Webbing Retractor Blocking Component Prevents Resin Deformation

Solution Overview

Problem

Existing webbing retractors face issues with deformation and breakage of retaining components due to load, leading to potential release of retention when a great load is applied, as they are made from resin and allow elastic movement of lock plates.

Innovation Solution

A webbing retractor design featuring a rotating component, an engaging component that blocks rotation, a retaining component that retains the engaging component in a movable state, and a blocking component that prevents deformation of the retaining component, with the blocking component having greater strength than the retaining component to prevent release of retention.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the retaining component is made from resin to allow elastic movement of the lock plate, then the lock plate can mesh with the lock gear, but the retaining component is easily deformed and may break under great load

Engineering Contradiction:

Improvemeshing reliabilityVSAvoidretaining component strength

Core Design Contradiction:

ReliabilityVSStrength

Solution Approach 1:

The retaining component is divided into two functional parts: a resilient portion made of resin that allows elastic movement for meshing, and a rigid blocking component (metal or resin) that prevents deformation under load. This segmentation allows each part to optimize its material properties for its specific function.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The retaining component combines different materials with complementary properties: resin provides elasticity for meshing engagement, while metal or rigid resin provides strength to prevent deformation. This composite approach resolves the contradiction between needing flexibility for engagement and strength for load-bearing.

Inventive Principle:

Principle #40Composite materials

2Strength

If the retaining component is made strong to prevent deformation, then it can resist great loads, but it cannot provide the elastic movement needed for the lock plate to mesh with the lock gear

Engineering Contradiction:

Improveretaining component strengthVSAvoidmeshing reliability

Core Design Contradiction:

StrengthVSReliability

Solution Approach 1:

The retaining component is divided into two functional parts: a resilient portion made of resin that allows elastic movement for meshing, and a rigid blocking component (metal or resin) that prevents deformation under load. This segmentation allows each part to optimize its material properties for its specific function.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

Different parts of the retaining component have different material properties tailored to their specific functions: the portion contacting the lock plate is made resilient for elastic movement, while the blocking portion is made rigid to prevent deformation. This local differentiation resolves the contradiction between flexibility and strength requirements.

Inventive Principle:

Principle #3Local quality

3Adaptability or versatility

If the retaining component is designed to be elastically deformable to retain the engaging component, then it can accommodate movement, but it deforms and breaks under great load causing release of retention

Engineering Contradiction:

Improvemovement accommodationVSAvoidretention reliability

Core Design Contradiction:

Adaptability or versatilityVSReliability

Solution Approach 1:

The retaining component is divided into two functional parts: a resilient portion made of resin that allows elastic movement for meshing, and a rigid blocking component (metal or resin) that prevents deformation under load. This segmentation allows each part to optimize its material properties for its specific function.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The blocking component is designed in advance to prevent excessive deformation of the resilient portion before it can lead to breakage or release of retention. This preemptive structural design ensures that the resilient portion remains within safe deformation limits even under great loads.

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 design effectively blocks deformation and release of retention, even under high loads, by ensuring the blocking component can absorb and distribute loads effectively, maintaining the retention of the engaging component and preventing deformation of the retaining component.

Implementation Method 1

the retaining component is elastically deformable and the blocking component blocks bending of the retaining component

Methodology Applied

Scientific EffectElasticity: Elasticity

Data Source

PatentUS7427044B2Webbing retractor

Publication Date: 2008.09.23 KK TOKAI RIKA DENKI SEISAKUSHO

AI summary

In the webbing retractor, a lock plate is supported by a circular axis so as to be circularly movable freely by a resin support portion of a gear case by insertion of the circular axis of the lock plate in a support hole of the gear case. Even at times when great load acts on the lock plate at the support portion side, deformation of the support portion caused by movement towards the support portion side of the lock plate is prevented due to the tip of the circular axis of the lock plate contacting the metal blocking portion of the cover plate. Due to this, release of the support of the lock plate by the support portion is prevented.