Hydraulic Pressure Regulating Valve for Access Platform Safety
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Solution Overview
Problem
Existing hydraulic systems in access arrangements, such as wheelchair lifts, fail to ensure safety by allowing the platform to stow with a user present, leading to potential injury, due to inefficiencies and potential failure points in multi-valve arrangements.
Innovation Solution
A hydraulic system with a pressure regulating valve that prevents the platform from moving to the stowed position if a load exceeding a specified threshold is present, ensuring the platform remains stationary even if a user is on it, by limiting hydraulic fluid pressure through a continually present pressure regulating valve in the hydraulic circuit.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a multi-valve arrangement is used to control platform movement, then the platform can be moved between positions, but safety is compromised because the system allows stowing with a user present
Solution Approach 1:
The patent extracts the safety function from the complex multi-valve arrangement by introducing a separate, dedicated pressure-regulating valve that independently monitors and controls hydraulic pressure. This isolated safety mechanism prevents platform stowing when users are present without requiring complex interconnections with the existing valve system.
Solution Approach 2:
The pressure-regulating valve acts as an intermediary between the hydraulic power unit and the hydraulic cylinder. It mediates the hydraulic fluid flow by continuously monitoring pressure and preventing fluid delivery to the cylinder when pressure exceeds the threshold, thereby blocking unsafe stowing operations.
2Reliability
If existing hydraulic systems allow platform stowing without restrictions, then operation speed is maintained, but user safety is compromised
Solution Approach 1:
The pressure-regulating valve applies preliminary anti-action by continuously monitoring hydraulic pressure before unsafe stowing can occur. When a user is on the platform, the valve detects the increased weight through pressure changes and proactively prevents hydraulic fluid delivery to the cylinder, blocking the stowing action before it can endanger the user.
Solution Approach 2:
The system implements continuous feedback through the pressure-regulating valve, which monitors hydraulic pressure in real-time and automatically adjusts fluid flow based on detected load conditions. This feedback mechanism ensures the platform cannot be stowed when users are present, as the valve responds immediately to pressure changes indicating user presence.
3Reliability
If a pressure threshold mechanism is added to prevent stowing with users, then safety is improved, but system complexity increases
Solution Approach 1:
The pressure-regulating valve is designed to automatically perform the safety function without external intervention. It self-monitors hydraulic pressure and autonomously prevents platform stowing when users are present, eliminating the need for additional sensors, control systems, or manual safety checks that would increase 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 enhanced safety by preventing the platform from stowing with a user on it, acting as a fail-safe mechanism that does not rely on positive actuation, thus avoiding potential injuries and ensuring safe operation.
Implementation Method 1
a pressure regulating valve positioned in a path between the at least one hydraulic power unit and the at least one hydraulic cylinder, wherein the pressure regulating valve is operable to prevent the at least one hydraulic cylinder from urging the platform to the stowed position if a load on the platform exceeds a specified threshold
Data Source
AI summary
A hydraulic system for an access arrangement having a platform configured for movement between a deployed position and a stowed position, the hydraulic system including: at least one hydraulic power unit configured to urge hydraulic fluid through a hydraulic circuit; at least one hydraulic cylinder directly or indirectly connected to a portion of the platform and configured to urge the platform towards at least one of the stowed position and the deployed position, wherein the at least one hydraulic cylinder is in fluid communication with the hydraulic power unit; and a pressure regulating valve in a path between the at least one hydraulic power unit and the at least one hydraulic cylinder, wherein the pressure regulating valve is operable to prevent the at least one hydraulic cylinder from urging the platform to the stowed position if a load on the platform exceeds a specified threshold.