Fluid Control End Adapter Locking Against Thread Loosening

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Solution Overview

Problem

Existing fluid devices with threaded end screw type end adapters face issues with inadvertent loosening due to high pressure, high temperature, corrosive/toxic fluid conditions, vibrations, or tampering, leading to undesirable disassembly.

Innovation Solution

Mechanical locking of the end adapter with the fluid device body by crimping or peening a deformable portion into a recessed area after full assembly, preventing rotation and securing the adapter in place.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If threaded end screw type end adapters are used for assembly, then ease of assembly is improved, but reliability deteriorates due to inadvertent loosening under high pressure, high temperature, vibrations, or tampering

Engineering Contradiction:
Improveease of assemblyVSAvoidresistance to inadvertent loosening
Core Design Contradiction:
Ease of operationVSReliability

Solution Approach 1:

The locking feature is pre-formed on the end adapter before assembly, and the recess is pre-formed on the body. Upon assembly, the locking feature automatically engages with the recess, performing the locking action in advance before any loosening can occur. This eliminates the need for separate locking operations while maintaining threadability during initial assembly.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The locking feature and recess act as intermediary mechanical elements between the threaded connection and the loosening forces. The locking feature protrusion physically interfaces with the recess to prevent relative rotation, serving as a mediator that transfers and resists the loosening forces generated by high pressure, temperature, vibrations, or tampering.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Reliability

If mechanical locking features are added to prevent loosening, then reliability is improved, but device complexity increases

Engineering Contradiction:
Improveprevention of looseningVSAvoidstructural complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The locking feature is merged with the end adapter structure, and the recess is merged with the body structure. These locking elements are integrated into the existing components rather than being separate parts, thereby preventing loosening while avoiding additional device complexity. The locking functionality is combined with the structural elements already present in the assembly.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The locking feature and recess are localized to specific positions on the end adapter and body respectively. Rather than redesigning the entire assembly, the locking mechanism is implemented as a localized geometric feature (protrusion and corresponding recess) at the interface between components, maintaining overall structural simplicity while providing targeted anti-loosening functionality.

Inventive Principle:
Principle #3Local quality

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

Ensures secure and stable attachment of the end adapter, preventing unintended loosening under challenging conditions.

Implementation Method 1

crimping or peening a deformable portion into a recessed area

Methodology Applied
Scientific EffectPlastic deformation: Plasticity

Data Source

PatentEP3877685B1Mechanically locking end screw arrangements
Publication Date: 2025.10.01 SWAGELOK CO
  • EP3877685B1 patent drawingFigure 1~2
  • EP3877685B1 patent drawingFigure 3~4
  • EP3877685B1 patent drawingFigure 5~6

AI summary

A fluid control assembly includes a body having a female threaded end port, and an end adapter including a male threaded end screw threadably assembled with the female threaded end port, an end connector, and an internal passage extending from the end connector to the end screw. One of the body and the end adapter includes at least one outer peripheral recess, and the other of the body and the end adapter includes a peripheral flange. A portion of the peripheral flange in circumferential alignment with the at least one recess is deformed into interlocking engagement with the at least one recess to rotationally secure the end adapter with respect to the body.