Collapsible Walking Aid Frame With Sliding Side Struts
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Solution Overview
Problem
Conventional collapsible walking aids are limited by their frame construction, which results in high stress on the front frame and connections, making them unsuitable for users with a high load, typically above 100 kg, and lack space-saving foldability.
Innovation Solution
The side struts are pivotably mounted in slides that can move longitudinally within the support tubes, with the support tubes articulating close to the front wheels and the side struts articulating close to the rear wheels, using devices connected to the support tubes to limit the unfolding movement and incorporating a U-shaped cross strut for additional stability and foldability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If the side struts are positioned as straight rods in line with the support tubes and connected to them, then the frame structure is simplified, but the load capacity is limited and the front frame experiences high stress
Solution Approach 1:
The side struts are made movable relative to the support tubes through slide mechanisms, allowing dynamic adjustment of the frame geometry. This enables the structure to adapt to load conditions and distribute forces more effectively, increasing load capacity while maintaining structural simplicity.
Solution Approach 2:
The side struts are separated from the support tubes through the slide mechanisms, creating independent movable segments. This segmentation allows each component to be optimized for its specific function - the support tubes for vertical support and the side struts for lateral stability - thereby improving overall load capacity.
2Strength
If the side struts are articulated close to the rear wheels and support tubes are articulated close to the front wheels, then the weight forces are distributed more effectively, but the foldability and space-saving design are compromised
Solution Approach 1:
The slide mechanisms enable dynamic reconfiguration of the side strut positions during folding and unfolding operations. This allows the structure to achieve optimal force distribution in the operational state while compactly folding when not in use, resolving the contradiction between strength and compactness.
Solution Approach 2:
The slide mechanisms allow the side struts to be positioned within the space defined by the support tubes during folding, creating a nested configuration. This enables compact storage while maintaining the ability to extend to the optimal force distribution configuration during use.
3Adaptability or versatility
If the slides are allowed to move freely in the longitudinal direction of the support tubes, then the adaptability and force distribution are improved, but the stability and control of the unfolding movement are reduced
Solution Approach 1:
The stop mechanisms provide positional feedback to the slide mechanisms, limiting the movement to optimal ranges. This feedback system allows the slides to move freely enough to adapt to force distribution requirements while being constrained to maintain stability and control during the unfolding process.
Solution Approach 2:
The stop mechanisms change the operational parameters of the slide mechanisms by defining specific movement boundaries. This allows the system to exploit the adaptability benefits of movable slides while preventing excessive movement that would compromise stability, through parameter limitation.
Data Source
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AI summary
The aid (1) has a set of support pipes (10) mounted in a chassis and accommodating a U-shaped retaining bracket (11) in a height-adjustable manner. Rear side supports (5) are mounted in slides (12) that are displaceable in a longitudinal direction of the support pipes. The support pipes are pivotably mounted in a U-shaped frame (2) between a set of front wheels (3) and a set of pivot bearings (8) for the rear side supports. Slide stop units (13) are firmly connected with the support pipes, and limits expanding movement of the chassis. The slide stop units limit displacement of the slides.