Rear Steer Portable Wheelchair Scissor Hinge Mechanism
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Solution Overview
Problem
There is a lack of portable and collapsible rear steer wheelchairs that can navigate moderately rough terrain while being lightweight and maneuverable.
Innovation Solution
A rear steer portable and collapsible wheelchair design featuring side frame assemblies with scissor hinge assemblies, front and rear wheels, collapsible pushing arms, armrests, a back support, and a seat support, which can be easily deployed and collapsed into a compact configuration using a geared scissor hinge mechanism, allowing for efficient transport and use on varied terrain.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If the wheelchair is designed to be portable and collapsible, then ease of transport is improved, but structural strength and stability deteriorate
Solution Approach 1:
The wheelchair frame is divided into multiple collapsible sections connected by scissor hinge assemblies, allowing the structure to be segmented into portable sections while maintaining structural integrity when assembled. The side frame assemblies can be independently collapsed and reconfigured.
Solution Approach 2:
The wheelchair employs dynamic scissor hinge mechanisms that allow the frame to transition between expanded (stable) and collapsed (portable) states. The geared hinge linkages provide controlled movement and locking positions, enabling the structure to adapt its configuration based on transport or usage requirements.
2Ease of operation
If the wheelchair uses a scissor hinge assembly for collapsing, then ease of deployment is improved, but device complexity increases
Solution Approach 1:
Multiple hinge functions are combined into a single scissor hinge assembly unit that integrates the collapsing mechanism, locking mechanism, and structural support functions. The geared hinge linkages combine motion transmission and position locking in one integrated component.
Solution Approach 2:
The scissor hinge assembly is designed to automatically lock into position when the side frame assemblies are spread apart, and can be released by pulling the handle, allowing the mechanism to self-regulate its state without requiring complex external control systems.
3Ease of operation
If the wheelchair is designed for rear steer capability, then maneuverability over rough terrain is improved, but weight increases
Solution Approach 1:
The rear steer capability is implemented specifically at the rear wheel assemblies where it is most needed for maneuverability, while the front wheels remain simpler in design. This localized application of complex mechanisms minimizes overall weight increase while achieving the desired handling characteristics.
Data Source
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AI summary
The present invention relates to improvements in the design of a rear-steer collapsible, in particular the invention relates to a number of safety enhancing features that provide a safer and more versatile rear steer portable wheelchair.