GB801888A - Improvements in or relating to hydraulically operated machines for stretching metal plates and other rolled or extruded metal members - Google Patents

Abstract

801,888. Stretching. FIELDING & PLATT, Ltd. Nov. 22, 1956 [Dec. 2, 1955], No. 34631/55. Class 83 (4). A machine for stretching metal plates and other metal members comprises a pair of gripping cross-heads for gripping opposite ends of the member to be stretched, said crossheads being movably supported on a foundation for movement towards and away from each other, hydraulic means for loading one crosshead in a direction away from the other to stretch a member gripped therebetween and compression members extending between the said cross-heads for supporting the thrust therebetween during the stretching operation, the said compression members being movable with respect to the foundation in the direction of relative movement of the crossheads. A pair of gripping cross-heads 4, 5, each supported on bogeys 6 running on rails 3, each comprises a plurality of gripping elements 7 the central elements being, if desired, stronger than the outer elements. A pair of compression members 9, 10 extend between'the cross-heads 4, 5 and are slidably supported on walls 2 of the machine pit at points 11 spaced along their length, hydraulically loaded cylinders (not shown) extending longitudinally of the walls 2 connect the walls 2 and the compression members to position the latter longitudinally. Laterally extending shoes 13 on the gripper head 4, support brackets 14 for supporting pins 15 adapted to extend through selected ones of holes 12 in the compression members 9, 10, thus permitting a limited angular displacement of the cross-head 4 with respect to the compression members. The other cross-head 5 has secured on each side a hydraulic cylinder 16, the rams 17 of which engage the ends of the compression members 9, 10 to load the head 5 away from the head 4 and-effect the stretching of a plate held between the heads 4 and 5. Alternatively, the cylinders 16 may be secured to the compression members 9, 10 and the rams 17 abut the cross-head 5. The rams 17 may have a slightly spherical seating on the compression members 9, 10. An auxiliary ram and cylinder 18 co-operates with each ram 17 for initially positioning the head 5. Control means may be provided for stopping the stretching if the heads 4, 5 tilt sideways too much. Shock absorbing means as described in Specification 801,887, to which reference is made, may be provided in case the plate being stretched breaks.