Patent GB-1347311-A (GB)
Title: Shearing apparatus
IPC: B26D1/04
Filed: 1971-04-19
Abstract: 1347311 Shearing D J WHEELER 19 April 1971 [17 April 1970] 9892/71 Heading B3W [Also in Division B4] A shear for shearing strips, sheets and plates comprises a carriage supporting means for shearing a strip &c, means for reciprocating the carriage and means for progressively advancing the shearing means towards the strip &c. so that shearing takes place progressively during reciprocation of the carriage. As shown, Fig. 1, disc cutters 33, mounted on a carriage 32 reciprocated by a motor-driven eccentric 38, co-operate with an upper blade 15<SP>1</SP>. Jacks 9<SP>1</SP> move the blade 151 to clamp the work against a support 16<SP>1</SP> before shearing begins. The disc cutter housing 46 is moved progressively towards the work, as the carriage 32 is reciprocated by axial movement of a wedge 48 through a hand-turned screw shaft 55, 61. Staggered arrangements of cutters are shown in Figs. 3-5 or cutters of different diameters may be used. Instead of a co-operating blade a recessed anvil (66), Fig. 6 (not shown), or electromagnets (67), Fig. 7 (not shown), may hold the work against the disc cutters. In an alternative embodiment, Figs. 8 and 10, linked carriages 101, 102 are reciprocated along I beams 99 by sprocket and chain drive 129-133. Each carriage supports a disc cutter 115 biased by a spring 123 towards a clamp plate 121 mounted on one of the I beams for alignment with a fixed blade 95. The clamp plate 121 is laterally adjustable by means of set screws 124. The beams 99 are vertically movable by hydraulic cylinders 119 and each cutter housing 109 is vertically movable relative to its carriage to advance the cutters 115 progressively into the work by adjustable-stroke hydraulic cylinders 127. During lowering of the beams 99 to clamp the work between the plate 121 and a support 97, the cylinders 127 are retracted so that the cutters clear the work. A sequence valve (not shown) may be actuated by pressure in cylinders 119 to admit fluid to the cylinders 127 to advance the cutters into the work at a variable or constant rate. The cutters may be advanced at different rates from each other. A limit switch may indicate when the work is sheared to initiate raising of the beams 99 and of the cutters relative to the carriages and stopping of the carriage drive motor. The carriages can be moved to a relieved portion at either end of the plate 121 for changing the cutters. One or more than two carriages may be provided. In a further embodiment, Fig. 12, upper and lower assemblies of disc cutters 146, 147 are mounted in a C-shaped carriage 141 reciprocable along rails 142 by sprocket and chain drive 151-154. The cutter assemblies are movable vertically by a common motor 155 which may apply a constant force to jacks 156, 157 to urge the blades into the work. Magnetic clutches actuated by limit switches 162 disengage the motor from the jacks at the end of each traverse of the work. Alternatively the cutters are only advanced between traverses or the wedge arrangement of Fig. 4 is used. Cutters in staggered formation and having single or double raked cutting edges may be used.