Saw Chain Link Labyrinth Design for Impurity Exclusion

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Solution Overview

Problem

The existing saw machines for cutting ornamental stones face issues with mud and dust entering the internal links, leading to the accumulation of hard material that prevents precise alignment and causes stress on articulation pins, resulting in reduced lifespan.

Innovation Solution

The design modifies the shape of internal and external links to minimize the opening between them, creating a labyrinth path that prevents the entry of impurities, and uses anti-unthreading articulation pins with a greater central diameter to secure the chain, ensuring minimal accumulation of extraneous material.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If the chain rotates around the pinion or toothed transmission wheel, then the chain performs its cutting function, but an opening is created between internal and external links allowing mud and dust to penetrate

Engineering Contradiction:
Improvecutting functionVSAvoidmud and dust penetration
Core Design Contradiction:
ProductivityVSObject-affected harmful factors

Solution Approach 1:

The external link is divided into two separate parts: a outer link body and an inner link insert. This segmentation allows the inner insert to be specifically designed with a shape that prevents mud and dust accumulation, while the outer link body maintains the structural integrity needed for cutting operations. The articulation pin with different diameter sections further segments the connection interface to prevent contaminant entry.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The inner link insert acts as an intermediary element between the articulation pin and the outer link body. This intermediate component creates a barrier that prevents mud and dust from entering the articulation area, while still allowing the necessary mechanical connection and movement for the chain's cutting function.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Reliability

If mud accumulates inside the external link, then the mass hardens creating thickness on the top internal part, but this prevents precise closure and alignment of the chain links

Engineering Contradiction:
Improvechain alignmentVSAvoidmud accumulation
Core Design Contradiction:
ReliabilityVSObject-affected harmful factors

Solution Approach 1:

By segmenting the external link into outer and inner parts, the design creates a controlled interface that prevents uncontrolled mud accumulation. The inner link insert can be designed with specific geometric features that eliminate dead zones where mud would otherwise accumulate and harden.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The invention changes the geometric parameters of the link interface by using an articulation pin with varying diameter along its length. This parameter variation ensures proper clearance and prevents mud accumulation while maintaining precise alignment, addressing both the contamination and alignment issues simultaneously.

Inventive Principle:
Principle #35Parameter changes

3Strength

If the articulation pin is subjected to additional stresses from mud accumulation, then the pin may break, but the pin is already under classical tensile stresses from normal operation

Engineering Contradiction:
Improvearticulation pin durabilityVSAvoidadditional stresses on pin
Core Design Contradiction:
StrengthVSStress or pressure

Solution Approach 1:

The inner link insert serves as a mediator that protects the articulation pin from direct contact with mud and dust. This intermediary component prevents contaminants from entering the articulation area, thereby eliminating the source of additional stresses that would otherwise compromise pin durability.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The articulation pin is designed with non-uniform diameter parameters - a larger central section and smaller end sections. This parameter variation increases the pin's strength at the critical central region where it experiences the highest stresses, while the smaller end sections allow for proper fit and rotation within the link holes.

Inventive Principle:
Principle #35Parameter changes

Data Source

PatentEP3177443B1Chain for saw machines for cutting ornamental stones, adapted to prevent the entrance of impurities between the internal link and the external link of the chain
Publication Date: 2018.09.19 FANTINI SUD
  • EP3177443B1 patent drawingFigure 1(a)~1(e)
  • EP3177443B1 patent drawingFigure 2(a)~2(d)
  • EP3177443B1 patent drawingFigure 3(a)~3(e)

AI summary

Cutting chain for chain saw machines for cutting ornamental stones, comprising internal links (1) and external links (2) connected together in an articulated manner by means of articulation pins (3), in which the links (1, 2) are configured in a manner so as to create a labyrinth interspace (12) with minimal size, which prevents the entrance of impurities inside the external link (2). The result is that of preventing the formation of a thickness of an extraneous material (mud, dust, etc.) inside the external link (2), which could obstruct the free rotation of the links in the realignment step and then give rise to stresses on the articulation pin (3).