Abstract: A wheeled object, such as a bed (26), is moved by means of a separate driving device (10). The total driving device (10) including a motor driven driving wheel (15) has such dimensions that it may be substantially fully housed in the space defined between lower surface of the bed and the floor surface and is moved into such space. Thereafter an upper surface (21) of the driving device is moved into force transmitting engagement with the lower surface of the bed or object and the driving wheel (15) is moved into driving engagement with the supporting surface or floor. A separate control unit (24) communicating with the motor driven driving wheel may then be operated so as to energize the driving means and move said object. Because the driving device does not extend substantially beyond the outlines of the bed (26) or object, a highly increased maneuverability is obtained.

Abstract: A wheeled object or vehicle, such as a hospital bed (10) comprises a main chassis or frame (12) supported by a plurality of supporting wheels or rollers (11), which define the vertices of a polygonal supporting surface (21). The bed, which is usually moved by a walking person, is provided with at least one motor driven driving device (15), including at least one driving wheel or roller (18), positioned within said polygonal supporting surface. The driving device is rotatable about a substantially vertical axis (14) in relation to the chassis or frame so as to change the angular position of the driving wheel (18) in relation to the chassis or frame. Biasing means, such as a compression spring or a pneumatic or hydraulic cylinder (22, 34) is provided for biasing the driving device (15) in a direction away from the main chassis or frame (12) and towards the supporting surface (21).