Grommet Removal Assembly With Ramp-Driven Arm Compression

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Solution Overview

Problem

Current grommet designs hinder removal due to spread arms snagging on edges, requiring destruction or rear access for removal, as they lock in place after installation and lack a method for removal via the primary side.

Innovation Solution

A grommet with flexure joint arms and a specialized removal tool featuring engagement ramps allow the arms to be compressed and retracted for easy removal from the primary side without damage, using a tool that aligns with the grommet's ramps to draw the arms inward, enabling secure retention during removal.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Strength

If grommet arms are designed to spread outward after installation to lock in place, then retention strength is improved, but removal difficulty increases as arms snag on edges

Engineering Contradiction:
Improveretention strengthVSAvoidremoval difficulty
Core Design Contradiction:
StrengthVSEase of operation

Solution Approach 1:

The grommet arms are pre-configured with engagement ramps that interface with the removal tool. Before removal begins, the tool engages these ramps to prepare the arms for controlled retraction, preventing them from snagging on edges during the removal process

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

A specialized removal tool acts as an intermediary between the operator and the grommet. The tool's engagement ramps translate linear pulling force into controlled compression of the grommet arms, mediating the removal process to prevent snagging while maintaining ease of operation

Inventive Principle:
Principle #24Intermediary (Mediator)

2Ease of operation

If grommet arms are made retractable for removal, then removal ease is improved, but structural complexity increases due to flexure joints

Engineering Contradiction:
Improveremoval easeVSAvoidstructural complexity
Core Design Contradiction:
Ease of operationVSDevice complexity

Solution Approach 1:

The grommet arms incorporate flexure joints that enable dynamic movement between extended and retracted positions. This dynamic capability allows the arms to adapt their configuration during removal without requiring complex mechanical assemblies, achieving removal ease while limiting complexity increases

Inventive Principle:
Principle #15Dynamics

3Device complexity

If grommet arms remain extended during removal, then structural simplicity is maintained, but removal is hindered as arms snag on edges

Engineering Contradiction:
Improvestructural simplicityVSAvoidremoval ease
Core Design Contradiction:
Device complexityVSEase of operation

Solution Approach 1:

The engagement ramps on the grommet arms are pre-configured to interface with the removal tool. This preliminary design feature enables the arms to be compressed and retracted smoothly during removal without requiring complex mechanisms, maintaining structural simplicity while improving removal ease

Inventive Principle:
Principle #10Preliminary action

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

Enables simplified and damage-free removal of grommets from materials like sheet metal, allowing for easy access and reuse without manual compression of arms, overcoming the snagging issue and enabling removal from the primary side.

Implementation Method 1

a plurality of arms extending from the body at a flexure joint, each of the plurality of arms including an inner surface that is flush with the inner surface of the wall in a first state, an angled surface, and a first engagement ramp. The arms are movable between the first state and a second state at the flexure joint.

Methodology Applied
Scientific EffectFlexure: Elasticity

Data Source

PatentEP3677799B1Grommet removal assemblies and methods
Publication Date: 2022.11.16 ILLINOIS TOOL WORKS INC
  • EP3677799B1 patent drawingFigure 1~2
  • EP3677799B1 patent drawingFigure 3~4
  • EP3677799B1 patent drawingFigure 5~6

AI summary

A grommet removal assembly includes a grommet (20) and a grommet removal tool (84). The grommet includes a body (22) defining a longitudinal axis, a plurality of arms (46) extending from the body, the plurality of arms defining first engagement ramps (94), and a plurality of legs (42) extending from the body. The grommet removal tool includes a shaft (136) and a plurality of wings (138) extending from the shaft and defining a plurality of second engagement ramps (96). The first engagement ramps of the wings are capable of engagement with the second engagement ramps along the plurality of arms to draw the arms inward, toward the longitudinal axis of the body.