Castor Locking Mechanism for Hospital Bed Stability
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Solution Overview
Problem
Existing castor designs for movable objects, such as hospital beds, experience instability due to relative movement between the fork and guide tube when the brake lever is actuated, resulting in undesirable movement.
Innovation Solution
A castor design featuring a locking element with a cylindrical bolt and tooth profiles on the fork and guide tube components, along with spring elements, ensures precise alignment and locking, preventing relative movement between the fork and guide tube, using materials like metal or plastic for optimal performance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a brake lever is actuated to lock the wheel, then the wheel is secured against movement, but relative movement between the fork and guide tube occurs causing instability
Solution Approach 1:
A locking element with tooth profiles serves as an intermediary component between the fork and guide tube. This locking element engages with corresponding tooth profiles on both the fork and guide tube, preventing relative movement between them while the brake lever is actuated, thus eliminating the instability caused by tolerances in the operatively connected elements.
2Device complexity
If simple locking mechanisms are used, then device complexity is reduced, but relative play between components cannot be eliminated
Solution Approach 1:
The solution adds a dimensional aspect by incorporating tooth profiles that engage in a locking mechanism. Instead of relying solely on the precision of the brake lever actuation, the tooth profiles provide a mechanical interlocking dimension that prevents relative movement between the fork and guide tube, achieving high alignment precision without excessive complexity.
Data Source
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AI summary
The roller i.e. bed roller, has a guide tube (5) pivotally arranged over a bearing (4) relative to a bracket (3). A locking element (8) is positioned within the guide tube and arranged in an operating connection with a running wheel (2). Locking units (19-21) are provided with profiles for locking the bracket relative to the guide tube and formed by tooth profiles (16-18). The locking units are connected with each other by actuation of the locking element such that play-free adjustment between the bracket and the guide tube is enabled.