| 摘要 |
The chair with vertical position adjustment includes a fixed tube (1) guiding the inner movable tube (5). The latter is provided with holes (8) whose dia. corresponds to the width of recesses (3) of bush (2). The holes hold detent balls (9) resting against the radiused top of piston (10) which is shifted inside tube (5). The piston is pressed upwards against the balls by spring (11) supported by collar (12), the piston controlled by its rod (14) operated by lever (16). Resetting of the chair position is carried out by releasing the detent when the level depresses slightly the piston and thus freeing the ball (9). The ball rolls down to the step (13) of the piston and then tube (5) is shifted. Release of the lever allows the spring to press the piston and the latter moves the balls to the next row of recesses for locking. |
