Patient Lift Friction Coupling Spreader Bar Stability
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Solution Overview
Problem
Arc-type patient lifts pose a risk of the spreader bar swinging towards the patient during manipulation, potentially causing injury, due to the need for a swinging movement to maintain the bar parallel to the floor throughout the lifting stroke, which is not present in column lifts.
Innovation Solution
A friction coupling mechanism, including various embodiments with damper elements and friction washers, is introduced to restrict the swinging motion of the spreader bar, ensuring it remains stable and prevents unwanted rotation, while allowing controlled movement by caregivers.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Stability of the object's composition
If a swinging movement is allowed at the connection point, then the spreader bar can stay parallel to the floor during the full lifting stroke, but the spreader bar may swing outwardly towards the patient causing safety risks
Solution Approach 1:
A friction coupling mechanism is introduced as an intermediary device between the boom and spreader bar. This coupling includes friction surfaces that allow controlled swinging motion while providing sufficient friction to prevent excessive swinging towards the patient, thus mediating between the need for movement and the need for safety
Solution Approach 2:
The friction coupling allows the connection parameters to change dynamically - permitting swing when needed for positioning while restricting swing when safety is concerned, based on the friction characteristics of the coupling surfaces
2Object-affected harmful factors
If a friction coupling is introduced to restrict swinging motion, then safety is improved by preventing spreader bar swing towards patient, but the device complexity increases
Solution Approach 1:
The coupling mechanism is segmented into separate components including a boom interface, spreader bar interface, and friction elements. This segmentation allows each component to be optimized independently and simplifies manufacturing and maintenance while achieving the safety function
Solution Approach 2:
The friction coupling is designed to be self-regulating through its friction characteristics, automatically providing the necessary restriction without requiring external control systems or complex actuation mechanisms, thus achieving safety through passive design
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The friction coupling effectively reduces the risk of the spreader bar swinging towards the patient, enhancing safety and ease of maneuverability for caregivers during patient transfers, applicable to both arc and column lifts.
Implementation Method 1
the friction coupling restricting the movement of the spreader bar and eliminating the risk of the spreader bar swinging against the patient's face. The friction reduces the swing of the patient when transferred in the lift.
Implementation Method 2
The friction coupling may include a damper element.
Data Source
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AI summary
A patient lift including a boom a spreader bar, and a friction coupling for securing the boom and the spreader bar. The friction coupling may include two friction washers disposed against respective inner faces of the boom. Two compression springs are disposed abutting the friction washers with a spreader bar support member in between. The compression springs urge the friction washers against the inner faces of the boom end. The spreader bar does not swing when the lift is moved without load. Also, the friction coupling reduces the swing of the patient, when transferred in the lift. This makes the lift easier to maneuver for the caregiver.