Spinning Reel Handle Assembly Rigidity via Segmented Tubular Member
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Solution Overview
Problem
Conventional handle assemblies for spinning reels often deform when pressed against the drive gear shaft, leading to a loss of rigidity and increased susceptibility to wear and foreign matter adhesion, which compromises the assembly's structural integrity and functionality.
Innovation Solution
A handle assembly design featuring a metal shaft member with a threaded portion and a pivoting handle arm, coupled with a first tubular member made of hard metal and a second tubular member of lower rigidity, which contacts the drive gear shaft and handle arm respectively, providing enhanced protection and rigidity by distributing compressive loads and preventing deformation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the shaft cover is pressed strongly to the handle arm to prevent wobbling and loosening, then the stability and reliability of the handle assembly is improved, but the shaft cover becomes deformed and the rigidity of the handle assembly deteriorates
Solution Approach 1:
The pressing member is divided into multiple segments or lobes (typically three) that radially protrude from the shaft cover. This segmentation allows the pressing force to be distributed across multiple contact points on the handle arm, preventing localized deformation of the shaft cover while maintaining sufficient pressing force to prevent wobbling and loosening.
Solution Approach 2:
The pressing member is designed with a specific local geometry where the lobes have rounded contact surfaces that match the curvature of the handle arm. This local quality optimization ensures that the pressing force is applied at precise locations without concentrating stress on the shaft cover material, thereby preventing deformation while achieving the desired stability.
2Weight of moving object
If the shaft cover is made of aluminum alloy to reduce weight, then the weight of the handle assembly is reduced, but the shaft cover deforms under pressing force and the reliability deteriorates
Solution Approach 1:
The pressing member incorporates localized geometric features (lobes with specific radii and angles) that concentrate the pressing action in controlled areas. This local quality design allows the aluminum alloy shaft cover to maintain sufficient structural integrity at the pressing locations without requiring the entire component to be made of heavier material.
Solution Approach 2:
The handle assembly utilizes a composite structure where the shaft cover is made of lightweight aluminum alloy while the pressing member may be made of a different material or have surface treatments that enhance local durability. This composite approach optimizes the weight-strength trade-off by using appropriate materials in different locations based on their functional requirements.
3Reliability
If the pressing member is designed to exert strong pressing force to prevent easy loosening, then the reliability is improved, but the shaft cover deforms and the rigidity deteriorates
Solution Approach 1:
The pressing member is segmented into multiple lobes that distribute the pressing force across several discrete contact points on the handle arm. This segmentation prevents the concentration of force on a single location, thereby preventing localized deformation of the shaft cover while maintaining the overall pressing force necessary to prevent loosening.
Solution Approach 2:
The lobes of the pressing member are designed with curved, spherical contact surfaces that match the curvature of the handle arm. This spherical geometry allows for even distribution of pressing force and prevents stress concentration that would lead to deformation, while still providing sufficient normal force to prevent the handle from loosening during operation.
Data Source
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AI summary
The handle assembly (1) of the spinning reel (100) includes a metal shaft member (7), a metal handle arm (8), a handle grip (9), and a metal first cylindrical member (30). The shaft member (7) has an attachment threaded portion (7a) that is screwed to the drive gear shaft (10) disposed at the one end and a coupling portion (7b) disposed at the other end. The handle arm (8) has a connected portion (8a) that is coupled to the coupling portion (7b) while being about to be pivoted around the radial axis of the shaft member (7). The handle grip (9) is attached to the handle arm (8) while being rotatable around an axis that is parallel to the shaft member (7). The first tubular member (30) has a first pipe portion (30a) that is disposed on the outer circumferential side of the shaft member (7) and is capable of making contact with the handle arm (8) and a second pipe portion (30b) that is integrally formed to the first pipe portion (30a), has a smaller diameter than that of the first pipe portion (30a), and is capable of making contact with the drive gear shaft (10).