Torque Limiting Fastening Assemblies for Fluidic Couplings
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Fluidic coupling devices, such as locking luer connectors, often experience overtightening issues due to excessive torque, leading to leaky connections or difficulty in disconnection, especially when used by technicians with varying physical strength.
Innovation Solution
The implementation of torque-limiting fastening assemblies in fluidic coupling assemblies, which include a male and female fitting with a rotatable fastening assembly and a resilient member that defines a threshold torque, preventing overtightening by allowing the driven member to rotate with the drive collar only until the threshold torque is reached.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a threaded assembly requiring torque to operate is used to secure the connection, then the connection can be tightened and secured, but excessive torque causes overtightening leading to leaky connections, failed connectors, or difficulty in disconnection
Solution Approach 1:
The patent changes the operational parameter from continuous torque application to discrete torque thresholds. The resilient member creates a threshold torque value that must be exceeded to engage the torque limiting mechanism. This transforms the tightening operation from a continuous process prone to overtightening into a controlled process with a defined engagement point, ensuring reliable connections without excessive force that would cause disconnection difficulties
Solution Approach 2:
The resilient member acts as an intermediary between the drive collar and driven member. It absorbs and limits the torque transmission, creating a buffer that prevents direct transmission of excessive torque to the connection. This intermediary mechanism ensures that the connection receives sufficient torque to secure properly while preventing the transmission of excessive torque that would cause overtightening and subsequent disconnection problems
2Reliability
If a threaded assembly requiring torque to operate is used to secure the connection, then the connection can be tightened and secured, but excessive torque causes overtightening leading to failed connectors
Solution Approach 1:
The patent introduces a threshold torque parameter defined by the resilient member's spring constant. This creates a distinct operational regime where torque below the threshold allows normal connection tightening, but torque exceeding the threshold triggers the torque limiting mechanism. This parameter change protects connector integrity by preventing the application of excessive torque that would cause failure while maintaining sufficient torque for reliable connection
Solution Approach 2:
The resilient member serves as a torque-limiting intermediary that decouples the relationship between applied torque and connection torque. It absorbs excess energy and prevents direct transmission of damaging torque forces to the connector components. This protective intermediary mechanism maintains connector integrity by ensuring torque remains within safe operational limits while still achieving secure connections
3Reliability
If a threaded assembly requiring torque to operate is used to secure the connection, then the connection can be tightened and secured, but excessive torque causes overtightening leading to leaky connections
Solution Approach 1:
The resilient member acts as a torque-mediated intermediary between the rotational input and the axial connection force. It transforms rotational torque into controlled axial compression through its elastic deformation, ensuring that the connection receives the precise force needed for a leak-free seal without the risk of overtightening. This mediated mechanism achieves reliable sealing while adding minimal complexity compared to traditional threaded assemblies
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
Prevents overtightening and ensures secure, leak-free connections that can be easily disconnected, regardless of the user's strength, by limiting torque and providing an audible click when the threshold torque is reached, thus maintaining the integrity of the fluidic pathway.
Implementation Method 1
at least one resilient member having a spring bias that defines a threshold torque of the rotatable fastening assembly
Implementation Method 2
the at least one resilient member yields and allows the at least one driving surface to bypass the at least one forcible surface
Data Source
AI summary
Fluidic coupling assemblies include a fitting body having a single integral piece or separable pieces such as male and female fittings such as luer fittings. The assemblies further comprise a rotatable fastening assembly having a drive collar and a driven member, and at least one resilient member having a spring bias that defines a threshold torque of the rotatable fastening assembly. The spring bias may be directed axially or radially with respect to the longitudinal axis of the fluidic coupling assembly. The resilient member is configured to prevent overtightening of the fluidic coupling assembly by allowing the drive collar to rotate the driven member only when less than a threshold torque is applied. Rotation of the rotatable fastening assembly imparts a compressive force on the resilient member, and the resilient member yields when the compressive force exceeds the spring bias of the resilient member.