Energy absorption mechanism for collapsible assembly

A collapsible steering assembly for a vehicle, said assembly comprising:

• a collapsible housing mountable to the vehicle;
• a collapsible steering shaft disposed within said housing;
• an energy absorption mechanism operably coupled with one of said housing and said steering shaft;
• movement of said energy absorption mechanism from an initial configuration to a collapsed configuration resisting collapse of said one of said housing and said steering shaft, said energy absorption mechanism comprising:
• a first member and a second member wherein said first and second members are relatively displaceable through a first stage of displacement and a second stage of displacement during movement of said energy absorption mechanism from said initial configuration to said collapsed configuration;
• said energy absorption mechanism generating a collapse resisting force with a first magnitude during said first stage of displacement and a different second magnitude during said second stage of displacement;
• and
• a metallic foam member operably disposed between said first and second members wherein relative movement of said first and second members during one of said first and second stages of displacement deforms said metallic foam member, said deformation of said metallic foam member generating said collapse resisting force for said one stage.

A method of absorbing energy during the collapse of a steering assembly in a vehicle, said method comprising:

• disposing a metallic foam member between first and second relatively displaceable members wherein the first and second displaceable members are relatively moveable along a displacement axis during collapse of the steering assembly;
• forming an open gap between the first and second displaceable members wherein the gap extends transverse to the displacement axis;
• and
• forcing at least a portion of the metallic foam member into the open gap during collapse of the steering assembly and thereby causing the deformation of the metallic foam member.