GB807159A - Improvements in or relating to the formation of shaped blanks from sheet material - Google Patents

Abstract

807,159. Punching. RHODES, C. J., and RIDGWAY, H. April 18, 1956 [April 18, 1955], No. 11090/55. Class 83 (4). A blank punching press has mating stops which positively arrest relative movement of the dies to prevent the male die entering the female die. The male and female dies 6, 7, which are mounted on the ram 5 and bed 8 of a crankoperated press, are each provided with four hardened steel stops 11, 12 respectively, the surfaces of which are flush with or project slightly beyond the faces of the respective dies 6, 7. To prevent undue elongation of the frame when the male die contacts the work, the frame is pre-compressed by, say, a 120 tons force applied through four tie-rods 3, or alternatively the frame is made of unusually heavy construction. Play in the moving parts is taken by hydraulic or pneumatic loading applied to a piston 14 connected by rods 18 to the ram 5 and an associated cylinder 15 secured to the frame.