Load limiting device for a seat belt

• US 6,196,589 B1
• Filed: 05/26/2000
• Issued: 03/06/2001
• Est. Priority Date: 10/14/1997
• Status: Expired due to Fees

• Current Assignee: Key Safety Systems, Inc. (Ningbo Junsheng Investment Group Co., Ltd.)
• Original Assignee: Breed Automotive Technology, Inc. (Ningbo Junsheng Investment Group Co., Ltd.)
• Inventors: Taylor, John, Park, Andrew, Downie, Andrew, Blackadder, David, Rees, Elizabeth, Smithson, Alan, Harte, Joe
• Primary Examiner(s): Dickson, Paul N.
• Application Number:
  US09/580,011
• Time in Patent Office: 284 Days
• Field of Search: 280/805, 280/806, 297/470, 297/471, 297/472, 188/377
• US Class Current: 280/805
• CPC Class Codes: B60R 2022/282 using fluids or vico-elastic materials
• CPC Class Codes: B60R 2022/288 with means to adjust or regulate the amount of energy to be absorbed
• CPC Class Codes: B60R 22/28 incorporating energy-absorbing devices belt anchors provided with energy-absorbing means for protecting the occupants in case of physical contact therewith B60R21/055; belt retractors comprising energy-absorbing means B60R22/341, B60R22/4676
• CPC Class Codes: B60R 22/3413 operating between belt reel and retractor frame B60R22/4676 takes precedence
• CPC Class Codes: C08L 2205/22 Mixtures comprising a continuous polymer matrix in which are dispersed crosslinked particles of another polymer
• CPC Class Codes: C08L 2207/20 Recycled plastic
• CPC Class Codes: C08L 23/0815 Copolymers of ethene with aliphatic 1-olefins
• CPC Class Codes: C08L 23/16 Elastomeric ethene-propene or ethene-propene-diene copolymers, e.g. EPR and EPDM rubbers
• CPC Class Codes: C08L 2312/00 Crosslinking
• CPC Class Codes: C08L 2666/04 Macromolecular compounds according to groups C08L7/00 - C08L49/00, or C08L55/00 - C08L57/00; Derivatives thereof
• CPC Class Codes: C08L 53/00 Compositions of block copolymers containing at least one sequence of a polymer obtained by reactions only involving carbon-to-carbon unsaturated bonds; Compositions of derivatives of such polymers

Abstract

A load limiting device is used with a vehicle seat belt during a crash to allow a limited and controlled forward motion of a vehicle occupant after the retractor has locked. The load limiting device decreases the forces exerted by the seat belt on the vehicle occupant'"'"'s torso. The load limiting device has a container which defines a flow path for a fluid, with a restriction in the flow path. An actuator is located within the container and is movable within the container under the action of a load transmitted to the seat belt webbing from the vehicle occupant under extreme acceleration conditions, to move the fluid through the restriction in the flow path to dissipate a predetermined portion of the load on the webbing.

Claims

1. A load limiting device for use with a vehicle safety restraint comprising

(a) a housing containing fluid,

(b) a plurality of blades located inside the housing, and

(c) an external passage for the fluid to travel, wherein a portion of the load transmitted to a seatbelt webbing from a vehicle occupant causes the blades to rotate inside the housing, a movement of the fluid through the external passage absorbs energy of a crash.

2. The load limiting device of claim 1 wherein the housing has an eccentric shape.

3. The load limiting device of claim 1 wherein the rotating blades are in constant contact with the housing preventing fluid from leaking from a chamber to an adjacent chamber.

4. The load limiting device of claim 1 wherein the rotating blades are telescopic, said effective volume of the chambers change as the blades rotate inside the eccentric housing.

5. The load limiting device of claim 1 wherein the diminishing of the effective volume of the chambers drives the fluid into the external passage.

6. A load limiting device for use with a vehicle safety restraint comprising

(a) a housing containing fluid,

(b) a plurality of blades located inside the housing,

(c) an external passage for the fluid to travel, and

(d) a restrictor means for controlling the fluid rate through the external passage, wherein a portion of the load transmitted to a seatbelt webbing from a vehicle occupant causes the blades to rotate inside the housing, a movement of the fluid through the external passage and the restrictor means absorb energy of a crash.

7. The load limiting device of claim 6 wherein the housing has an eccentric shape.

8. The load limiting device of claim 6 wherein the rotating blades are in constant contact with the housing preventing fluid from leaking from a chamber to an adjacent chamber.

9. The load limiting device of claim 6 wherein the rotating blades are telescopic, said effective volume of the chambers change as the blades rotate inside the eccentric housing.

10. The load limiting device of claim 6 wherein the diminishing of the effective volume of the chambers drives the fluid into the external passage.