Patent ID: 7878594
Filing Date: 2011-02-01
Classification: B60N

Abstract:
1. A seat reclining device comprising a differential transmission mechanism for adjusting an opening angle of a hinge through which a seating portion and a backrest portion of a seat are coupled together, said differential transmission mechanism comprising an internal gear, an external gear having a smaller number of teeth than said internal gear and meshing with said internal gear, said external gear having a shaft hole and said internal gear having a shaft, said shaft hole and said shaft defining an arcuate gap therebetween, a pair of wedge-shaped pieces received in said arcuate gap such that their narrow ends face in opposite directions to each other, a spring received in said arcuate gap and biasing said wedge-shaped pieces away from each other, whereby when said wedge-shaped pieces are pushed by a cam provided on said shaft of said internal gear and slide in said arcuate gap, said external gear is configured to separate from said internal gear, thereby making it possible to adjust the opening angle of the hinge; characterized in that each of said wedge-shaped pieces is formed by integrally laminating a low-friction sliding material on a substrate through an intermediate layer.