| 摘要 |
An easy to assemble, height adjustable chair base in which a column (20) telescopically received within a hub tube (10) includes a spring (40) and nut (50) located within the bottom of the column and carried on a threaded post (80) fixedly secured and projecting upwardly within the hub tube (10). A spring housing (30) is rotatably carried within the column (20) and the top abuts against an abutment shoulder (21) located within the column. The spring (40) is located within a spring housing (30) and both the spring and spring housing bear down on a washer (20) which in turn bears down on the nut (50). The column includes detent means (60) located on the column below the nut which disengages the nut when a person sits on the chair, but which is biased upwardly towards engagement with the nut by the action of the spring when the chair is unoccupied. When the chair is unoccupied, rotation of the chair will cause the nut to rotate upwardly or downwardly on the threaded post. |
