Patent GB-1342585-A (GB)
Title: Cutting presses
IPC: B26D7/26
Filed: 1970-04-21
Abstract: 1342585 Cutting-out presses BRITISH UNITED SHOE MACHINERY CO Ltd 19 April 1971 [21 April 1970] 19095/70 Heading B4B A cutting press comprises an upper platen 16 movable towards and away from a lower platen 4 by means of an hydraulic cylinder means, and a stroke control means including a switch arrangement and an actuator arrangement therefor, the arrangements being mounted for relative movement between them when relative movement is effected between the platens so as to cause a switch LS 1 of the switch arrangement to be actuated by an actuator 22 of the actuator arrangement thereby terminating the stroke of the press. The switch LS1 is mounted on a plate 52 which is secured to a bar 56 slidable in a guideway 58, the assembly being biased in an upward direction by a spring 59, Fig. 4. The switch LS1 is clamped in a selected position by means of a locking bar 70 having a cam portion 76 urged into locking engagement with the bar 56 by an adjustable spring 78; the locking action of the bar 70 may be released by means of a cable 84 connected to a lever 86, Fig. 1. A latch member 90, Fig. 3, is pivotally mounted on the plate 52 and is provided with one arm 92 adapted to actuate a safety switch SS1 and a second arm 98 having an abutment surface 108 for engagement with a lug 26 secured to a bar 30 slidable in a guide means 46, 49. A rod 24 is slidably mounted on the bar 30 and is provided with the actuator 22; the position of the actuator relative to the bar may be varied by means of a spool member 33 engaging a threaded end of the rod, the spool being rotatable by means of a flexible cable and handle 36, Fig. 1. In order to set the lower position of the platen 16 in relation to a particular height of cutting die 8 positioned on a cutting block 6, the lever 86 is actuated causing the switch L51 and plate 52 to rise under the action of the spring 59. As the plate rises a roller 100, Fig. 3, on the latch 90 is moved by a cam 104 into the position shown in Fig. 3 in which the abutment surface contacts the lug 26. In this position, push-buttons (PB1, PB2) Fig. 6 (not shown) are operated thereby causing, via an electronic circuit, Fig. 6 (not shown), a solenoid operated valve (VI) Fig. 7, (not shown) to be energized; this valve then allows hydraulic fluid to actuate a piston (134) thereby lowering the platen 16 and, together, the actuator 22 and switch LS 1. As the platen approaches the upper edge of the die, a spring urged shorting strip 112 first contacts the edge and, then a striker plate 15 on the platen contacts the die such contact completing an electrical circuit and thereby deenergizes the solenoid-operated valve (V1). The upper platen then returns to its initial upper position, which may be set by a hand wheel 130, Fig. 1, and the switch LS1 remains in its set position by being clamped by the locking bar 70. The electronic and hydraulic circuits are so constructed that an electrically conductive pad may be used in place of the cutting block 6. When such a pad is used it is unnecessary to "set" the cutting stroke since contact between the striker plate, cutting die and cutting pad creates an electric circuit by which the cutting stroke is terminated and a return stroke initiated.