Patent GB-993034-A (GB)
Title: Impact apparatus
IPC: B21J7/24
Filed: 1962-09-05
Abstract: 993,034. Extruding; forging. INTERNATIONAL ELECTRONIC RESEARCH CORPORATION. Sept. 5, 1962 [Sept. 11, 1961], No. 34000/62. Headings B3H and B3P. A fluid pressure operated hammer comprises a frame 12 supporting a pair of tups 14, 16 providing opposed platens 18, 20 and having opposed pressure surfaces 124, 126 between which pressure fluid is admitted for urging the tups together. The hammer may be used for forging, forming sheet metal or impact extruding and may be operated by compressed air, gas or vapour or by liquid pressurized by compressed air. Upper tup 14 supports an upper die 22 and is adjustably secured by an exchangeable spacer 140 and rings 136 to a depending sleeve 130 connected to an inner sleeve 128 with a conical pressure surface 126. The lower tup 16 carries a die 24 and comprises upper and lower members 64, 66 interconnected by a bayonet joint 89 to give axial lost motion between them determined by the fluid pressure in a chamber 90. Member 66 is connected to inner and outer cylinders 92, 94 sealed by an annular base 98 to provide an annular fluid pressure reservoir 106. A sleeve 122 connected to the lower tup depends into the annular space between the sleeves 128, 130 and has an inner conical pressure surface 124. The tups are supported by an annular frame 12 connected to a base 46 by a collar 54 which can fit between alternative pairs of shoulders 56 for varying the height of the tups. An annular cushioning chamber 234 is provided within the frame 12. The frame may be hinged for pivotal movement to a horizontal position, Fig. 2 (not shown) to enable some impact operations to be performed horizontally. In operation a workpiece 36, Fig. 1, is heated in a furnace 38 and moved by conveyor 40 to the space between dies 22, 24. Doors 30, 32 are then closed and a protective atmosphere is supplied from unit 34. The internal reservoir 106, Fig. 7, is charged , continuously with compressed gas from compressor 26 and control unit 28. To initiate the blow, an adjustable valve unit 146 is operated which admits pressure from reservoir 106 to the space between conical surfaces 124, 126 thereby driving the tups together to deliver an impact upon the workpiece, followed by a squeeze as the fluid in chamber 90 is expelled through adjustable by-pass valves, and finally a second impact as the two members 64, 66 of the lower tup positively engage each other. The speed of impact is adjusted by a pinion 196, Fig. 11 (not shown). The tups are retracted automatically by pressure fluid in an annular chamber 226 when the space between the pressure surfaces 124, 126 is exhausted. A dashpot chamber 232 cushions the return stroke. Fluid may be bled from chamber 226 to provide an inching stroke for the tups. The workpiece is removed from the die 24 by a fluid actuated ejector 202 and transferred by conveyer 42, Fig. 1, to a quenching and carburizing unit 44. Liquid may be used instead of-gas to operate the hammer and is pressurized in reservoir 106 by an accumulator piston 108 whose lower space 104 is supplied with compressed air through duct 112. The upper tup or the lower tup may be used to carry an extruding die. In another embodiment, Figs. 17-20 (not shown) the cushioning chamber 234 and accumulator chamber 104 are omitted. In a further embodiment, Fig. 22, for impact extruding a workpiece 36, the extrusion die 260 is carried by lower tup 16 and the punch 258 by upper tup 14. The annular space 284 between conical pressure surfaces is supplied from internal reservoir 266. A dashpot 276 controlled by valve 280 damps the movement of the lower tup part 66. In another embodiment, Figs. 25-28 (not shown) two separate impacts are performed by coining dies upon a workpiece without an intermediate squeezing stage.