METHOD OF MAKING A COLLAPSIBLE STEERING COLUMN FOR A VEHICLE

摘要

A tubular first part (1) of the column is swaged or formed onto a second part (2) of the column in a controlled and tuned sense with respect to a predetermined collapse load, making it suitable for chest or vehicle frontal impact. The first part can be of circular cross-section prior to swaging or forming onto the second part, whilst the second part can be a solid or tubular shaft of flattened configuration to give a back-to-back or double D-configuration. A layer (3) of plastics material is provided between the two parts and the first part is swaged onto the second part with such a force that a swage overload occurs to cause the plastics material to creep to a known, controllable base stress level.