Load limiting device for a seat belt

• US 6,183,015 B1
• Filed: 05/26/2000
• Issued: 02/06/2001
• 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:
  US09/580,918
• Time in Patent Office: 256 Days
• Field of Search: 280/805, 297/470, 297/471, 297/472, 267/34, 267/70, 267/71, 267/73, 267/74, 267/120, 188/371, 188/286, 188/287
• 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 cylinder,

(b) a piston arranged within the cylinder and operable to act on a fluid, and

(c) a ball valve controlling the release of fluid from the cylinder under load limiting conditions, wherein a portion of the load transmitted to a seatbelt webbing from a vehicle occupant drives the piston against the fluid, the setting of the ball valve determines the amount of fluid released from the cylinder.

2. The load limiting device of claim 1 further comprising a spring having a role in the operation of the ball valve.

3. The load limiting device of claim 1 further comprising a vent preventing the creation of a vacuum in the non-fluid portion of the cylinder.