Undercutting Tool Chamfer Ring for Blind Hole Consistency

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Solution Overview

Problem

Existing undercutting tools for producing blind holes in hardenable mixtures face issues such as inconsistent stripping bevel formation due to varying shell materials and moisture accumulation, leading to potential mold or rust formation and surface imperfections in the hardened products.

Innovation Solution

Incorporation of a chamfered ring that forms a consistent stripping bevel independent of shell material, along with a jacket that bulges to create the blind hole shape, and features like ventilation grooves and anti-adhesive coatings to prevent moisture and residue issues.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If a deformable jacket with cavities is used to form blind holes in hardenable mixtures, then the blind hole shape can be formed corresponding to the jacket geometry, but moisture accumulates in the cavities leading to mold or rust formation

Engineering Contradiction:
Improveblind hole shape consistencyVSAvoidmold and rust formation
Core Design Contradiction:
Manufacturing precisionVSObject-generated harmful factors

Solution Approach 1:

The jacket is designed with a porous structure containing multiple cavities that allow moisture to escape during the hardening process. The porous material maintains the deformable characteristics needed for blind hole formation while providing drainage pathways that prevent water accumulation and subsequent mold or rust formation in the cavities.

Inventive Principle:
Principle #31Porous materials

Solution Approach 2:

The jacket structure is segmented into multiple sections with distributed cavities throughout its body. This segmentation allows moisture to escape at multiple locations rather than accumulating in a single cavity, thereby preventing localized mold and rust formation while maintaining the overall blind hole shaping function.

Inventive Principle:
Principle #1Segmentation

2Adaptability or versatility

If different shell materials are used for the jacket, then the blind hole can be formed with varying properties, but the stripping bevel formation becomes inconsistent

Engineering Contradiction:
Improvejacket material selectionVSAvoidstripping bevel consistency
Core Design Contradiction:
Adaptability or versatilityVSManufacturing precision

Solution Approach 1:

A chamfered ring is introduced as a preliminary action that occurs before the jacket material contacts the mixture. This ring pre-forms a consistent stripping bevel geometry that is independent of the jacket material properties, ensuring uniform bevel formation regardless of which deformable material is used for the jacket.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The chamfered ring acts as an intermediary element between the jacket and the mixture. It mediates the interaction by providing a standardized surface that contacts the mixture first, thereby controlling the stripping bevel formation process and eliminating variability caused by different jacket materials.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Manufacturing precision

If the jacket completely encloses the mandrel, then the blind hole shape is precisely formed, but moisture and residue accumulate leading to product defects

Engineering Contradiction:
Improveblind hole geometry accuracyVSAvoidmoisture accumulation
Core Design Contradiction:
Manufacturing precisionVSObject-generated harmful factors

Solution Approach 1:

The jacket is constructed from porous material that maintains complete enclosure of the mandrel for precise blind hole geometry while the porous structure provides internal pathways for moisture and residue to escape. This resolves the contradiction by allowing the jacket to be both enclosing and permeable to harmful substances.

Inventive Principle:
Principle #31Porous materials

Solution Approach 2:

The cavities within the jacket, which could potentially trap moisture and cause harm, are instead designed to channel and expel moisture and residue outward. The harmful accumulation is converted into a beneficial drainage system that actively removes contaminants during the hardening process.

Inventive Principle:
Principle #22Blessing in disguise (Convert harm into benefit)

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

Ensures uniform and consistent blind hole formation with reduced risk of mold or rust, maintaining product quality and surface finish, even in products with complex shapes like roof tiles.

Implementation Method 1

The geometry of the cavity is specified in such a way that the jacket bulges locally under pressure along the longitudinal axis of the mandrel in the area of the cavity

Methodology Applied
Scientific EffectPressure: Pressure Increase

Implementation Method 2

a jacket (5) made of a material that can be reversibly deformed under pressure

Methodology Applied
Scientific EffectElastic deformation: Elasticity

Data Source

PatentEP2960027B1Undercutting tool for producing a blind hole
Publication Date: 2017.04.19 GRUSS CHRISTOPH
  • EP2960027B1 patent drawingFigure 1~2b
  • EP2960027B1 patent drawingFigure 3a~3c
  • EP2960027B1 patent drawingFigure 4a~4b

AI summary

The invention relates to an undercutting tool for producing a blind hole in flowable, curable mixtures. The undercutting tool comprises a connecting piece (2) for connecting the undercutting tool to a mold (1). It also comprises a mandrel (3) which is slidably mounted along its longitudinal axis in the connecting piece (2). The mandrel (3) is sealed in the direction of the mixture by a cover cap (4). The undercutting tool also comprises a sleeve (5) which is made of a material that is reversibly deformable under pressure and which encloses the mandrel (3), wherein the sleeve (5) has at least one cavity (6) with a defined geometry around the mandrel (3).The geometry of the at least one cavity (6) is defined such that, under pressure, the mandrel (5) bulges locally in the area of ​​the cavity (6) along the longitudinal axis of the mandrel (3), thereby forming a blind hole in the mixture surrounding the mandrel (5) with a shape corresponding to the mandrel (5) in its bulged state. Such an undercutting tool includes a chamfer ring (7) for creating a cut-out chamfer in the mixture. The mandrel (5) completely encloses the mandrel (3) between the chamfer ring (7) and the cover cap (4) on the outside, and the chamfer ring (7) rests against the mandrel (5) on the side of the mandrel (5) opposite the cover cap (4) along the longitudinal axis of the mandrel (3).