Circular Saw Blade Asymmetrical Tooth Grouping

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Solution Overview

Problem

Existing circular saw blades face challenges in achieving high cutting quality across a wide range of materials, including wood, wood-based materials, plastics, and non-ferrous metals, while maintaining low drive power and extending tool life.

Innovation Solution

The circular saw blade design features asymmetrical teeth arranged in groups with specific pitch angles, including a smaller second pitch angle and a larger third pitch angle, combined with symmetrical clearing teeth, which reduces tooth spacing and allows for a smaller quality-determining distance between cutting corners, enabling reduced tooth count without compromising cutting quality.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Use of energy by moving object

If the number of teeth on the saw blade is reduced, then energy consumption and cutting forces are reduced, but cutting quality may deteriorate due to larger tooth spacing

Engineering Contradiction:
Improveenergy consumptionVSAvoidcutting quality
Core Design Contradiction:
Use of energy by moving objectVSManufacturing precision

Solution Approach 1:

The saw blade teeth are segmented into different functional groups: cutting teeth (with cutting edges) and clearing teeth (without cutting edges). This segmentation allows the cutting teeth to be spaced farther apart, reducing the number of cutting teeth and thus energy consumption, while the clearing teeth maintain cutting quality by removing chips and preventing binding between cuts.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

Different teeth on the saw blade have different local qualities - cutting teeth have sharp cutting edges for material removal, while clearing teeth have rounded or removed cutting edges optimized for chip removal. This local differentiation allows each tooth type to perform its specific function optimally, maintaining overall cutting quality with fewer total teeth.

Inventive Principle:
Principle #3Local quality

2Use of energy by moving object

If cutting teeth are spaced farther apart to reduce tooth count, then energy consumption decreases, but chip removal may be insufficient leading to binding

Engineering Contradiction:
Improveenergy consumptionVSAvoidchip removal efficiency
Core Design Contradiction:
Use of energy by moving objectVSProductivity

Solution Approach 1:

The tooth sequence is segmented into alternating cutting teeth and clearing teeth. Clearing teeth are positioned between cutting teeth to specifically handle chip removal. This segmentation ensures that even with reduced tooth count and larger spacing between cutting teeth, chip removal efficiency is maintained through the dedicated clearing teeth.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The alternating sequence of cutting teeth and clearing teeth ensures continuous useful action - while one tooth type cuts, the other removes chips. This continuous alternation between cutting and chip removal functions maintains productivity and prevents binding throughout the cutting process, even with fewer total teeth.

Inventive Principle:
Principle #20Continuity of useful action

3Manufacturing precision

If all teeth are designed as cutting teeth with equal spacing, then cutting quality is maintained, but the number of teeth must be high increasing energy consumption

Engineering Contradiction:
Improvecutting qualityVSAvoidenergy consumption
Core Design Contradiction:
Manufacturing precisionVSUse of energy by moving object

Solution Approach 1:

Instead of uniform tooth design, the patent applies local quality by differentiating between cutting teeth (with sharp edges for quality cutting) and clearing teeth (with modified edges for chip removal). This allows reduced tooth count while maintaining cutting quality through the specialized cutting teeth, with clearing teeth handling the non-cutting functions.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The clearing teeth serve multiple functions: they remove chips from the cut, prevent binding between cutting teeth, and maintain the rhythmic cutting action. This multi-functionality allows the saw blade to maintain cutting quality with fewer teeth, as the clearing teeth compensate for the reduced number of cutting teeth.

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

4Productivity

If the saw blade is designed for high cutting speed, then productivity increases, but cutting forces and energy consumption increase

Engineering Contradiction:
Improvecutting speedVSAvoidenergy consumption
Core Design Contradiction:
ProductivityVSUse of energy by moving object

Solution Approach 1:

The tooth sequence segments cutting functions and chip removal functions into alternating teeth. This allows the cutting teeth to be optimized for high-speed cutting with appropriate spacing, while clearing teeth handle chip removal. The reduced total tooth count from this segmentation lowers rotational inertia and cutting forces, enabling high cutting speed with reduced energy consumption.

Inventive Principle:
Principle #1Segmentation

Data Source

PatentEP3075480B1Circular saw blade with group toothing
Publication Date: 2019.08.14 LEITZ GMBH & CO KG
  • EP3075480B1 patent drawingFigure 1
  • EP3075480B1 patent drawingFigure 2
  • EP3075480B1 patent drawingFigure 3

AI summary

A circular saw blade with cutting teeth (1, 2, 3, ...) arranged around its circumference in groups (I, II), in which each group (I, II) comprises at least three cutting teeth (1, 2, 3), of which, in a cutting sequence, the first tooth (1) is symmetrical in the front view and the second and third teeth (2, 3) are alternately asymmetrical, and in which a first pitch angle (τ1) is set between the cutting edges (10, 20) of the first (1) and the second (2) tooth, a second pitch angle (τ2) is set between the cutting edges (20, 30) of the second (2) and the third (3) tooth, and a third pitch angle (τ3) is set between the cutting edge (30) of the last tooth (3) of a first group (I) and the cutting edge (10) of the first tooth (1) of a subsequent group (11), is characterized in that the asymmetrical teeth (2, 3) are grouped together to form a first pair of teeth (Z1), and the second division angle (τ2) is smaller than the first division angle (τ1).