US Patent 11299070 Electric seat slide device

A screw shaft attached to the upper rail is screwed into a nut member attached to the lower rail. When the screw shaft is rotated with respect to the nut member by a drive unit, the screw shaft is moved rearward and forward with respect to the nut member, and the upper rail is also moved rearward and forward with respect to the lower rail. A fixing nut is fixed to an inner surface of the lower rail behind the nut member, and a stopper bolt is fastened to the fixing nut from below the lower rail. When the upper rail moves forward, a stopper portion provided at a tip of the stopper bolt contacts the stopper plate to restrict an excessive forward movement of the upper rail.