Patent GB-524884-A (GB)
Title: Improvements in or relating to shoe upper conforming machines
IPC: A43D21/16
Filed: 1939-02-10
Abstract: 524,884. Lasting-machines. BRITISH UNITED SHOE MACHINERY CO., Ltd., KEALL, F. B., and LANE, H. Feb. 10, 1939, No. 4365. [Class 17 (i)] Relates to pulling-over machines of. the kind described in Specificaton 12304/03, [Class 17], comprising toe and side grippers for tensioning an upper over a last and means for fastening the upper in tensioned condition, and consists in the provision of separate double-acting fluidoperated piston and cylinder devices for actuating the toe gripper mechanism and each of the side gripper mechanisms. A gear pump draws oil from a reservoir and delivers to an accumulator 22 whence the fluid passes to a pressure relief valve adjustable by a knurled head 66 and having an exhaust pipe 37 leading oil back to the reservoir. Oil at such adjusted pressure passes to a valve controlling the flow to a cylinder in which slides the piston for the toe grippers, and also to a pressure reducing valve 50 for the cylinders of the side grippers. The toe grippers are controlled by a bar 90 guided by a pivoted arm 94. linked to a piston in a cylinder supplied with oil by pipes 108, 110. An inlet pipe 40 and exhaust ports 118, 120 cooperate with pistons 124, 126, 128 on a stem having a roll 132 engaging an inclined slot at the end of a link 136 pivoted to a cam-actuated lever 140. 'The toe gripper is caused to exert tension on the upper before the side grippers, and then to relieve its tension as the side grippers are about to tension the side portions of the upper. The side and toe grippers then move downwardly together. The pull of the toe grippers is less than that of the side grippers, its cylinder being smaller. A spring 164 resists the pull of the toe gripper, and is readily adjustable. While the grippers move downwardly their control valve tends to close in order that their speed of downward movement may correspond to the movement of their cam lever. For this purpose a link 180 supports the rear end of the link 136, and is yieldingly connected by arms 182, 186 to a link 188 connected to the toe-gripper bar. Similar mechanism is provided for the side grippers. The valve casings 208, 210 for the side grippers have projecting valve stems carrying rolls 212, 214 engaging grooves at right angles in a lever 288 pivoted at 235 to a lever 236 supported by an arm 240 fixed to a rock shaft 241 and engaging a slot 246 in a link 248 connected by a slot 249 to a cam-operated lever 250. Downward movement of the lever 228 admits oil to the upper ends of the cylinders of the side grippers to cause the grippers to close on the upper and exert pulling-over strain thereon. The pressure reducing valve 50 comprises an inlet port 266 and an outlet port 270 connected with a port 300. The valve comprises pistons 278, 280, 282 and is depressed by a spring adjustable by a knurled head, 296. The pressure of the oil is thus that of the spring. To prevent sticking of the valve its lower end is oscillated by a cam 310. The side grippers are connected by links 314, 316, arms on shafts 184, 324 and a link 350 to the rear end of the link 248, so that as the grippers descend the rear end of the link 248 is lowered. Oil thus flows to their cylinders at substantially constant rate, and the movement of the grippers corresponds to the movement of their camactuated lever. When the grippers have come to rest and the operator has inspected the upper a lever 356 is operated to open the valve 50 to allow the full pressure of the oil to act on the pistons and move the grippers further downwardly. The lever 356 is linked to a lever 370 resiliently connected to an arm 376 actuated by a hand lever 384 held in operative position by a pawl and ratchet 392. A roll at the end of the lever 370 co-operates with a cam to move the grippers rapidly away in front of the advancing tackers when pulling-over has been completed and the upper clamped. To allow the upper to be shifted on the last in case it has not been seated properly thereon the gripper tension is first relieved by depressing a treadle 420 connected by a Bowden cable to an arm 416 moving with an arm 412 actuating a link 410 supporting the forward end of the link 248. A second Bowden cable connects the treadle with the link 136 controlling the toe gripper. A hand lever 424 secured to the shaft 241 may then be swung laterally to cause the grippers at one side of the toe to rise and those on the other side to descend, the swing of the arm 240 causing the lever 228 to move laterally and thus depress one valve plunger and raise the other. The lever 228 is additionally coupled back to the gripper bars to cause them to move through distances directly proportional to the movements of the lever 424. As usual, all parts return to starting position at the end of the machine's cycle. Specifications 16398/15, 150,424, [both in Class 17 (i)], 373,125, 373,183 and 461,326 also are referred to.