Metal Spool Stepped Indicators for Corrosion Resistance

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Conventional fishing reel spools suffer from impaired corrosion resistance due to inadequate formation of anodized layers on V-shaped grooves used for indicating the amount of fishing line wound, leading to exposure of metal surfaces and potential corrosion.

Innovation Solution

The spool design incorporates stepped portions on the flange portions with different axial heights, eliminating the need for V-shaped grooves, allowing for complete coverage by anodized treatment and enhancing corrosion resistance.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If V-shaped grooves are cut into the metal flange surface to create indicators, then the indicator function is achieved, but the corrosion resistance is impaired due to inadequate layer formation on groove surfaces

Engineering Contradiction:
Improveindicator functionVSAvoidcorrosion resistance
Core Design Contradiction:
Measurement precisionVSReliability

Solution Approach 1:

The patent removes the harmful V-shaped grooves from the flange surface and replaces them with stepped portions that extend radially outward. This extraction eliminates the surface geometry that prevented proper anodized layer formation, thereby resolving the contradiction between indicator functionality and corrosion resistance.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

Instead of cutting grooves inward from the surface (creating recesses), the patent inverts the approach by forming stepped portions that protrude outward from the surface. This inversion ensures that the indicator structures are external and accessible to the anodized treatment, eliminating the corrosion resistance problem.

Inventive Principle:
Principle #13The other way round (Inversion)

2Ease of manufacture

If the anodized treatment is performed after V-shaped grooves are formed, then the corrosion protection process is completed, but the grooves remain inadequately coated leaving metal exposed

Engineering Contradiction:
Improveanodized treatment processVSAvoidcorrosion resistance
Core Design Contradiction:
Ease of manufactureVSReliability

Solution Approach 1:

The patent forms the stepped portions before performing the anodized treatment, ensuring that the indicator structures are already in their final configuration. This preliminary formation allows the anodized layer to be applied uniformly to all surfaces including the indicator portions, preventing subsequent corrosion issues.

Inventive Principle:
Principle #10Preliminary action

3Measurement precision

If narrow V-shaped grooves are formed for indicators, then the indicator precision is maintained, but the anodized and coating layers cannot be optimally formed on groove bottom and edge portions

Engineering Contradiction:
Improveindicator precisionVSAvoidlayer formation quality
Core Design Contradiction:
Measurement precisionVSManufacturing precision

Solution Approach 1:

The patent inverts the traditional groove geometry by creating stepped portions that protrude outward rather than recess inward. This inversion transforms the narrow, hard-to-coat groove geometry into wide, external stepped surfaces that are easily accessible to anodized and coating layers, ensuring optimal layer formation while maintaining indicator precision.

Inventive Principle:
Principle #13The other way round (Inversion)

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 stepped portion indicators on the spool effectively prevent corrosion by ensuring the anodized layer covers the entire surface, maintaining the spool's integrity and preventing metal exposure, thus enhancing the corrosion resistance of the metal spool.

Implementation Method 1

the anodized treatment (e.g., alumite treatment) is performed on the surface of the spool to enhance its corrosion resistance

Methodology Applied
Scientific EffectAnodized treatment: Anodising

Data Source

PatentEP2074884B1Spool of fishing reel
Publication Date: 2012.06.13 SHIMANO INC
  • EP2074884B1 patent drawingFigure 1
  • EP2074884B1 patent drawingFigure 2
  • EP2074884B1 patent drawingFigure 3

AI summary

An indicating section (70) is formed in a rear flange portion (4c) of a metal spool (4). The indicating section includes first and second stepped portions (71,72). These portions are indicators for the amount of fishing line wound around spool. The first stepped portion (71) is formed by first and second surfaces (81,82). The first surface (81) is part of the surface of the rear flange portion. The second surface (82) is formed radially outward of the first surface. The axial heights of the first and second surfaces are different from each other. The second stepped portion (72) is formed by third and fourth surfaces (83,84) and is also formed radially outward of the first stepped portion (71). The third surface (83) is part of the surface of the rear flange portion. The fourth surface (84) is formed radially outward of the third surface. The axial heights of the third and fourth surfaces are different from each other.