摘要 |
To prevent "shimmying", due to uncontrolled swivelling of a castor during non-engagement of its wheel or wheels with the ground, frictional resistance to swivelling is provided. An upper or lower cap or cover for the bearing between the castor body and its mounting head can thus be non-rotatably engaged with the mounting head and frictionally engaged with the body. Additionally, or instead, a spring washer around the mounting head in an aperture in the body containing the bearing can provide this friction. |