Fold-out Ramp Assembly with Two-Phase Actuation
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Solution Overview
Problem
Fold out ramps for vehicles face challenges such as requiring more torque for operation due to their length, difficulty in manual operation without power, and obstacles created by the stowed ramp depression in the vehicle floor, while also needing to accommodate varying curb heights and surface conditions.
Innovation Solution
A ramp assembly with a rotatable ramp portion and movable panels that deploy through a two-phase motion, using an actuator to rotate and lower the ramp, and a drive arm to adjust the pivot axis, allowing for a longer ramp surface with reduced slope and a compact operating system that can be manually operated.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If the ramp is made longer to reduce the slope angle, then accessibility is improved, but the weight and torque requirement increase
Solution Approach 1:
The ramp is divided into multiple panels that can be folded and collapsed. The ramp includes a first panel, second panel, and additional panels that can be arranged in different configurations to achieve the desired length while managing weight and torque requirements through segmented construction.
Solution Approach 2:
The ramp employs a dynamic folding mechanism with multiple pivot points and joints that allow the ramp to transition between extended and retracted positions. The panels can be rotated and folded to adjust the ramp length and angle, enabling adaptive configuration based on accessibility needs while controlling the torque profile during deployment.
2Power
If a power source is added to meet torque requirements, then deployment capability is improved, but manual operation capability is lost
Solution Approach 1:
The ramp mechanism incorporates self-servicing features including spring-loaded assistance systems and friction-controlled joints that enable the ramp to be deployed and operated manually without requiring external power sources. The design allows the ramp to utilize its own weight and gravitational forces to assist in the deployment process.
Solution Approach 2:
The ramp system allows for adjustment of operational parameters such as friction coefficients, spring tension, and joint resistance to optimize the balance between powered and manual operation modes. The mechanism can be configured to require minimal force for manual deployment while still providing sufficient support when powered assistance is available.
3Volume of moving object
If the ramp is stowed in a depression in the vehicle floor, then space efficiency is improved, but the depression creates an obstacle for wheelchair passengers
Solution Approach 1:
The ramp panels are extracted from the traditional recessed stowage configuration and positioned to extend along the side of the vehicle interior. The panels can be stored in a linear configuration along the vehicle wall rather than being folded into a floor depression, eliminating the creation of obstacles while maintaining compact stowage.
Solution Approach 2:
The ramp stowage configuration transitions from a vertical floor-based depression to a horizontal arrangement along the vehicle side wall. By utilizing the lateral dimension of the vehicle interior rather than the vertical floor space, the design achieves compact stowage without creating tripping hazards or obstacles in the vehicle's entry path.
4Adaptability or versatility
If the ramp is made adjustable to varying curb heights, then versatility is improved, but device complexity increases
Solution Approach 1:
The ramp incorporates dynamic adjustment mechanisms including movable panels with adjustable angles and positions. The panels can be rotated and repositioned to accommodate different curb heights and ground conditions, providing versatility through dynamic configuration rather than multiple fixed-position ramps.
Solution Approach 2:
The ramp design integrates multiple functions into a single unified structure that can operate in various configurations. The same panel assembly serves multiple purposes by adjusting its angle and extension, eliminating the need for separate mechanisms for different deployment scenarios and reducing overall device complexity.
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
The solution provides a longer, more accessible ramp surface with reduced slope, ensuring greater independence and safety for wheelchair users, while being compact and efficient, and capable of manual operation without power.
Implementation Method 1
a ramp portion (110) that is coupled for rotational movement between a stowed position and a deployed position
Implementation Method 2
An elongate drive arm (250) extends radially from a third axis (182), and is operably coupled to the ramp portion. An actuator rotates the drive arm about the third axis to move the ramp portion through a deployment motion.
Data Source
AI summary
A ramp assembly includes a ramp portion coupled for rotational movement between a stowed position and a deployed position. A first panel is rotatably coupled about a first axis to the ramp portion. A second panel is movable between a lowered position and a raised position. A curbside end of the second panel rotatably associated with a roadside end of the first panel. An actuator drives the ramp assembly through a deployment motion having a first phase and a second phase. During the first phase, the actuator rotates the ramp portion about the first axis. During the second phase, the actuator moves the first axis from a raised position to a lowered position.