Overmolded Cable Grommet Locking for Compact Sensor Housings

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Solution Overview

Problem

Existing sensor designs with cable connections are structurally complex, requiring large installation space and additional mechanical components for strain relief, leading to increased design complexity and size.

Innovation Solution

A grommet is overmolded onto the cable sheath, with a locking segment that is pressed into the housing opening, secured by the housing geometry, eliminating the need for additional mounting components and providing strain relief.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If plug connections with sockets are used to connect cable to sensor, then reliable electrical connection is achieved, but device complexity and installation space increase

Engineering Contradiction:
Improveelectrical connection reliabilityVSAvoidconnection device complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The invention extracts the cable connection function from the housing structure and implements it through a separate cable guide component that routes conductors through the housing wall. This separates the electrical connection function from the mechanical housing structure, reducing overall device complexity while maintaining reliable connection through the dedicated cable guide and connector assembly.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The cable guide acts as an intermediary component between the cable and the housing. It provides a dedicated pathway for the cable conductors through the housing wall, facilitating reliable electrical connection while mediating the mechanical integration between the cable and housing structures, thereby reducing the need for complex direct mounting solutions.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Reliability

If grommets are attached to cables to store them in housing opening, then cable strain relief is achieved, but additional mechanical components are required increasing design complexity

Engineering Contradiction:
Improvecable strain reliefVSAvoidmechanical components complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The invention merges the cable strain relief function with the cable guide component. The cable guide is designed to directly receive and secure the cable within the housing opening, combining the routing and strain relief functions into a single integrated component rather than requiring separate grommets and mounting hardware, thereby reducing design complexity.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The cable guide component serves multiple functions simultaneously: it provides a dedicated pathway for cable conductors, offers strain relief for the cable, and facilitates secure mounting within the housing opening. This multi-functional design eliminates the need for separate specialized components for each function, reducing overall device complexity.

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

3Reliability

If cable conductors are routed through housing cover and soldered with heat-shrink tubing, then secure electrical connection is achieved, but manufacturing complexity and installation time increase

Engineering Contradiction:
Improveelectrical connection securityVSAvoidmanufacturing process simplicity
Core Design Contradiction:
ReliabilityVSEase of manufacture

Solution Approach 1:

The invention segments the cable connection process into distinct functional components: the cable guide provides a dedicated routing pathway, the connector assembly handles electrical connection, and the housing provides mounting structure. This segmentation allows each component to be optimized independently and simplifies the overall manufacturing process compared to integrated soldering and heat-shrink solutions.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The cable guide is pre-configured within the housing structure to provide a ready-made pathway for cable conductors. This preliminary preparation eliminates the need for complex during-manufacturing routing and soldering operations, simplifying the manufacturing process while ensuring secure electrical connection through the pre-positioned connector assembly.

Inventive Principle:
Principle #10Preliminary action

4Reliability

If additional mechanical components are used to secure and strain-relieve cable, then cable fixation reliability is improved, but device complexity and size increase

Engineering Contradiction:
Improvecable fixation reliabilityVSAvoidmechanical components quantity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The invention combines multiple cable fixation functions into the single cable guide component. It simultaneously provides mechanical securing of the cable within the housing opening, strain relief through its structured design, and electrical pathway guidance. This merging eliminates the need for multiple separate mechanical components, reducing device complexity while maintaining fixation reliability.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The cable guide is designed as a universal component that performs multiple functions: cable routing, mechanical securing, strain relief, and electrical connection facilitation. This multi-functionality reduces the total number of mechanical components required, simplifying the device structure while ensuring reliable cable fixation without compromising any single function.

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

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 solution simplifies the cable connection by integrating the grommet into the housing, ensuring secure and strain-relieved cable fixation without additional parts, reducing design complexity and size.

Implementation Method 1

A grommet (13) is provided, which is produced by overmolding a sheath surface of the cable (9) with grommet material

Methodology Applied
Scientific EffectOvermolding:

Implementation Method 2

The grommet (13) is pressed into the housing opening (10)

Methodology Applied
Scientific EffectMechanical Force: Mechanical Force

Implementation Method 3

The grommet (13) has a locking segment (16) by means of which the grommet (13) is secured against being detached from the housing

Methodology Applied
Scientific EffectMechanical Locking: Mechanical Fastener

Implementation Method 4

This also ensures strain relief

Methodology Applied
Scientific EffectStrain Relief:

Data Source

PatentEP4464988B1Sensor with housing and cable
Publication Date: 2026.03.25 LEUZE ELECTRONIC GMBH & CO KG
  • EP4464988B1 patent drawingFigure 1~2
  • EP4464988B1 patent drawingFigure 3a~3b

AI summary

The invention relates to a sensor with a housing (2) in which sensor components are integrated. A cable (9) serves as the connection means and is located in a housing opening (10) in a housing wall (11) of the housing (2). A grommet (13) is provided, which is produced by overmolding a sheath surface of the cable (9) with grommet material. The grommet (13) is pressed into the housing opening (10) and has a locking segment by means of which the grommet (13) is secured against being removed from the housing opening (10).