| 摘要 |
A swivel chair having a main screw connected to the chair seat and rotatably supported in a mounting assembly on the chair base enabling rotation of the seat relative to the base without varying the height of the seat. Height adjusting apparatus provides for the selective adjustment of the height of the chair seat and includes a nut member threadably mounted on the screw member. The nut member has a thread that is deformed into frictional engagement with the screw thread and when a seating load is applied to the nut member, the magnitude of the frictional resistance of the nut to turning on the screw is increased. As a result, rotation of the chair seat and the screw member will cause the nut member to rotate relative to the mounting assembly and remain fixed relative to the screw member to prevent an unintended varying of the height of the chair seat when it is rotated during use, while still enabling manual intended rotation of the nut when the chair height is to be adjusted.
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