Collapsible Handrail Assembly for Retractable Vehicle Access
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing retractable access systems for earthmoving and construction vehicles face challenges in integrating a collapsible handrail that deploys and retracts with the access means without the need for complex structural connections to the vehicle, while ensuring safety and operational standards are met.
Innovation Solution
A collapsible handrail assembly is pivotably connected to the access means, operated by a retraction mechanism, eliminating the need for direct connection to the vehicle and using a linkage arrangement to avoid overcentre issues, allowing the handrail to collapse and extend in concert with the access means during deployment and retraction.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a handrail is physically connected to the vehicle and access means, then safety support is provided, but complex structural folding and telescoping connections are required
Solution Approach 1:
The handrail assembly is extracted from the vehicle structure and repositioned to be mounted on the access means itself. This removes the need for complex telescoping connections between the handrail and vehicle body, while the handrail remains functional when the access means is deployed. The handrail assembly can be collapsed against the access means when retracted, eliminating the need for complex folding mechanisms.
Solution Approach 2:
The handrail assembly is merged with the access means structure, forming an integrated unit. The handrail is mounted on the access means and moves together with it during deployment and retraction. This combination eliminates the need for separate complex connection mechanisms between the handrail and vehicle, as they become a unified moving assembly.
2Reliability
If a handrail is included in the retractable access system, then personnel safety is improved, but space requirements and structural robustness challenges increase
Solution Approach 1:
The handrail assembly is designed to be dynamic rather than static. It can be positioned in multiple configurations - extended outward when the access means is deployed to provide safety support, and collapsed inward when the access means is retracted to minimize space requirements. This dynamic positioning allows the handrail to adapt its space occupation based on operational needs.
Solution Approach 2:
The handrail assembly is designed to collapse and nest against the access means structure when not in use. The handrail can be folded or telescoped into a compact configuration that fits within or alongside the access means, significantly reducing the overall volume occupied by the handrail when the system is in its retracted state.
3Reliability
If the access means is made retractable to increase ground clearance and safety, then vehicle safety and ground clearance are improved, but the access means requires complex retraction mechanisms
Solution Approach 1:
The retraction mechanism is merged with the access means structure itself, forming an integrated system. The access means includes built-in retraction capability that allows it to be deployed and retracted without requiring separate complex external mechanisms. The handrail assembly is part of this integrated system, moving with the access means during retraction.
Data Source
AI summary
An access system (10) for a vehicle, equipment or installation, the access system (10) including at least one section having multiple treads/steps (56), a retraction mechanism with at least one actuator (28), the retraction mechanism arranged to retract and allow deployment of the access means (12), and at least one handrail assembly (32), the at least one handrail assembly (32) being pivotably connected to the access means (12) such that the handrail assembly (32) collapses relative to the at least one section for stowage and extends to provide a handrail for supporting a user when the access means (12) is deployed.