Adaptive energy absorbing device for a steering column

Abstract

An energy absorbing device for a collapsible steering column of a vehicle is able to compensate for the severity of a crash and the weight of the driver to better manage the absorption of energy in a crash event. A housing has at least one fixed abutment surface, and at least one adjuster disposed in the housing for selective lateral slidable movement. At least one anvil is disposed adjacent an initial abutment surface of the adjuster in spaced relation to the fixed abutment surface of the housing in a first position of the anvil associated with high energy absorption. A plastically deformable strap is supported between the anvil and the housing. The adjuster slides out of the path of the anvil in a crash event in response to input of a control signal allowing the anvil to slide into contact with the fixed abutment surface of the housing to define a second position of the anvil associated with lower energy absorption.

1 . An energy absorbing device for a collapsible steering column of a vehicle, comprising: 
 a housing having at least one fixed abutment surface;    at least one adjuster disposed in said housing for selective laterally slidable movement therein and having an initial abutment surface, said adjuster further comprising an explosive device emitting a gas in response to a signal in a crash condition of the vehicle to undertake said selective laterally slidable movement;    at least one anvil having a mating arcuate surface, said anvil being disposed in said housing abutting said initial abutment surface of said adjuster and spaced longitudinally from said fixed abutment surface in a first position of said anvil;    a plastically deformable strap supported and configured in a generally S-shaped pattern between said anvil arcuate mating surface and said housing; and    said anvil arcuate mating surface engaging said strap so as to restrict slidable movement therebetween and having a base portion for engaging said initial abutment surface of said adjuster maintaining said base portion in spaced relation from said fixed abutment surface of said housing and said adjuster being laterally slidable in response to said signal in a crash condition of the vehicle so as to remove said adjuster from between said anvil and said housing allowing said base portion of said anvil to move from said first position into mating contact with said fixed abutment surface of said housing in response to an applied force from said strap defining a second position of said anvil, said arcuate surface of said anvil having a first coefficient of friction with said strap while said anvil is in said first position and said arcuate surface having a second coefficient of friction with said strap while said anvil is in said second position, said second coefficient of friction being less than said first coefficient of friction allowing the steering column to collapse under a lighter axial load while said anvil is in said second position.    
   
   
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