Auxiliary vehicle seat support rail with dynamic seat belt and seat back anchoring

In a vehicle having a seat with a weight supporting seat cushion frame and a seat back having a pair of outboard brackets supported on said seat cushion frame in such a way as to remain stationary when subjected to ordinary rearward forces to allow limited rearward rotation of said seat back relative to said seat cushion frame about a pivot axis in the event of extraordinary rearward forces caused by extraordinary vehicle acceleration, said seat back also having at least one inboard bracket intermediate said outboard brackets and rotatable therewith about said same pivot axis, with said seat cushion supported on a vehicle floor by a pair of primary, parallel seat adjuster tracks, and also having a seat belt with a lower attachment point, said seat belt attachment point being subject to normal, forwardly directed tension forces in ordinary operation and potentially subject to higher than normal tension forces in the event of extraordinary vehicle deceleration, an auxiliary seat support with combined seat belt and seat back dynamic anchoring, comprising;

• at least one auxiliary support rail fixed to said vehicle floor beneath said seat cushion frame and intermediate said primary tracks, said auxiliary rail having a substantially horizontal upper rail edge and a series of locking teeth below said upper rail edge,
• a seat belt support slidably supported on said auxiliary support rail and having a pair of forward and rearward, side by side pivot pins, said pivot pins each having a roller freely journaled thereon so that said seat belt support can freely roll back and forth on said upper rail edge, said seat belt support further providing said lower seat belt attachment point above said rollers so that belt tension forces can pull forwardly on said seat belt support to create a forward moment acting about said forward roller and pivot pin,
• an inboard seat back bracket support pivotally supported to said seat belt support at said forward pivot pin, so that said seat belt support can pivot forward independently of and relative to said inboard seat back bracket support about said forward pivot pin, said inboard seat back bracket support further being fixed to said inboard seat back bracket so that a portion of the weight of said seat acts downwardly through said inboard bracket and bracket support on said forward pivot pin to maintain said forward roller on said rail upper edge in opposition to ordinary rearward forces acting on said seat back and so that extraordinary rearward forces on said seat back create a rearward moment on said inboard seat back bracket support sufficient to lift said forward roller from said rail edge,
• a tension spring connected between said seat belt support and inboard seat back bracket support, said spring being sufficiently strong to create a rearward moment on said seat belt support acting about said forward pivot pin and roller and to maintain said rearward roller on said upper rail edge in opposition to normal tension forces acting on said seat belt support, but insufficiently strong to oppose extraordinary belt tension forces pulling on said seat belt attachment point, which are sufficient to create a forward moment about said forward roller and pivot pin sufficient to lift said rearward roller from said upper rail edge,
• a rearward locking pin fixed to said seat belt support and spaced below said locking teeth when said rollers are both engaged with said upper rail edge, and
• a forward locking pin fixed to said inboard seat back bracket support and spaced below said locking teeth when said rollers are both engaged with said upper rail edge,
• whereby, when said seat belt and seat back are both subject to ordinary forces, said seat belt support and inboard seat back bracket support can move together along said upper rail edge, on said rollers, as said seat moves fore and aft on said primary seat tracks and said locking pins remain below said locking teeth and said seat belt attachment point maintains a constant position relative to said seat cushion frame, with the weight of said seat at least partially supported by said rollers rolling on said rail upper edge, and when said seat belt is subject to extraordinary tension forces, said seat belt support rotates forward on said forward pivot pin and roller independently of said inboard seat back bracket support, lifting said rearward roller and pivot pin from said upper rail edge while concurrently stretching said tension spring and lifting said rearward locking pin into said rail locking teeth to anchor said seat belt support and seat belt against said extraordinary tension forces, and when said seat back is subject to extraordinary rearward forces, said inboard seat back bracket support and said seat belt support rotate together with said seat back and said outboard seat back brackets while lifting said forward roller and pivot pin from said rail upper edge and concurrently lifting said forward locking pin into said rail locking teeth to anchor said inboard seat back bracket support and inboard seat back bracket against said extraordinary rearward forces.

