Linear Detector Cable Chafing Prevention via Transition Boot

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Linear heat detection cables experience chafing issues between the cable and the protective outer sheath in the terminal transition region, particularly due to sharp surfaces and vibrations, which can cause the core wires to short, rendering the cable inoperative.

Innovation Solution

A method involving wrapping heat-resistant tape around the distal end of the polymer tube, spirally wrapping tape over the transition area between the sheath and the cable, and positioning a transition boot to prevent chafing, followed by heat shrinking to secure the assembly, ensuring a protective barrier without direct bonding between the sheath and the cable.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Object-affected harmful factors

If the linear detector cable is covered with protective sheathing to protect against abrasion and radiant heat, then the cable's resistance to harsh environments is improved, but chafing occurs at the open end of the conduit where sharp surfaces contact the polymer covering

Engineering Contradiction:
Improveprotection against abrasion and radiant heatVSAvoidchafing at open end
Core Design Contradiction:
Object-affected harmful factorsVSObject-generated harmful factors

Solution Approach 1:

A transition boot made of heat-resistant material is introduced as an intermediary component between the protective conduit and the detector cable. This transition boot has a tapered design that fits over the open end of the conduit, providing a smooth transition surface that eliminates sharp edges and prevents chafing of the cable's polymer covering while maintaining the protective function of the conduit.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The transition boot is pre-installed on the conduit before the detector cable is inserted. This preliminary action ensures that the protective transition surface is already in place, preventing chafing from the beginning and eliminating the need for post-installation adjustments or repairs.

Inventive Principle:
Principle #10Preliminary action

2Strength

If the open end of the protective conduit is left sharp to maintain structural integrity, then the conduit's protective function is maintained, but the sharp surfaces cause chafing and potential shorting of core wires

Engineering Contradiction:
Improvestructural integrity of conduitVSAvoidoperational reliability of detector cable
Core Design Contradiction:
StrengthVSReliability

Solution Approach 1:

The protective system is segmented into three distinct components: the main protective conduit, the transition boot, and the detector cable. The transition boot acts as a separate segment that specifically addresses the sharp edge problem at the conduit end, allowing the conduit to maintain its structural integrity while the transition boot provides the smooth transition surface needed to prevent chafing and ensure reliable cable operation.

Inventive Principle:
Principle #1Segmentation

3Adaptability or versatility

If continuous vibration is present in the operating environment, then the cable experiences constant movement, but this vibration exacerbates chafing at the transition region between the conduit and cable

Engineering Contradiction:
Improveoperation in vibrating environmentVSAvoidvibration-induced chafing
Core Design Contradiction:
Adaptability or versatilityVSObject-generated harmful factors

Solution Approach 1:

The transition boot provides beforehand cushioning by creating a smooth, gradual transition surface that reduces stress concentration and friction at the conduit-cable interface. This pre-cushioning effect protects the cable from vibration-induced chafing by eliminating sharp edges that would otherwise concentrate stress and accelerate wear during continuous vibration cycles.

Inventive Principle:
Principle #11Beforehand cushioning (Prior cushioning)

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 method effectively prevents chafing and ensures the linear detector cable remains operational by creating a protective transition area that withstands harsh environments and vibrations, maintaining the integrity of the polymer coating and preventing unnecessary shorts.

Implementation Method 1

wrapping heat resistant tape around a distal end of the tube to form a stop surface

Methodology Applied
Scientific EffectFriction: Friction

Implementation Method 2

wrapping heat resistant tape around a distal end portion of the polymer tube

Methodology Applied
Scientific EffectAdhesion: Adhesive

Implementation Method 3

spirally wrapping a layer of heat resistant tape over an end portion of the protective outer sheath, the distal end portion of the tube and the linear detector cable

Methodology Applied
Scientific EffectFriction: Friction

Implementation Method 4

heat shrinking to secure the assembly

Methodology Applied
Scientific EffectThermal contraction: Thermal Contraction

Data Source

PatentEP3203594B1Method for preventing chaffing between a linear detector cable and a protective outer sheath
Publication Date: 2020.10.28 KIDDE TECHNOLOGIES INC
  • EP3203594B1 patent drawingFigure 1~3
  • EP3203594B1 patent drawingFigure 4~6
  • EP3203594B1 patent drawingFigure 7~9

AI summary

A method for preventing chaffing between a linear detector cable and a protective outer sheath including the steps of preparing an elongated polymer tube having a predetermined length and outer diameter, wrapping heat resistant tape having a given width around a distal end portion of the tube to locally enlarge the outer diameter of the tube, and inserting a proximal end portion of the tube into an open end of a metallic protective sheath having a predetermined inner diameter that is slightly greater than or equal to the outer diameter of the tube, so that the heat resistant tape wrapped around the distal end portion of the tube abuts against the end of the sheath to acts as a stop surface.