GB856977A - Improvements in seal and method of making same - Google Patents

Abstract

856,977. Making joint-making packing; corrugating. ROBERTSHAW-FULTON CONTROLS CO. Dec. 16, 1957 [March 25, 1957], No. 39077/57. Class 83 (2) and 83 (4). [Also in Groups XXIII, XXVI and XXVIII] A metal sealing-ring (see Group XXVI) of V cross-section is formed by inserting a metal tube in a die, deforming it so as to shape it to the desired cross-section, cutting off the ends of the ring and finishing the peripheral edges by a grinding operation. As applied to the making of a three-ply seal, a tubular member 96, Fig. 19, which has been previously cut from a composite tube formed by drawing three nested tubes through a die, is first inserted into the aperture 104, 106 of a die formed by upper and lower members 100, 98 which are supported in a base 110 and retained therein by a threaded cap 112. The member 96 with an inner resilient plug 146 is located on a shoulder 122 of a stationary lower punch 118 carried in the base. A movable punch 124, connected by a yoke member 132 to the piston-rod 134 of an hydraulic piston-and-cylinder arrangement 136, is lowered into the die so that, when pressure is applied to the piston, a shoulder 128 on the punch 124 coacts with the shoulder 122 on the punch 118 to deform a portion of the member 96 and the resilient plug into a cavity 102 formed in the die members 100, 98. After deformation, the member 96 is withdrawn from the die, and the deformed portion 148, Fig. 21, is severed from the rest of the member 96 and, after a heattreatment process, then has its severed edges 150, 152 finished into accurate sealing surfaces by a grinding process. In order to produce the alternative type of seal shown at 184, Fig. 26, the die arrangement is modified by providing an intermediate member between the upper and lower die members 100, 98 so that two corrugations 180, 182, may be formed. The wasted end portions 180, 182 are then cut off and the sealing surfaces 186, 188 produced as previously described. The seal may also be formed by being cut from a tube provided with a number of corrugations in a bellows-forming machine.