The retainer is provided so as to be prevented from being rotatable with respect to the rotary shaft, and rotation of the input-side rotary member is reduced in speed and transmitted to the output-side rotary member through intermediation of the balls which engage with both of the ball engagement grooves. A raceway center line of the second ball engagement groove is formed of a wave-shaped curve. When a speed reduction ratio of the speed reducer is represented by i, the wave-shaped curve has such a shape that the balls which engage with the first ball engagement groove engage with the second ball engagement groove at a given rotation angle () of the input-side rotary member in a state in which the output-side rotary member is at a rotation angle (i).

The retainer is provided so as to be prevented from being rotatable with respect to the rotary shaft, and rotation of the input-side rotary member is reduced in speed and transmitted to the output-side rotary member through intermediation of the balls which engage with both of the ball engagement grooves. A raceway center line of the second ball engagement groove is formed of a wave-shaped curve. When a speed reduction ratio of the speed reducer is represented by i, the wave-shaped curve has such a shape that the balls which engage with the first ball engagement groove engage with the second ball engagement groove at a given rotation angle () of the input-side rotary member in a state in which the output-side rotary member is at a rotation angle (i).

Gear mechanism, in particular coaxial gear mechanism or linear gear mechanism, having a toothing system, a tooth carrier with radially oriented guides, teeth which are received in the guides for engagement with the toothing system, the teeth being mounted in the guides such that they can be displaced radially relative to the tooth carrier in the direction of their longitudinal axis, a cam disk for radially driving the teeth, the tooth carrier comprising a first tooth carrier part and a second tooth carrier part.

Gear mechanism, in particular coaxial gear mechanism or linear gear mechanism, having a toothing system, a tooth carrier with radially oriented guides, teeth which are received in the guides for engagement with the toothing system, the teeth being mounted in the guides such that they can be displaced radially relative to the tooth carrier in the direction of their longitudinal axis, a cam disk for radially driving the teeth, the tooth carrier comprising a first tooth carrier part and a second tooth carrier part.

The improved motorized gearbox mechanism of the present invention includes a plurality of cam-actuated gear block assemblies, which transfer power from an integral rotor and stator assembly contained in a cam/rotor assembly, to a secondary or output gear element. Each gear block assembly includes a gear block having a surface that periodically interfaces with a secondary or output gear element. When energized, the stator assembly interacts with the rotor assembly inducing the cam/rotor assembly to rotate about its central axis, thereby driving the output gear element via the plurality of cam-actuated gear block assemblies. The motorized gearbox mechanism may be powered electrically, hydraulically, pneumatically or by steam, or any conventional power source that can be adapted to use an integral stator/rotor assembly configured in the cam assembly body to generate rotative power in the cam/rotor assembly.

The improved motorized gearbox mechanism of the present invention includes a plurality of cam-actuated gear block assemblies, which transfer power from an integral rotor and stator assembly contained in a cam/rotor assembly, to a secondary or output gear element. Each gear block assembly includes a gear block having a surface that periodically interfaces with a secondary or output gear element. When energized, the stator assembly interacts with the rotor assembly inducing the cam/rotor assembly to rotate about its central axis, thereby driving the output gear element via the plurality of cam-actuated gear block assemblies. The motorized gearbox mechanism may be powered electrically, hydraulically, pneumatically or by steam, or any conventional power source that can be adapted to use an integral stator/rotor assembly configured in the cam assembly body to generate rotative power in the cam/rotor assembly.

The gearbox mechanism of the invention includes a plurality of cam-actuated gear block assemblies, which transfer power from a power shaft to a secondary or output gear element. Each gear block assembly includes a gear block having a surface that periodically interfaces with a secondary or output gear element. In a preferred embodiment the interface surface comprises a plurality of projections or teeth which correspond to complementary projections or gear teeth on the output gear element. Each gear block assembly further includes a gear block, a rocker arm, cam followers and/or gear block tracking post, which connect or link the gear block to a cam assembly, which in turn is connected to a power source. The cam assembly includes about its circumference a unique pathway or groove for each cam followers and/or gear block tracking post of a particular gear block assembly so that the movement of the gear block may be controlled in two or three dimensions in accordance with a certain design parameter.

The gearbox mechanism of the invention includes a plurality of cam-actuated gear block assemblies, which transfer power from a power shaft to a secondary or output gear element. Each gear block assembly includes a gear block having a surface that periodically interfaces with a secondary or output gear element. In a preferred embodiment the interface surface comprises a plurality of projections or teeth which correspond to complementary projections or gear teeth on the output gear element. Each gear block assembly further includes a gear block, a rocker arm, cam followers and/or gear block tracking post, which connect or link the gear block to a cam assembly, which in turn is connected to a power source. The cam assembly includes about its circumference a unique pathway or groove for each cam followers and/or gear block tracking post of a particular gear block assembly so that the movement of the gear block may be controlled in two or three dimensions in accordance with a certain design parameter.

An actuator for use in effecting movement of a movable member with respect to a first member of a patient support apparatus. A motor is provided for generating rotational torque. A carrier is adapted to be secured to the first member. An input member is coupled to the motor for concurrent rotation. An output member is adapted to be coupled to the movable member. A reduction geartrain is supported between the input member and the output member. A clutch assembly is disposed in torque-translating relationship between the reduction geartrain and the output member and moves between: an engaged configuration wherein torque from the motor is translated across the reduction geartrain to move the movable member with respect to the first member, and a disengaged configuration wherein torque is at least partially interrupted across the reduction geartrain to allow movement of the movable member independent of rotation of the motor.

An actuator for use in effecting movement of a movable member with respect to a first member of a patient support apparatus. A motor is provided for generating rotational torque. A carrier is adapted to be secured to the first member. An input member is coupled to the motor for concurrent rotation. An output member is adapted to be coupled to the movable member. A reduction geartrain is supported between the input member and the output member. A clutch assembly is disposed in torque-translating relationship between the reduction geartrain and the output member and moves between: an engaged configuration wherein torque from the motor is translated across the reduction geartrain to move the movable member with respect to the first member, and a disengaged configuration wherein torque is at least partially interrupted across the reduction geartrain to allow movement of the movable member independent of rotation of the motor.