Sharpened-Flight Auger Geometry for Tough Polyurethane Grinding

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Solution Overview

Problem

Existing augers designed for grinding polyurethane rubber are inadequate for processing newer, tougher materials, leading to damage and disposal in landfills, as they fail to effectively grind blends of virgin polyurethane and crumb rubber granules without causing mechanical issues.

Innovation Solution

A redesigned auger with a smaller central cylinder, larger flights, and specific angular positioning of flights around the circumference, featuring sharpened leading edges and no outer edge notches, which enhances cutting efficiency and internal work volume, allowing for effective grinding of the new material.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If a large central cylinder with short flights is used in the auger, then the structural simplicity is maintained, but the cutting efficiency and internal work volume are insufficient for processing tougher materials

Engineering Contradiction:
Improvecutting efficiencyVSAvoidauger structure complexity
Core Design Contradiction:
ProductivityVSDevice complexity

Solution Approach 1:

The auger flights are segmented into multiple pairs positioned at specific angles around the central cylinder, with each pair having sharpened leading edges. This segmentation allows the material to be cut and processed at multiple points simultaneously, significantly improving cutting efficiency for tougher materials while maintaining a relatively simple overall structure.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The flights are designed with varying characteristics: sharpened leading edges for cutting, specific angular positioning (50-60 degrees between successive pairs) for optimal material engagement, and extended reach (halfway around the circumference) for increased internal work volume. These localized quality variations enable effective processing of tougher materials without requiring complete structural redesign.

Inventive Principle:
Principle #3Local quality

2Productivity

If flights with outer edge notches are used, then the manufacturing is simplified, but the grinding effectiveness on tougher materials is reduced

Engineering Contradiction:
Improvegrinding effectivenessVSAvoidflight manufacturing complexity
Core Design Contradiction:
ProductivityVSEase of manufacture

Solution Approach 1:

Instead of using notched flights as in conventional designs, the invention uses continuous flights that extend fully around the central cylinder without interruptions. This inverted approach maintains structural integrity and cutting effectiveness on tougher materials while actually simplifying manufacturing by eliminating the need to create precise notches in the flight edges.

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

3Area of stationary object

If fewer flight pairs are used around the circumference, then the device complexity is reduced, but the coverage and processing capability are insufficient

Engineering Contradiction:
Improvecircumferential coverageVSAvoidnumber of flight pairs
Core Design Contradiction:
Area of stationary objectVSDevice complexity

Solution Approach 1:

Each flight pair is designed to perform multiple functions: cutting material with sharpened leading edges, conveying material through the grinder, and providing structural support. By optimizing the angular positioning and geometry of each flight pair, the invention achieves comprehensive circumferential coverage with a manageable number of flight pairs, avoiding excessive complexity while maximizing processing capability.

Inventive Principle:
Principle #6Universality (Multi-functionality)

Data Source

PatentEP3972805B1Auger for grinding polyurethane for a tire filling machine
Publication Date: 2023.12.27 CARLISLE CONSTRUCTION MATERIALS LLC
  • EP3972805B1 patent drawingFigure 1
  • EP3972805B1 patent drawingFigure 2
  • EP3972805B1 patent drawingFigure 3

AI summary

An auger for a grinder material for a tire filling machine, having: a cylindrical column; and a plurality of flights extending outwardly from the cylindrical core, wherein (i) the flights are arranged in pairs extending radially outwards from the cylindrical column at 180 degrees to one another, and (ii) each flight has a sharpened leading edge. Each pair of flights are positioned at angles of approximately 50 or 60 degrees to one another, and each flight extends approximately half way around the circumference of the cylindrical column, and there are no outer edge notches in the flights.