GB1378183A - Punch presses - Google Patents

Abstract

1378183 Punching US AMADA Ltd 26 Jan 1972 [19 Feb 1971] 3587/72 Heading B3W In a punch press a pair of turrets 20, 21 are indexed simultaneously to position a selected station below a punch striker by a drive including means which sense the approach of the selected station to the punching position and decelerate the turret movement and further means which sense the arrival of the selected station in the punching position and stop the drive. The turrets are rotated by racks 76 driven by a piston rod 72 in an hydraulic cylinder 58. A slide switch 80 carrying a stop contact 84 flanked by decelerating contacts 85, 86, is mounted on the upper turret for movement along a bar 82 which carries command contacts 88, each corresponding to a station on the turrets and coupled to a manual control 91 or a numerical control 90. Hydraulic accumulators 46, 48 are connected to the ends of cylinder 58 respectively via flow control valves 54, 64 in by-passes 52, 62 and decelerating valves 56, 66. Pressurized air is supplied to the accumulators 46, 48 from a fourway solenoid valve 38 energized by the controls 90 or 91. If, say, the furthest left contact 88 is energized when the switch 80 is in the position shown, the valve 38 will be actuated to supply air to the accumulator 48 until the contact 86 engages the contact 88. This signals the decelerating valve 66 to close and slow down the travel of piston 72 and thus of the rack and the turrets. When the contact 84 engages contact 88 it signals the valve 38 to close. With the turrets stationary, shot pins 30 can be inserted in bushes. The cylinder 58 may be replaced by a conventional rotary actuator (58a), Fig. 3 (not shown), which rotates the turrets by means of a belt and sprocket device (76a).