| 摘要 |
PURPOSE: A secondary backrest for a chair is provided to be movably coupled to a pair of rails equipped in a backrest and selectively hung on an uneven part on the rail, thereby freely controlling the height of a support mounted to an up and down movable part. CONSTITUTION: A secondary backrest(3) for a chair(1) comprises a support frame(9) which is connected to a chair coupled to a backrest(4); an up and down movable part(11) which is coupled to the support frame to move up and down; a back and forth tilting part(13) which is coupled to be hinge-coupled to a lower part and allows an upper part to rotate clockwise or counterclockwise; a first elastic member(15) which is arranged between the up and down movable part and the back and forth tilting part and elastically pressurizes the back and forth tilting part; and a support plate(17) which is located in the back and forth tilting part, has elasticity, and elastically supports a back side. |
