Patent GB-1353168-A (GB)
Title: Shearing method and apparatus
IPC: B26D3/10
Filed: 1971-05-26
Abstract: 1353168 Shearing HURCO MFG CO Inc 26 May 1971 [1 June 1970] 17168/71 Heading B3W A notching shear for cutting sheet or plate material into parts of predetermined size comprises two rigidly connected sets of blades 26U, 26L and 27U, 27L arranged at right angles to each other. A continuous rake on the upper blades allows the blades 26 to function alone, Fig. 12 (not shown). Hinged at 43 to a support frame 39 for the shear ram 76 is a hold down 42 consisting of pneumatically-actuated spaced feet 44. A sheet-supporting table consists of a plane portion 34 and a slatted portion 35. The slats are mounted at each end on rollers 45A which run in tracks 55, (553), Fig. 10 (not shown), fixed to, and curving down below, a gripper housing 36. A carriage 104, supporting grippers 38 actuated by inflatable tubes 116, Fig. 6, is movable lengthwise within the housing 36 and the housing itself is movable towards and away from the shears on pedestals 73A, 73B, 73C, Fig. 4. Track 553 stops short of the blades, level with the forward ends 111 of the grippers 38 and the rollers 54A between the track and the shears are supported on plates (453), Fig. 10 (not shown), which are pivoted out of the way by a cam (454) mounted on the track 553. As the housing moves towards the shears, the slats 35 run down the tracks to lie on rails 65, Fig. 5. Each pedestal 73 includes an hydraulic/pneumatic cylinder block such as 142, Fig. 6, which through a chain and sprockets moves the housing 36 along rods 102, towards and away from the shears. Similar cylinder and chain and sprocket arrangements drive the gripper carriage 104 along rails 108, 109, Fig. 6. Rotary encoders 149 and (133), Fig. 8, (not shown), relay travel of the housing 36 and gripper carriage 104 respectively to binary comparators in an automatic control system. To compensate for dimensional variations in the cylinder blocks such as 142 each slack has an adjustable compensating cylinder such as (167) (Fig. 9, not shown). Through valves (not shown), carriage travel over significant distances is carried out at fast, slow and creep speeds. In automatic operation, a sheet 21 is positioned against a gauging stop 251, Fig. 4, by means of a programme tape 67 in a control console 64, Fig. 4, and a tube 92 is inflated to press the feet 44 against the sheet. A ram bellows 83 is inflated and a piston cylinder unit 51 actuated to pivot a torsion bar 46, Figs. 4 and 5, and drive the ram 76 downwards. The initial position of the ram is variable by rotation of a pivot shaft 79 by handles 56 (one shown in Fig. 4). The bellows, is vented, the ram is returned by springs 80 and the hold down feet are raised. The sequence is repeated for each cut and cutting ends when the tape dictates. A number of blanks of the same size may be sheared automatically after the dimensions and number of blanks have been set manually in the control console 64. The sheet is fed in increments along one axis to shear a strip into blanks, moved one increment along the other axis and the next strip is similarly sheared into blanks. Cut parts are removed on a conveyer 61 which can be moved diagonally to leave an L-shaped slot between it and the blades through which scrap can be delivered to a bin or conveyer. The apparatus enables a sheet to be sheared into blanks of different sizes (Fig. 2, not shown) without the need for any blanks to be carried back from the delivery to the feed side for shearing into smaller parts.