Convex Cutting Blade for Rigid Conductor Pipe Shears

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Solution Overview

Problem

Conventional material processing shears are poorly suited to cut conductor pipes due to their rigidity, which requires excessive deformation force, leading to insufficient cutting power and potential stalling, and the V-shaped blades cut at multiple locations, distributing force inefficiently.

Innovation Solution

The use of material processing shears with pivotally connected jaws and a fluid-driven actuator, featuring a convexly shaped cutting blade that focuses cutting force on a single location, supported by a cradle to minimize deformation, allowing efficient cutting of conductor pipes with inner and outer metal pipes and grouting in between.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Force

If conventional heavy-duty shears with flat shearing blades are used to cut conductor pipes, then the shears can apply clamping force to the pipe, but the rigidity of the conductor pipe resists deformation and much of the force is wasted in a clamp-like manner, leaving insufficient power to actually cut the pipe

Engineering Contradiction:
Improvecutting forceVSAvoidenergy wasted in deformation
Core Design Contradiction:
ForceVSLoss of energy

Solution Approach 1:

The cutting blade is designed with a convex curved surface instead of a flat surface. This curvature allows the blade to concentrate the applied force at a specific point of contact on the conductor pipe, creating high localized stress that facilitates cutting. The convex shape enables the force to be focused rather than distributed, overcoming the pipe's rigidity without wasting energy on general deformation.

Inventive Principle:
Principle #14Spheroidality (Curvature)

2Ease of operation

If V-shaped upper and lower shearing blades are used to cut conductor pipe, then the shears can engage the pipe, but the V shape distributes the cutting force at two different locations, leaving less power at each cutting location and may result in stalling of the shears

Engineering Contradiction:
Improveengagement of pipeVSAvoidpower at cutting location
Core Design Contradiction:
Ease of operationVSPower

Solution Approach 1:

The cutting system uses a convex curved blade that concentrates cutting action at a single localized point rather than distributing force across two locations. This local quality approach ensures maximum power is applied at the specific intersection point where cutting is needed, preventing stalling while maintaining ease of operation through proper blade geometry.

Inventive Principle:
Principle #3Local quality

3Strength

If conventional shears attempt to deform the conductor pipe cross-section before cutting, then the shears can grip the pipe, but the force used to deform the cross-section detracts from the force available to actually cut the pipe

Engineering Contradiction:
Improvegrip strengthVSAvoidcutting force
Core Design Contradiction:
StrengthVSForce

Solution Approach 1:

The convex curved cutting blade design eliminates the need for cross-section deformation by directly concentrating cutting force at the contact point. The curvature allows the blade to pierce and cut through the rigid conductor pipe without requiring preliminary deformation, thereby preserving all available force for the cutting action itself while still achieving secure engagement.

Inventive Principle:
Principle #14Spheroidality (Curvature)

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 method enables efficient cutting of large, rigid conductor pipes by concentrating cutting force at a single intersection point, reducing deformation and increasing cutting power, thereby overcoming the limitations of conventional shears.

Implementation Method 1

a fluid driven actuator operatively extending between the jaws for selective powered movement of the jaws between their open and closed positions

Methodology Applied
Scientific EffectHydraulic pressure: Hydraulic Press

Data Source

PatentEP2363229B1Method for cutting a conductor pipe having inner and outer metal pipes with grouting disposed between the inner and outer pipes
Publication Date: 2012.09.19 STANLEY BLACK & DECKER INC
  • EP2363229B1 patent drawingFigure 1~3
  • EP2363229B1 patent drawingFigure 4~5
  • EP2363229B1 patent drawingFigure 6~7

AI summary

A method of using a material processing shears (10), the shears (10) comprising: first and second jaws (20,30) pivotally connected to each other for relative pivotal movement about a jaw axis (100) between open and closed positions, the first jaw (20) having a first cutting blade (200) with a first cutting edge (200a); and a fluid driven actuator (50) operatively extending between the jaws (20,30) for selective powered movement of the jaws (20,30) between their open and closed positions, the method comprising: positioning the shears (10) such that a work piece (190) is disposed between the first and second jaws (20,30); and cutting the work piece (190) primarily with the first cutting blade (200) such that the cutting of the work piece (190) is predominantly localized at an intersection between the work piece (190) and the first cutting blade (200), while the second jaw (30) predominantly supports the work piece (190) without cutting into it, wherein the work piece (190) comprises a conductor pipe having inner and outer metal pipes with grouting disposed between the inner and outer metal pipes.