Knife for High Speed Planer Head

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

High-speed planer heads face challenges in maintaining surface finish quality while increasing production efficiency, as higher wood travel speeds degrade finish quality, and existing knife designs limit density and require costly replacements for different wood types.

Innovation Solution

A knife design with mirror image symmetry, dual cutting edges, and deflector ridges, combined with a frustoconical ramping screw system for secure clamping, allowing for denser knife spacing and efficient adjustment for different wood types.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If the speed of wood travel is increased to improve production efficiency, then productivity increases, but the quality of surface finish deteriorates

Engineering Contradiction:
Improveproduction efficiencyVSAvoidsurface finish quality
Core Design Contradiction:
ProductivityVSManufacturing precision

Solution Approach 1:

The cutting edge is segmented into multiple discrete cutting points along the knife length, with each segment capable of independent chip evacuation. This segmentation allows chips to be removed more efficiently from each cutting zone, preventing chip marks even at higher wood travel speeds, thus maintaining surface finish quality while enabling increased productivity

Inventive Principle:
Principle #1Segmentation

2Manufacturing precision

If the density of knives on the planer head is increased to improve surface finish quality, then manufacturing precision improves, but device complexity increases due to clamping requirements

Engineering Contradiction:
Improvesurface finish qualityVSAvoidclamping system complexity
Core Design Contradiction:
Manufacturing precisionVSDevice complexity

Solution Approach 1:

The clamping function and the knife holder structure are merged into a single integrated component. The knife is clamped directly to the planer head drum through this integrated structure, eliminating the need for separate gibs, collars, and multiple fasteners. This merging allows for higher knife density without proportionally increasing clamping system complexity, as each knife requires fewer individual clamping parts

Inventive Principle:
Principle #5Merging (Combining)

3Reliability

If traditional clamping methods with screws, gibs, and collars are used to secure knives, then reliability of knife securing is achieved, but the potential for increasing knife density is limited

Engineering Contradiction:
Improveknife securing reliabilityVSAvoidknife density
Core Design Contradiction:
ReliabilityVSProductivity

Solution Approach 1:

The traditional gib and collar components are extracted and eliminated from the clamping system. The knife is secured directly to the drum through a simplified clamping mechanism that uses fewer parts. This extraction of unnecessary components reduces the space required for each knife assembly, enabling higher knife density while maintaining reliable knife securing through the direct clamping action

Inventive Principle:
Principle #2Taking out (Extraction)

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

The solution enables improved surface finish quality and increased production throughput by allowing denser knife spacing and easier adjustment for cutting various wood types, reducing machine downtime and costs.

Implementation Method 1

A threaded member has a frustoconical ramping portion for producing a wedging force against the knife when the threaded member is threaded into a threaded hole in the hub

Methodology Applied
Scientific EffectWedge: Wedge

Data Source

PatentEP1979138B1Knife for a high speed planer head
Publication Date: 2010.10.20 KEY KNIFE INC
  • EP1979138B1 patent drawingFigure 1A~1B
  • EP1979138B1 patent drawingFigure 2~3
  • EP1979138B1 patent drawingFigure 4A

AI summary

A high speed planer head. A threaded member (34) having a frustoconical portion wedges against a knife (104), to clamp a knife to a hub for rotating the knife about an axis of revolution. The knife has a front and back side, two cutting edges (136a, 136b) and mirror image symmetry about a mirror plane passing through the knife. To cut both a planar face and two opposed, radiused corners, the cutting edges include respective linear face-cutting portions disposed between two concave, arcuate corner-cutting portions.