Impact Machine

1,191,942. Forging hammers. J. P. KUZKO, V. A. LIVANOV, L. N. KONSTANTINOV, A. P. CHEKINOV, S. D. FAINBRON, A. I. MAZUR, M. I. SURKOV, A. I. NAZAROV, A. P. MONAKHOV, N. N. MAIOROV, B. A. STOPACHINSKY, S. V. RYNDENKOV, G. A. SHEBEKO, A. V. ANDROSOV and V. G. TITOV. 30 May, 1967 [28 May, 1966], No. 24896/67. Heading B3H. A double-drive hammer comprises a reciprocable main frame 1 carrying a first die 9 and providing a differential cylinder 2 containing an operating ram 5 carrying a second die 6 and a free piston 7 subjected on one side A to liquid pressure and on the opposite side B to air pressure. The main frame 1 is reciprocable vertically in guides 3, 4. High-pressure liquid is supplied through passage 12 to the space A between the ram 5 and piston 7 to raise the ram and the frame 1 into their upper positions as determined by bolts 20. Compressed air from one of several air cylinders operating at different pressures, is then supplied through passage 13 and passage 22 into space C to hold up the frame 1 whilst the liquid is partially drained from space A to permit the ram 5 to fall against a key 23. To perform a working stroke the air is released from space C whereby housing 1 falls by gravity until radial ports 14 communicate with space B. The compressed air thus acts below piston 7 to move it upwardly and also to accelerate the downward movement of the frame 1. Liquid trapped in space A thus causes the ram 5 also to move upwardly. Towards the end of the working stroke, annular projections 16, 17 on the ram and piston co-operate to cushion the movement and reverse the motion of the piston 7 before impact occurs.