Patent attributes
An armrest height-adjusting device has a collar (10) fixed to an arm frame (8) and a spring (11). The spring (11) includes a coil portion (11A), provided around the collar (10), a first leg portion (11B) engaging with the seat back frame (5), and a second leg portion (11C) received in a window portion (41) of the arm frame (8). A diameter of the coil portion (11A) becomes short by the downward rotation of the arm frame (8) and becomes large by the upward rotation of the arm frame (8). The second leg portion (11C) is guided into the hook (24) by abutting against the window portion (41) when the arm frame (10) is rotated upward beyond a predetermined position. When the second leg portion (11C) is engaged with the hook (24), the diameter of the coil portion (11A) is kept in a state of becoming large.
