A hospital bed, trolley or lifter includes a steering wheel (6) mounted on a wheel support arm (2) extending from which is a ratchet mechanism (7) which can co-operate with a tooth (8) of an adjustment mechanism. When the tooth (8) is engaged in the ratchet teeth of the ratchet mechanism (7) the wheel (6) can be raised and held in the raised position until the tooth (8) is disengaged. The wheel adjustment mechanism also includes an eccentric wheel (11) for raising the tooth (8) in periodic manner to cause periodic raising of the wheel (6). A damper (3) is attached to the support arm (2) for dampening the drop of the wheel (6) from the tooth (8) is disengaged. A mechanism provides a steering wheel which can be held at intermediate positions between its uppermost and lowermost positions and which can be held in an engaged position in a plurality of different positions relative to casters of the bed or trolley. The system can also make use of a small capacity drive motor whilst still retaining speed of operation.
