Key Unit Metal Holder Ring Attachment Mechanism

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Solution Overview

Problem

Conventional key units with integrated immobilizer and keyless entry functions result in increased grip case thickness, making it difficult to attach a metal holder ring securely and efficiently, as the load on the holder ring is substantial, requiring enhanced attachment strength and simplified assembly processes.

Innovation Solution

A key unit design featuring a grip case with synthetic resin case members, a metal holder ring with fitting projections and engagement hooks, and a torsion spring mechanism that facilitates resilient engagement and secure attachment of the holder ring, dispersing external forces and simplifying assembly operations.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If a metal holder ring is attached to the grip case, then key holder connection is facilitated, but the attachment strength must withstand substantial load requiring enhanced design

Engineering Contradiction:

Improveease of attaching holder ringVSAvoidattachment strength

Core Design Contradiction:

Ease of operationVSStrength

Solution Approach 1:

The attachment mechanism is divided into multiple components: engagement hooks on the holder ring engage with engagement projections on the grip case, while separate fitting protrusions fit into fitting recesses. This segmentation allows the attachment function to be distributed across multiple structural elements, enhancing both ease of attachment and load-bearing strength.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The holder ring is nested between the front case and rear case of the grip case assembly. The engagement hooks extend from the holder ring to engage with the grip case, creating a nested configuration where the holder ring is held securely within the grip case structure while maintaining easy attachment through the engagement mechanism.

Inventive Principle:

Principle #7Nested doll (Nesting)

2Adaptability or versatility

If the grip case thickness increases due to additional functions, then immobilizer and keyless entry functions are integrated, but attaching a metal holder ring becomes difficult

Engineering Contradiction:

Improveintegration of additional functionsVSAvoidease of attaching holder ring

Core Design Contradiction:

Adaptability or versatilityVSEase of manufacture

Solution Approach 1:

The grip case is designed with localized attachment structures (engagement projections and fitting recesses) at specific positions on the front case and rear case. This local quality approach allows the holder ring to be attached to specific regions of the grip case without requiring modifications to the entire case structure, facilitating attachment even when the overall case thickness increases due to integrated functions.

Inventive Principle:

Principle #3Local quality

3Ease of operation

If an opening for connecting a key holder is provided in the grip case, then key holder connection is enabled, but the key holder becomes large

Engineering Contradiction:

Improvekey holder connectionVSAvoidkey holder size

Core Design Contradiction:

Ease of operationVSVolume of moving object

Solution Approach 1:

Instead of providing a large opening in the grip case for key holder connection, the invention utilizes the thickness dimension of the grip case by extending engagement hooks from the holder ring to engage with projections on the grip case. This dimensional approach allows compact key holder attachment without requiring large openings, maintaining a compact overall size.

Inventive Principle:

Principle #17Another dimension (Dimensionality change)

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 enhances assembly strength and simplifies the attachment process of the metal holder ring to the grip case, ensuring secure attachment and reduced complexity in assembly operations without requiring specialized tools or skilled workers.

Implementation Method 1

an engagement hook is projectingly provided integrally on one of the case members so as to resiliently engage with an engagement hole provided in the holder ring

Methodology Applied

Scientific EffectResilient engagement: Elasticity

Implementation Method 2

a torsion spring has one end engaging with the key head so as to exhibit a resilient force for urging the mechanical key to a side that causes the key plate to project

Methodology Applied

Scientific EffectTorsion spring: Torsion Spring

Data Source

PatentUS7370501B2Key unit

Publication Date: 2008.05.13 HONDA LOCK MFG CO LTD

AI summary

A key unit includes a grip case which includes at least a pair of synthetic resin case members joined to each other, and a mechanical key supported in the grip case and having a pivotable key head. A plurality of fitting projections are projectingly provided integrally on a metal holder ring held between the case members. The fitting projections are respectively fitted into a plurality of fitting holes provided in at least one of the case members. An engagement hook resiliently engaging with an engagement hole provided in the holder ring is projectingly provided integrally on one of the case members. This facilitates assembling and enhances assembly strength in attaching the metal holder ring to the grip case.