Prism-Shaped Handsaw Teeth for Chip Clogging

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Solution Overview

Problem

Conventional handsaws with triangular teeth suffer from chip clogging due to tapered gullets, leading to deteriorated cutting performance, and have issues with tooth spacing and cutting edge area, resulting in coarse pitch and incomplete cutting.

Innovation Solution

The handsaw features prism-shaped teeth with a constant rising angle, ensuring consistent spacing and preventing chip clogging, while maintaining a wider cutting edge area and improved tooth density for enhanced cutting performance.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If triangular teeth are used in conventional handsaws, then the tooth structure is simple and easy to manufacture, but the gullets become tapered and clog with chips, deteriorating cutting performance

Engineering Contradiction:
Improvetooth structure simplicityVSAvoidcutting performance
Core Design Contradiction:
Ease of manufactureVSProductivity

Solution Approach 1:

The patent changes the tooth geometry from traditional triangular shape to a shape with substantially parallel sides, maintaining the gullet width substantially constant from tooth base to tip. This parameter change in tooth configuration prevents gullet tapering and chip clogging, resolving the contradiction between manufacturing simplicity and cutting performance.

Inventive Principle:
Principle #35Parameter changes

2Ease of manufacture

If triangular teeth with tapered gullets are used, then the tooth structure is conventional and easy to produce, but chip clogging occurs in the tapered gullets, making cutting quality deteriorate

Engineering Contradiction:
Improvetooth configurationVSAvoidcutting quality consistency
Core Design Contradiction:
Ease of manufactureVSReliability

Solution Approach 1:

The patent modifies the gullet width parameter to be substantially constant from the base of the tooth to the tip, eliminating the traditional tapered geometry. This parameter change prevents chip accumulation and maintains consistent cutting quality throughout the tooth's service life, resolving the contradiction between ease of manufacture and reliability.

Inventive Principle:
Principle #35Parameter changes

3Object-affected harmful factors

If triangular teeth are arranged with larger spacing, then chip clogging is reduced, but the pitch becomes coarse and cutting performance is incomplete

Engineering Contradiction:
Improvechip cloggingVSAvoidpitch fineness
Core Design Contradiction:
Object-affected harmful factorsVSManufacturing precision

Solution Approach 1:

The patent changes the gullet geometry parameter from tapered to substantially constant width, which prevents chip clogging without requiring increased spacing between teeth. This allows for finer pitch arrangements while maintaining effective chip evacuation, resolving the contradiction between reducing chip clogging and achieving fine pitch.

Inventive Principle:
Principle #35Parameter changes

4Volume of moving object

If the top edge area is reduced to accommodate triangular tooth geometry, then the tooth structure is compact, but the cutting edge area becomes insufficient for effective cutting

Engineering Contradiction:
Improvetooth compactnessVSAvoidcutting edge area
Core Design Contradiction:
Volume of moving objectVSArea of moving object

Solution Approach 1:

The patent changes the tooth side geometry to be substantially parallel rather than converging to a point, which maintains a larger top edge area while keeping the tooth structure compact. This parameter change provides sufficient cutting edge area for effective cutting without compromising tooth compactness, resolving the contradiction between tooth compactness and cutting edge area.

Inventive Principle:
Principle #35Parameter changes

Data Source

PatentEP3153287B1handsaw
Publication Date: 2021.04.28 UM INDS
  • EP3153287B1 patent drawingFigure 1
  • EP3153287B1 patent drawingFigure 2(A)~2(B)
  • EP3153287B1 patent drawingFigure 3

AI summary

A handsaw is provided with which chip clogging is eliminated significantly, the pitch of the tooth points can be kept fine rather than coarse, and a large area can be secured for the cut end face, called "top edge", of each of the teeth, whereby degradation in cutting performance caused by the chip clogging can be prevented sufficiently, and the cutting performance is improved significantly. The handsaw has a plurality of saw teeth arranged on a longitudinal edge (21) of the saw blade (20). The saw teeth are formed as prism-shaped teeth (30) each having a shape of a prism, which are configured such that at least adjacent prism-shaped teeth (30) rise at a same rising angle θ from the edge surface (21a) of the longitudinal edge (21) of the saw blade (20), to cause the space (S) between the adjacent prism-shaped teeth to be constant in the rising direction in which the teeth rise.