Collapsible steering columns

Claim 2

A collapsible steering column assembly comprising: first and second coaxially and telescopically related torque transmitting members For connection between a steering wheel and a steering gear of a vehicle; coupling means connecting said first and second members for mutual rotation; at least one shearable member connecting said first and second members to normally prevent relative telescopic movement therebetween and shearable to permit relative telescopic movement upon the application of an abnormal axial load on said assembly; and a third member, separate from said first and second members, disposed between said first and second members, said third member forced axially through the outer one of said coaxial members by the inner one of said coaxial members upon application of an abnormal axial load and including at least a portion having a lateral dimension greater than that of the outer member which causes progressive deformation of said members and consequent energy absorption, said first member including a shaft, said second member including a tube mounted coaxially about said shaft, said shaft including a section having a polygonal cross section, and comprising a sleeve mounted within said tube and having a complemental polygonal bore receiving said polygonal cross section of said shaft, said section of said shaft including means defining a peripheral groove therein, said shearable member including a shear pin extending through said tube and said sleeve and into said groove.

Claim 3

A collapsible steering column assembly as claimed in claim 1 comprising a bearing receiving said shaft therein and mounted in said tube for supporting said shaft.

Claim 4

A collapsible steering column assembly as claimed in claim 1, wherein said third member comprises a ductile material and progressively deforms during relative telescopic movement of said first and second members.

Claim 5

A collapsible steering column assembly as claimed in claim 1, wherein said third member comprises a ductile material selected from the group consisting of mild steel, aluminum, copper and plastics.

Claim 6

A collapsible steering column assembly as claimed in claim 1, wherein said third member comprises a ductile material selected from the group consisting of silicone rubber, nitrile/neoprene rubber and a polyurethane plastic material.

Claim 7

A collapsible steering column assembly as claimed in claim 1, wherein said polygonal cross section of said shaft section is a square cross section and said complemental polygonal bore of said sleeve is a complemental square bore.

Claim 8

A collapsible steering column assembly comprising: first and second coaxially and telescopically related torque transmitting members for connection between a steering wheel and a steering gear of a vehicle; coupling means connecting said first and second members for mutual rotation; at least one shearable member connecting said first and second members to normally prevent relative telescopic mvement therebetween and shearable to permit relative telescopic movement upon the application of an abnormal axial load on said assembly; and a third member, separate from said first and second members, disposed between said first and second members, said third member forced axially through the outer one of said coaxial members by the inner one of said coaxial members upon application of an abnormal axial load and including at least a portion having a lateral dimension greater than that of the outer member which causes progressive deformation of said members and consequent energy absorption, said first member including a shaft, said second member including a tube mounted coaxially about said shaft, said tube including two sections of different diameter and a shoulder section joining said two sections, and said third member including a dish-shaped member mounted within said tube in the area of said shoulder section, and said shaft including an end mounted adjacent and spaced from said dish-shaped member.

Claim 9

A collapsible steering column assembly comprising: first and second coaxially and telescopically related torque transmitting members for connection between a steering wheel and a steering gear of a vehicle; coupling means connecting said first and second members for mutual rotation; at least one shearable member connecting said first and second members to normally prevent relative telescopic mvement therebetween and shearable to permit relative telescopic movement upon the application of an abnormal axial load on said assembly; and a third member, separate from said first and second members, disposed between said first and second members, said third member forced axially through the outer one of said coaxial members by the inner one of said coaxial members upon application of an abnormal axial load and including at least a portion having a lateral dimension greater than that of the outer member which causes progressive deformation of said members and consequent energy absorption, said first member including a shaft, said second member including a tube mounted coaxially about said shaft, said tube including two sections of different diameter and a shoulder section joining said two sections, and said third member including a dish-shaped member mounted within said tube in the area of said shoulder section, and said shaft including an end mounted adjacent and spaced from said dish-shaped member.

Claim 10

A collapsible steering column assembly as claimed in claim 7, wherein said dish-shaped member includes a base portion having an extErnal diameter equal to the internal diameter of said tube and a sidewall portion extending from said base portion and lying along said shoulder section and generally directed in the axial direction toward said shaft.

Claim 11

A collapsible steering column assembly as claimed in claim 8, wherein said base portion of said dish-shaped member includes an aperture therethrough having a shaped internal surface and said shaft includes an end extending adjacent said base portion and having a complemental surface to be received by the aperture in said base portion upon axial collapse of the assembly.

Claim 12

A collapsible steering column assembly comprising: first and second coaxially and telescopically related torque transmitting members for connection between a steering wheel and a steering gear of a vehicle; coupling means connecting said first and second members for mutual rotation; at least one shearable member connecting said first and seocnd members to normally prevent relative telescopic movement therebetween and shearable to permit relative telescopic movement upon the application of an abnormal axial load on said assembly; and a third member, separate from said first and second members, disposed between said first and second members, said third member forced axially through the outer one of said coaxial members by the inner one of said coaxial members upon application of an abnormal axial load and including at least a portion having a lateral dimension greater than that of the outer member which causes progressive deformation of said members and consequent energy absorption, said first member including a shaft, said second member including a tube mounted coaxially about said shaft, said tube including two sections of different diameter and a shoulder section joining said two sections, said shaft including an end having a base portion and a reduced portion extending from said base portion, and said third member including a split ring disposed about said reduced portion and against said base portion in the area of said shoulder section and having an external diameter greater than the internal diameter of said tube and an internal diameter greater than the external diameter of said reduced portion.

