GB1276728A - Improvements in or relating to impact shearing of metals - Google Patents

Abstract

1276728 Shearing HJO MEKANISKA VERKSTAD KZV SMEDBERG 30 May 1969 [31 May 1968] 27519/69 Heading B3W An end portion is sheared from an elongated metal rod or like blank by subjecting a movable shear blade to an impact force sufficient to shear the blank but so low that substantially the whole of the energy is absorbed in the shearing operation, the free end face of the portion to be sheared being axially supported during the initial stage only of the shearing operation and displacement of the movable shear blade being arrested as soon as the shearing operation is completed. As shown, a slide 19 reciprocable along rails 18 between adjustable stops 22 by a piston and cylinder 21, 20 carries a fluidoperated gripper 25 for feeding a rod 11 to a shear 10. The shear comprises fixed and movable apertured cutters 30, 31 mounted in a housing 32-34, a sleeve 58 locating the cutter 31 axially of the shear. The cutter 31 is maintained with its aperture aligned with that of cutter 30 by a spring 56, shoulders (51) on the cutter (Fig. 3, not shown) abutting a stop 52 on the housing. A pneumatic cylinder or air cushion may replace the spring 56. The cutter 31 is moved to shear a slug from the rod 11 by a high-energy impact from a heavy weight 42 mounted on a piston 41 associated with a pneumatic cylinder 39. The weight may be replaced or the feed pressure to the cylinder varied for stock of different sections and/or material. Readily replaceable stops 54 end the cutter stroke as soon as the slug has been sheared. The stops 54 and the spring 56 may be replaced by a liquid-braked piston/ cylinder arrangement which would also absorb any surplus energy of the cutter after the slug has been sheared. The aperture of the cutter 31 may be cut away at (63) and (64) (Fig. 4, not shown) to facilitate feed of the rod and ejection of the slugs. An apertured plate 67 is maintained during the initial part of the shearing stroke with an edge portion 71 abutting against the leading end of the rod 11 to counteract any bending moment. The plate is raised in synchronism with the cutter 31 to allow the slug to be ejected, e.g. by means of a piston and cylinder device 72, 73 actuated by pressure-responsive means in one of the stops 54.