Patient Lift

Overview

A patient lift is a wheeled hoist that raises an immobile patient in a fabric sling and moves them between bed, wheelchair, commode, and floor without a caregiver taking the weight. It exists because manual transfers are the leading cause of back injury among nurses and carers, and because a dropped patient is a serious event. With a lift, one person can transfer someone safely: roll the base under the bed, hook on the sling, press a button, and swing the load across.

The structure is a Mast & Boom, a vertical column and a swinging boom, standing on a wheeled Wheeled Base. A Linear Actuator between mast and boom does the lifting, and a Spreader Bar hangs from the boom tip to carry the sling. Power comes from a removable Battery Pack, the caregiver works a Hand Control pendant, and a Emergency Lowering system guarantees the patient can always be brought down.

How it works

Lifting force comes from the Linear Actuator, a self-locking jack built around a Ball Screw. The Actuator Motor, a geared DC motor, turns the screw, and because a ball screw will not back-drive under load, the boom holds its height the instant the motor stops, with no brake needed. The actuator pushes between the Mast Column and the Boom Arm, swinging the boom up about its pivot; Limit Switch pairs cut the motor at the ends of travel.

The caregiver drives it from the Hand Control pendant, whose buttons feed a Control Board that runs the motor through direction relays and watches the Battery Pack and load. The Spreader Bar hangs the sling on hooks through a free Swivel Joint, so the patient can be turned to face a chair without repositioning the lift. The Wheeled Base legs splay wide around a wheelchair for stability, then narrow via the Leg-Spread Mechanism to clear doorways, all rolling on braked Swivel Caster wheels. If the electronics or Battery Pack fail mid-lift, the Emergency Lowering system lets the patient down either by a hard-wired electrical button or by a mechanical screw release on the actuator, so they are never left suspended.