Foldable Ramp Lifting Arm for Low-Force Wheelchair Access
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Solution Overview
Problem
Current foldable ramps for wheelchair access in passenger cars require high operational forces for initial uplift from a horizontal passive position, especially due to resistance from latching mechanisms and limited accessibility, which complicates handling and increases maintenance costs.
Innovation Solution
A lifting mechanism with a swivel lifting arm and force accumulator, such as a spring, that automatically uplifts the ramp from a passive lying position without operator input, using a mechanical transmission to reduce necessary forces and simplify handling, featuring a biasing system that pre-tensions the swivel lifting arm to generate a lifting force.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If a foldable ramp is equipped with motor driven support mechanisms to reduce operational forces for initial uplift, then the necessary force for a user to uplift the ramp is reduced, but the device complexity and maintenance costs increase
Solution Approach 1:
The patent extracts the force accumulation function from a complex motor-driven system and implements it through a simple spring element. The spring is pre-tensioned to store potential energy, which is then released to assist with the initial uplift of the ramp, eliminating the need for motors and complex control systems while maintaining ease of operation.
Solution Approach 2:
Instead of using an active motor system that requires power input and control, the invention uses a passive spring system that stores energy during ramp deployment and releases it during retraction. This inversion of the energy flow direction simplifies the mechanism while reducing operational forces.
2Stability of the object's composition
If a foldable ramp uses a latching mechanism to hold positions, then the ramp stability is improved, but the operational forces required for initial uplift increase
Solution Approach 1:
The spring mechanism is pre-tensioned during ramp deployment to accumulate elastic potential energy. This preliminary action stores the force needed to overcome the latching mechanism's resistance, so that when the ramp needs to be lifted, the pre-stored energy is released to assist the user, reducing the operational force required.
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
Significantly reduces the manual force required for initial uplift, enhances ergonomic handling, and reduces maintenance costs by eliminating the need for complex motor-driven support mechanisms, allowing easy and safe operation for users with varying physical abilities.
Implementation Method 1
A lifting mechanism with a swivel lifting arm and force accumulator, such as a spring, that automatically uplifts the ramp from a passive lying position
Implementation Method 2
featuring a biasing system that pre-tensions the swivel lifting arm to generate a lifting force
Data Source
AI summary
A lifting mechanism for a foldable ramp may include a swivel lifting arm being biased in a passive position of the foldable ramp and being activatable for releasing and transmitting its bias into a lifting force on the foldable ramp. The foldable ramp may be for providing wheelchair access to a passenger car rear door. The foldable ramp can be swivelled between several positions including a passive position in which the foldable ramp is arranged in the car in a lying position.