A seat slide device includes: a first rail which extends in a longitudinal direction; a second rail which extends in the longitudinal direction and is joined to the first rail to be capable of relative movement in the longitudinal direction; lock holes which form the first rail, are open in a portion facing the second rail, are provided to extend such that one end in a short direction of the first rail forms an opening portion, another end forms a base portion including a base wall, and which are disposed at an equal interval in the longitudinal direction; and a lock lever which is joined to the second rail in a state of being capable of reciprocal movement in the short direction and is provided integrally with engaging protrusions capable of entering and exiting any of the lock holes in accordance with the reciprocal movement.

A vehicle seat slide device includes: a first rail provided to extend in a front-rear direction of a vehicle and including first side wall portions, and first flanges overhanging from tips of the first side wall portions to inside and further folded to a base end side of the first side wall portions; a second rail joined to the first rail to be capable of moving in the front-rear direction and including second side wall portions, a connecting wall portion connecting base ends of the second side wall portions, and second flanges overhanging to an outside and further folded so as to be surrounded by the first side wall portions and the first flanges; and a locking member joined to the second rail to rotate around an axial line extending in the width direction and capable of restricting relative movement of the first and second rails.

An adjusting device for longitudinal adjustment of a vehicle seat comprises a lower rail 2 and a second rail 1 movably guided relative to the first rail. A first end stop 4 is supported on the second rail 1 or on the first rail 2 at a central position so as to be displaceable in the longitudinal direction, for defining the front end position and/or rear end position of the second rail 1 by cooperation with the first rail 2 or the second rail 1 and edges of a retainer cage 6 used for accommodating bearing members. According to the invention the total travel range of the adjusting device can be extended, because the central end stop can be displaced in longitudinal direction.