Energy absorbing steering wheel assembly

• US 4,390,193 A
• Filed: 07/07/1980
• Issued: 06/28/1983
• Est. Priority Date: 07/07/1980
• Status: Expired due to Term

• Current Assignee: General Motors Corporation (General Motors Company)
• Original Assignee: General Motors Corporation (General Motors Company)
• Inventors: Hopf, Philip W., Williams, Phillip G., Strahan, Robert M.
• Primary Examiner(s): Song, Robert R.
• Application Number:
  US06/166,549
• Time in Patent Office: 1,086 Days
• Field of Search: 280/751, 280/752, 280/753, 280/777, 280/750, 74/552, 74/492, 188/1 C
• US Class Current: 280/777
• CPC Class Codes: B62D 1/11 incorporating energy-absorbing arrangements, e.g. by being yieldable or collapsible padded linings associated with the steering wheel B60R21/05; shock absorbers using plastic deformation of members in general F16F7/12
• CPC Class Codes: Y10T 74/20834 Hand wheels

Abstract

A steering wheel assembly for vehicles which incorporates an energy absorbing coupling which mounts the steering wheel for tilting movement with respect to a column to an optimum impact position when the wheel receives inertia load and which provides for subsequent energy management by deformation of a plurality of metallic legs which collapse at controlled rates.

Claims

1. A steering wheel operatively interconnected to a rotatable steering shaft of a steering column and thereby being disposed at a predetermined position in a vehicle, said steering wheel comprising an outer rim and an inner hub interconnected to one another by a plurality of spokes which space said rim outwardly of said hub, an energy absorbing coupling operatively connected to an end portion of said steering shaft for yieldably supporting said steering wheel axially outwardly from the end of said steering shaft, said energy absorbing coupling being of a plastically deformable material having an annular base drivingly connected to said steering shaft and having a plurality of arcuately spaced and separate energy-absorbing legs extending upwardly from said base and surrounding the longitudinal steering axis of said steering shaft, each of said legs having a radial and inwardly extending bend therein located at a predetermined distance above said base and terminating in an outwardly extending foot portion, fastener means connecting each said foot portion to said inner hub of said steering wheel such that an inertia force of at least a predetermined magnitude directed to a lower portion of said rim will compressively load and buckle said legs of a corresponding lower portion of said coupling while tensioning said legs of an upper portion of said coupling to thereby turn said steering wheel on an axis transverse to said steering axis and from said predetermined position to a second position angularly disposed with respect to said predetermined position so that additional portions of said rim will receive said force for transmission to and subsequent compressive deformation of all of said legs for energy dissipation.

2. A steering wheel and energy absorbing coupling assembly for interconnection to a rotatable steering shaft of a motor vehicle comprising an outer rim and an inner hub interconnected to one another by a plurality of spokes which space said rim axially outwardly from said hub, said energy absorbing coupling operatively interconnecting said hub to an end portion of said steering shaft so that said steering wheel is disposed in a predetermined angular plane, said energy absorbing coupling being formed from plastically deformable metal having a radially extending base drivingly secured to an upper end portion of said steering shaft, said coupling having a plurality of separate energy absorbing legs extending from said base, each of said legs being prebent radially inwardly at a predetermined distance from said base and each terminating in a radially extending outer end, fastener means connecting the outer end of each of said legs to said hub of said steering wheel so that said steering wheel can be manually turned to turn said steering shaft and so that a force of at least a predetermined magnitude applied to a lower portion of said rim compressively load and buckle some of said legs on a corresponding lower portion of said coupling and stretch some of said legs on the upper portion of said coupling so that said steering wheel will be displaced from said predetermined angular plane to a different and upwardly extending plane without substantial deformation of said spokes of said steering wheel so that additional portions of said rim will receive and transmit said force for subsequent compressive deformation of said legs for energy dissipation.

3. A steering wheel arranged for interconnection by an energy absorbing coupling to a rotatable steering shaft of a motor vehicle consisting of an outer handwheel and an inner hub member interconnected to one another by a plurality of spokes which space said handwheel radially outwardly from said hub member, said energy absorbing coupling operatively connecting said hub member axially outwardly of an upper end of said steering shaft characterized in that said coupling is a plastically deformable metallic unit having a base portion secured to an upper end of said steering shaft and having a plurality of separate and substantially identical energy absorbing legs arcuately spaced from one another that surround the axis of said steering shaft and extend upwardly from said base portion for secure connection at their outer ends to said inner hub member, each of said legs being prebent inwardly such that a force of at least a predetermined magnitude applied to a lower portion of said handwheel will compressively load and buckle some of said legs on the lower part of said coupling and elongate some of said legs on an upper part of said coupling by tension load so that said handwheel will pivot into a position transverse to said force without substantial distortion of said spokes allowing additional portions of said handwheel to receive and transmit said force and allowing said legs of said coupling to bend radially inwardly to dissipate the energy of said force.