| 摘要 |
A twin-wheel castor incorporates brake means comprising an externally-operable brake member which is rockably mounted in a body of the castor for engagement with the wheels of the castor to lock the wheels against rotation. The brake member has a detent projection engageable with a formation of the body to retain the brake member in the braking position, and projecting locking stubs which are engageable between internally projecting webs of the wheels to lock the latter against rotation. The locking stubs are resiliently mounted so that their connection to the main body of the locking member on which the detent projection is mounted will yield, should locking movement of the locking stubs be blocked by engagement with the edge of one of the webs, thus allowing the detent projection to engage the body formation and retain the locking member in the locking position. Thus, as soon as the wheel concerned turns, the resilient mounting of the locking stubs causes the latter to move into a wheel-locking position. |
