Abstract: The present invention provides a headrest module including a mounting base; a rack bracket having a rack gear part and mounted on the mounting base to enable translational motion along an extended direction of the rack gear part; a moving gear having a pinion gear part engaged with the rack gear part and being installed to enable rotational motion and translational motion with respect to the mounting base; and a stopping unit formed to stop the rotational motion of the moving gear as the pinion gear part, which makes the rotational motion due to the translational motion of the rack gear part, makes the translational motion in one direction.

Abstract: Disclosed herein is an arm rest for a seat including a connection shaft formed to be fixedly coupled to the seat; a body unit coupled to the connection shaft to rotate about the connection shaft; a fixed unit having a first teeth portion, and fixedly coupled to the connection shaft; a movable unit having a second teeth portion engaged with the first teeth portion, and installed to be rotatable and positionally movable on the body unit; and a stopping unit fixedly installed on the body unit, and engaged with the second teeth portion to stop the rotation of the movable unit at a stop position as the movable unit positionally moves.

Abstract: Disclosed herein is an arm rest for a seat including a connection shaft formed to be fixedly coupled to the seat; a body unit coupled to the connection shaft to rotate about the connection shaft; a fixed unit having a first teeth portion, and fixedly coupled to the connection shaft; a movable unit having a second teeth portion engaged with the first teeth portion, and installed to be rotatable and positionally movable on the body unit; and a stopping unit fixedly installed on the body unit, and engaged with the second teeth portion to stop the rotation of the movable unit at a stop position as the movable unit positionally moves.