Saw Chain Link Offset Footprint Design

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Existing saw chains face challenges in minimizing kerf width without causing knife edging on bar rails, maintaining sufficient kerf to bar clearance, and ensuring chain strength, which affects cutting efficiency and power consumption.

Innovation Solution

The saw chain design features rail engaging links with offset footprints that distribute contact evenly across the rail, preventing knife edging and allowing for thinner chain components without compromising bar width or cutter offset, while incorporating an offset feature to facilitate lubricant distribution and drive sprocket penetration.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Use of energy by moving object

If thinner chain components are used to narrow the kerf, then power consumption is reduced, but knife edging occurs on the bar rails and links

Engineering Contradiction:
Improvepower consumptionVSAvoidknife edging prevention
Core Design Contradiction:
Use of energy by moving objectVSReliability

Solution Approach 1:

The rail engaging link is segmented into multiple foot portions (leading foot portion and trailing foot portion) that contact the bar rail at different locations. This segmentation allows the contact load to be distributed across multiple points rather than concentrated at a single point, preventing knife edging even when using thinner chain components.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The invention introduces an offset dimension to the footprint of the rail engaging link, creating a leading foot portion and a trailing foot portion that are offset from each other in the direction of travel. This dimensional change allows the link to engage the bar rail in a way that distributes contact evenly across the rail width without requiring increased component thickness.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

2Use of energy by moving object

If the kerf is narrowed to minimize power consumption, then cutting efficiency improves, but the kerf to bar clearance becomes unacceptable

Engineering Contradiction:
Improvepower consumptionVSAvoidkerf to bar clearance
Core Design Contradiction:
Use of energy by moving objectVSEase of operation

Solution Approach 1:

The rail engaging link has different foot portions with different contact characteristics. The leading and trailing foot portions are positioned to contact specific regions of the bar rail, creating localized contact zones that maintain adequate clearance while allowing the kerf to be narrower overall.

Inventive Principle:
Principle #3Local quality

3Ease of operation

If the bar width is narrowed to maintain kerf to bar clearance, then chain strength is reduced, but cutting performance is affected

Engineering Contradiction:
Improvekerf to bar clearanceVSAvoidbar strength
Core Design Contradiction:
Ease of operationVSStrength

Solution Approach 1:

By segmenting the rail engaging link into multiple foot portions, the invention allows the bar to maintain its full width and strength while still achieving adequate kerf to bar clearance through the distributed contact pattern of the segmented link.

Inventive Principle:
Principle #1Segmentation

4Use of energy by moving object

If the cutter offset is reduced to narrow the kerf, then power consumption decreases, but chip flow up the side of the bar is negatively affected

Engineering Contradiction:
Improvepower consumptionVSAvoidchip flow
Core Design Contradiction:
Use of energy by moving objectVSProductivity

Solution Approach 1:

The rail engaging link exhibits asymmetric contact with the bar rail through its offset footprint design, with leading and trailing foot portions positioned at different locations. This asymmetric configuration maintains adequate cutter offset for proper chip flow while allowing the kerf to be narrower, resolving the contradiction between power consumption and chip flow performance.

Inventive Principle:
Principle #4Asymmetry

Data Source

PatentEP2081741B1Saw chain link with offset footprint
Publication Date: 2018.03.21 BLOUNT INC
  • EP2081741B1 patent drawingFigure 1~2
  • EP2081741B1 patent drawingFigure 3A~3F
  • EP2081741B1 patent drawingFigure 3G~3J

AI summary

In various embodiments, a saw chain is provided that includes a rail engaging link that has an offset footprint within the link itself and/or with respect to other links in the chain that are adapted to ride on the same rail. Saw chains as provided may be used in a variety of applications, including but not limited to wood cutting and aggregate cutting applications.