Patent ID: 9150073
Filing Date: 2015-10-06
Classification: B21C,B21D,B21K,B60G,Y10T

Abstract:
1. A method of making a unitary tubular cross-beam member for use in a twist-axle of a vehicle, the cross-beam member having two connection regions defining a longitudinal direction and a central section formed between the connection regions, the central section being torsionally elastic and having a generally open transverse profile, the connection regions being torsionally stiff in at least a portion thereof, the cross-beam member having a wall thickness that is generally uniform circumferentially and varying longitudinally from the torsionally elastic central section to each of the torsionally stiff connection regions, the method comprising: a) cold forming an initial tubular blank of uniform wall thickness to obtain a tubular blank of variable wall thickness, the tubular blank having a central region corresponding to the central section, the variable wall thickness of the tubular blank corresponding to the wall thickness of the cross-beam member, and b) deforming the central region of the tubular blank to conform with the generally open transverse profile of the central section to obtain the cross-beam member.