| 摘要 |
<p>A chair column has a spindle (2) for securing at its upper end (3) to a chair seat, the lower portion (6) of the spindle threadedly carrying a first clutch dog in the form of a nut (7). A second clutch dog is provided by an indent (8) in a tubular casing (9), the lower end (22) of which is secured in use to a chair base. In order to adjust the height of the chair seat relative to the base, the unoccupied seat is turned, and the interengaged clutch dogs will effect an adjustment. When a person sits on the seat the spindle moves down to compress a spring (10), and the clutch dogs are automatically disengaged. In order to prevent inadvertent adjustment of the nut (7) by swivelling of the occupied chair seat, the nut (7) is arranged to be locked to the spindle (2) by a locking member (12) which is conically shaped in its upper half to have a wedging engagement with the spindle (2) and nut (7). The lower half of locking member (12) is also of conical shape but with a larger cone angle to provide a self-centring bearing with a spring abutment member (11). <IMAGE></p> |
