| 摘要 |
There is disclosed a castor (11) comprising a wheel (12) mounted for rotation on a yoke (13) swivellable about a swivel axis (14) in a mounting arrangement, the wheel (12) being adapted for limited swivelling by a captive rolling member riding up the wheel when the wheel rotates and releasable for normal swivelling when the wheel (12) stops by the rolling member falling back down the wheel. |
