Pipe Splitter Blade and Mandrel for Utility-Safe Pipe Replacement

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Solution Overview

Problem

Existing pipe splitting methods face challenges in efficiently replacing large diameter HDPE gas pipes and other materials without damaging adjacent utilities, and in managing shape memory effects that cause friction during pipe replacement.

Innovation Solution

A splitter system with blades having a cutting depth less than the pipe's wall thickness to avoid adjacent utilities, combined with a shaping mandrel to form a predictable pipe configuration, and an expander to facilitate the insertion of a new pipe, while using a primary blade for consistent fracture and reducing shape memory issues through scoring.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If a cutting blade is pulled through the pipe to be replaced, then the pipe is split and a new pipe can be pulled into the space, but adjacent utilities may be damaged

Engineering Contradiction:

Improvepipe replacement efficiencyVSAvoiddamage to adjacent utilities

Core Design Contradiction:

ProductivityVSObject-affected harmful factors

Solution Approach 1:

The cutting blade is designed with varying cutting depths at different locations - a first portion with a first cutting depth and a second portion with a second cutting depth that is less than the first cutting depth. This local differentiation allows the blade to cut through the pipe wall effectively while stopping before damaging adjacent utilities, thus resolving the contradiction between replacement efficiency and utility protection.

Inventive Principle:

Principle #3Local quality

2Productivity

If the pipe is split using traditional methods, then replacement is possible, but shape memory effects cause friction during new pipe insertion

Engineering Contradiction:

Improvepipe replacement efficiencyVSAvoidfriction during insertion

Core Design Contradiction:

ProductivityVSForce

Solution Approach 1:

The cutting blade performs preliminary scoring and fracturing of the pipe wall before the expansion process. By pre-weakening the pipe structure through controlled cutting and fracturing, the subsequent expansion requires less force and creates a smoother pathway for new pipe insertion, thereby reducing friction caused by shape memory effects and improving overall replacement efficiency.

Inventive Principle:

Principle #10Preliminary action

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 minimizes damage to adjacent utilities, reduces friction during new pipe insertion, and ensures safe and efficient replacement of HDPE gas pipes by creating a predictable break line and relaxing shape memory, allowing for smooth pipe replacement with minimal operational risk.

Implementation Method 1

scoring and fracturing the pipe wall to create a predictable break line

Methodology Applied

Scientific EffectFracture: Fracture Mechanics

Implementation Method 2

an expander to facilitate the insertion of a new pipe

Methodology Applied

Scientific EffectExpansion:

Data Source

PatentUS20210372554A1Device and method to split pipe near utilities

Publication Date: 2021.12.02 TT TECHNOLOGY INC

AI summary

A splitter system and methods are shown. Examples of splitter systems provide limited possibility of damage to adjacent utilities in the ground. Further, examples of splitter systems relax a shape memory of split pipe, which in turn reduces friction in a splitting operation. Configurations are further shown that provide lubrication to splitting operations in a number of locations along a splitter system. Configurations are also shown that provide electrical isolation to cutting blades.