Torque Indicator Fitting With Positive Lock Against Nut Loosening
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Solution Overview
Problem
Conventional fluid connector fittings lack effective visual indication of proper torque tightening and are prone to nut loosening due to vibrational and environmental factors, requiring cumbersome manual quality control and costly safety wire installation.
Innovation Solution
A fluid fitting assembly with a torque indicating mechanism featuring a visual indicator that changes color from red to green upon reaching the desired torque value, along with a retention mechanism that prevents nut loosening, using a resilient member and spring pin configuration to provide resistance against dynamic loads.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If manual quality control inspection with torque wrench is used to verify proper tightening, then tightening accuracy is improved, but installation time and labor cost increase
Solution Approach 1:
The fitting assembly performs self-inspection through the visual indicator mechanism that automatically displays whether proper torque has been applied, eliminating the need for external inspectors and torque wrenches. The system serves itself by providing immediate visual feedback during installation.
Solution Approach 2:
The patent replaces the mechanical inspection system (torque wrench and manual measurement) with a visual indication system that provides immediate feedback. The mechanical verification process is substituted by a visual display mechanism that shows tightening status without requiring additional tools or personnel.
2Reliability
If safety wire is installed to prevent nut loosening, then connection reliability is improved, but installation complexity and labor cost increase
Solution Approach 1:
The patent removes the safety wire component entirely and replaces it with an integrated retention mechanism built into the fitting assembly. The external anti-loosening measure is extracted and replaced by an inherent design feature that provides the same function without additional parts or steps.
Solution Approach 2:
The retention mechanism is merged with the nut and fitting assembly structure, combining the fastening and anti-loosening functions into a single integrated component. This eliminates the need for separate safety wire installation while maintaining reliability.
3Productivity
If visual indicator mechanism is added to show torque status, then quality control efficiency is improved, but device complexity increases
Solution Approach 1:
The visual indicator mechanism serves multiple functions: it indicates proper torque application, provides visual feedback during installation, and eliminates the need for separate inspection procedures. This multi-functionality justifies the added complexity by providing several benefits simultaneously.
Solution Approach 2:
The patent uses color changes in the visual indicator to communicate torque status, providing immediate and unambiguous information. This simple optical method achieves effective quality control without requiring complex electronic or mechanical indication systems.
4Reliability
If retention mechanism is added to prevent nut back-off, then connection stability is improved, but ease of disassembly for maintenance decreases
Solution Approach 1:
The retention mechanism is designed to be dynamic rather than permanent, allowing it to engage during normal operation to prevent loosening but disengage when intentional loosening force is applied. This dynamic behavior provides both stability during use and ease of maintenance when needed.
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 a reliable visual indication of proper torque tightening without the need for a torque wrench and prevents nut loosening, reducing installation time and labor costs while ensuring secure connections under various operational conditions.
Implementation Method 1
a resilient member that couples the sleeve to the nut. As the nut is rotated to apply torque to the nut, the resilient member biases the sleeve in a fixed position and the nut rotates relative to the sleeve
Implementation Method 2
The visual indicator assembly rotates relative to the sleeve to alter which portion of the visual indicator assembly is visible through the window
Data Source
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AI summary
A fitting assembly includes an indicator assembly that provides a visual indication of torque value to verify when the desired operational torque value is achieved. The fitting assembly includes a nut, and a visual indicator assembly positioned on the nut which has a plurality of visual indicators that provide a visual indication of a torque level being applied. A sleeve is attached to the nut and includes a window through which a portion of the visual indicators is visible based on the torque level being applied. A resilient member couples the sleeve to the nut. As the nut is rotated to apply torque to the nut, the resilient member biases the sleeve in a fixed position and the nut rotates relative to the sleeve, whereby the visual indicator assembly rotates relative to the sleeve to alter which portion of the visual indicator assembly is visible through the window to provide a visual indication of when the operational torque level is being applied. The fitting assembly includes a positive locking feature that interacts with a serrated portion of a nipple fluid connection to positively lock a position of the nut to prevent nut loosening.