GB544466A - Improvements in or relating to apparatus for deforming thin wall tubular shells - Google Patents

Abstract

544,466. Treating tubes ; stamping. CLIFFORD MANUFACTURING CO. Feb. 3, 1941, No. 1431. Convention date, Jan. 25, 1940. [Classes 83 (ii) and 83 (iv)] Thin circular tubes are converted into (e.g.) hexagonal shape by fluid pressure directly applied internally by apparatus having means that initially closes the tube ends and then creates and applies sufficient pressure to deform the tube to fit the die within which the tube is clamped. The die is two-part each part made in three sections 36, 38, Fig. 5, held in seating blocks 30 mutually guided at 32 and provided with opening springs 34 and a closing eccentric 48 operated by levers 46 connected by a handle 66, Fig. 1. The ends of the tubes are expanded to enlarged hexagonal shape by the parts 57, Fig. 2, of plungers 50 having pilot portions 55 and shoulders 58 that seal the tube ends against corresponding formations in the die. The die also forms enlargements at intermediate points in the length of the tubes. The plungers are carried by rams 62 guided by splines 66 in bearings 64 and coupled to pistons 70 the cylinders for which are formed in the main pistons 74. On admission of fluid pressure at 92 the two pistons move as one under the influence of a coupling spring 82 until the shoulders 58 effect sealing arresting the pistons 70. The pistons 74 continue to advance compressing the springs 82 and causing the fluid at 80 to pass under high pressure through the bore 100 to the interior of the tube to deform it to hexagonal shape. On the return stroke non-return valves 86 permit the cylinder 80 to refill with oil or other pressure fluid.