Portable Cutting Tool Depth Adjustment Mechanism

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Solution Overview

Problem

Conventional portable cutting tools face challenges in maintaining the parallelism of the cutting blade during depth adjustment, with existing mechanisms either causing deformation or increasing the tool's size due to protrusions.

Innovation Solution

A compact portable cutting tool design featuring a link part with an elongated hole, a guide part, and a cam mechanism with an elastic member, which holds the link part orthogonally to the rotational shaft, allowing for adjustable cutting depth without compromising parallelism.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If the adjustment link is fixed from the side surface using a screw or the like, then the cutting depth can be adjusted, but deformation occurs in the adjustment link in the axial direction of the rotational shaft, lowering the parallelism of the cutting blade with respect to the cutting tool

Engineering Contradiction:
Improvecutting depth adjustmentVSAvoidparallelism of cutting blade
Core Design Contradiction:
Ease of operationVSManufacturing precision

Solution Approach 1:

The guide part acts as an intermediary component that mediates between the adjustment link and the housing. It guides the adjustment link in the axial direction of the rotational shaft, preventing lateral deformation while allowing smooth adjustment movement. This intermediary structure ensures that the adjustment link moves precisely without compromising the parallelism of the cutting blade.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Manufacturing precision

If a cam-based fastening tool is used to fix the adjustment link from the rearward of the protection cover, then the parallelism of the cutting blade is maintained, but the overall cutting tool becomes large in size due to the fastening tool protruding from the rear end

Engineering Contradiction:
Improveparallelism of cutting bladeVSAvoidoverall tool size
Core Design Contradiction:
Manufacturing precisionVSLength of moving object

Solution Approach 1:

The invention repositions the adjustment mechanism from the rear end (one-dimensional extension) to the side surface of the protection cover (utilizing lateral space). This dimensional change allows the cam-based fastening tool to be positioned laterally rather than extending from the rear, maintaining parallelism while avoiding increased overall tool length.

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

Solution Approach 2:

The adjustment link and cam-based fastening tool are integrated within the side surface structure of the protection cover, nesting the adjustment mechanism within the existing tool geometry rather than adding external protrusions. This nesting approach maintains compact overall dimensions while preserving the parallelism-maintaining cam mechanism.

Inventive Principle:
Principle #7Nested doll (Nesting)

3Adaptability or versatility

If the adjustment link is fixed using a screw or the like from the side surface, then cutting depth adjustment is achieved, but the adjustment link deforms in the axial direction reducing adjustment precision

Engineering Contradiction:
Improvecutting depth adjustabilityVSAvoidadjustment precision
Core Design Contradiction:
Adaptability or versatilityVSMeasurement precision

Solution Approach 1:

The guide part serves as an intermediary that ensures precise axial guidance of the adjustment link during depth adjustment. This intermediary structure prevents lateral play and deformation, ensuring that each adjustment position is precisely maintained while preserving full adjustability across the cutting depth range.

Inventive Principle:
Principle #24Intermediary (Mediator)

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 a compact tool that maintains the parallelism of the cutting blade during depth adjustment, preventing deformation and minimizing the tool's size, thus enhancing usability and efficiency.

Implementation Method 1

an elastic member interposed between the cam and the link part, and the cam abuts on the link part via the elastic member

Methodology Applied
Scientific EffectElasticity: Elasticity

Data Source

PatentEP2149438B1Portable cutting tool
Publication Date: 2014.09.03 KOKI HLDG CO LTD
  • EP2149438B1 patent drawingFigure 1
  • EP2149438B1 patent drawingFigure 2
  • EP2149438B1 patent drawingFigure 3

AI summary

The portable cutting tool (1) includes a housing (2) that rotatably supports a cutting blade (3), a base (6) to be connected with the housing (2) and having an opening (68) through which the cutting blade (3) is protrudable, and a protrusion amount changing mechanism (5). The protrusion amount changing mechanism (5) has a link part (52) extending from the base (6), and a fixing part (53, 54) which is provided at the housing (2), comes to a fixed state with respect to the link part (52) when moved in one direction in a direction orthogonal to a rotational shaft (31) of the cutting blade (3), and comes to a moving state to be movable with respect to the link part (52) when moved in an other direction in the direction orthogonal to the rotational shaft (31), whereby a protrusion amount of the cutting blade (3) from a second side (67) of the opening (68) is changed as the fixing part (53, 54) is moved with respect to the link part (52).