Mechanical Extraction of Drum Cutter Sleeve via Nut Torque

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

Existing holder block assemblies for cutting tools rely on hydraulic fluid for extraction, which is not practical in all scenarios, particularly where hydraulic sources are unavailable or impractical.

Innovation Solution

A mechanical extraction system using an externally threaded shank with a nut that, when rotated, generates axial force to overcome interference fits between the sleeve and holder block, allowing for manual extraction without hydraulic fluid, utilizing a spanner wrench to apply torque to the nut.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a hydraulic extraction system is used to extract the sleeve from the holder block, then the extraction force is sufficient to overcome interference fits, but the system requires hydraulic fluid and external hydraulic sources which are not always available

Engineering Contradiction:

Improveextraction capabilityVSAvoidenvironmental adaptability

Core Design Contradiction:

ReliabilityVSAdaptability or versatility

Solution Approach 1:

The patent replaces the hydraulic extraction system with a purely mechanical extraction mechanism. A threaded rod is inserted through the sleeve flange and threaded into the sleeve. By rotating the threaded rod using a spanner wrench, axial extraction force is generated mechanically to overcome the interference fits between the sleeve and holder block, eliminating the need for hydraulic fluid and external hydraulic sources.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The mechanical extraction system is self-contained and can be operated with simple hand tools (spanner wrench). The threaded rod and nut assembly creates a self-sufficient extraction mechanism that does not require external infrastructure, allowing the system to service itself in various field conditions without dependency on hydraulic infrastructure.

Inventive Principle:

Principle #25Self-service

2Adaptability or versatility

If a mechanical extraction system using a threaded rod and nut is used, then no hydraulic fluid is required, but the device complexity increases due to additional components

Engineering Contradiction:

Improveenvironmental adaptabilityVSAvoidextraction system complexity

Core Design Contradiction:

Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The threaded rod serves multiple functions: it acts as an extraction mechanism, a positioning element during assembly, and a force transmission component. The spanner wrench is a universal hand tool that can be used to rotate the threaded rod. This multi-functionality reduces the need for specialized components and simplifies the overall system despite the mechanical extraction approach.

Inventive Principle:

Principle #6Universality (Multi-functionality)

3Manufacturing precision

If the nut is made larger than the holder block hole, then the insertion depth is limited and axial positioning is accurate, but the device complexity increases

Engineering Contradiction:

Improveaxial positioning accuracyVSAvoidcomponent size variation

Core Design Contradiction:

Manufacturing precisionVSDevice complexity

Solution Approach 1:

The nut is designed with a predetermined size that is larger than the holder block hole, establishing the correct insertion depth and axial positioning of the sleeve before the actual interference fit is created. This preliminary action ensures that the sleeve is positioned at the correct depth during assembly, eliminating the need for additional positioning features or adjustment mechanisms.

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

Enables the simple, on-site extraction of the sleeve from the holder block using a hand tool, eliminating the need for compressed air or hydraulic fluid, and ensuring reliable operation in various environments.

Implementation Method 1

the nut is rotated by applying torque to the nut so that the cooperating threads of the nut and shank urge the nut towards the holder block. The applied torque generates an axial force urging the sleeve away from the holder block

Methodology Applied

Scientific EffectTorque: Torque

Implementation Method 2

A nut is threaded onto the threaded shank portion before the sleeve is driven into the hole of the holder block. The nut is tightened against a radially enlarged portion of the shank

Methodology Applied

Scientific EffectThreaded fastener mechanical advantage: Screw

Implementation Method 3

cooperating pairs of holder block and shank cross sections define multiple interference fits between them that retain the sleeve in the holder block

Methodology Applied

Scientific EffectInterference fit: Friction

Data Source

PatentUS11248366B1Holder block assembly with mechanical extraction device

Publication Date: 2022.02.15 SULOSKY WILLIAM P

AI summary

A holder block assembly for a drum-type cutting tool has a holder block and a sleeve that is removably held in the holder block to carry a cutter bit. The sleeve includes a shank received in a hole in a cutter block and a nut threaded on the shank. The nut is turned by a hand tool to extract the sleeve from the holder block.