摘要 |
Each of reclining devices is formed so as to have a different size. An external gear wheel of each of the reclining devices has a diameter smaller than an internal gear wheel thereof and has a teeth number different from the internal gear wheel. The internal gear wheels and the external gear wheels of the connection devices respectively have the same teeth number as each other. The internal gear wheels and the external gear wheels of the connection devices are formed such that distances between centers thereof are equal to each other. Further, a meshing line of the internal gear wheel and the external gear wheel of each of the connection devices is formed between two curves defining a meshing range and is drawn as a line that extends from a side of a radially inwardly positioned curve in a circumferential direction in which the two curves are gradually spaced from each other and reaches to a side of a radially outwardly positioned curve.
|