Patent GB-1283199-A (GB)
Title: Improvements in or relating to machines for cutting sheet material, particularly sheet metal
Inventor: CANTELLI ALVES
IPC: B21D43/00
Filed: 1969-07-17
Abstract: 1283199 Sheet metal guides A CANTELLI 17 July 1969 [10 Aug 1968 4 June 1969] 36043/69 Heading B3W In a machine for shearing sheet metal, edge guide blocks are pivotally mounted on slides movable along guides parallel with shear blades fixed to the machine bed. The guide blocks may be adjustably connected to the slides to allow partial rotation of the blocks relative to the slides, partial rotation and translation or pure translation of the block and slide assemblies along the guides. As shown, Fig. 3, a guide block 34 is pivoted to a slide 20 at 35-37 and to a control rod 41 at 39, 40. Alternative mounting holes 38 for rod 41 are arranged symmetrically about the bolt 35. Rigidly secured to the slide 20 is the piston-rod 29 of a double-acting pneumatic cylinder 28 fixed to a second slide 21 adjustable along the guide 11 and then screwed to the bed 8 at 23. Cut-out 32 in plate 31 on slide 20 and cut-out 26 in the slide 21 receive the rod 41 and engagement of one of four adjustable stops 42-48 with plate 31 or slide 21 controls the movements of the block during actuation of the rod 29. If the rod 29 is retracted from the Fig. 3 position the stop 44 will first abut the slide 21 and continued retraction of the ram will cause the block to rotate about the bolt 35. Cut-outs 33 and 25 allow the rod 41 to be mounted on the other side of the rod 29. Guide block 49 and its mounting are identical with block 34. Valves 57 at each end of each cylinder are supplied with compressed fluid via a valve 52 which is controlled through a lever 69 by a cam 70, Fig. 2, mounted on the machine frame. Correct location of a workpiece relative to the blocks trips micro-switches (77), Fig. 4 (not shown), in the edge of the blocks and actuates a slide 3 including a head 6 carrying a blade for co-operation with the fixed blades 10 on the machine bed 8. On downward cutting movement of the slide, an inclined surface 74A on a hook 74 of a spring-loaded lever 72 runs over pins 71 on the cam 70 and on upward movement of the slide the hook hooks round a pin and rotates the cam through one-eighth of a revolution, thus changing the position of the valve 52. Pressurized fluid is supplied to the opposite ends of the cylinders, the guide blocks are moved to a second position, determined by adjustment of the stops 42-45 and the workpiece having been located against the guide blocks again the shearing operation is repeated. If only one kind of cut is to be made, i.e. there is no need to move the guide blocks between successive operations, a knob 82, Fig. 2, on the slide can be rotated to move an eccentric 80 to maintain the lever 72 out of engagement with the pins 71. One guide block and slide assembly can be moved in the opposite direction to the other by reversing the supply lines to its actuating ram. If no rotation of the blocks is required, the control rod is fixed to the rear slide and one pair of stops determines how far the block can travel. In another embodiment, Fig. 7 (not shown), the plate 31 is omitted and a control rod is mounted on each side of the piston-rod, each control rod carrying an adjustable stop fore and aft of the rear slide.