Threaded Coupling Locking Assembly for Low-Weight Secure Timing

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Solution Overview

Problem

Existing threaded couplings in the aerospace industry face challenges with bulky locking assemblies that increase weight and length, making them unsuitable for weight-sensitive applications and requiring additional secondary locking mechanisms to ensure safety during flight.

Innovation Solution

A compact locking assembly using a pin portion and flexible cable portion that restricts movement in all directions, allowing for secure locking and timing adjustments with reduced material and length, while also serving as a safety wire to prevent lock nut loosening, thereby minimizing weight and cost.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a traditional locking assembly with lock washer and keyway is used, then locking and timing are achieved, but weight and length of the threaded coupling increase significantly

Engineering Contradiction:
Improvelocking securityVSAvoidweight of threaded coupling
Core Design Contradiction:
ReliabilityVSWeight of moving object

Solution Approach 1:

The patent combines the locking function and timing function into a single integrated locking assembly comprising a locking member and a cable portion, eliminating the need for separate lock washers, keyways, and secondary locking mechanisms. This merging of functions reduces the overall number of components and their associated weight while maintaining reliable locking and timing capabilities.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The locking assembly is designed to perform multiple functions simultaneously: the locking member provides primary locking, the cable portion provides secondary locking and timing, and the integrated design serves both structural and safety functions. This multi-functionality eliminates the need for additional specialized components, reducing weight.

Inventive Principle:
Principle #6Universality (Multi-functionality)

2Reliability

If a traditional locking assembly with lock washer and keyway is used, then locking and timing are achieved, but the length of the threaded coupling increases considerably

Engineering Contradiction:
Improvelocking securityVSAvoidlength of threaded coupling
Core Design Contradiction:
ReliabilityVSLength of moving object

Solution Approach 1:

The locking member and cable portion are integrated into a compact assembly that occupies minimal axial space. The cable portion is routed through the locking member rather than requiring separate clearance spaces, significantly reducing the overall length of the threaded coupling while maintaining effective locking and timing functions.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The cable portion is nested within or through the locking member structure, with the cable running through holes in the locking member. This nesting arrangement allows the cable portion to provide secondary locking and timing functions without adding significant axial length to the assembly.

Inventive Principle:
Principle #7Nested doll (Nesting)

3Reliability

If traditional locking assemblies are used, then locking is provided, but additional secondary locking mechanisms are required to meet safety requirements

Engineering Contradiction:
Improvelocking securityVSAvoidnumber of locking mechanisms
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The locking assembly is designed so that the cable portion serves dual purposes: it provides timing adjustment and simultaneously acts as a secondary locking mechanism (safety wire) that prevents the locking member from loosening. This eliminates the need for separate safety wires or additional secondary locking components, reducing overall device complexity while meeting safety requirements.

Inventive Principle:
Principle #6Universality (Multi-functionality)

4Reliability

If bulky locking assemblies are used, then locking and timing are achieved, but weight-sensitive applications are compromised

Engineering Contradiction:
Improvelocking securityVSAvoidsuitability for weight-sensitive applications
Core Design Contradiction:
ReliabilityVSAdaptability or versatility

Solution Approach 1:

The integration of locking and timing functions into a single compact assembly, along with the cable portion serving as both timing mechanism and safety wire, dramatically reduces the weight of the threaded coupling. This weight reduction makes the design suitable for weight-sensitive applications such as aerospace while maintaining full locking security and timing capabilities.

Inventive Principle:
Principle #5Merging (Combining)

Data Source

PatentEP3611391B1Threaded couplings with locking
Publication Date: 2021.10.06 CROMPTON TECH GROUP
  • EP3611391B1 patent drawingFigure 1
  • EP3611391B1 patent drawingFigure 2~3
  • EP3611391B1 patent drawingFigure 4

AI summary

A threaded coupling 2 comprises a first coupling member 4, a second coupling member 6 and a locking assembly 20. The locking assembly 20 comprises a locking member comprising a pin portion 9 fixed to a flexible cable portion 8, and a lock nut 10. When the first coupling member 4 is coupled to the second coupling member 6 the locking assembly 20 is arranged to restrict radial, circumferential and axial movement of the pin portion 9.