| 摘要 |
PROBLEM TO BE SOLVED: To suppress the inclination of a pole with respect to a rachet with simple structure by providing a regulating wall for suppressing the inclination of the pole with respect to the guide wall by abutting onto the pole. SOLUTION: At the time of operating an operation lever 44, a cam member 43 is rotated clockwise to release the slidable contact of the member 43 and the cam surface 13b of the pole 13 and the pole 13 moves along the side surface of a guide part 11 so as to make the pole 13 approach a rotary shaft 4 by the operation of a cam slit hole. At the time of releasing the operation of the lever 44, the member 43 and the surface 13b of the pole 13 are brought into slidable contact with each other and the pole 13 moves away from the shaft 4 to fit the pole 13 and the rachet 21. When a high load is operated to an upper arm 2 through a seat back in a state where the rotation of the upper arm 2 with respect to a lower arm 1 is regulated, the side surface of the projecting wall 14 of the part 11 and the side surface of the recessed groove 15 of the pole 13 are in contact with each other and the projecting part 43a of the member 43 and the contact surface 13d of the pole 13 are in contact with each other. |
