Patent ID: 8782898
Filing Date: 2014-07-22
Classification: B21D,E04C,Y10T

Abstract:
1. A method of longitudinally twisting a hollow elongate member to a desired spiral form comprising: (a) fabricating a plurality of longitudinal parts integral with joint means complementarily fastenable to each other into forming said hollow elongate member; (b) fastening said plurality of longitudinal parts with said joint means to assemble said hollow elongate member; (c) twisting said assembled hollow elongate member to said desired spiral form; and (d) bracing to maintain the hollow elongated member in the desired twisted spiral form, wherein the bracing step includes integrally fabricating features with the longitudinal parts which features, upon assembly, form internal bracing features within the hollow elongate member, wherein the internal bracing features include a sleeve formed by complementary semi-cylindrical halves integral with each of the longitudinal parts, and wherein said semi-cylindrical halves are joinable to each other by sleeve joints.