| 摘要 |
<p>A castor has a brake rod (20;120;220) extending through a hollow stem (10) on which a body (4) carrying a pair of castor wheels (2) is rotatably mounted. The brake rod is moveable substantially vertically between an inoperative position and a braking postion in which its lower end engages the surface on which the wheel (2) rest. Opposition to braking movement can be provided by a return spring (39;222) or by a spring arm (122). Movement of the brake rod can be effected by a cam (140) acting on the spring arm (122) or by a cam (40;240) acting on a lever (35;230) engaging the upper end of the brake rod. The brake rod (10) can be arranged to have an intermediate position in which rotation of the castor body (4) is prevented.</p> |
