Patent ID: 7200894

Claim:
Roller ( 1 ), suitable for use as a castor of a hospital bed, with rotational movement of a running wheel ( 12 ), the roller comprising: the running wheel ( 12 ), a control cam ( 19 ), a toothed gear mechanism ( 38 ), and an operating shaft ( 20 ) which passes through the control cam ( 19 ) of the roller ( 1 ) to engage with a shaft ( 39 ) of an electric motor ( 37 ), wherein the shaft ( 39 ) of the electric motor ( 37 ) connects via the gear mechanism to the operating shaft ( 20 ) to operate the cam, the toothed gear mechanism ( 38 ) having a driven gear wheel ( 41 ), a hub ( 40 ) of which is passed through by the operating shaft ( 20 ), and two intermediate gear wheels ( 44 ) on opposite sides of the electric motor shaft ( 39 ); and wherein a portion of the operating shaft ( 20 ) is configured for disengagement from the toothed gear mechanism ( 38 ) to permit manual rotation of the operating shaft ( 20 ) upon axial displacement of the operating shaft ( 20 ) relative to a gear of the toothed gear mechanism ( 20 ).