Breed Automotive Technology, Inc.

Key Safety Systems, Inc.

Matthew Barber

John Bell

Brian A Jack

Martyn N Palliser

Howard James Foster

Graham Jack

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.

Seat belt retractor

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.

Growing community of inventors

Carlisle, United Kingdom

Matthew Barber