Patent GB-623347-A (GB)
Title: Improvements in or relating to machines for performing lasting or analogous operations upon shoe parts
IPC: A43D21/12
Filed: 1947-05-03
Abstract: 623,347. Lasting-machines. BRITISH UNITED SHOE MACHINERY CO., Ltd. (United Shoe Machinery Corporation). May 3, 1947, No. 11955. Addition to 598,216. [Class 17 (i)] The gripper mechanism of the parent Specification is improved to give a substantially uniform pull to the lasting margin of stock being lasted but which may be varied at will in accordance with the condition of the work. The gripper mechanism comprises rear and front toothed jaws 10, 12, respectively, the former being reciprocated towards the latter through adjustable spring-means 80 which extend between a rod 52 connected to the jaw 10 and an adjustable member 82 on a carrier 62 which is reciprocated by power means through a constant distance. The jaw 12 is clamped and unclamped in time relation to the reciprocating jaw 10 to successively grip, tension and release the stock. The jaw 10 is carried by an arm 50 pivoted to the forward end of the rod 52 which is urged by the springs 80 to the left, and is slidable in guides 54, 56 in upstanding portions 58, 60 on the carrier 62. The rod 52 is clamped to a block 64 at its right-hand end, and a block 69 of cushioning material is interposed between the block 64 and the portion 60 of the carrier 62. This latter is supported on rocker arrrs 110, 112 and is reciprocated by an eccentric 114 as in the parent Specification. A coil spring 144, stretched between an arm 38, by means of which the shoe bottom rest 14 may be moved to inoperative and operative positions, and a rearwardly extending part 140 of a lever 136 pivoted on a lug 130 on the arm 38, tends to hold this lever in the position shown with an abutment face 142 thereon pressed against a block 146 of cushioning material held in a recess in a shoulder 132 on the arm 38. An upstanding part 148 of the front gripper jaw 12 is clamped, in a manner which permits its vertical adjustment, to an arm 138, and a locking rod 164, which is pivoted to the arm 138, extends through guide holes in the portions 58, 60 and between locking blocks 172, 174 supported on an eccentric 184 formed integrally with a lever 186. This latter is rotatably mounted on a pin 191 and has a cam surface 192 which at times is engaged by a roll 194 towards which the lever 186 is swung by a spring. The roll 194 is mounted on a bell-crank lever 204 which is oscillated from the eccentric 114 by linkage 206, 208, 210. The end of the rod 164 extends through a notch 212 in a projection 214 on the lever 186 and is screwed at its end to receive a nut 216 by which its operative length may be adjusted. A grooved' roll 222 is supported by the lever 136 in line with the rear gripper jaw 10 and, when this jaw is advanced towards the jaw 12, on reciprocation of the carrier 62, a rib 224 on the jaw 10 co-operates with the roll 222 to effect relative closing of the jaws. A leaf spring 228 lifts the arm 50, to an extent limited by stops, when the jaw 10 is withdrawn from the jaw 12. In operation, after the jaw 10 has been moved longitudinally towards the jaw 12 by the springs 80 it is moved transversely to this direction by engagement of rib 224 with roll 222 to cause the jaws yieldingly to close on and grip the stock, continuing movement of the jaw 10 moving the jaw 12 with it against the spring 144 to tension the stock, the tensioned stock being positively released from the gripper device by moving the jaw 12 positively away from the jaw 10 by the clamped rod 164. During the transverse movement of the jaw 10, the spring 144 is restrained from acting on the jaw 12, being held by the clamping pressure of the eccentric 184 on the blocks 172, 174, which intermittently causes the rod 164 to be clamped and released in time relation to the reciprocation of carrier 62 and actuation of the jaw 10.