Spool Flange Design for Fishing Reel Backlash Prevention
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Solution Overview
Problem
Conventional spools for spinning reels often result in backlash due to the fishing line being wound to the limit of the front flange, causing it to bunch and fall forward, leading to tangling and looped lines.
Innovation Solution
The spool design features a cylindrical bobbin trunk with a front flange and a rear flange, where the rear flange's protruding portion has the same radial length as the front flange, and the front flange includes an oblique portion that expands in diameter, preventing the line from moving forward and thus avoiding backlash.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If the fishing line is wound onto the bobbin trunk up to the height corresponding to the tip of the front flange, then the maximum winding capacity is achieved, but the fishing line may be bunched and fall forward from the front flange causing backlash
Solution Approach 1:
The rear flange is designed with a protruding portion that extends in the radial direction to a position aligned with the tip of the front flange. This preliminary structural arrangement creates a visual and physical reference point that guides the angler to stop winding before the line reaches the front flange tip, preventing bunching and backlash before they can occur
Solution Approach 2:
The protruding portion of the rear flange acts as an intermediary reference element between the bobbin trunk and the front flange. It provides a measurable indicator that mediates the winding process, allowing the angler to gauge the appropriate winding limit without directly observing the front flange tip position
2Device complexity
If the front flange and skirt portion have approximately the same radial protrusion length, then the spool structure is simplified and symmetric, but the fishing line can be wound to the limit causing bunching and backlash
Solution Approach 1:
While maintaining overall structural symmetry for simplicity, the invention introduces asymmetric functional elements: the front flange includes an oblique portion that slopes upward from the bobbin trunk toward the front flange tip, while the rear flange has a protruding portion that extends radially outward. This asymmetric design within a symmetric framework provides the necessary winding guidance without significantly increasing structural complexity
3Quantity of substance
If the fishing line is allowed to reach the front flange tip position, then maximum line capacity is utilized, but the line becomes bunched and tangled during casting
Solution Approach 1:
The oblique portion on the front flange is designed to guide the fishing line upward and outward before it reaches the front flange tip. This preliminary guidance action prevents the line from becoming horizontal and bunching at the tip position, ensuring smooth line discharge during casting while still maximizing winding capacity
4Reliability
If the front flange is designed with an oblique portion that expands in diameter, then backlash is prevented, but the spool structure becomes more complex
Solution Approach 1:
Instead of making the entire front flange complex, the invention applies a localized oblique portion only where needed - on the upper surface of the front flange extending from near the bobbin trunk toward the front flange tip. This local modification provides the necessary line guidance and backlash prevention without complicating the overall flange structure
Data Source
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AI summary
A spool (4) for preventing backlash includes a bobbin trunk (7a), a rear flange portion (18e), and a front flange portion (8). The front flange portion (8) includes a first protruding portion (117a) and a first oblique portion (117b) that protrudes upward and forward from a tip of the first protruding portion (117a). The rear flange portion (18e) includes a second protruding portion (18a) and a second oblique portion (18b) that protrudes upward and rearward from a tip of the second protruding portion (18a). A length (B) in the radial direction of the second protruding portion (18b) is approximately the same as a length (A) of the first protruding portion (117a).