Quarter-Turn Fastener Assembly for Push-In Lock and Easy Release

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Solution Overview

Problem

Traditional pin and grommet fastener assemblies are difficult to engage and disengage, often causing damage to components during removal.

Innovation Solution

A two-piece fastener assembly with a pin and grommet where the pin is installed via a straight push to engage box prongs with slots in the grommet, and can be easily removed by rotating 90 degrees to depress the box prongs, allowing for secure attachment and easy disengagement.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If the pin is pulled out in the opposite direction of insertion to remove it, then the pin can be disengaged from the grommet, but this causes difficulty in removal and may damage the components

Engineering Contradiction:

Improveease of disengagementVSAvoidcomponent damage

Core Design Contradiction:

Ease of operationVSObject-affected harmful factors

Solution Approach 1:

The pin is designed with an asymmetric cross-sectional shape that allows insertion in one orientation but requires rotation 90 degrees for removal. The engagement features (protrusions on the pin and corresponding recesses in the grommet) are configured so that the pin can be inserted by pushing straight in, but removal requires rotating the pin to disengage the features, eliminating the need to pull straight out and preventing component damage

Inventive Principle:

Principle #13The other way round (Inversion)

Solution Approach 2:

The fastening system transitions from a static insertion/extraction mechanism to a dynamic one involving rotational motion. The pin includes engagement features that lock during insertion but allow controlled rotation for removal. The grommet's recesses are shaped to guide the pin during insertion and to permit rotation during removal, creating a dynamic disengagement process that protects components

Inventive Principle:

Principle #15Dynamics

2Reliability

If traditional pin and grommet fasteners are used, then secure attachment can be achieved, but the fastening and unfastening processes are difficult and time-consuming

Engineering Contradiction:

Improvesecure attachmentVSAvoidtime for fastening and unfastening

Core Design Contradiction:

ReliabilityVSLoss of time

Solution Approach 1:

The asymmetric pin design with engagement features creates a secure locked state during insertion, but the same features enable quick rotational release. The pin's cross-sectional shape and engagement feature geometry ensure reliable attachment when inserted, while requiring only a 90-degree rotation for removal, dramatically reducing the time and effort needed for both fastening and unfastening operations

Inventive Principle:

Principle #13The other way round (Inversion)

Data Source

PatentUS20230417269A1Quarter Turn Fastener

Publication Date: 2023.12.28 ILLINOIS TOOL WORKS INC

AI summary

Described is a two-piece fastener assembly having a pin and a grommet. The pin can be installed with a straight push to engage box prongs with slots contained in the grommet. To remove the pin, the pin can be rotated (e.g., 90 degrees) to depress the box prongs. The box prongs include a chamfer or round on the side edge of the box prong to facilitate rotation and depression. Once the box prongs are depressed, the pin will is free for removal.