GB743544A - New or improved work-handling means for power-presses and like machines - Google Patents

Abstract

743,544. Work handling means for presses. EVANS, F. A. May 11, 1954 [May 11, 1953], No. 13028/53. Class 83 (4). A work handling device for a power press or like machine comprises rigid substantially vertical arm 12 pivoted to swing about a fixed pivot 15 at its upper end and having pivoted to its lower end a work-gripping mechanism 65, 66 and a motor 33, preferably operated by pressure fluid, which when energized first moves the gripping mechanism about its pivot 46 to lift the workpiece clear of the tools or the like, and then swings the arm about its pivot 15 to carry the workpiece clear of the press to a point of discharge. The gripping mechanism comprises a pair of adjustable pins 65 mounted on a bar 62 and a spring-loaded jaw 66 pivoted at 68 to the bar which is secured to a sleeve 63 slidable along a spindle 61 carried by a block 60 adjustably secured by bolts 56 to a bracket 45 pivoted at 46 to a telescopically adjustable extension 40 of the swinging arm 12. A fluid-pressure motor 72 rigid with the block 60 acts through a strong spring 75 to slide the bar 62 and the pins and jaw 65, 66 along the spindle 61 towards the workpiece whereby the pins pass over the workpiece and the jaw under it. When the sleeve 63 engages an abutment 64, further movement of the motor 72 causes the spring 75 to be compressed, whereby a cam 70 on the motor rod moves the jaw 66 about its pivot to grip the workpiece. A main fluid-pressure motor 33 is then energized whereby its rod 32 moves a pair of quadrant plates 28 about their pivot 25 on a main mounting bracket 10. These quadrants are connected by a rod 30 and an adjustable screwed rod 49 to the bracket 45 so that the latter and hence the gripper jaws are moved about their pivot 46 to raise the workpiece. An abutment 37, Fig. 2 (not shown), on the quadrant plates subsequently engages a block 38 adjustably secured to a pair of arms 24 pivoted to the pivot 25 and to a collar 18 adjustably mounted on the arm 12. The upper end of the latter is secured within a fitting 13 carried by bell-crank levers 14 pivoted at 15 to the main bracket 10. Continued movement of the motor 33 thus causes movement of the arms 24 about the pivot 25 whereby the arm 12 and bell-crank levers 14 move about the pivot 15 to swing the workpiece clear of the press. The motor 72 is then reversed to release the workpiece and the motor 33 is reversed to bring the arm back to its starting position. The device is detachably mounted on the frame of the press and is preferably operated automatically in timed sequence therewith. The starting movement of the device is initiated by a switch operated by a cam on the crankshaft of the press when the latter begins its return stroke and switch means are provided for preventing the clutch of the press being engaged if the gripping mechanism is in the way of the press tools. Instead of gripping jaws, the gripping mechanism may comprise a suction device or an electro-magnetic device. Two work-handling devices operating in synchronism may be fitted to the press.