GB1152294A - Steering Column Assemblies for Motor Vehicles - Google Patents

Abstract

1,152,294. Collapsible steering columns. GENERAL MOTORS Ltd. 2 May, 1968 [8 May, 1967], No. 21365/67. Heading B7H. In a vehicle steering column assembly in which a steering shaft 10 is collapsible telescopically in response to abnormal impact forces on a vehicle steering wheel, an upper portion 12 of the shaft 10 has a thrust bearing connection 16 to a telescopically deformable member 20 which is deformed as the shaft 10 collapses telescopically, and in the region of the connection 16 the deformable member 20 is connected to a support 42 by at least one mounting member 44, 46 which breaks away in response to an abnormal impact force on the steering wheel and thereupon constrains the part of the deformable member 20 in the region of the connection 16 to move in a direction oblique to the longitudinal axis of the uncollapsed steering shaft. The deformable member may extend coaxially of the steering shaft 10 (Fig. 1) or obliquely of the shaft (Fig. 6, not shown). The steeling shaft comprises upper and lower portions 12, 14 interconnected by shearable pins 30, which are preferably of plastics material injection-moulded in situ, and is pivotally mounted either on a toeboard at the lower end, preferably by a resilient bushing 28, or to the front firewall by a generally upright link (50) (Figs. 3, 5, not shown). The mounting members 44, 46 are secured to the support 42, of H-crosssection, and mounted in open-upper-ended slots in a bracket 40 secured to the deformable member 20, in which slots they are slidable after their frangible connections with the support have broken upon impact. These frangible connections are preferably of in situ injectionmoulded shearable plastics material. Engagement of the portion 48 of the bracket 40 with the support 42 prevents rearward movement of the steering column assembly in an accident.