Energy absorbing device with double spring means for steering columns
AssigneeLemforder Nacam S.A.
InventorsChristophe Dufour, Pascal Millet, Vincent Fargeas
Life of this patent
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Abstract
A motor vehicle steering column comprises a steering shaft mounted in a body-tube connected via a support assembly to the chassis of the vehicle, the support assembly comprising a mobile support, a fixed support attached to the chassis of the vehicle and a double winding mounted on a member rotating on a fixed shaft. The double winding has a central portion mounted on the mobile support connected to the body tube so that in the event of an impact the mobile support pushes the double winding and unwinds it to absorb energy.
Claims6
An energy absorbing device for connecting the steering column of a motor vehicle with the vehicle chassis, comprising:
- (a) fixed support means (8) adapted for connection with the vehicle chassis;
- (b) steering column means including a support tube (2) and a steering shaft (1) rotatably mounted concentrically within said support tube;
- (c) movable support means (9) connected with said support tube;
- (d) first connecting means connecting said movable support means for displacement in a given direction generally parallel with said support tube between first and second positions, said connecting means including a fixed shaft (48) connected with said fixed support means and extending in a plane normal to said given direction;
- and
- (e) spring means normally biasing said movable support means toward said first position, said spring means including:
- (1) a support sleeve (47),rotatably mounted concentrically about said fixed shaft;
- (2) a pair of metal helical torsion spring portions (31, 32) mounted in axially spaced relation concentrically about said support sleeve, said torsion spring portions having coil turns that extend in opposite directions, respectively;
- (3) a central metal portion (42) integral with and projecting tangentially from the adjacent ends of said torsion spring portions, respectively;
- and
- (4) second connecting means (29) connecting said central spring portion with said movable support means, said second connecting means being operable upon the application of an impact force to the vehicle chassis to progressively displace said central spring portion away from said support sleeve and thereby unwind the adjacent turns of said torsion spring portions, respectively, whereby the energy of the impact force is absorbed by said spring means.
Dependencies are inferred from the claim text.