GB1235672A - Improvements in or relating to cutting presses - Google Patents

Abstract

1,235,672. Cutting presses. BRITISH UNITED SHOE MACHINERY CO. Ltd. 2 Aug., 1968 [3 May, 1967; 21 June, 1967], Nos. 20415/67 and 28533/67. Heading B4B. A "travelling head" type cutting or clicking press comprises a lower platen 34, Fig. 1, to support a cutting block 36 on which are placed material to be cut and a superposed cutting die. The upper platen 120, Fig. 11, comprising a block 180, Fig. 1, is mounted above the lower platen, and is movable widthwise. The cutting stroke is effected by up and down movement of a ram including a slider 72 by admission of pressure fluid via pipes HP2, HP1, respectively. Start switches 216, to initiate press operation, are spaced apart on a control member or bar 214 so that both hands are required to start operation of the press. The control member is movable from a central position in one or other of opposite directions to control widthwise movement of the platen to left or right. As described this movement is controlled by left or right movement of the control bar 214, which actuates limit switches LS6, LS7. Forward or backward movement is effected by a rack-andpinion and pneumatic system 124, 158, 160, 162, Fig. 5, and widthwise movement is effected by an arrangement comprising a motor HM, Fig. 2, and a chain 64 and sprockets 60, 62. One start switch moves the upper platen forward and the second moves it heightwise to effect cutting. The pneumatic cylinder 124, Fig. 5, is adjustable in length to vary the rearward position of the upper platen and the position is locked by a plunger assembly 174. The extent of movement of the upper platen in carrying out a cutting stroke can be limited either by a conductive cutting pad (in known manner) or according to the depth of the cutting die by an electrical limit switch whose height is adjustable relative to the upper platen. The limit switch LS3, Fig. 7, is actuated by a spring- urged sleeve 210 carried by a post 186 mounted for movement with the upper platen. The heightwise position of the limit switch is adjustable by a knob 204, Fig. 7. Movement of the upper platen takes place under low pressure until it engages the cutting die. After a cutting stroke has been effected, the upper platen automatically moves widthwise in a direction selected by the operator. Electronic/ electrical circuitry including a time-constant circuit permits the upper platen to rise before retreating rearwards. Traverse movement of the carriage 42, Fig. 1, is controlled by a rheostat Rh1, Fig. 12A (not shown). In a modification, the operator can position the die with one hand and actuate one of the start buttons SB1 ... 4, Fig. 13 (not shown) with the other hand to bring the upper platen forward. Control of pressure fluid to the main press ram may also be controlled hydraulically rather than electrically. Material to be cut is fed to the lower cutting block only when the upper platen is rendered inoperative, under control of a pedal switch FS1, Fig. 12B (not shown). When the pedal is released, the feeder device (not shown) is returned to its withdrawn position.