Key Safety Systems, Inc.

Breed Automotive Technology, Inc.

Brian A Jack

John Bell

Martyn N Palliser

Matthew Barber

David Blackadder

Howard James Foster

David Hunter

Graham Jack

A pretensioner for a three point vehicle safety restraint seat belt has a mounting for one end of the seat belt. The mounting has a first member fixed to a load bearing part of the vehicle and a second member attached to the end of the seat belt. A force reservoir, such as a pyrotechnic unit, moves the second member relative to the first member in a pretensioning direction in response to activation by a crash sensor.

Seat belt pretensioner

A pretensioner for a three point seat belt has a cylinder adapted to be attached to a structural member of a vehicle and a piston disposed within the cylinder. A pyrotechnic means moves the piston in a direction that is longitudinal relative to the cylinder in a pretensioning direction. A slider bar is oriented substantially parallel to a longitudinal axis of the cylinder. A seat belt webbing is looped around the slider bar such that the seat belt webbing can freely move along a portion of the slider bar that is oriented substantially parallel to a longitudinal axis of the cylinder so long as the pyrotechnic means for moving the piston has not been activated. A cable extends from the piston and loops around the seat belt webbing to cause the seat belt webbing to move along the slider bar in a pretensioning direction when the pyrotechnic means for moving the piston is activated.

A pretensioner for a three point seat belt has a cylinder adapted to be attached to a structural member of the vehicle and a piston disposed within the cylinder. The piston can move translationally relative to the cylinder in a pretensioning direction. A flexible member is arranged in a curved profile with a seat belt webbing being attached to the flexible member. The flexible member has a first end that can be pulled by the piston and a second end releasably connected to an exterior of the cylinder such that when the piston moves translationally relative to the cylinder the second end of the flexible member moves translationally relative to the cylinder along the exterior of the cylinder.

A pretensioner for a three point vehicle safety restraint seat belt, has a mounting for one end of the seat belt. The mounting is a first member fixed to a load bearing part of the vehicle. A second member is attached to the end of the seat belt. A means is provided for moving the second member relative to the first member in a pretensioning direction in response to activation of a crash sensor. The mounting may be a flexible cable that functions as a slider bar. A piston-cylinder force reservoir may be used either to pull the slider bar via a carriage mounted on a rail, or to pull the cable directly. Return motion is preferably inhibited. The arrangement provides a space saving pretensioner suitable for two-door vehicles while allowing access to the vehicle rear.

A seat belt pretensioner acts upon the sill end of a three point seat belt. A fixed member of the pretensioner is adapted to be fixed to a load bearing part of the vehicle. A movable member is connected to the sill end of the seat belt and is slideable with respect to the fixed member. The movable member is moved in a direction that is longitudinal relative to the fixed member to move the sill end of the seat belt in a pretensioning direction in response to a signal from a crash sensor. In this way the sill end of the seat belt is free to move along a connecting member when the seat belt is not under tension either from use in restraining a seat occupant and/or from a pretensioning operation.

A seat belt retractor has a spool mounted for rotation on the retractor, for retraction or payout of seat-belt webbing depending upon the rotation direction of the spool. The spool is locked against rotation when a crash condition is sensed. A force limiter allows further payout of the seat belt webbing after the spool shaft has locked, under the influence of a vehicle occupant's forward momentum. The force limiter has a first resilient component attached in the force path between the spool and the locking component. A second resilient component is a wire releasably held in the force path between the spool and the locking component by a locking plate engaged with the locking component. The wire is released from the force path by disengagement between the locking plate and the locking component.

Seat belt retractor

A seat belt retractor has a rotatable spool for retraction or payout of seat belt webbing wound thereon, depending upon the rotation direction of the spool. A locking wheel is attached to one end of the spool. The spool to is locked to the locking wheel when a crash is sensed. A force limiter allows further payout of the seat belt webbing after the spool has locked to the locking wheel, under the influence of a vehicle occupant's forward momentum. The force limiter includes a torsion bar attached at one end to the locking wheel and at the other end to the spool, and a secondary force limiter mechanism releasably coupled in the force path between the spool and the locking wheel, and a mechanism for de-coupling the secondary mechanism after a predetermined number of turns of the torsion bar. The locking mechanism has a locking element that is resiliently biased to a position wherein it locks the spool to the locking wheel and is held out of locking engagement by the secondary force limiting mechanism. The retractor is converted into a standard locking retractor after load limiting ensuring that the vehicle occupant is securely restrained against secondary impacts.

A seat belt retractor has a rotatable spool mounted in a frame, a primary locking mechanism for arresting rotation of the spool and a load absorbing mechanism arranged to come into effect at a predetermined load for absorbing a portion of the spool locking load. The load absorbing mechanism may be a section of an inwardly facing peripheral edge of the frame having a serrated or roughened texture and which is positioned and adapted so that above a predetermined load it co-operates with a smooth surfaced spool bearing face to absorb some of the load. Spool rotation is prevented on engagement of the primary locking mechanism and the load on the primary mechanism rises causing the frame side walls to deform and the serrated or roughened section is pushed closer to, and eventually against the spool bearing face, roughening the smooth surface and increasing its coefficient of friction to absorb some of the load and resist rotation of the spool.

An improved safety belt buckle for use with a buckle end pretensioner. The buckle for a vehicle safety restraint belt comprises a latch ( ) moveable between a tongue engaging position in which the buckle is fastened and a tongue disengaged position in which the buckle is open, a button ( ) moveable in the direction of tongue insertion to lift the latch against the action of a biasing spring ( ), into the disengaging position. A securing means ( ) in the form of a slidable plate is mounted in the buckle frame and is moveable between a position in which it restrains a movement of the latch into the disengaging position and a position in which it does not restrain movement of the latch. The securing plate is biased to the unrestraining position by a leaf spring ( ), the strength of which is chosen so as to be overcome during the deceleration phase of a pretensioner so that the securing plate ( ) moves to the restraining position and prevents opening of the buckle but so that when pretensioning forces dissipate, the securing plate moves back to the unrestraining position. In this buckle, the securing plate moves into the latch restraining position during the deceleration phase of the pretensioning operation and thus reduces the danger of the buckle jamming.

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Annan, United Kingdom

Brian A Jack