Sliding device

A sliding device, comprising:

• a lower rail that is a long member to be fixedly attached to a mounting surface over which the seat is arranged;
• an upper rail having a portion to be fixedly attached to the seat, and guided by the lower rail movably in a longitudinal direction of the lower rail;
• and
• a lock mechanism that is attached to the upper rail for locking the upper rail in a specific position in the longitudinal direction, wherein
• the lower rail includes a pair of side walls extending in the longitudinal direction and facing each other, and at least one inner wall located between the pair of side walls and extending in the longitudinal direction,
• the inner wall having a predetermined lock teeth zone bearing a plurality of lock teeth protruding downward and arrayed in the longitudinal direction, and a free zone located adjacent to the lock teeth zone and extending in the longitudinal direction without a lock tooth, and
• the lock mechanism includes:
• a lock plate located between the pair of side walls of the lower rail, having a plurality of engaged parts arrayed in the longitudinal direction to be engageable with the lock teeth, and being configured to move together with the upper rail over the free zone and the lock teeth zone in the longitudinal direction;
• and
• an urging member that urges the lock plate upward so that the engaged parts are engaged with the lock teeth,
• the lock plate having at least one pair of protrusions protruding in a width direction perpendicularly intersecting the longitudinal direction respectively from opposite side surfaces of the lock plate that face in the width direction at positions closer to the lock teeth zone on the opposite side surfaces,
• the sliding device further comprising:
• a pair of guide parts that restrict shifting of the lock plate in an up-down direction by coming into contact with the pair of protrusions, wherein
• the pair of guide parts are configured to, in progress of the lock plate moving from the free zone into the lock teeth zone, restrict the lock plate from shifting upward and toward the lock teeth until the lock plate reaches an engageable position where a first lock tooth that is closest to the free zone among the lock teeth is engageable with an engaged part that is closest to the free zone among the engaged parts of the lock plate, and allow the lock plate to shift upward and toward the lock teeth when the lock plate reaches the engageable position.