Patent ID: 8333530

Claim:
A latch device for a vehicle seat having a latch assembly for fixing, to a car body, a vehicle seat which is movably provided on the car body, said latch assembly comprising: a base plate having a striker groove for receiving a striker; a latch rotatably mounted on the base plate via a latch shaft and having a striker engaging groove to be engaged with the striker in a latched position; a ratchet rotatably mounted on the base plate via a ratchet shaft and comprising a pawl for engaging the latch in the latched position and preventing rotation of the latch in an unlatch direction; and a looseness eliminating lever rotatably attached to the latch by means of a pin; wherein one end of the looseness eliminating lever is provided with a latch holding face and an unlatch face adapted to contact with the ratchet shaft; wherein the other end of the looseness eliminating lever is engaged with a spring connected with the ratchet for biasing the latch holding face or the unlatch face to be always in contact with the ratchet shaft and for rotating the latch in the unlatch direction when the ratchet is rotated such that the pawl is released from the latch; wherein an apex as a dead center is formed between the latch holding face and the unlatch face; wherein the latch holding face is formed in an arc-shaped inclined surface so as to be remoter from the pin from a start end to a terminal end; wherein the looseness eliminating lever is provided with a cam hole having a cam face, an engaging protrusion formed on the ratchet is fit into the cam hole, and when the ratchet is rotated in a direction such that the pawl is released from the latch, the engaging protrusion comes in sliding contact with the cam face, and the looseness eliminating lever acts to release the latch holding face from the ratchet shaft, so that the unlatch face, replacing the latch holding face, comes in sliding contact with the ratchet shaft.