Single-Piece Expansion Plug for High-Pressure Hole Sealing

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Solution Overview

Problem

Existing multi-piece expansion plugs for sealing holes are costly and complex to manufacture, and may not provide adequate sealing under elevated pressures due to potential scratching of the hole surfaces during installation.

Innovation Solution

A single-piece expansion plug with a tapered body and recess design, accompanied by a specialized tool featuring a tapered end and spring-loaded pin, allows for reliable and repeatable sealing by expanding outwardly into a tapered hole without excessive force on the hole surface, reducing the risk of scratching.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If a simple non-expanding plug is forced into a hole to seal it, then the manufacturing complexity is reduced, but the plug may scratch the hole sides and create leakage pathways, reducing sealing performance under elevated pressures

Engineering Contradiction:
Improveplug manufacturing simplicityVSAvoidsealing performance under elevated pressures
Core Design Contradiction:
Ease of manufactureVSReliability

Solution Approach 1:

The plug transitions from a static simple cylinder to a dynamic expanding structure. The plug body includes expansion elements (such as radial blades or segmented sections) that remain collapsed during insertion but expand outward upon installation to seal against the hole walls, preventing scratching while maintaining simplicity in the initial plug design

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The plug is divided into functional segments: a simple outer cylinder for easy insertion and a set of radial expansion elements (blades or segments) that can be collapsed for insertion and then expanded to create the seal. This segmentation allows the plug to combine the simplicity of a basic cylinder with the sealing capability of an expanding mechanism

Inventive Principle:
Principle #1Segmentation

2Reliability

If multi-piece expansion plugs are used to achieve reliable sealing, then sealing performance is improved, but manufacturing cost and complexity increase due to multiple pieces requiring machining and assembly

Engineering Contradiction:
Improvesealing performanceVSAvoidnumber of pieces to be machined and assembled
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

Multiple functional elements that would traditionally require separate pieces (the outer cylinder, expansion blades, and locking mechanisms) are merged into a single monolithic plug body. The expansion elements are integrated as radial sections of the same piece, eliminating the need for assembly while maintaining the expansion sealing function

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The plug utilizes material properties and geometric parameters to achieve expansion without multiple pieces. By designing the plug with specific radial sections or blade structures that can flex or spread apart, and by controlling the insertion force and expansion timing, the plug achieves multi-piece functionality through parameter-controlled deformation of a single piece

Inventive Principle:
Principle #35Parameter changes

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 solution provides a cost-effective, single-piece sealing solution that effectively resists elevated pressures while minimizing hole surface damage during installation, ensuring reliable and repeatable sealing performance.

Implementation Method 1

The friction between the plug and the hole prevents the plug from being pulled out of the hole

Methodology Applied
Scientific EffectFriction: Friction

Data Source

PatentEP3607235B1Single piece expansion sealing plug
Publication Date: 2022.03.16 ENGINEERED INSERTS & SYSTEMS INC
  • EP3607235B1 patent drawingFigure 1~5
  • EP3607235B1 patent drawingFigure 6~8
  • EP3607235B1 patent drawingFigure 9~10

AI summary

A single piece expansion plug and method of using the same in connection with a tool is provided. The plug has an inner recess extending partially into a top of the plug, the inner recess defining a tapered inner wall. The plug is installed with a tool having a tapered end at a greater angle with respect to the taper inner wall. The tool presses against the tapered inner wall to expand the plug against a hole. The tool includes a pin that retracts against a spring to seat the plug in the hole to be sealed such that the pin contacts the plug prior to the tapered inner wall and tapered end coming into contact.