Pipe Cutting Accessory With Internal Roller for Precise Embedded Cuts

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Solution Overview

Problem

Existing pipe cutting accessories for power tools face challenges in maintaining precise cutting and durability when cutting pipes embedded in concrete, particularly due to the risk of blade dislodgment and wear from abrasive materials.

Innovation Solution

A pipe cutting accessory featuring a shaft with a disc-shaped cutting blade and a concentric roller, where the cutting blade is fixedly coupled to the shaft with an axial pin and the roller has a smaller radius than the blade, allowing it to roll along the pipe's inside wall, reducing blade wear and enabling precise cutting with an optional depth stop mechanism.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the cutting blade is used to cut pipes embedded in concrete, then the cutting function is achieved, but the blade experiences wear and dislodgment due to abrasive materials and operational forces

Engineering Contradiction:
Improveblade durabilityVSAvoidblade wear from abrasive materials
Core Design Contradiction:
ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The roller portion acts as an intermediary between the cutting blade and the concrete environment. It contacts the pipe's outside surface and rolls along it, serving as a mediator that stabilizes the blade's position and prevents direct contact between the blade and abrasive concrete, thereby reducing wear and dislodgment

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The roller portion provides beforehand cushioning by absorbing and distributing the forces generated during cutting. It cushions the blade against shocks and vibrations from cutting through concrete-embedded pipes, preventing blade dislodgment before it occurs

Inventive Principle:
Principle #11Beforehand cushioning (Prior cushioning)

2Productivity

If the cutting blade is inserted deep into the pipe to cut through concrete-embedded pipes, then the cutting effectiveness is improved, but the precision of cutting depth control deteriorates

Engineering Contradiction:
Improvecutting effectivenessVSAvoidcutting depth precision
Core Design Contradiction:
ProductivityVSManufacturing precision

Solution Approach 1:

The roller portion provides feedback-based depth control by rolling along the pipe's outside surface. As the blade cuts into the pipe from the inside, the roller's rotation and position provide tactile feedback that allows the operator to precisely control the cutting depth, ensuring the blade reaches the required depth without excessive insertion

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The roller portion replaces direct manual depth control mechanisms with a rolling contact system. Instead of relying solely on mechanical stops or manual measurement, the roller's natural rolling motion along the pipe surface provides a more precise and reliable method for controlling cutting depth

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

3Productivity

If the cutting blade rotates at high speed to cut through pipes, then the cutting speed is improved, but the blade experiences increased wear and potential dislodgment

Engineering Contradiction:
Improvecutting speedVSAvoidblade stability
Core Design Contradiction:
ProductivityVSReliability

Solution Approach 1:

The roller portion acts as a counterbalancing element that offsets the centrifugal forces and vibrations generated by high-speed blade rotation. By rolling along the pipe's outside surface, it provides a stabilizing counter-force that maintains blade stability even at high rotational speeds, preventing dislodgment while allowing high cutting speeds

Inventive Principle:
Principle #8Anti-weight (Counterweight)

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 enhances cutting precision and durability by minimizing blade contact with concrete, reducing wear and breakage, and allowing for accurate depth control, thereby increasing the accessory's effectiveness in cutting pipes embedded in concrete.

Implementation Method 1

the roller has a cylindrical outer surface configured to roll along an inside wall of a pipe while the shaft and cutting blade rotate about the axis to cut a pipe from an inside of the pipe

Methodology Applied
Scientific EffectRolling friction: Friction

Data Source

PatentEP4311619A1Pipe cutting accessory for power tool
Publication Date: 2024.01.31 BLACK & DECKER CORP
  • EP4311619A1 patent drawingFigure 1
  • EP4311619A1 patent drawingFigure 2
  • EP4311619A1 patent drawingFigure 3

AI summary

An exemplary pipe cutting accessory (100, 110, 200, 300, 310) includes a shaft (102, 122, 202, 222, 302) extending along an axis and having a front end portion (104, 204, 304) a rear end portion (106, 206, 306) configured to be coupled to a tool holder (252) of a power tool (250). A disc-shaped cutting blade (112, 212, 312, 314) is fixedly coupled to the front end portion (104, 204, 304) of the shaft (102, 122, 202, 222, 302) and configured to rotate about the axis together with the shaft (102, 122, 202, 222, 302). A roller portion (130, 230, 330, 350) is concentrically received over the front end portion (104, 204, 304) rearward of the cutting blade (112, 212, 312, 314). The roller portion (130, 230, 330, 350) has a cylindrical outer surface (131, 231, 331) configured to roll along an inside wall of a pipe while the shaft (102, 122, 202, 222, 302) and cutting blade (112, 212, 312, 314) rotate about the axis to cut a pipe from an inside of the pipe. A depth stop (330, 350) may be movably coupled to the shaft (102, 122, 202, 222, 302) or the roller portion (130, 230, 330, 350) and configured to abut an end of the pipe.