Holesaw Arbor Decoupling for Fast Plug Removal

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Solution Overview

Problem

The existing holesaw systems require the use of a secondary tool to remove the plug of material, which can be difficult and time-consuming, as the plug often gets stuck inside the holesaw.

Innovation Solution

A holesaw system with an arbor that has a decoupling mechanism allowing the pilot drill bit to rotate independently of the holesaw, enabling the plug to be removed without a secondary tool by changing the rotational direction of the arbor, which engages a frictional surface to securely hold the plug for easy extraction.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If a secondary tool is used to remove the plug from the holesaw, then the plug can be removed, but the process becomes difficult and time-consuming

Engineering Contradiction:
Improveease of plug removalVSAvoidtime required for plug removal
Core Design Contradiction:
Ease of operationVSLoss of time

Solution Approach 1:

The pilot drill bit is designed to remove the plug itself without requiring a secondary tool. The pilot drill bit rotates independently of the holesaw to engage the plug and extract it automatically, allowing the system to serve itself rather than requiring external intervention for plug removal

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

The arbor is divided into separate functional components: a holesaw holder portion and a pilot bit holder portion that can be independently rotated. This segmentation allows the pilot drill bit to be decoupled from the holesaw rotation and used specifically for plug removal, separating the cutting function from the plug extraction function

Inventive Principle:
Principle #1Segmentation

2Ease of operation

If the pilot drill bit is rotatable independently of the holesaw, then the plug can be removed easily, but the device complexity increases

Engineering Contradiction:
Improveease of plug removalVSAvoidcomplexity of arbor mechanism
Core Design Contradiction:
Ease of operationVSDevice complexity

Solution Approach 1:

The arbor incorporates a dynamic decoupling mechanism that allows transition between coupled rotation (for cutting) and independent pilot bit rotation (for plug removal). The mechanism uses movable elements like drive pins and cam surfaces that can engage or disengage based on rotation direction, providing dynamic adaptability without permanent complexity

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

Instead of designing a mechanism that actively drives the pilot bit during normal operation, the invention uses reverse rotation to disengage the one-way drive mechanism. By rotating the arbor in the opposite direction, the drive pins disengage from the cam surfaces, allowing independent pilot bit rotation for plug removal without complex active control systems

Inventive Principle:
Principle #13The other way round (Inversion)

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 easier and faster removal of the plug from the holesaw without the need for a secondary tool, reducing the complexity and time required for the process.

Implementation Method 1

engages a frictional surface to securely hold the plug for easy extraction

Methodology Applied
Scientific EffectFriction: Friction

Data Source

PatentEP4342612A1Holesaw system
Publication Date: 2024.03.27 BLACK & DECKER CORP
  • EP4342612A1 patent drawingFigure 1
  • EP4342612A1 patent drawingFigure 2
  • EP4342612A1 patent drawingFigure 3

AI summary

A holesaw system (10) comprises a holesaw (20) including a base (22) and a generally cylindrical wall (24) with a proximal end coupled to the base and a distal end with a cutting edge (26); a pilot drill bit (30) including a front cutting tip (36), a rear shank portion (32), and an intermediate portion (34) between the front cutting tip and the rear shank portion; and an arbor (40) coupleable to the holesaw and to the pilot drill bit. The arbor is configured to be operable in a first mode in which the holesaw and the pilot drill bit are rotatable in unison to form a hole in a workpiece and in a second mode in which the pilot drill bit is rotatable independently of the holesaw to remove a plug of material from the holesaw.