| 摘要 |
PURPOSE: To make an adjuster of a chair securely operate by supporting the back of the chair with free ends of rotary levers fixed at the back, attaching the seat with bearings so that the center part can be rotated by the rotary levers, and supporting the front part of the seat by a chair rack by way of guide levers. CONSTITUTION: A rotary lever 13 is fixed at the end of a support arm 11 on each side of the chair 20 with a joint shaft 12. The seat 20 is attached to a support board 14 for a bearing of the rotary lever 13 by the bearing so that it can be rotated at the center. When the seat 20 is moved downward in the direction 26, the rotation angle of the rotary lever 13 is restricted by the gap between the rotation shaft 15 and the joint shaft 12. As a guide lever 17 does a rotational movement in the same direction, the seat 20 sinks at the front part and moves backward toward the back 25 as well. The back 25 does not only a wide tilting motion 28 but also a sinking motion 29 with a length adjusting joint 24, so that comfort will be given to a user. In this way, this adjuster 24 can be securely operated only by normal rotation and the rotary bearings. |
