Adjustable Strain Relief Insert for Electric Wire Fastening

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Solution Overview

Problem

Existing strain relief mechanisms for electric wires and cables are designed for specific thicknesses, requiring installation workers to carry multiple devices for varying wire sizes, which is inconvenient and inefficient.

Innovation Solution

A strain relief insert with a cable retention member and fastener system that can accommodate wires of different thicknesses, providing bi-directional strain relief by preventing movement of the fastener and distributing applied strain to the installation box, allowing for easy 'plug and play' assembly and secure cable retention.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a strain relief is designed for a predetermined wire thickness, then the strain relief can securely fasten wires of that specific thickness, but installation workers must carry multiple strain relief devices for different wire sizes

Engineering Contradiction:
Improvesecure fasteningVSAvoidwire thickness accommodation
Core Design Contradiction:
ReliabilityVSAdaptability or versatility

Solution Approach 1:

The strain relief device incorporates an adjustable fastening mechanism with a movable clamp member that can be positioned at different locations along its length. This allows a single strain relief device to securely fasten wires of various diameters, eliminating the need for multiple specialized devices. The clamp member can be adjusted to accommodate different wire thicknesses while maintaining secure fastening through the same basic structure.

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

Solution Approach 2:

The strain relief employs a dynamic fastening system where the clamp member can move along the body of the strain relief. This dynamic adjustment capability allows the device to adapt to different wire diameters by repositioning the clamp, providing both secure fastening and versatility in a single device.

Inventive Principle:
Principle #15Dynamics

2Reliability

If multiple strain relief devices for different wire thicknesses are carried, then each wire size can be securely fastened, but installation becomes more complex and time-consuming

Engineering Contradiction:
Improvesecure fasteningVSAvoidinstallation simplicity
Core Design Contradiction:
ReliabilityVSEase of operation

Solution Approach 1:

By designing a single strain relief device that can accommodate multiple wire diameters through adjustment, the installation process is simplified. Workers no longer need to select from multiple specialized devices, reducing installation time and complexity while maintaining secure fastening capability.

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

Solution Approach 2:

The strain relief device is pre-configured with an adjustable mechanism that can be quickly modified during installation to match the required wire diameter. This preliminary design of the adjustment mechanism eliminates the need for workers to carry and switch between multiple pre-configured devices.

Inventive Principle:
Principle #10Preliminary action

3Adaptability or versatility

If a strain relief is designed to accommodate various wire thicknesses, then versatility is improved, but the device complexity increases

Engineering Contradiction:
Improvewire thickness accommodationVSAvoidstrain relief structure
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The strain relief uses a simple dynamic mechanism where a clamp member can slide or move along the body to accommodate different wire diameters. This dynamic element adds versatility without significantly increasing overall device complexity, as the adjustment mechanism is integrated into the basic structure rather than adding separate complex subsystems.

Inventive Principle:
Principle #15Dynamics

Data Source

PatentEP3531520B1Assembly of an installation box and electric installation material, and strain relief insert
Publication Date: 2021.03.24 ABB (SCHWEIZ) AG
  • EP3531520B1 patent drawingFigure 1
  • EP3531520B1 patent drawingFigure 2A
  • EP3531520B1 patent drawingFigure 2B

AI summary

The invention relates to an assembly of an installation box and electric installation material with at least one electric wire, the installation box comprising a housing with a bottom wall and a circumferential wall together enclosing an installation space, the circumferential wall being provided with a passage opening for the electric wire or cable to pass there through in an insert direction, and a strain relief insert inserted into the installation space and installed at the passage opening, the strain relief insert being provided with a strain relieving or cable retention member having a strain relieving or cable retention body extending substantially parallel to the insert direction, a fastener for fastening the electric wire or cable to the strain relieving or cable retention member, the fastener surrounding the electric wire or cable and the strain relieving or cable retention member.