Patent GB-605308-A (GB)
Title: Improvements in or relating to shoe-upper conforming machines
IPC: A43D21/12
Filed: 1945-12-20
Abstract: 605,308. Lasting-machines. BRITISH UNITED SHOE MACHINERY CO., Ltd. (United Shoe Machinery Corporation.). Dec. 20, 1945, No. 34486. [Class 17(i)] In a machine for conforming the upper of a shoe of the welted, McKay or Veldschoen type, especially at the toe end, to a last wherein grippers pull the upper against the last prior to wipers moving it heightwise of the last, and also exercise a second pull on the upper at a later stage in the operation of the machine prior to the advancing movement of the wipers, the second pull is arranged to apply less tension than the first. The invention is described as applied to a fluid-pressure operated machine functioning generally to last and trim the inner layers of an upper in the manner described in Specification 574,977, and is provided with an automatic pressure-controlling valve which predetermines the force with which the grippers hold the upper the second time by supplying fluid at a reduced pressure to the operating cylinders. The shoe is clamped at the beginning of the operation, against a shoe rest 2, Figs. 2, 6, which has a spur 4 to enter an indentation formed in a predetermined position in the insole, by a rising toe rest 6 and an instep support 8, by fluid-operated means. The heel is similarly held by a rest. The toe-end gripper 10 and two side grippers 12 are caused to close on a margin of the upper prior to starting the cycle of operations of the machine and may be re-opened if it should be necessary to rearrange the grip. These grippers pull the toe end of the upper mainly in an outward direction by lengthwise and widthwise movement respectively. While the upper is held under tension a wiper support which carries a U-shaped toe former 16 is moved upwards to wipe the toe of the upper heightwise of the last. Toe-embracing wipers 18 carried by the wiper support wipe the margin of the outer layer of the upper after the inner layers have been trimmed away by a pair of side knives 22 and an end trimming knife 20 supported on a movable carrier 24. The side knives 22 carry vertical slitting knives 28 which detach from the upper and strip off waste material cut by the knives 20, 22. After trimming the upper, the toe former 16 is withdrawn lengthwise of the shoe by movement of the wiper support and downwardly to starting point, and the operations of gripping and pulling the upper and wiping it heightwise are repeated with the grippers holding the outer layer of the upper. The carrier 24 is raised and swung to one side to carry cement-applying means supported therein into position over the toe end of the shoe, when it is moved down to apply cement to the insole. After the uppers have been conformed to the last the second time, the wipers 18 wipe the margin of the upper over the insole, the cementing means serving as a retarder for the upper. The upper and lower jaws 34, 32, respectively, of the toe-end gripper 10, Figs. 1, 6, are pivoted together at 40 and the gripping force applied by them, due to movement of a fluid-pressure operated piston 46 in a cylinder 48 mounted on a slide 36 on a support 38 common to all the grippers, may be set independently of the grip exerted by side grippers 12 by varying the effective length of a lever arm 50 by adjusting the position of a pivoted bar 54. The side grippers each comprise upper and lower jaws 68, 66, respectively, the jaw 66 being secured to a slide 70 movable in guides in the support 38 while the jaw 68 is connected to a piston 74 in a cylinder 76 fast on a slide 70 and the jaws are normally held open by springs 78. Fluid for closing the grippers and for operating other parts of the machine is obtained from a manifold, fluid being admitted to cylinders 48, 76 simiultaneously by a supply valve which is operated in the first instance by a treadle and thereafter automatically. The grippers are moved to pull on the upper by moving the slides 36, 70 in their guides on the support 38, the toe end gripper by a lever 86 operated by bodily movement of a cylinder 92, which also by movement of a piston 98 operates the left-hand side gripper. The right-hand side gripper is operated by admission of fluid from a tube 104 to a cylinder 106 acting on a piston 108 connected to the slide 70 of that gripper. The side grippers are adjustable towards each other by a manually rotatable rod 110. The force which the gripper jaws exert on the upper is controlled by making them somewhat smooth and by interposing a compression spring- loaded pressure-controlling valve 112 between the cylinders 48, 76 and the supply valve to reduce automatically to a variable degree the pressure of fluid supplied to these cylinders below the pressure in the manifold 82. Between the first and second actions of the grippers, fluid is admitted to the lower end of a cylinder 174 to swing a lever 172 about its axis on a shaft 162 until an adjustable screw 182 therein engages an abutment face 184 on the machine frame. An arm 164 also is locked on shaft 162 and through the link 158 and bell-crank lever 154 acts to reduce load on and amount of compression of spring 118 in valve 112. Adjustment of the arm 164 relative to the lever 172 by a pin 168 serves to vary the force with which the upper is gripped by all the grippers at both times, and the force of the second grip on the upper is varied independently of the force exerted by the grippers when they first grip the upper by adjusting the screw 182. Adjustment of the bar 54 in recesses 52 in the arm 50 varies independently of the side grippers the force of the pull of the end gripper. Opening of the gripper jaws is effected by return movement of the valve 84 to exhaust position.