摘要 |
An expander device for anchoring in a hole to secure a castor to a part which forms the hole, comprises a conical expander engaged in a sleeve having a conical interior. The expander and the sleeve are mouldings of reinforced plastics material. The expander is screwed onto a coaxial bolt with a 3-start thread. The sleeve is axially slotted from either end, the slots from one end being angularly spaced from one another by 90 DEG as are the other slots with which they are assymetrical so that alternate major and minor sleeve portions are formed between adjacent slots. Deformation takes place predominantly in the minor portions as the sleeve is expanded by axial movement of the conical expander into the internal taper of the sleeve which is caused by rotation of the bolt. |