Rising Stem Valve Cam Lever Locking Mechanism
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Manually operated valves on tanker trucks are prone to safety issues due to pinch points between the handle and bonnet, which can cause injury when a vacuum forms during unloading, pulling the plunger and handle back to the closed position.
Innovation Solution
A rising stem valve design with a locking mechanism using cam levers and a groove on the valve stem, allowing the handle and bonnet to remain separated, eliminating potential pinch points and ensuring safe operation even under vacuum conditions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Volume of moving object
If the handle and bonnet are positioned close together for compact design, then the valve structure is more compact, but pinch points are created that can cause injury when vacuum pulls the plunger back
Solution Approach 1:
A locking mechanism with cam levers and a groove on the valve stem acts as an intermediary between the handle and bonnet. This mechanism maintains a predetermined safe distance between the handle and bonnet, preventing direct contact while still allowing the valve to function. The cam levers engage with the groove to lock the plunger/seal assembly in the closed position, eliminating the pinch point hazard.
2Ease of operation
If the handle is allowed to move freely with the plunger, then the valve operates smoothly, but the handle can be pulled back into the bonnet creating safety hazards
Solution Approach 1:
The locking mechanism applies preliminary anti-action by preventing the handle from moving backward into the bonnet. The cam levers are positioned to engage with the groove on the valve stem before any harmful movement can occur, locking the plunger/seal assembly in the closed position and maintaining a safe distance between the handle and bonnet.
Solution Approach 2:
The locking mechanism serves as an intermediary that decouples the handle movement from the plunger movement. When the valve is closed, the cam levers engage with the groove to prevent the handle from following the plunger backward, thus protecting the operator's fingers while maintaining operational smoothness.
3Object-affected harmful factors
If a locking mechanism is added to prevent pinch points, then safety is improved, but the device complexity increases
Solution Approach 1:
The locking mechanism with cam levers and groove serves as an intermediary safety device that adds minimal complexity. The cam levers are attached to the bonnet and engage with a groove on the valve stem, creating a simple yet effective locking system that prevents pinch points without significantly complicating the overall valve structure.
Solution Approach 2:
The locking mechanism is designed to be self-activating through the natural movement of the valve components. As the plunger/seal assembly moves to the closed position, the cam levers automatically engage with the groove on the valve stem, locking the handle in place without requiring additional actuators or complex control systems.
Data Source
AI summary
A rising stem valve comprises a hollow valve body having a pair of ports defining a flow path through the valve body, a flange base through which one of the ports extends and a valve bonnet opposite the flange base. The valve includes a plunger/seal assembly able to be extended within the valve body to a first position for sealing the port in the flange base and to a second position for unsealing the port in the flange base. The valve also includes a locking mechanism for securing the plunger/seal assembly in the first position. The locking mechanism includes at least one cam lever attached to the valve body and a corresponding groove in a valve stem of the plunger/seal assembly.