Abstract: A hospital bed including a base adapted to roll over the floor, a litter disposed on the base upon which the patient rests, a lift assembly designed to selectively position the litter a selected vertical distance above the base and at least one stabilizer unit between the litter and the base. Each stabilizer unit includes a pair of rack-and-pinion assemblies that extend between the base and the litter. The pinions of the rack-and-pinion assembly are connected together to rotate in unison. Owing to the interconnection of the pinions, the rack-and-pinion assemblies are prevented from moving vertically in directions opposite to each other. This lock-out of the rack-and-pinion movement prevents the litter from moving side-to-side. The stabilizer unit thus prevents the undesirable side-to-side rocking movement of the litter.

Abstract: A drive mechanism for a hospital bed effects relative vertical movement of a base and a patient litter. The drive mechanism includes spaced, telescoping threaded screw assemblies, which are driven by a single electric motor through a train of gears having helical teeth oriented to offset inherent frictional forces of the screw assemblies. A support for the motor and a component of the drive train are made of electrically nonconductive materials to electrically isolate the motor, and are arranged to damp vibrations produced by the motor. Two coiled electrical cords extend between the base and patient litter, and are each received in a recess in the patient litter when the patient litter is adjacent the base. A sensor arrangement provides an electrical signal indicative of the relative vertical positions of the patient litter and base, and a manual drive arrangement is provided to permit the gear train to be manually driven.

Abstract: A hospital bed includes an articulatable patient support with a fowler portion movable between horizontal and inclined positions relative to a frame of the bed. A reversible electric drive motor is supported on the frame of the bed and, through a reduction gearing arrangement and a releasible coupling mechanism, can rotatably drive a threaded shaft. A nut engages and is held against rotation with the shaft, and a linkage arrangement couples the nut to the fowler portion to effect reciprocal movement of the fowler portion in response to reciprocal movement of the nut along the shaft. A manual release is provided on the fowler portion and, when actuated, disengages the releasible coupling mechanism so that the threaded shaft is free to rotate independently of the motor and gearing arrangement.

Abstract: A hospital bed includes a base supported by casters, and a lift arrangement vertically movably supports a patient support section on the base. The lift arrangement includes a threaded first member secured to and projecting downwardly from the patient support section, a rotatably supported tubular second member having an internal thread which engages the threaded first member and having an external thread, and a further member which is supported on the base and has a thread engaging the external thread on the tubular second member. In one embodiment, the further member is a nut fixedly supported on the base, and a drive member rotatably supported on the base has an opening through which the second member extends and has a key portion which slidably engages an axially extending slot provided in the second member.

Abstract: A motor-driven rotary actuator includes an electric drive motor adapted to be configured for providing one of a plurality of output torques. A power transmission is coupled to the drive motor and includes a rotatable output shaft and drive elements adapted to be formed of disparate materials selected for transmitting one of the output torques. An electric controller is coupled to the motor for providing rotation positioning control of the output shaft in response to digital command signals.

Abstract: A motor-driven rotary actuator includes an electric drive motor adapted to be configured for providing one of a plurality of output torques. A power transmission is coupled to the drive motor and includes a rotatable output shaft and drive elements adapted to be formed of disparate materials selected for transmitting one of the output torques. An electric controller is coupled to the motor for providing rotation positioning control of the output shaft in response to digital command signals.

Abstract: A motor-driven rotary actuator includes an electric drive motor adapted to be configured for providing one of a plurality of output torques and power transmission means including a rotatable output shaft. The transmission means is coupled to the drive motor and includes drive elements adapted to be formed of disparate materials selected for transmitting one of the output torques. An electric controller is coupled to the motor for providing rotation positioning control of the actuator output shaft in response to analog command signals.