Vehicle seat adjuster

A power seat adjuster (10) for bucket type vehicle seats includes inboard and outboard track assemblies (16, 14) each including a fixed lower section (20, 18), a movable upper or movable section (21, 19) and a precision sliding interface including roller bearings (23, 24) between the moving upper track and the fixed lower track, the surfaces of the tracks that are engaged by the roller bearings being crowned to provide a bearing surface (78) that is slightly convex when the seat is unoccupied but which becomes nearly flat when the seat is occupied, and the bearing surfaces of the track being coated with a multi-layer dry film lubricant (80) including a base coating (81) of an anti-friction material and a top coating (82) of an anti-stick material. The power seat adjuster includes screw drive mechanisms (26, 30, 31, 32) for providing horizontal fore-and-aft adjustment, vertical up-and-down adjustment and adjustment in the inclination of the seat back, with the length of travel being limited by travel limit stops that include anti-jam mechanisms (102, 130, 161) which are adapted to reduce the breakaway torque required to move the drive screws of the screw drive mechanisms away from either end position.