Patent GB-795097-A (GB)
Title: Improvements in or relating to machines suitable for use in rounding shoe soles
IPC: A43D87/00
Filed: 1956-09-18
Abstract: 795,097. Sole rounding machines. BRITISH UNITED SHOE MACHINERY CO., Ltd. Sept. 18, 1956 [Sept. 26, 1955; Jan. 17, 1956], No. 28438/56. Class 17(1) A sole rounding machine having a cutter carrying head 10 and a jack for supporting a lasted shoe which are relatively movable so that the cutter progresses around the periphery of the shoe has the following additional features: (1) means to bias the head towards the shoe with increasing and diminishing pressures during the progress of the cutter; (2) a forepart gauge and crease guide mounted on the head for movement between operative and inoperative positions, with means which move the gauge and guide in mutually opposite directions to bring either into operative position, and co-operate with the head and jack moving means to interchange the gauge and guide at predetermined stages of the operation; (3) means to move the cutter into engagement with the shoe and into inoperative position, and a member movable into operative relation with the jack and acting to remove from the last clamping pressure exerted by the jack, the movement of the member to and from operative position being in response to like movements of the cutter; (4) means to cause the relative movement of the gauge and guide to take place at a variable velocity, giving a period of deceleration as the operation passes the junction of the shank and forepart. The machine has twin units to operate on right and left hand shoes, the former being illustrated. The shoe on the jack is clamped by the adjustable abutment 18, jack pin 20, and forepart rest 22 as a result of spring 298 (not shown) acting on the jack pin. When lever 30 is actuated the cutter head 10 is released, and engaged with the shoe by fluid operated mechanism 32, being subjected to a variable fluid pressure which balances the varying pressure it exerts as its inertia varies. The head, as it advances, is swung by the operator by means of handle 34 so as to engage guide 36 in the welt crease, with the guide 36 and anvil 16 bearing against the welt. Operation of lever 38 engages the bottom rest 40 with the shoe bottom with yielding pressure. A cycle is initiated by depression of treadle 42, causing the jack carrier 44 to oscillate about the vertical axis 46, and the jack to rotate upon the carrier about axis 48. In four oscillations the operation takes place along the outside, the toe, the inside, and the heel, the adjustable reciprocating knife 14 co-operating with the anvil under control of the crease guide at the shank portions and of the forepart gauge at the remainder. At the end of the operation the jack is stopped at its original position, and the cutter head retracted by mechanism 32, releasing means 26 being actuated so that plunger 24 operates member 28 to unclamp the shoe. The jack carrier is oscillated clockwise and counterclockwise by a cam 98, on shaft 116, which acts through roll 96 and a linkage 78, 76 to turn a sleeve 68 to which the carrier is secured, the fulcrum of lever 78 being adjustable by handwheel 88 to vary the magnitude of the oscillations. Shaft 116 also carries cams 118, 120, and 155, and a gear 114, and is driven by motor 130 via a one-revolution clutch which is engaged by depression of treadle 42, and normally disengaged and latched under control of cam 155, but may be disengaged during a cycle by depression of treadle 180. Gear 114, through gears 200, 202, rotates shaft 204 to which arm 206 is connected with arms 208, 214 rotatable thereon. Arm 208 has engagement with a fixed cam 212, and arm 214 is connected to a free gear 218 coaxial with gear 202. Thus rotations of gear 218 is increased or decreased relatively to gear 202 under control of cam 212. Gear 218 acts through gear 220; shaft 198 on which the latter is angularly adjustable, and gears 196, 194, 58 to rotate the jack about axis 48 and so increase or decrease the speed of the jack relatively to the carrier. Rotation of the jack on the carrier is mostly counterclockwise, decelerations occuring as the operation passes the toe, heel, and outer ball line, and an extreme deceleration is obtained. as the operation passes from the inner ball line to the shank, by means of slope on cam 212 which causes the jack to rotate clockwise for a short period. The jack is pitched to maintain the bottom of the sole horizontal at the point of operation by movement of a rack 66 which drives a gear 62 meshing with a gear segment 60 on the base of the jack, arcuate runners 52 on the jack being supported on rolls 54. Movement of the jack is controlled by a selected one of two cams 256, 258. The cutter head 10, which is counterbalanced by an adjustable spring 356 so that it normally lies above the shoe, swings horizontally on a carriage 326 which is advanced and retracted along a vertically adjustable slide 328 by movement of a piston 354 in a cylinder 352. The head is normally locked in its inoperative position by a latch 506 (Fig. 1). Movement of the adjustable crease guide 36 between operative and inoperative positions is controlled by a cam 420, and the forepart guage 41, which is slightly concave, is controlled in its movements by a cam selected from a series of cams 448 to give the required sole edge extension. Cams 420, 448 rotate at constant velocity. The fluid system includes, in addition to means 26 and 32,a pump 137, reservoir 138, valve 480 to control the cutter head operating means, valve 482 to control the jack operating means, and a variable relief valve 484 to control the fluid pressure applied to valve 480 and the cutter head operating means, shown in their normal positions in Fig. 21. When lever 30 is moved, forwardly it disengages latch 506, and piston 354 advances the cutter head, whereupon arm 524 is caused to swing clockwise (Fig. 21) so that the roll thereon moves down the cam surface 528 on arm 529 and the latter is swung clockwise. Plunger 534 moves safety finger 532 to follow arm 529 and so sets valve 482 in its "out" condition, when pipe 492 is closed, and the jack releasing means 26 exhausted through 536, 586, 583, plunger 24 then being retracted by spring 587, and spring 293 acting to clamp the shoe. Cam 118 causes finger 532 to be retracted from between plunger 534 and arm 529 at the beginning of a cycle, and to be held in this position for one cycle, and at the end of the cycle causes plunger 500 of valve 480 to be moved to its "in" position whereby the cutter head is automatically retracted, and finger 532 to be interposed between plunger 534 and arm 529, roll 526 moving up slope 528 then moving plunger 534 inwardly so that plunger 24 is moved to operate the releasing member 28. Plunger 500 is returned by spring 502. The variation of fluid pressure to equalize the pressure of the cutter on the shoe, i.e. a decrease in fluid pressure as the cutter head is pushed rearwardly by the shoe, and vice versa, is brought about by valve 484 which is controlled by cam 120 to bleed more or less fluid from pipe 492. An increase in fluid pressure is also applied to ensure the seating of the crease guide in the welt crease while the cutter traverses the inner ball line.