Fiber Optic Connector Strain Relief Assembly Stiffness Transition

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Existing fiber optic connectors face challenges in managing the transition from high stiffness at the connector body to low stiffness at the cable, leading to stress concentration points and potential cable bending, which existing strain relief solutions inadequately address.

Innovation Solution

A fiber optic connector design featuring a strain relief assembly with a support and boot formed from different materials, where the support has a high stiffness and the boot is less rigid, with a radial flare outward and taper inward geometry to provide a smooth transition in stiffness, reducing stress concentrations and improving manufacturability and space constraints.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Strength

If a rigid connector body is used to withstand forces during handling and use, then the connector can maintain structural integrity and protect the optical connection, but stress concentrations occur at the transition point where the cable meets the connector body, potentially causing cable bending beyond minimum bend radius

Engineering Contradiction:
Improvestructural integrityVSAvoidstress concentration
Core Design Contradiction:
StrengthVSObject-affected harmful factors

Solution Approach 1:

The strain relief assembly is divided into multiple functional segments: a rigid support structure (first material) for structural integrity, a flexible boot (second material) for stress absorption, and a transition region with varying stiffness. This segmentation allows each component to address specific aspects of the problem without compromising overall performance.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

Different regions of the strain relief assembly have different material properties tailored to local requirements. The support portion uses high-stiffness material to maintain structural integrity, while the boot portion uses low-stiffness material to absorb stresses. The transition region incorporates intermediate stiffness to smoothly bridge these differences and eliminate stress concentrations.

Inventive Principle:
Principle #3Local quality

2Object-affected harmful factors

If a flexible boot is used to provide stiffness transition between connector and cable, then stress concentrations are reduced, but conflicting conditions at opposite ends of the boot (high stiffness at connector end, low stiffness at cable end) are difficult to address, leading to boot weakness or inadequate stress relief

Engineering Contradiction:
Improvestress concentrationVSAvoidboot strength
Core Design Contradiction:
Object-affected harmful factorsVSReliability

Solution Approach 1:

The strain relief assembly uses composite construction with two distinct materials: a rigid first material for the support structure and a flexible second material for the boot. This composite approach allows the assembly to simultaneously provide structural integrity and stress absorption, resolving the conflicting stiffness requirements at different locations.

Inventive Principle:
Principle #40Composite materials

Solution Approach 2:

The assembly transitions material stiffness parameters gradually from the rigid support to the flexible boot through a transition region. This parameter change approach allows the boot to satisfy both boundary conditions (high stiffness requirement at connector end, low stiffness requirement at cable end) without creating weak points.

Inventive Principle:
Principle #35Parameter changes

3Object-affected harmful factors

If existing strain relief designs are used to address stiffness transition, then some stress relief is provided, but manufacturability challenges and space constraints are not adequately addressed

Engineering Contradiction:
Improvestress reliefVSAvoidmanufacturability
Core Design Contradiction:
Object-affected harmful factorsVSEase of manufacture

Solution Approach 1:

The support and boot are designed as an integrated assembly where the boot is received over the support structure. This merging of components simplifies manufacturing by reducing the number of separate parts and assembly steps while maintaining the functional benefits of both rigid and flexible elements.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The boot is nested over the support structure, with the boot extending over at least 75% of the support length. This nested configuration allows the flexible boot to be installed over the rigid support in a single operation, improving manufacturability and reducing assembly complexity.

Inventive Principle:
Principle #7Nested doll (Nesting)

Data Source

PatentEP3321721B1Strain relief assembly for a fiber optic connector
Publication Date: 2022.04.27 CORNING OPTICAL COMMUNICATIONS LLC
  • EP3321721B1 patent drawingFigure 1~2
  • EP3321721B1 patent drawingFigure 3~4
  • EP3321721B1 patent drawingFigure 5~6

AI summary

A strain relief assembly for a fiber optic connector includes a support having a front end, a back end, and an internal cavity extending between the front end and the back end. The strain relief assembly also includes a boot extending over at least a portion of the support and rearwardly from the back end. The boot is less rigid than the support and includes an internal passageway communicating with the internal cavity of the support. Additionally, the boot is arranged about a central axis. The boot bulges radially outward from the central axis as the boot extends over the back end of the support.