Tool-less Valve Stem Connector Assembly
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Solution Overview
Problem
Conventional methods for connecting a globe valve actuator to a valve stem in HVAC systems require tools and both hands, increasing labor intensity and installation time, thereby raising the 'installed' cost.
Innovation Solution
A tool-less valve stem connector assembly that includes a retainer with rotatably secured cams and a latch, allowing for secure connection of the lead screw to the valve stem without tools, utilizing a snap-fit mechanism and spring-loaded features for hands-free operation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If a conventional method using tools and both hands is used to connect the globe valve actuator to the valve stem, then the connection is secure, but the labor intensity and installation time increase
Solution Approach 1:
The connector assembly is designed to be self-securing through the interaction between the cam mechanism and the latch. When the connector is pushed onto the valve stem, the cam automatically rotates and engages with the latch, creating a secure connection without requiring tools or two hands. The spring provides the necessary force for the cam to rotate and lock into place automatically.
Solution Approach 2:
The cam mechanism introduces dynamic movement to the connection process. The cam rotates from an initial position to a locked position during assembly, transforming a static connection problem into a dynamic locking process. This rotational movement enables the single-handed operation by allowing the connector to self-lock as it is pushed onto the valve stem.
2Ease of operation
If a conventional method using tools and both hands is used to connect the globe valve actuator to the valve stem, then the connection is secure, but the labor intensity increases
Solution Approach 1:
The connector assembly is divided into distinct functional components: the retainer body, the cam mechanism, the latch, and the spring. Each component performs a specific function - the retainer body provides the mounting structure, the cam creates the locking action, the latch secures the cam position, and the spring provides the necessary force. This segmentation allows for easier manufacturing and assembly while achieving the tool-less connection function.
3Loss of time
If a tool-less connection mechanism is used, then installation time is reduced, but the connection security may be compromised
Solution Approach 1:
The cam mechanism utilizes curved surfaces and rotational movement to create a secure locking action. The cam's curved profile engages with the latch in a way that distributes forces evenly and creates a mechanically strong connection. The rotational locking action ensures that the connector remains securely attached to the valve stem during operation.
Solution Approach 2:
The spring is pre-loaded within the connector assembly before installation, storing potential energy that is released during the connection process. This preliminary action ensures that when the connector is pushed onto the valve stem, the spring immediately drives the cam to rotate and lock into place, providing consistent and reliable connection security without requiring tools or adjustment during installation.
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 quick, tool-free securement of the valve stem to the lead screw, reducing installation time and costs by allowing single-handed operation, while maintaining a secure connection.
Implementation Method 1
at least one cam rotatably secured to the retainer... a cam surface configured to initially engage the retainer latch to move the at least one cam from the normally unlocked position to the locked position
Implementation Method 2
at least one spring formation formed on the retainer body, with the at least one spring formation being configured to engage the inner surface of the retainer latch to secure the retainer latch to the retainer when in the retainer latch is in the locked position
Implementation Method 3
The retainer latch is configured to move from a normally unlocked position in which the valve stem is unsecured from the lead screw and a locked position in which the retainer latch moves toward the retainer to rotate the at least one cam
Data Source
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AI summary
A valve stem connector assembly (40), which connects a lead screw (36) of a globe valve actuator (10) to a valve stem (34) of a globe valve (12), includes a retainer (44) secured to the lead screw (36). The retainer includes a retainer body (54) and at least one cam (48) rotatably secured to the retainer (44). The valve stem connector assembly further includes a retainer latch (46) coupled to the lead screw and the retainer (44). The retainer latch (46) is configured to move from a normally unlocked position in which the valve stem (34) is unsecured from the lead screw and a locked position in which the retainer latch (46) moves toward the retainer (44) to rotate the at least one cam (48) to secure the valve stem (34) to the lead screw (36). A method of releasably securing a valve stem of a globe valve to a lead screw of a globe valve actuator is further disclosed.