Pipe Grooving Cam Assembly for Precise Groove Radius Control

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Solution Overview

Problem

Existing roll grooving machines face challenges in accurately forming circumferential grooves in pipes with precise tolerances, often resulting in flare and requiring significant torque and operator involvement, which complicates the design and manufacture of mechanical couplings and seals.

Innovation Solution

A device comprising a pinion, carriage, cup, and cam bodies with specific cam surfaces and traction surfaces that rotate around the pinion axis, allowing for minimal torque application and precise groove formation, with the cup accommodating pipe diameter tolerances and controlling flare, enabling efficient and accurate groove creation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If roll grooving machines are used to form circumferential grooves, then grooves can be formed in pipe elements, but the groove radius cannot be produced within desired tolerance range and flare occurs at pipe ends

Engineering Contradiction:
Improvegroove radius toleranceVSAvoidoperator adjustment requirement
Core Design Contradiction:
Manufacturing precisionVSEase of operation

Solution Approach 1:

The cam mechanism is designed with predetermined geometry that automatically ensures the groove is formed at the correct radius without requiring operator adjustment. The cam profile itself encodes the precise groove location and shape, making the system self-regulating for this critical parameter.

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

The invention changes the operational parameters by using a cam mechanism instead of traditional rollers, which fundamentally alters how the groove formation process works. The cam's rotational motion converts to linear motion that precisely controls the grooving tool's position and pressure, achieving desired tolerance ranges.

Inventive Principle:
Principle #35Parameter changes

2Productivity

If roll grooving machines apply significant torque to pipe elements, then grooves can be formed, but production rate is low requiring many revolutions

Engineering Contradiction:
Improveproduction rateVSAvoidtorque application
Core Design Contradiction:
ProductivityVSForce

Solution Approach 1:

The invention replaces the traditional roller-based mechanical system with a cam-based mechanism. The cam converts rotational motion into precise linear motion, allowing groove formation with minimal torque and in a single revolution, dramatically increasing production rate.

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

3Ease of manufacture

If prior art devices are used, then grooves can be formed, but devices are complicated requiring actuators and operator adjustment

Engineering Contradiction:
Improvedevice simplicityVSAvoidactuator and adjustment mechanism
Core Design Contradiction:
Ease of manufactureVSDevice complexity

Solution Approach 1:

The invention extracts and eliminates the complex actuator and adjustment mechanisms from the grooving device. By using a simple cam mechanism with predetermined geometry, the device achieves precise groove formation without requiring additional actuators or operator adjustments, significantly simplifying the overall device.

Inventive Principle:
Principle #2Taking out (Extraction)

4Manufacturing precision

If circumferential grooves are impressed near pipe ends, then grooves can be formed, but pipe end expands in diameter causing flare

Engineering Contradiction:
Improveflare controlVSAvoidcoupling design complexity
Core Design Contradiction:
Manufacturing precisionVSEase of operation

Solution Approach 1:

The cam mechanism is designed to apply force in a way that prevents flare from occurring in the first place. The cam's geometry and motion profile are predetermined to distribute pressure evenly and avoid the concentrated force that causes pipe end expansion, thus preventing the harmful effect before it can occur.

Inventive Principle:
Principle #9Preliminary anti-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 device achieves rapid and accurate formation of circumferential grooves with minimal torque, accommodating various pipe diameters and reducing flare, thus simplifying the design and manufacture of mechanical couplings and seals.

Implementation Method 1

A cup spring may act between the cup and the pinion to bias the cup away from the pinion

Methodology Applied
Scientific EffectElasticity: Elasticity

Implementation Method 2

A stop spring may act on the pipe end stop and to bias the pipe end stop away from the pinion

Methodology Applied
Scientific EffectElasticity: Elasticity

Implementation Method 3

A plurality of gears are mounted on the carriage. Each gear is rotatable relatively to the carriage about a respective gear axis. At least one of the gears engages directly with the pinion

Methodology Applied
Scientific EffectFriction: Friction

Implementation Method 4

a plurality of first cam surfaces extend around a respective one of the cam bodies and are engageable with the pipe element received within the opening

Methodology Applied
Scientific EffectCold-forming: Cold-forming

Data Source

PatentEP4414096A1Pipe grooving device
Publication Date: 2024.08.14 VICTAULIC
  • EP4414096A1 patent drawingFigure 1
  • EP4414096A1 patent drawingFigure 1A
  • EP4414096A1 patent drawingFigure 2

AI summary

A pipe grooving device adapted to receive the pipe. The assembly includes a cup which surrounds a pipe end stop. The cup and the pipe end stop may be mounted on a fixed pinion about which a carriage rotates. The carriage carries geared cams which engage the pinion and rotate synchronously when the carriage rotates relatively the pinion. The cams engage a pipe element received by the cup and form a circumferential groove in the pipe element. The cup and the pipe end stop move independently of one another axially along a pinion shaft to actuate rotation of the carriage. The cup accommodates dimensional pipe diameter tolerances and mitigates pipe flare and maintains pipe roundness during the grooving process.