Patent ID: 6287508
Filing Date: 2001-09-11
Classification: B29C

Abstract:
A method for manufacturing a curved tubular article wherein said tubular article is composed of a thermoplastic, thermosetting, elastomeric, or a hybrid construction of an elastomer and a thermoplastic or thermosetting material, said tubular article having a predetermined three-dimensional serpentine configuration wherein said article exhibits a consistent wall gauge and circular cross-section uniformly throughout the length of said article, said method comprising:providing a formable tubular preform wherein said tubular preform is composed of a thermoplastic, thermosetting, elastomeric, or a hybrid construction of an elastomer and a thermoplastic or thermosetting material;securing the ends of said preform to respective coupling members such that said preform is longitudinally interposed between said coupling members, said coupling members being mounted on opposite sides of a base such that elongational tension is capable of being placed on said preform;filling the hollow interior of said preform with a first fluid at a temperature high enough to soften said preform to a point where it is formable, said fluid being at a pressure sufficient to support said preform;applying mechanical pressure to the fluid-containing preform at one or more specified locations on the exterior surface of said fluid-containing preform such that said preform is shaped into a predetermined configuration;replacing the first fluid in said preform with a second fluid at a temperature cool enough to set said preform in the desired configuration whereby the predetermined configuration of said preform is set; andremoving said second fluid from said preform, said fluid being totally removed.