Lock mechanism for seat track slide device

A lock mechanism for a seat track slide device that is arranged between a floor and a seat in a vehicle and selectively restricts and permits sliding of the seat, the lock mechanism comprising:

• a pair of lower rails configured by a first lower rail and a second lower rail fixed to the floor;
• a pair of upper rails configured by a first upper rail and a second upper rail that are fixed to the seat and supported to be movable with respect to the first lower rail and the second lower rail, respectively;
• a plurality of lock portions that are formed in at least the first lower rail of the first and second lower rails, the lock portions being aligned in a movement direction of the first and second upper rails;
• a lock member that is inserted into and attached to at least the first upper rail of the first and second upper rails, the lock member having an end;
• a handle extending from the lock member;
• a support portion that supports the lock member by means of engagement between a recessed portion formed in one of the first upper rail and the lock member and a projection formed in the other, such that the lock member is pivotable relative to the first upper rail;
• and
• a stopper portion that maintains the engagement between the recessed portion and the projection of the support portion, by limiting movement of the lock member in a widthwise direction which is perpendicular to the movement direction of the first upper rail, wherein the stopper portion includes:
• a pair of first stopper portions provided in the lock member, and a second stopper portion provided on the first upper rail, the second stopper portion comprising a tab bent downwardly from the first upper rail and being inserted and held between the first stopper portions;
• wherein the first upper rail is switchable between a locking state, in which the first upper rail is locked to the first lower rail, and an unlocking state, in which the first upper rail is unlocked from the first lower rail, by selectively engaging and disengaging the lock member with respect to the lock portions through manipulation of the handle.