Coupling Device Locking Mechanism for Pipe Stress Relief

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Solution Overview

Problem

Existing coupling devices for high-pressure and high-temperature fluid transmission lack reliability and ergonomics, particularly in connections involving tubes passing through plates, with issues such as imperfect sealing and cumbersome disassembly.

Innovation Solution

A coupling device featuring a fitting body with a bearing part and an end piece ring, along with a locking mechanism using a slider or balls for secure connection and disconnection, allowing for quick and ergonomic assembly and disassembly without the need for preliminary adjustments, and ensuring constant tightening and freedom of rotation to prevent pipe stress.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If a traditional coupling device with cam lever and threaded washer is used, then sealing can be achieved through metal-to-metal contact, but the device width exceeds tube diameter making disassembly inconvenient and requiring preliminary adjustment of axial play

Engineering Contradiction:
Improvedisassembly convenienceVSAvoiddevice width
Core Design Contradiction:
Ease of operationVSDevice complexity

Solution Approach 1:

The coupling device is divided into three main segments: a body portion, an intermediate member with locking mechanism, and an end piece with cam lever. This segmentation allows the disassembly force to be applied locally at the end piece without requiring the entire device to be removed through the plate hole, solving the problem of inconvenient disassembly when device width exceeds tube diameter.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The intermediate member acts as an intermediary between the body and end piece, providing a locking mechanism that secures the connection without requiring the end piece to be fully removed. The locking balls or sliders in the intermediate member enable secure locking during operation and facilitate controlled disassembly by releasing the lock before removing the end piece.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Reliability

If axial play is taken up by action on threaded washer before cam lever actuation, then sealing can be achieved, but the operation becomes complex requiring multiple adjustment steps

Engineering Contradiction:
Improvesealing reliabilityVSAvoidnumber of adjustment steps
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The threaded washer is pre-adjusted during manufacturing or initial setup to take up axial play between the tube and sealing surface. This preliminary action ensures that when the cam lever is actuated, the sealing surfaces are already in the correct position, eliminating the need for complex multi-step adjustments during each connection operation while maintaining reliable sealing.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The design allows the threaded washer to automatically compensate for minor variations in tube positioning and manufacturing tolerances through its adjustable thread engagement. This self-service feature maintains reliable sealing without requiring precise manual adjustment of multiple components during each connection cycle.

Inventive Principle:
Principle #25Self-service

3Reliability

If locking mechanism blocks connecting element in forward direction, then secure connection is achieved, but rotation freedom must be ensured to prevent pipe stress

Engineering Contradiction:
Improveconnection securityVSAvoidrotation freedom
Core Design Contradiction:
ReliabilityVSEase of operation

Solution Approach 1:

The locking mechanism uses locking balls or sliders that engage with specific localized features on the tube surface, providing secure blocking in the forward direction only at these specific points. This localized locking allows the rest of the connection to remain free for rotation, preventing pipe stress while maintaining connection security. The locking action is applied locally rather than constraining the entire assembly.

Inventive Principle:
Principle #3Local quality

Data Source

PatentEP2587109B1Connecting device
Publication Date: 2016.12.07 STAUBLI FAVERGES SA
  • EP2587109B1 patent drawingFigure 1
  • EP2587109B1 patent drawingFigure 2~4
  • EP2587109B1 patent drawingFigure 5~6

AI summary

The device (110) has an intermediate part (160) comprising a ball locking mechanism (170) movable between a blocking position and a position, where the locking mechanism allows for a male coupling element to be withdrawn from the intermediate part. The mechanism is located in the blocking position when the intermediate part is uncoupled from an end piece ring (20). A bearing portion of an end piece body (30) is brought in sealing contact with the element for sealingly coupling first and second pipes. The mechanism is housed partially inside a groove (104) made in the element.