end, a cam lever 168 fixed to the shaft 98 operates a spring-pressed plunger 170 slidable within a valve 118 to supply compressed air to the upper end of the large cylinder 120. This causes a relatively heavy pressure to be applied to the workpiece. Further downward movement of the handle 75 causes the knife-carrying mechanism to be operated, the handle 75 being retained in its operative position by the latch arm 103. Near the completion of a cycle of the machine when the table 8 has almost completed a revolution, the cam 107 engages the arm 106 causing the latch arm 103 to be moved off the arm 102 of the handle 75 which immediately returns to its original position by the action of a spring 79 (not shown). Such movement of the handle 75 causes the cam lever 168 to release the plunger 170 so as to cut off the supply of compressed air to the upper part of the large cylinder 120 and allow air from such upper part to be exhausted. The knife 7 has by now come to rest again. The treadle 114 is then released to cause compressed air from the upper part of the small cylinder 130 to be exhausted and compressed air to be supplied to the lower part of the large cylinder 120. The clamp 110 now moves upwardly and the plunger 163 moves outwardly of the casing 164 to bring the stop 160 directly over the screw 161.