Patent GB-748026-A (GB)
Title: Improvements in or relating to machines for applying pressure to shoe bottoms
IPC: A43D25/06
Filed: 1953-03-18
Abstract: 748,026. Shoe bottom presses. BRITISH UNITED SHOE MACHINERY CO., Ltd. (United Shoe Machinery Corporation). March 17, 1954 [March 18, 1953], No. 7438/53. Class 17 (1). A shoe bottom press comprises a pressure fluid operated motor which operates a pressureapplying device, a valve to control the flow of pressure fluid from a supply to the motor, and a timing device which causes the pressureapplying operation to cease after a predetermined period of time, the flow of fluid to the motor occurring during this period only. The timer may be connected with an operator actuable electric switch. A manually operable stopping switch may be used to stop the flow of pressure fluid at any time before the completion of the predetermined period, the subsequent pressing operation taking place for the full predetermined period. In the two station machine described the shoe is moved upwardly on a pad box until it is clamped against heel and toe abutments, and then pressed. The pad box is first raised rapidly by means of a small piston 32, Fig. 2, in a cylinder 34 by fluid passing from pump 58 through 62, 104, 98, 36 and as piston 28 moves upwardly with the integral piston 32 fluid is drawn into cylinder 30 from reservoir 38 via 40, 42, 44. Fluid is then admitted automatically to cylinder 30 to act on the large piston 28 to apply the final heavy pressure as valve 50 in the chamber of valve 42 is forced downwardly against spring 52 by pressure of fluid in cylinder 34, connecting the pressure supply line 54 through 56 to cylinder 30 and cutting off pipe 40. Fluid from pump 58 passes to a pressure-regulating valve 66, which determines the maximum pressure of fluid admitted to cylinder 34, an adjustable relief valve 68, and check valves 96 to supply pipe 54. When valve 106 is de-energized, as shown, fluid from 62, 108 depresses valve 100 against spring 102 and fluid discharges from cylinder 34 through 36, 110, and from cylinder 30 through pipe 40, but when the valve is operated fluid is discharged from above valve member 100 through 108, 112 so that member 100 is returned upwardly and fluid flows through 66, 98, 36, to cylinder 34. Pump 58 is driven by motor 114 controlled by a switch 116 including coil 118 which interconnects terminals 120 and 122, and 150 when energized by means of switch 146 through closed contacts 148 and closed switch 26. Coil 118 is kept energized by a holding circuit through 26, 150. The timers 130 include contacts 148 normally connected by a snap-acting switcharm 140 on rod 141, and contacts 132. When coil 136 is energized, by closing the treadleoperated switch 142, rod 141 is moved downwardly, snapping arm 140 to the dotted line position where it connects contacts 132 and disconnects contacts 148, and piston 143 forces air from the pneumatic dashpot 138 through check valve 147. When coil 136 is de-energized spring 145 returns the piston but the air is admitted to the dashpot via the adjustable needle valve 144 which thereby determines the time required for the piston to return to the position shown in Fig. 2 with the arm 140 snapped back to again connect contacts 148. During this predetermined time while contacts 132 are connected a circuit through 124, 132, 134, 135, 126 energizes the coil to move valve 106 from the position shown in Fig. 2 to the lower position, whereby pressure fluid flows to cylinder 30. The operation may be stopped before the completion of the predetermined period by depressing button 26<1> which opens the stopping switch 26, thereby breaking the circuit through switch 116 to de-energize valve 106 and stop motor 114, and the operation cannot be resumed until the timer has returned to again connect contacts 148 and ensure that the next pressing operation is performed for the full predetermined time. In the construction shown in Fig. 3 armature 190 is urged into contact with the separate rod 141<1> by a spring stronger than spring 145<1> which urges the rod upwardly, so that in the normal position shown, the switch arm on rod 141<1> connects contacts 132<1>. Closing of switch 142 closes contacts 182, 184, the former completing circuits through coil 136<1>, and valve 106, and the latter completing a holding circuit through contacts 132<1>. When coil 136<1> is thus energized armature 190 is raised and withdrawn from rod 141<1> which is raised by spring 145<1> under the restraint of piston 143<1> in its dashpot, until at the end of the predetermined period the switch arm snaps to open contacts 132<1>. The holding circuit through coil 180 is thus broken causing coil 136<1> to become de-energized, and armature 190 moves rod 141<1> down to close contacts 132<1> again. Thus in this construction there is no unnecessary delay in resetting the timer. An additional manually operable stopping switch 192 may be operated to relieve pressure before completion of the predetermined period, but will not stop the motor so that there is no delay while the pump builds up pressure again. Specification 623,295 is referred to.