Retractable Winding Post for Coil Strain Relief

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Solution Overview

Problem

Mechanical tension in electrical conductors of coils within electrical, electronic, or electro-optic devices, such as sensors and motors, can lead to conductor rupture under mechanical and thermal stress, resulting in device failure, especially after potting with a compound.

Innovation Solution

A strain-relief arrangement featuring a moveable winding post within a casing section that reduces mechanical tension by retracting into a recess, allowing the conductor to lose contact and reducing radial size, thereby alleviating initial tensile loads, and is integrated into the device's housing for protection.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Stability of the object's composition

If the conductor is wound under tension and fixed to the winding post, then the conductor is securely held in position during winding, but mechanical tension accumulates in the conductor leading to potential rupture under stress

Engineering Contradiction:
Improveconductor position stabilityVSAvoidconductor integrity
Core Design Contradiction:
Stability of the object's compositionVSReliability

Solution Approach 1:

The winding post is designed to be moveable relative to the casing section, transitioning from an extended position during winding to a retracted position after winding. This dynamic adjustment allows the system to adapt: the post extends to provide stable positioning during winding, then retracts to reduce mechanical tension on the conductor, preventing rupture while maintaining position stability.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The strain-relief arrangement preemptively counteracts the harmful mechanical tension by providing a path for the winding post to retract into the casing section. This preliminary anti-action prevents the accumulation of dangerous tensile loads in the conductor before they can cause rupture, while still allowing secure winding operation.

Inventive Principle:
Principle #9Preliminary anti-action

2Ease of manufacture

If the winding post remains in extended position, then the conductor maintains contact and tension for secure winding, but additional mechanical stress accumulates that may cause conductor rupture

Engineering Contradiction:
Improvewinding process simplicityVSAvoidconductor strength
Core Design Contradiction:
Ease of manufactureVSStrength

Solution Approach 1:

The winding post transitions from a static extended position to a dynamic system that can retract. During the winding process, the post remains extended to simplify the winding operation and maintain conductor contact. After winding completes, the post retracts into the casing section to reduce mechanical stress on the conductor, preserving its strength while maintaining manufacturing simplicity.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The winding post is functionally segmented into two operational phases: an extended winding phase that simplifies manufacturing, and a retracted protection phase that preserves conductor strength. This segmentation allows each phase to optimize for its specific function without compromise.

Inventive Principle:
Principle #1Segmentation

3Manufacturing precision

If the conductor is kept under tension to maintain position, then winding accuracy is improved, but the conductor becomes vulnerable to rupture under mechanical and thermal loads

Engineering Contradiction:
Improvewinding position accuracyVSAvoidconductor durability
Core Design Contradiction:
Manufacturing precisionVSReliability

Solution Approach 1:

The system dynamically adjusts the conductor's mechanical state: during winding, the extended post maintains tension for positioning accuracy; after winding, the retracted post releases tension to prevent rupture. This temporal separation allows high manufacturing precision during winding while ensuring long-term reliability during operation.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The strain-relief mechanism performs preliminary action by providing a retraction path for the winding post before operational stresses occur. This preliminary configuration change from extended to retracted position prevents the conductor from being vulnerable to rupture during subsequent mechanical and thermal loading.

Inventive Principle:
Principle #10Preliminary action

Data Source

PatentEP3091641B1Strain-relief arrangement for an electric conductor and method for establishing a strain-relief for an electric conductor
Publication Date: 2020.03.04 TYCO ELECTRONICS BELGIUM EC
  • EP3091641B1 patent drawingFigure 1
  • EP3091641B1 patent drawingFigure 2~3
  • EP3091641B1 patent drawingFigure 4

AI summary

The present invention relates to a strain-relief arrangement (20) for an electric conductor (30), particularly a varnished electric wire (30) of a coil, of an electrical, electronic or electro-optic device (1), particularly a sensor (1), a detector (1) or an electric motor (1), comprising a casing section (100) of the electrical, electronic or electro-optic device (1) and a moveable winding post (200) at/in the casing section (100) for guiding the conductor (30) while winding the coil, wherein the casing section (100) further comprises a recess (112) into which the winding post (200) is at least partially retractable after winding the coil. Furthermore, the present invention relates to a method for establishing a strain-relief for an electric conductor (30), particularly a varnished electric wire (30) of a coil, of an electrical, electronic or electro-optic device (1), wherein the conductor (30) is at least partially wound around a moveable winding post (200) of a casing section (100) of the electrical, electronic or electro-optic device (1), and wherein the winding post (200) is later retracted into a recess (112) in the casing section (100), thereby reducing a mechanical tension in the conductor (30), and subsequently the casing section (100) is at least partially covered with a potting compound.