| 摘要 |
<p>PROBLEM TO BE SOLVED: To give a comfortable rocking state all around the back-tilting area of a back part. SOLUTION: The retreating movement of a slide shaft (first shaft) 9 to which a back-resting load is operated is supported by a coil spring 16 and a rubber 43. Then, elasticity recovering according to a moment operated to the back part can be generated by an elasticity supporting means consisting of the spring 16 and the rubber 43 by the existence of the rubber 43 and as a result the comfortable rocking state is obtained all around the back-tilting area of the back part.</p> |
