Latch device for vehicle seat

A latch assembly includes a base plate having a striker groove , a latch provided in the base plate and having a striker engaging groove , and a ratchet for regulating rotation of the latch in unlatch direction. A looseness eliminating lever is attached to the latch by means of a pin moving around a latch shaft , one end of the looseness eliminating lever is provided with a latch holding face and an unlatch face to contact with a post provided at a specified position, the other end of the lever is provided with a spring for biasing the guide face or the sliding face to be always in contact with the post , and an apex as a dead center is formed between the guide face and the sliding face . The guide 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.