Segmented Nut Release Device for Aviation

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Solution Overview

Problem

Existing pyrotechnical release devices in machinery, aviation, and aerospace are limited by their explosive nature, causing management, transportation, and maintenance challenges, along with contamination and poor cost-efficiency, and suffer from reliability issues due to fixed connections between detent balls and locking sleeves, which affect the release function under different loads.

Innovation Solution

A non-explosive release device using a segmented nut with a cage, housing, locking balls, driving spring, separation cone, and separation/reset spring, where the locking balls are movably placed, allowing for balanced forces and adjustable release loads, and featuring a compact structure for enhanced reliability and ease of reset.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Device complexity

If detent balls are fixed in the locking sleeve, then the structure is simplified, but the release function is severely affected under different loads

Engineering Contradiction:
Improveconnection complexityVSAvoidrelease function reliability
Core Design Contradiction:
Device complexityVSReliability

Solution Approach 1:

The detent balls are made movable within the locking sleeve through a guide hole structure, allowing them to dynamically adjust their position along the radial direction. This dynamic capability enables the detent balls to adapt to different load conditions while maintaining reliable release function, resolving the contradiction between structural simplicity and release reliability.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

A guide hole structure is introduced as an intermediary element between the detent balls and the locking sleeve. This guide hole allows the detent balls to move freely in the radial direction while being constrained within the locking sleeve, enabling the system to handle varying loads without compromising release reliability.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Ease of manufacture

If detent balls are fixed in the locking sleeve, then assembly is simplified, but axial downward component force excessively compresses the detent balls

Engineering Contradiction:
Improveassembly processVSAvoiddetent ball compression
Core Design Contradiction:
Ease of manufactureVSStrength

Solution Approach 1:

The guide hole structure serves as an intermediary that allows the detent balls to move radially while preventing excessive axial compression. This structure enables the detent balls to self-adjust their position, reducing the harmful axial downward component force while maintaining simple assembly requirements.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

By making the detent balls movable within the guide hole, the system dynamically adjusts the detent ball position to optimize force distribution. This prevents excessive compression while maintaining assembly simplicity, as the detent balls automatically find their optimal position under different load conditions.

Inventive Principle:
Principle #15Dynamics

3Stability of the object's composition

If detent balls are fixed in the locking sleeve, then the structure is more stable, but release capability varies significantly under different loads

Engineering Contradiction:
Improvestructural stabilityVSAvoidrelease capability under different loads
Core Design Contradiction:
Stability of the object's compositionVSAdaptability or versatility

Solution Approach 1:

The detent balls are designed to move within the guide hole structure, providing dynamic adaptability to different load conditions. This movement capability allows the system to maintain stable structure while adjusting release capability according to the applied load, resolving the contradiction between structural stability and load adaptability.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The position of the detent balls along the radial direction is changed as a variable parameter based on the applied load. This parameter change enables the system to adapt its release capability to different load conditions while maintaining overall structural stability through the guide hole constraints.

Inventive Principle:
Principle #35Parameter changes

4Strength

If welding and interference fit are used to fix detent balls, then connection strength is improved, but device complexity and manufacturing difficulty increase

Engineering Contradiction:
Improvedetent ball connection strengthVSAvoidassembly process complexity
Core Design Contradiction:
StrengthVSDevice complexity

Solution Approach 1:

The guide hole structure serves as a simple intermediary that provides both guidance and constraint for the detent balls without requiring complex connection methods. This approach maintains connection strength while avoiding the need for welding, interference fit, or adhesive bonding, thus reducing device complexity and manufacturing difficulty.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The detent balls utilize the guide hole structure to self-position and self-constrain within the locking sleeve, eliminating the need for external fastening methods. This self-service mechanism maintains connection strength while significantly simplifying the assembly process and reducing manufacturing complexity.

Inventive Principle:
Principle #25Self-service

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 device achieves reliable and efficient release under varying loads without the need for complex assembly methods like welding, with improved reliability and simplified reset processes, reducing the complexity of components and facilitating serialization design.

Implementation Method 1

The lower end of the separation cone is tightly supported by the separation/reset spring to maintain the spatial position of the separation cone

Methodology Applied
Scientific EffectElastic potential energy: Elasticity

Implementation Method 2

The driving spring is pre-compressed to compress the locking sleeve

Methodology Applied
Scientific EffectElastic force: Elasticity

Data Source

PatentEP3677519B1Split nut type unlocking device with non-explosive actuator
Publication Date: 2021.07.07 BEIJING SMART WING AEROSPACE TECH LTD
  • EP3677519B1 patent drawingFigure 1
  • EP3677519B1 patent drawingFigure 2
  • EP3677519B1 patent drawingFigure 3

AI summary

The present disclosure provides a non-explosive release device using a segmented nut, and relates to the technical field of release mechanisms used in machinery, aviation and aerospace. In a locking state of the release device, the segmented nut is locked by the locking ball, the thread is closed to realize the connection function. When separated, the non-explosive actuator pushes the detent latch to move upward to release the constraint on the locking sleeve, so as to release the constraint on the segmented nut. The segmented nut is opened under the action of the separation/reset spring to disconnect the screw connection and complete the release process. When reset, the reset tool is inserted from the bottom of the release device to pin the locking sleeve up to the locked position of the locking sleeve. The detent latch pushes downward the detent ball to re-lock the locking sleeve. Meanwhile, the locking sleeve can also squeeze all the locking balls back to the locked positions of the locking balls to re-lock the segmented nut, so as to complete the reset process. The present disclosure has the advantages of simple structure, compact size, high release reliability and easy reset.