Patent GB-416581-A (GB)
Title: Improvements in or relating to pattern reproducing for shoe-making
IPC: A43D8/10
Filed: 1933-03-13
Abstract: 416,581. Pattern-grading machines. BRITISH UNITED SHOE MACHINERY CO., Ltd., KESTELL, T. A., and BURTON, S., Union Works, Belgrave Road, Leicester. March 13, 1933, No. 7508. [Class 97 (iii).] In a pantographic pattern-grading machine for producing from a model shoe upper pattern a set of larger or smaller upper patterns having a modified pantographic enlargement or adapted to fit a series of lasts of different sizes but having the same toe spring and heel height, movement in one direction of the model, which is tracked round a model guide, is adapted to cause automatically relative movement between the work carrier and tool in a transverse direction to effect a widthwise restriction in the pantographic reproduction. The invention is shown applied to the pattern grading machine described in Specifications 335,200, [Class 97 (iii)], and 364,550, new and immediately associated parts being shown in full lines and other portions of the machine in chain lines. The work holder and model holder 200 are supported on a carriage 204 slidably mounted upon carriage 206 so that the model may be tracked round a guide pin 202, the desired pattern being cut in the work by a punch fixed in the machine. The guide pin is shifted in a horizontal plane to give the required grading by a length pantograph lever 208 and a width pantograph lever 210. In order to effect widthwise restriction on the pattern to be produced the model is mounted on the model holder with its length running forwardly and rearwardly of the machine and a width pantograph trunnion 290 is caused to move in a transverse direction with fore and apt movement of the model holder by a link 286 connected to one arm 234 of a bellcrank lever the other arm 236 of which is rocked by a rod 224 connected to a plate 214 extending from the arcuate member 212 (corresponding to the arcuate member 29 of Specification 364,550). The trunnion 290 is supported on a trolley 288 which slides on a fixed guide 292 and has a bracket 294 enabling it to be clamped to a rod 298. The latter carries a scale 300 to one of the supporting arms 302 of which the link 286 is pivoted. The other end of the link 286 is pivoted at 282 to a block 280 slidable in a guide 278. Bowden wires 322 connected at one end to the block 280 and at the other to the periphery of a drum 314 enable the block 280 to be adjusted so that the distance of the pivot 282 from the pivot 232 of the bellcrank lever 234, 236 corresponds to the amount of widthwise restriction desired and the length over which the gradual increase in restriction is to be spread, a set of concentric scales being provided on the drum to facilitate this adjustment. Adjustable stops 330 are provided on the support for the drum 314 so that the operating handle 326 of the drum may be swung easily from the position in which the block 280 is in the desired position to that in which it lies vertically over the pivot 232, the movement imparted to the trunnion 290 then being nil. Mechanism enabling the rod 224 to be connected to the arm 236 only at the desired point in the movement of the model holder comprises a small bell-crank lever 244 pivoted at 242 on the arm 236 and having at the end of one of its arms 248 a roller 254 running in a cam groove 252 in a platform 250 supported by the arm 228 which extends from the carriage 206 and carries the pivot 232. The main central part of the groove 252 is formed as the arc of a circle with centre at the pivot 232 but the two end portions 256 and 258 diverge sharply from this arc and are formed as small arcs having a radius equal to the distance from the pivot 242 to the roller 254. When the model holder.is at the front of the machine the bell-crank 244 is positioned so that the roller 254 is at the extreme end of the groove 256 and is held there by the engagement of the rod 224 with a surface 260 on the lever. As the model holder moves to the rear of the machine the rod 224 slides past the bell-crank 244 until a step 262 on the rod engages a stop surface 264 and causes the bell-crank to rock bringing roller 254 into the part 252 of the groove and a stud 268 on the bell-crank into engagement with a recess 266 in the rod 224. Further movement of the rod 224 thereupon rocks the larger bell-crank 236, 234 until the diverging part of the groove 258 causes the smaller bell-crank 244 to rock further and release the engagement of the rod 224 with the arm 236. The pivotal attachment of the rod 224 to the plate 214 may be adjusted along the slot 216 by clamp 226 to enable the mechanism to be set so that the rod 224 begins to rock the arm 236 and apply the restriction at the desired part of the pattern. In Fig. 9 abc<1>de denotes a pattern produced by pantographic enlargement and abcde a pattern in which a widthwise restriction has been effected along the straight portion bc<1>. By applying a similar restriction to the lower edge of the heel portion, a pattern suitable for a last having the same toe spring &c. as the last for which the model pattern is designed may be produced. Specifications 143,622, [Class 83 (iii)], 350,940, and 355,798 also are referred to.