In a vehicle having a seat with a weight supporting seat cushion frame and a seat back having a pair of outboard brackets supported on said seat cushion frame in such a way as to remain stationary when subjected to ordinary rearward forces to allow limited rearward rotation of said seat back relative to said seat cushion frame about a pivot axis in the event of extraordinary rearward forces caused by extraordinary vehicle acceleration, said seat back also having at least one inboard bracket intermediate said outboard brackets and rotatable therewith about said same pivot axis, with said seat cushion supported on a vehicle floor by a pair of primary, parallel seat adjuster tracks, and also having a seat belt with a lower attachment point, said seat belt attachment point being subject to normal, forwardly directed tension forces in ordinary operation and potentially subject to higher than normal tension forces in the event of extraordinary vehicle deceleration, an auxiliary seat support with combined seat belt and seat back dynamic anchoring, comprising;

• at least one auxiliary support rail fixed to said vehicle floor beneath said seat cushion frame and intermediate said primary tracks, said auxiliary rail having a substantially horizontal upper rail edge and a generally horizontal slot beneath said edge with series of locking teeth located below said upper rail edge,
• a seat belt support comprising a pair of plates located on either side of said support rail, said plates and held together by a pair of forward and rearward, side by side pivot pins, said pivot pins each having a roller freely journaled thereon so that said seat belt support can freely roll back and forth on said upper rail edge, said seat belt support further providing said lower seat belt attachment point above said rollers so that belt tension forces can pull forwardly on said seat belt support to create a forward moment acting about said forward roller and pivot pin,
• an inboard seat back bracket support pivotally supported to said seat belt support at said forward pivot pin, so that said seat belt support can pivot forward independently of and relative to said inboard seat back bracket upport about said forward pivot pin, said inboard seat back bracket support further being fixed to said inboard seat back bracket so that a portion of the weight of said seat acts downwardly through said inboard bracket and bracket support on said forward pivot pin to maintain said forward roller on said rail upper edge in opposition to ordinary rearward forces acting on said seat back and so that extraordinary rearward forces on said seat back create a rearward moment on said inboard seat back bracket support sufficient to lift said forward roller from said rail edge,
• a resilient means connected between said seat belt support and inboard seat back bracket support sufficiently strong to create a rearward moment on said seat belt support acting about said forward pivot pin and roller and to maintain said rearward roller on said upper rail edge in opposition to normal tension forces acting on said seat belt support, but insufficiently strong to oppose extraordinary belt tension forces pulling on said seat belt attachment point, which are sufficient to create a forward moment about said forward roller and pivot pin sufficient to lift said rearward roller from said upper rail edge,
• a rearward locking pin joined to each of said seat belt support plates and located in said slot, so as to capture said seat belt support to said rail in cooperation with said forward and rearward pivot pins, said rearward locking pin also being spaced below said locking teeth when said rollers are both engaged with said upper rail edge, and
• a forward locking pin fixed to said inboard seat back bracket support and spaced below said locking teeth when said rollers are both engaged with said upper rail edge,
• whereby, when said seat belt and seat back are both subject to ordinary forces, said seat belt support and inboard seat back bracket support can move together along said upper rail edge, on said rollers, as said seat moves fore and aft on said primary seat tracks and said locking pins remain below said locking teeth and said seat belt attachment point maintains a constant position relative to said seat cushion frame, with the weight of said seat at least partially supported by said rollers rolling on said rail upper edge, and when said seat belt is subject to extraordinary tension forces, said seat belt support rotates forward on said forward pivot pin and roller independently of said inboard seat back bracket support, lifting said rearward roller and pivot pin from said upper rail edge is opposition to said resilient means while concurrently lifting said rearward locking pin into said rail locking teeth to anchor said seat belt support and seat belt against said extraordinary tension forces, and when said seat back is subject to extraordinary rearward forces, said inboard seat back bracket support and said seat belt support rotate together with said seat back and said outboard seat back brackets while lifting said forward roller and pivot pin from said rail upper edge and concurrently lifting said forward locking pin into said rail locking teeth to anchor said inboard seat back bracket support and inboard seat back bracket against said extraordinary rearward forces.