Abstract: The invention relates to a roller (1), preferably comprising two wheels (2) and a locking device, an activating part (10) acting on the locking device for releasing or locking, and the activating part (10) being movable by a drive, a movement of a transmission part (7) that is generated by the drive being transmitted via spring force to the activating part (10) for moving same, and a spring (8) being supported on the transmission part. In order to provide a roller that allows an advantageous constructional design, it is proposed that a support region is formed for the spring (8) and/or the spring (9) and/or the compression spring (44) on the activating part (10), through which region the transmission part (7) can pass.

Abstract: An additional roller has a rigid frame, with a drivable wheel which is mounted in the frame and has an axle. The wheel together with the frame can be raised or lowered by pivoting relative to a chassis, on which the additional roller is to be mounted. A compression spring is coupled rotatably at one end to the chassis, in order, in the lowered position, to load the wheel in respect of ground contact. A transverse connection connects two frame parts in the direction of an axle of the wheel. The compression spring is coupled at the other end to the transverse connection. The compression spring together with the frame pivots about the chassis-mounted pivot point during raising and lowering of the wheel.

Abstract: The invention relates to a roller (1), preferably comprising two wheels (2) and a locking device, an activating part (10) being able to act on the locking device for releasing or locking in a position that corresponds to a directional lock and/or in a position that corresponds to a total lock, and the activating part (10) being movable by a drive, a linear movement of a transmission part (7) that is generated by the drive being transmitted via spring force to the activating part (10) in order to move the activating part, and the activating part (10), in any case in a position corresponding to the total lock or in any case in a position corresponding to the direction lock, being in addition movable relative to the stationary transmission part, against a spring supported on the transmission part, into a release position by means of an actuating handle (11) that is movable independently of the drive and preferably by hand so as to override the total lock or the directional lock.

Abstract: The invention relates to a roller (1), preferably comprising two wheels (2) and a locking device, an activating part (10) acting on the locking device for releasing or locking, and the activating part (10) being movable by a drive, a movement of a transmission part (7) that is generated by the drive being transmitted via spring force to the activating part (10) for moving same, and a spring (8) being supported on the transmission part. In order to provide a roller that allows an advantageous constructional design, it is proposed that a support region is formed for the spring (8) and/or the spring (9) and/or the compression spring (44) on the activating part (10), through which region the transmission part (7) can pass.

Abstract: The invention relates to a roller (1), preferably comprising two wheels (2) and a locking device, an activating part (10) being able to act on the locking device for releasing or locking in a position that corresponds to a directional lock and/or in a position that corresponds to a total lock, and the activating part (10) being movable by a drive, a linear movement of a transmission part (7) that is generated by the drive being transmitted via spring force to the activating part (10) in order to move the activating part, and the activating part (10), in any case in a position corresponding to the total lock or in any case in a position corresponding to the direction lock, being in addition movable relative to the stationary transmission part, against a spring supported on the transmission part, into a release position by means of an actuating handle (11) that is movable independently of the drive and preferably by hand so as to override the total lock or the directional lock.

Abstract: The invention relates to an additional roller having a rigid frame (3), with a drivable wheel (2) which is mounted in the frame (3) and has an axle (12), wherein the wheel (2) together with the frame (3) can be raised or lowered by pivoting relative to a chassis, on which the additional roller is to be mounted, and a compression spring (13) which is coupled rotatably at one end to the chassis is provided, in order, in the lowered position, to load the wheel (2) in respect of ground contact.

Abstract: The invention relates to a hospital bed (3) with a chassis (2), with four rollers (4) arranged on the chassis (2), and with at least one further auxiliary roller (1) that can be brought into contact with the floor or can alternatively be driven, wherein the auxiliary roller (1) is mounted on a rigid frame (5) and, together with the frame (5), can be raised or lowered relative to the chassis (2) by pivoting, wherein a drive motor (9) secured on the frame (5) is additionally provided for the auxiliary roller (1), and a separate pivot drive (23) is provided for raising and lowering the auxiliary roller (1). To advantageously design a hospital bed of this type in the manner specified at the outset, it is proposed that the separate pivot drive (23) is secured entirely on the frame (5) and pivots with the latter.