Geared Vehicle Ramp Assembly for Flush Floor Wheelchair Access
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Solution Overview
Problem
Mass-produced passenger vehicles lack the necessary modifications to accommodate physically limited passengers, such as those using wheelchairs, with existing ramp systems facing challenges in stowing and ensuring a flush deployment with the conventional vehicle floor.
Innovation Solution
A ramp assembly with a frame, drive block, and wheel system that allows for longitudinal translation and rotational movement, enabling the ramp to be stowed, lowered, and raised relative to the vehicle floor, ensuring smooth ingress and egress for wheelchair passengers.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If a ramp is stored below the conventional vehicle floor and deploys to accommodate entry and exit, then accessibility for physically limited passengers is improved, but challenges arise related to stowing the ramp and ensuring it is flush with the conventional vehicle floor when deployed
Solution Approach 1:
The ramp assembly employs a dynamic mechanism with a drive block that translates along a track system and a rotatable wheel that pivots the ramp between stowed and deployed positions. This dynamic system allows the ramp to transition smoothly between configurations, automatically achieving flush alignment with the vehicle floor during deployment and retraction operations.
Solution Approach 2:
The ramp assembly is divided into separate functional components: a ramp surface, a drive block for translation, and a wheel mechanism for rotation. This segmentation allows independent optimization of each component's function, with the drive block handling longitudinal movement along the track and the wheel handling angular deployment, thereby simplifying the overall operation.
2Adaptability or versatility
If a ramp assembly includes a drive block and wheel system for longitudinal translation and rotation, then the ramp can achieve multiple positions (stowed, lowered, raised) for seamless integration with the vehicle floor, but the device complexity increases
Solution Approach 1:
The drive block serves multiple functions: it translates the ramp assembly longitudinally along the track system and also supports the wheel mechanism that provides rotational movement. This multi-functionality reduces the need for separate mechanisms for each degree of freedom, thereby managing complexity while achieving multiple position capability.
Solution Approach 2:
The wheel acts as an intermediary component between the drive block's linear motion and the ramp's rotational deployment. By introducing this intermediate element, the system achieves complex multi-position capability through a combination of simple linear translation and rotation, rather than requiring a directly actuated complex mechanism.
Data Source
AI summary
A ramp assembly to accommodate a wheel-chaired passenger to enter or exit a motorized vehicle having a conventional floor includes a frame, a ramp, and a side rail assembly. The ramp is slidably coupled to the frame for movement between a stowed position and an extended position. Once extended, the rear end of the ramp is movable between a raised position and a lowered position. The side rail assembly is moveable from a collapsed position to a lifted position as the ramp moves from the lowered position to the raised position.