Reclining mechanism for vehicle seat

Abstract

A reclining mechanism for a vehicle seat composed of a first arm member for attachment to a frame structure of a seat cushion or a back rest of the vehicle seat; a second arm member for attachment to a frame structure of the other of the back rest or the seat cushion, the second arm member being connected with the first arm member by means of a hinge pin for relative rotation about the hinge pin and having a pair of diametrically opposed semi-circular ratchet portions concentric with the hinge pin; a pair of diametrically opposed slide pawls slidably coupled with the first arm member in a radial direction with respect to the hinge pin to be moved toward and away from the ratchet portions of the second arm member; and a cam element slidably coupled with the first arm member in a lateral direction perpendicular to the slide pawls and disposed between the slide pawls, the cam element being operatively connected with the hinge pin to be moved by rotation of the hinge pin in the lateral direction for engaging the slide pawls with the ratchet portions of the second arm member and for disengaging the slide pawls from the ratchet portions of the second arm member, wherein the hinge pin is loaded by a torsion spring assembled thereon to bias the cam element in the lateral direction for maintaining the slide pawls in engagement with the ratchet portions of the second arm member.

What is claimed is:  
     
         1 . A reclining mechanism for a vehicle seat, comprising: 
 a first arm member for attachment to a frame structure of a seat cushion or a back rest of the vehicle seat;    a second arm member for attachment to a frame structure of the other of the back rest or the seat cushion, the second arm member being connected with the first arm member by means of a hinge pin for relative rotation about the hinge pin and having a semi-circular ratchet portion concentric with the hinge pin;    a slide pawl slidably coupled with the first arm member in a radial direction with respect to the hinge pin to be moved toward and away from the ratchet portion of the second arm member; and    a cam element slidably coupled with the first arm member in a lateral direction perpendicular to the slide pawl and operatively connected with the hinge pin to be moved by rotation of the hinge pin in the lateral direction for engaging the slide pawl with the ratchet portion of the first arm member and for disengaging the slide pawl from the ratchet portion of the first arm member;    wherein the hinge pin is loaded by a torsion spring assembled thereon to bias the cam element in the lateral direction for maintaining the slide pawl in engagement with the ratchet portion of the second arm member,    wherein the slide pawl is formed at its outer end with a semi-circular toothed portion to be engaged with the ratchet portion of the first arm member and its inner end with a pair of laterally spaced projections for engagement with a flat end surface of the cam element, and    wherein the cam element is formed at the flat end surface thereof with a pair of laterally spaced recesses to be engaged with the spaced projections of the slide pawl for permitting disengagement of the slide pawl from the ratchet portion of the first arm member.