Back to results
US 2003/0189331 A1Published application
Seat belt retractor with hydraulic load limiting
AssigneeKey Safety Systems, Inc.
InventorThomas Heckmayr
Life of this patent
Estimating the term…
Abstract
A seat belt retractor for a vehicle seat belt has a belt reel for the seat belt. A free-flowing load limiting medium is arranged in a working chamber. A displacement means is drivable by the belt reel. The load limiting medium is transported through at least one flow channel by the displacement means. The flow cross-section in the flow channel is selected as a function of the kinematic viscosity of the load limiting medium, to achieve a belt force limitation profile over time which approaches that of a torque rod.
Claims5
A seat belt retractor comprising:
- a belt reel;
- a free-flowing load limiting medium arranged in a working chamber;
- a displacement means drivable by the belt reel;
- at least one flow channel through which the load limiting medium is transported by the displacement means;
- the flow cross-section in the at least one flow channel exhibits, as a function of the kinematic viscosity of the load limiting medium, a constant area, the dimensions of which lie, in the case of a displacement means, in the range delimited by the two curves (KL1, KL2) (KR1, KR2) in FIG. 6 or, in the case of a rotary displacement means, in the range delimited by the two curves (KR1, KR2) in FIG. 7.
2 more elements
Dependencies are inferred from the claim text.