Retractable Vehicle Access Device Linkage Mechanism
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing access devices for vehicles do not efficiently provide compact storage while allowing easy access between elevated and substrate surfaces without interfering with normal vehicle operations.
Innovation Solution
A retractable access device with a concertina-like configuration, featuring pivotally connected links, guide rails, and guide rollers, which moves between contracted and expanded configurations using a hydraulic actuator, ensuring compact storage and safe, horizontal tread step movement.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If the access device is extended to provide easy access between surfaces, then the ease of operation is improved, but the device occupies more space and may interfere with normal vehicle operations
Solution Approach 1:
The access device transitions from a static structure to a dynamic, movable system. The tread steps are connected via linkage assemblies that allow the device to move between an expanded configuration (providing easy access) and a contracted configuration (minimizing storage space). This dynamic transformation resolves the contradiction by enabling the device to adapt its spatial footprint based on operational needs.
Solution Approach 2:
The access device employs a nested arrangement where the tread steps are folded together in a concertina-like manner during retraction. Each step is nested within or alongside the others, allowing the entire structure to be compacted into a minimal storage space under the vehicle, thereby resolving the space occupation issue while maintaining full functionality when deployed.
2Area of stationary object
If the access device is retracted to a compact position for storage, then the area occupied is reduced, but the ease of access between surfaces is compromised
Solution Approach 1:
The device utilizes a dynamic linkage mechanism that enables rapid transformation between compact storage and expanded access configurations. The linkage assemblies allow the tread steps to be deployed smoothly and securely, ensuring that when space is minimized, the device can still be quickly reconfigured to provide safe and easy access when needed.
Solution Approach 2:
The access device is extracted from its compact storage position and deployed to the expanded configuration on demand. The linkage assemblies facilitate this extraction by allowing the tread steps to be unfolded and positioned independently, ensuring that the ease of access is restored when the device is taken out from its space-saving storage state.
3Reliability
If guide rails and guide rollers are added to control tread step movement, then the reliability and safety are improved, but the device complexity increases
Solution Approach 1:
Guide rails and guide rollers are introduced as intermediary elements between the tread steps and the vehicle body. These intermediaries control the movement path of the tread steps, ensuring they remain horizontal and stable during deployment and retraction. The guide rails provide the structural framework, while the rollers facilitate smooth movement, together enhancing reliability without requiring complex control mechanisms.
Solution Approach 2:
The guiding function is segmented into two distinct components: guide rails that provide the structural constraint and guide rollers that enable controlled movement. This segmentation allows each component to perform its specific function efficiently, with the rails ensuring stability and the rollers ensuring smooth operation, thereby improving reliability while keeping the overall structural complexity manageable.
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
Enables compact storage under vehicles without hindering operations and provides safe, easy access between surfaces through controlled upward and downward movement of tread steps, maintaining horizontal position and stability.
Implementation Method 1
a pair of guide rollers, each guide roller extending from an intermediate pivot point of an uppermost pair of links, and adapted to engage with a respective guide rail to guide said tread step during upward/downward movement of said device
Implementation Method 2
which moves between contracted and expanded configurations using a hydraulic actuator
Implementation Method 3
a pair of linkage assemblies, each linkage assembly being pivotally attached to a respective side edge of each tread step, and includes a plurality of pivotally connected links to support and effect upward and downward movement of each tread step
Data Source
Figure 1~1(d)
Figure 2~2(d)
Figure 3~3(d)
AI summary
A retractable access device (1) adapted to be moved between a first contracted configuration and a second expanded configuration. The access device (1) includes a landing (2), at least one tread step (3), and a pair of linkage assemblies (4). Each linkage assembly (4) is pivotally attached to a respective side edge of each step (3), and includes a plurality of pivotally connected links to support and effect upward and downward movement of each tread step (3) relative to said landing (2).