Patent GB-682130-A (GB)
Title: Improvements in or relating to machines suitable for use in performing lasting or analogous operations on shoe parts
IPC: A43D21/12
Filed: 1950-12-29
Abstract: 682,130. Lasting and pulling over machines. BRITISH UNITED SHOE MACHINERY CO., Ltd. Dec. 29, 1950 [Dec. 31, 1949], No. 31539/50. Class 17 (i). A machine for performing lasting and analogous operations on shoe parts has gripper means for seizing and tensioning intermittently different portions of the stock to be tensioned, wiper means for laying the successively tensioned portions of the stock at one side of the gripper means against a shoe bottom member to secure them by adhesive, and means, operable in time relation to the gripper means, to retain the tensioned successive portions of the stock against loosening when they are released by the gripper means. In an illustrative form of machine, loosening of the tension on the stock between successive operations of a power operated gripper device having jaws 20-22 which seize and tension the stock over a shoe bottom number is avoided by clamping the stock against the shoe bottom by a member 28 operated in time relation with the gripper. A continuously acting wiper 24 rotating at high speed wipes the stock inwards and presses it against a shoe bottom member on the side of the wiper opposite the gripper and also imparts a rapid series of pressure impulses to the stock to increase its adhesion to the shoe bottom. The gripper feeds the shoe intermittently through the machine and presents the lasting margin of the stock to the wiper and also tensions the stock inwards over the edge of the shoe bottom to assist the action of the wiper. The extent and intensity of pull of the gripper may be varied, either by varying the upward movement of the grippers after they have closed on the stock, or by varying the compression of a spring associated with the gripper actuating mechanism. The shoe is held by the operator in heightwise relation to the operating element of the machine against a shoe bottom rest 26 and edge guide roll 30. The mechanism for operating the machine is enclosed in a hollow casting 32 having removable top and rear covers 34, 36 and a detachable front 38 and supported on a base 40. The gripper jaw 22 is rigidly mounted on a bracket 42 secured to the lower end of a shaft 44 and the jaw 20 extends from a shaft 48 journalled in the bracket 42. An arm 52, to the lower end of which is attached a link 54 by a ball and socket joint, is secured to the shaft 48. The shaft 44 may move vertically in its bearings against the resistance of a friction device comprising plates 82, 84 (Fig. 9 not shown) and these devices open and close and raise and lower the jaws 20, 22, which are forced together by a spring 92 (not shown) the compression of which is adjustable so that axial movement of shaft 44 in either direction is opposed. The link 54 is reciprocated rapidly during the operation of the machine to operate, by a linkage 102, 106, 108, 114, 130, 131, 137, 138, the gripper jaws from the main driving shaft 142 of the machine, the arrangement being such that, by shifting the block 130 in its guideway 132 in arm 134, the extent cf upward movement of the gripper through a spring 122 after the jaws have been closed may be varied, but the jaws are returned always to the same lowermost position. The block 130 is moved in its guideway by a link 146 one end of which is connected to the block 131 and the other to an arm 148 secured to a shaft 150 to which also is secured an arm 154 which is connected by link 156 to arm 158 carried by a shaft 160, a cam 164 on one end of which is held by a spring against a multi-purpose cam 168 operated by a treadle-operated rod 176 of limited upward movement. A heavy spring 184 is mounted on the rod 176 against an adjustable collar 186. On depression of the treadle against action of spring 182, to bring collar 186 into engagement with spring 184, cam 168 is turned and simultaneously the drive on main shaft 142 is started. The clamping member 28 and edge guide 30 are moved to operating positions. At this point on the cam 168 the block 130 is moved to a point where the minimum upward movement is given to the gripper by its operating link 54 and hence to the jaws 20, 22 after these have closed. Further depression of rod 176 will cause block 130 to move further and heightwise movement of the jaws 20, 22 may then be in.. creased up to a point where downward movement of rod 176 is stopped. Upward movement of the jaws is then effected against the compression of spring 184 so that the operator may sense by feel the variation in movement of the gripper jaws and control the action of the gripper in accordance with the conditions at different points around the shoe. The grippers 20, 22 are mounted in offset relation to the shaft 44 so that they are moved lengthwise and laterally of the shoe to feed the shoe and also draw the lasting margin of the stock over the edge of shoe bottom member, and, as shaft 44 is 'oscillated through a small angle in time relation to the opening and closing and heightwise movement of the jaws 20, 22, by stud 230, link 234, bell-crank lever 236 having slot 237 in which is adjustably secured a stud 244 on link 238 on eccentric 240 on main shaft 142, the jaws while closed move in an arcuate path towards the wiper 24 and are then returned along same path after stock has been released. The clamping member 28 is secured to lower end of arm 250 pivoted on stud 254 on casting 32. A link 256 on arm 250 is operated by an arm 258 on a shaft 260 journalled in the casting and to which other arms 264, 266 are also secured. An eccentric 274 (Fig. 9 not shown), on the main driving shaft 142 carries a link 272 pinned to rod 270 which passes through a block 268 on arm 266. A spring 276 the compression of which is adjustable, surrounds the rod 270. By these means the member 28 is swung to and from the shoe bottom to clamp the lasting margin of the stock against it just before the gripper jaws are opened to release the stock. A latch member 280 is releasably held in engagement with the arm 264 by a spring 282 to prevent oscillation of the shaft 260 so that the action of the eccentric 274 may be absorbed by spring 276. A rubber edge guide roll 30 is adjustably mounted on a bar 320 slidable in a guideway 322 in a bracket 324 adjustable in three directions at right angles and connected to a shaft 284 so that when that shaft is rotated by depression of treadle rod 276 the guide roll is projected downwards and forwards from a retracted position to operative position. The rotary wiper 24 is made of three discs 25, 27, 29 (Figs. 15, 16, not shown) assembled together to give hollows and lands offset from each other on the periphery. The wiper is adjustable in two horizontal directions at right angles. The shoe bottom rest 26 is screwed to a holder 400 on a shaft 404 journalled in bearing block 406 adjustably secured to a web 410 on the head 38 of casting 32. A coil spring 422 tends to swing the holder 400 and rest 26 towards the wiper 24 against an adjustable stop screw to move the side edge 436 of a flange 432 on the operative end of the rest relatively to the plane of the side of the wiper 24. The holder 400 is bored to receive an electrical heating unit for heating the bottom rest 26. The drive is such that on initial depression of the treadle rod 176, cam 168 is turned to move clutch member 450 into engagement with pulley 370 to drive the main shaft. Further depression of the treadle rod to increase the vertical movement of the gripper jaws does not affect the setting of the clutch member 450 so that clamping member 28 is released, guide roll 30 is moved to operative position and gripper jaws 20, 22 and member 28 are set in operation. Release of the treadle rod permits the main shaft to run under its momentum until latch 280 causes shaft to stop and hold the member 28 away from shoe bottom rest. The jaws 20, 22 come to rest in their lowermost open position to facilitate entry of lasting margin of stock at beginning of another lasting operation by elevation of block 130 by spring 166. A lubricating pump 606 in well 604 in head casting 32 causes oil to be sprayed over the operating mechanisms and friction plates 82, 84, Fig. 6 (not shown).