| 主权项 |
1. A caster comprising:
(a) a monolithic fork comprising a substantially annular wheel-supporting portion and a chair-supporting portion, the wheel-supporting portion having a pass-through aperture and at least a portion of an inner surface of the fork around the pass-through aperture configured to receive a retainer; (b) a rotational bearing supported on the wheel-supporting portion of the fork; (c) a wheel comprising a load-supporting rim, the rim supported on the bearing such that the wheel rotates on the bearing in the vertical plane, the rim comprising a pass-through aperture aligned with the pass-through aperture of the fork, the rim further comprising a non-load bearing substantially annular ring at an inside edge of the bearing to retain the bearing between the rim and the fork and to inhibit debris from contacting the bearing; and, (d) a retainer configured to be received by the inner surface of the fork, the retainer comprising a pass-through aperture aligned with the pass-through aperture of the fork, the retainer further comprising a bearing-retaining portion at an outside edge of the bearing to retain the bearing between the rim and the fork and to inhibit debris from contacting the bearing. |
