Collapsible steering column assembly

Claim 2

In a steering column assembly adapted for telescopic collapse in an energy absorbing mode, the combination comprising, a first tube member, a second tube member disposed relative to said first tube member for axial telescopic bodily movement, means on one of said first and said second tube members defining a track portion extending longitudinally of said one tube member, means on the other of said first and said second tube members defining a seat portion, a key member including a frittion surface portion complementary to said track portion and a key portion adapted to engagement on said seat portion, said key member being disposed between said first and said second tube members with said key portion engaging said seat portion for preventing relative bodily movement between said key member and said other tube member and with said friction surface engaging said track portion, said key member including spring means urging relative separation between said seat portion and said friction surface thereby to generate substantial mechanical friction between said friction surface and said track portion for normally maintaining said first and said second tube members in axially fixed relation and for effecting energy absorption at a predetermined rate during relative telescopic movement therebetween.

Claim 3

In a steering column assembly adapted for telescopic collapse in an energy absorbing mode and including an axially collapsible steering shaft for transferring steering torque between a steering gear and a manual steering instrumentality, the combination comprising, a first tube member disposed around said steering shaft for rotation and for axial bodily movement relative thereto, a second tube member disposed around said steering shaft for rotation and for axial bodily movement relative thereto and for axial telescopic bodily movement relative to said first tube member, means on one of said first and said second tube members defining a plurality of angularly spaced longitudinally extending track portions, means on the other of said first and said second tube members definining a corResponding number of seat portions adapted for registry with respective ones of said track portions, a plurality of key members corresponding in number to the number of said track portions and each including a friction surface portion complementary to said track portions and a key portion adapted for engagement on respective ones of said seat portions, each of said key members being disposed between said first and said second tube members with respective ones of said key portions engaging corresponding ones of said seat portions for preventing relative bodily movement between said key members and sai other tube member and with respective ones of said friction surfaces engaging corresponding ones of said track portions, each of said key members including spring means urging relative separation between corresponding ones of said seat portions and said friction surfaces thereby to unite said first and said second tube members for unitary rotation while generating substantial mechanical friction between said friction surfaces and said track portions for normally maintaining said first and said second tube members in axially fixed relation and for effecting energy absorption at a predetermined rate during relative telescopic movement therebetween.

Claim 4

In a steering column assembly adapted for telescopic collapse in an energy absorbing mode and including an axially collapsible steering shaft for transferring steering torque between a steering gear and a manual steering instrumentality, the combination comprising, a first tube member disposed around said steering shaft for rotation and for axial bodily movement relative thereto, a second tube member disposed around said steering shaft for rotation and for axial bodily movement relative thereto and for axial telescopic bodily movement relative to said first tube member, means on one of said first and said second tube members defining a plurality of angularly spaced longitudinally extending track portions, means on the other of said first and said second tube members definining a corResponding number of seat portions adapted for registry with respective ones of said track portions, a plurality of key members corresponding in number to the number of said track portions and each including a friction surface portion complementary to said track portions and a key portion adapted for engagement on respective ones of said seat portions, each of said key members being disposed between said first and said second tube members with respective ones of said key portions engaging corresponding ones of said seat portions for preventing relative bodily movement between said key members and sai other tube member and with respective ones of said friction surfaces engaging corresponding ones of said track portions, each of said key members including spring means urging relative separation between corresponding ones of said seat portions and said friction surfaces thereby to unite said first and said second tube members for unitary rotation while generating substantial mechanical friction between said friction surfaces and said track portions for normally maintaining said first and said second tube members in axially fixed relation and for effecting energy absorption at a predetermined rate during relative telescopic movement therebetween.

Claim 5

In a steering column assembly adapted for axial collapse in an energy absorbing mode and including an axially collapsible steering shaft assembly for transferring steering torque between a steering gear and a manual steering instrumentality and an axially collapsible mast jacket assembly surrounding said steering shaft assembly, the combination comprising, a first shift tube member disposed between said steering shaft assembly and said mast jacket assembly for rotation and for axial bodily movement relative to each, a second shift tube member disposed between said steering shaft assembly and said mast jacket assembly for rotation and for axial bodily movement relative to each and for axial telescopic bodily movement relative to said first shift tube member, means on one of said first and said second shift tube members defining a trio of longitudinally extending track portions spaced equally about the circumference of said one tube member and having semicircular configurations in cross section, means on the other of said first and said second shift tube members defining a trio of seat portions spaced equally around the circumference of said other tube member and having semicircular configurations in cross section, and a trio of cylindrical spring pins each having a longitudinally extending gap therein and each defining a friction surface complementary to said track portions and a key portion adapted for engagement on a respective one of said seat portions, each of said spring pins being disposed between said first and said second shift tube members with respective ones of said key portions engaging corresponding ones of said seat portions for preventing relative bodily movement between said spring pins and said other shift tube member and with respective ones of said friction surfaces engaging corresponding ones of said track portions, each of said spring pins having natural resiliency urging relative separation between said seat portions and said friction surfaces thereby to unit said first and said second shift tube members for unitary rotation while generating substantial mechanical friction between said friction surfaces and said track portions for normally maintaining said first and said second shift tube members in axially fixed relation and for effecting energy absorption at a predetermined rate during relative telescopic movement therebetween.

Claim 6

In a steering column assembly adapted for axial collapse in an energy absorbing mode and including an axially collapsible steering shaft assembly for transferring steering torque between a steering gear and a manual steering instrumentality and an axially collapsible mast jacket assembly surrounding said steering shaft assembly, the combination comprising, a first shift tube member disposed between said steering shaft assembly and said mast jacket assembly for rotation and for axial bodily movement relative to each, a second shift tube member disposed between said steering shaft assembly and said mast jacket assembly for rotation and for axial bodily movement relative to each and for axial telescopic bodily movement relative to said first shift tube member, means on one of said first and said second shift tube members defining a trio of longitudinally extending track portions spaced equally about the circumference of said one tube member and having semicircular configurations in cross section, means on the other of said first and said second shift tube members defining a trio of seat portions spaced equally around the circumference of said other tube member and having semicircular configurations in cross section, and a trio of cylindrical spring pins each having a longitudinally extending gap therein and each defining a friction surface complementary to said track portions and a key portion adapted for engagement on a respective one of said seat portions, each of said spring pins being disposed between said first and said second shift tube members with respective ones of said key portions engaging corresponding ones of said seat portions for preventing relative bodily movement between said spring pins and said other shift tube member and with respective ones of said friction surfaces engaging corresponding ones of said track portions, each of said spring pins having natural resiliency urging relative separation between said seat portions and said friction surfaces thereby to unit said first and said second shift tube members for unitary rotation while generating substantial mechanical friction between said friction surfaces and said track portions for normally maintaining said first and said second shift tube members in axially fixed relation and for effecting energy absorption at a predetermined rate during relative telescopic movement therebetween.