Patent ID: 6460250
Filing Date: 2002-10-08
Classification: B21D,Y10T

Abstract:
A process for forming an elongate structural element of determined shape being of large and small cross-sectional dimensions at spaced locations along its length, the process including the steps of:(i) selecting a first tube for forming a, first selected length of the element having cross-sectional dimensions within a first range of relatively small cross-sectional dimensions within the hydro-forming-elongation ratio capabilities of the material from which the first tube is formed, said first tube being of constant wall thickness and being of a first constant cross-sectional dimension along its length, (ii) selecting a second tube for forming a second selected length of the element adjacent to the first length, the second length of the element having cross-sectional dimensions within a second range of relatively large cross-sectional dimensions within the hydro-forming elongation ratio capabilities of the material from which the second tube is formed, said second tube being of constant wall thickness and being of a second constant cross-sectional dimension along its length which is different to said first constant cross-sectional dimension, (iii) joining said first and second tubes together end to end by forming an end portion of the first tube, forming an end portion of the second tube, overlapping said end portions, and fixedly securing together said overlapping end portions, and (iv) performing forming operations on the first and second tubes to produce said determined shape of the element in which the element has large and small cross-sectional dimensions at spaced locations along its length.