Patent ID: 7648186

Claim:
A locking mechanism for a rotation seat for use in an industrial vehicle, comprising: a plate member fixed to an underside of the rotation seat; a stopper member attached to the plate member; a base member fixed to a base of the industrial vehicle, the base member being formed with a guide slot for defining a rotatable range of the plate member; a rotary shaft for supporting the plate member rotatably with respect to the base member; a locking recess formed in an intermediate portion of the guide slot for locking the stopper member, the locking recess being formed continuously from the guide slot so that width thereof narrows with distance from the guide slot; and a resilient member provided in the plate member for urging the stopper member in a direction in which the stopper member is locked to the locking recess; wherein when the plate member rotates with respect to the base member, the stopper member is guided along the guide slot and is locked by the locking recess, whereby the plate member becomes locked so that the plate member is unrotatable relative to the base member, and wherein when the stopper member moves in at least one guide direction along the guide slot and gets into the locking recess, the stopper member is urged in the direction in which the stopper member is locked to the locking recess so that a contact portion of the stopper member and the locking recess press each other while the plate member and the stopper member are in contact with each other.