Claim 13

A collapsible steering column assembly comprising: first and second coaxially and telescopically related torque transmitting members for connection between a steering wheel and a steering gear of a vehicle; coupling means connecting said first and second members for mutual rotation; at least one shearable member connecting said first and seocnd members to normally prevent relative telescopic movement therebetween and shearable to permit relative telescopic movement upon the application of an abnormal axial load on said assembly; and a third member, separate from said first and second members, disposed between said first and second members, said third member forced axially through the outer one of said coaxial members by the inner one of said coaxial members upon application of an abnormal axial load and including at least a portion having a lateral dimension greater than that of the outer member which causes progressive deformation of said members and consequent energy absorption, said first member including a shaft, said second member including a tube mounted coaxially about said shaft, said tube including two sections of different diameter and a shoulder section joining said two sections, said shaft including an end having a base portion and a reduced portion extending from said base portion, and said third member including a split ring disposed about said reduced portion and against said base portion in the area of said shoulder section and having an external diameter greater than the internal diameter of said tube and an internal diameter greater than the external diameter of said reduced portion.

Claim 14

A collapsible steering column assembly comprising: first and second coaxially and telescopically related torque transmitting members for connection between a steering wheel and a steering gear of a vehicle; coupling means connecting said first and second members for mutual rotation; at least one shearable member connecting said first and second members to normally prevent relative telescopic movement therebetween and shearable to permit relative telescopic movement upon the application of an abnormal axial load on said assembly; and a third member, separate from said first and second members, disposed between said first and second members, said third member forced axially through the outer one of said coaxial members by the inner one of said coaxial members upon application of an abnormal axial load and including at least a portion having a lateral dimension greater than that of the outer member which causes progressive deformation of said members and consequent energy absorption, said first member including a shaft and said second member including a tube mounted coaxially about said shaft, and said third member comprising a plug including a first portion disposed within and of the same general diameter as the inner diameter of said tube and a second portion disposed adjacent an end of said shaft and having a diameter greater than the inner diameter of said tube.

Claim 15

A collapsible steering column assembly comprising: first and second coaxially and telescopically related torque transmitting members for connection between a steering wheel and a steering gear of a vehicle; coupling means connecting said first and second members for mutual rotation; at least one shearable member connecting said first and second members to normally prevent relative telescopic movement therebetween and shearable to permit relative telescopic movement upon the application of an abnormal axial load on said assembly; and a third member, separate from said first and second members, disposed between said first and second members, said third member forced axially through the outer one of said coaxial members by the inner one of said coaxial members upon application of an abnormal axial load and including at least a portion having a lateral dimension greater than that of the outer member which causes progressive deformation of said members and consequent energy absorption, said first member including a shaft and said second member including a tube mounted coaxially about said shaft, and said third member comprising a plug including a first portion disposed within and of the same general diameter as the inner diameter of said tube and a second portion disposed adjacent an end of said shaft and having a diameter greater than the inner diameter of said tube.

Claim 16

A collapsible steering column assembly comprising: first and second coaxially and telescopically related torque transmitting members for connection between a steering wheel and a steering gear of a vehicle; coupling means connecting said first and second members for mutual rotation; at least one shearable member connecting said first and second membErs to normally prevent relative telescopic movement therebetween and shearable to permit relative telescopic movement upon the application of an abnormal axial load on said assembly; and a third member, separate from said first and second members, disposed between said first and second members, said third member forced axially through the outer one of said coaxial members by the inner one of said coaxial members upon application of an abnormal axial load and including at least a portion having a lateral dimension greater than that of the outer member which causes progressive deformation of said members and consequent energy absorption, said second member including a tube, said first member including a shaft coaxially disposed within said tube and including longitudinally extending surface serrations, and said coupling means comprising a sleeve within said tube and coaxial with said tube and said shaft, said sleeve fixed to said tube for rotary movement and including an internal surface having serrations for mating with serrations on said shaft during axial collapse of the assembly to maintain the steering ability of the vehicle upon collapse of the assembly.

Claim 17

A collapsible steering column assembly comprising: first and second coaxially and telescopically related torque transmitting members for connection between a steering wheel and a steering gear of a vehicle; coupling means connecting said first and second members for mutual rotation; at least one shearable member connecting said first and second membErs to normally prevent relative telescopic movement therebetween and shearable to permit relative telescopic movement upon the application of an abnormal axial load on said assembly; and a third member, separate from said first and second members, disposed between said first and second members, said third member forced axially through the outer one of said coaxial members by the inner one of said coaxial members upon application of an abnormal axial load and including at least a portion having a lateral dimension greater than that of the outer member which causes progressive deformation of said members and consequent energy absorption, said second member including a tube, said first member including a shaft coaxially disposed within said tube and including longitudinally extending surface serrations, and said coupling means comprising a sleeve within said tube and coaxial with said tube and said shaft, said sleeve fixed to said tube for rotary movement and including an internal surface having serrations for mating with serrations on said shaft during axial collapse of the assembly to maintain the steering ability of the vehicle upon collapse of the assembly.