Hole-Edge Chamfer Tool With Centering Guide and Chip Windows

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Solution Overview

Problem

Existing tools for creating a chamfer on the edge of a bore for inserting a hollow-wall socket are either complex, difficult to handle, or inefficient in producing a chamfer with minimal effort.

Innovation Solution

A device with a centering extension that forms a guide flank and a stop surface, featuring a handle for easy gripping, cutting edges that engage in an annular space to create a chamfer, and a base body with a thin wall and conical surfaces for efficient material removal, allowing for easy rotation and chip removal through windows.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If a traditional milling cutter or bell-shaped attachment is used to produce a chamfer, then the chamfer can be created, but the device complexity increases and handling becomes difficult

Engineering Contradiction:
Improveease of handlingVSAvoiddevice complexity
Core Design Contradiction:
Ease of operationVSDevice complexity

Solution Approach 1:

The device is segmented into distinct functional components: a centering extension with guide flank for positioning, a stop surface for depth control, and cutting edges for chamfering. This segmentation allows each component to perform its specific function efficiently while keeping the overall structure simple and easy to handle.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The base body serves multiple functions simultaneously: it forms the guide flank for centering, provides the stop surface for depth limitation, and supports the cutting edges for chamfering. This multi-functionality reduces the number of separate components needed, simplifying the overall device structure while maintaining ease of operation.

Inventive Principle:
Principle #6Universality (Multi-functionality)

2Productivity

If a solid base body is used for the device, then structural strength is sufficient, but material removal efficiency and chip evacuation are reduced

Engineering Contradiction:
Improvematerial removal efficiencyVSAvoidstructural strength
Core Design Contradiction:
ProductivityVSStrength

Solution Approach 1:

The base body incorporates windows that create a porous or open structure in specific regions. These windows enable efficient chip evacuation during the chamfering process while maintaining sufficient structural strength in the critical load-bearing areas of the device.

Inventive Principle:
Principle #31Porous materials

Solution Approach 2:

Material is extracted from the base body to form windows and hollow regions. This extraction creates pathways for chip removal and reduces the amount of material that would otherwise hinder efficient material removal during chamfering, while maintaining structural integrity where needed.

Inventive Principle:
Principle #2Taking out (Extraction)

3Ease of operation

If the handle diameter is made large for easy gripping, then ease of operation improves, but the device size and complexity increase

Engineering Contradiction:
Improvegripping comfortVSAvoiddevice size
Core Design Contradiction:
Ease of operationVSDevice complexity

Solution Approach 1:

The handle is merged with the base body as an integrated structure rather than a separate component. The handle's outer surface forms part of the base body, and its inner surface defines the gripping area. This integration allows the handle to provide comfortable gripping dimensions without adding unnecessary device complexity or requiring additional parts.

Inventive Principle:
Principle #5Merging (Combining)

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 device efficiently produces a chamfer on the edge of a bore with minimal effort, ensuring easy handling and effective material removal, making it suitable for inserting a cavity wall socket with a radial extension.

Implementation Method 1

At least one cutting edge engages in this annular space, which, when the device is rotated about an axis in one direction, cuts a chamfer on the outer edge of the bore

Methodology Applied
Scientific EffectMechanical cutting: Abrasion

Implementation Method 2

The centering extension preferably has the shape of a cylinder or nearly a cylinder and, with its cylindrical surface, forms a guide flank that can bear against the inner wall of the bore

Methodology Applied
Scientific EffectFriction contact: Friction

Data Source

PatentEP4223440A1Device for producing a chamfer at the edge of a hole for inserting a hollow wall box
Publication Date: 2023.08.09 WOLFCRAFT GMBH
  • EP4223440A1 patent drawingFigure 1~2
  • EP4223440A1 patent drawingFigure 3~4
  • EP4223440A1 patent drawingFigure 5

AI summary

The invention relates to a device for producing a chamfer (2) at the edge of a bore (1) for inserting a cavity wall box, comprising a base body (13) which forms a guide flank (4) formed by a centering extension (3) that can be inserted into the bore (1) and which extends at least partially on a cylindrical surface around an axis (A), wherein a stop surface (5) extending transversely to the axis (A) adjoins the guide flank (4), wherein the guide flank (4) and the stop surface (5) define an annular space extending around the axis (A), into which the cutting edges (8) of cutting edges (7) project, and comprising a drive element formed by the base body (13) for generating a rotation of the cutting edges (7) around the axis (A). The drive element is a handle (12) which has a diameter of approximately one hand width, so that it can be gripped by a user's hand. The centering process (3) is formed on the handle (12) using the same material.