Fastener Stringer With Concave Fixing Sections
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional fastener elements made of synthetic resin have issues with unstable locking mechanisms and increased manufacturing costs due to asymmetrical shapes, which affect their appearance and functionality compared to metallic fastener elements.
Innovation Solution
The fastener stringer features fastener elements with tapered shapes and concave surfaces on the fixing sections, allowing for improved engagement with locking paws and reduced manufacturing complexity by using plane-symmetrical designs, along with the incorporation of metal fine pieces in the synthetic resin for enhanced strength and appearance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If the element width dimension is increased to ensure fixing strength, then the fixing strength is improved, but the appearance quality deteriorates because it does not resemble metallic fastener elements
Solution Approach 1:
The patent uses synthetic resin as a composite material to create fastener elements that combine the aesthetic advantages of metal (thin appearance) with the manufacturing benefits of resin (injection molding). The resin material allows for complex geometries including tapered shapes and concave surfaces that provide both visual appeal and functional locking capability.
Solution Approach 2:
The patent employs curved surfaces, specifically concave surfaces on the fixing section and tapered shapes on the extending section, to create visual depth and shadow effects that mimic metallic fastener elements. These curved geometries provide both aesthetic quality and functional engagement surfaces for locking mechanisms.
2Shape
If asymmetrical shapes are used to enhance appearance quality and touch, then the appearance quality is improved, but the manufacturing complexity increases due to requiring different dies for right- and left-side insertions
Solution Approach 1:
The patent applies asymmetry selectively to the extending section (which has a tapered shape for visual effect) while maintaining symmetry in the fixing section. This allows the fastener element to have aesthetic variety and tactile quality without requiring different manufacturing dies for left- and right-side insertions, as the symmetrical fixing section can be produced with a single die.
3Shape
If the element width dimension is decreased to resemble metallic fastener elements, then the appearance quality is improved, but the fixing strength deteriorates
Solution Approach 1:
The patent divides the fastener element into distinct functional sections: a fixing section with concave surfaces for locking engagement, and an extending section with tapered shapes for visual appeal. This segmentation allows each section to be optimized independently - the fixing section provides sufficient width for strong attachment to the fastener tape, while the extending section tapers to create a thin, metallic-like appearance.
4Ease of manufacture
If conventional fastener elements are used, then the manufacturing cost is reduced, but the locking mechanism stability deteriorates
Solution Approach 1:
The concave surfaces on the fixing section create curved engagement surfaces that provide stable locking for the locking pawl. These curved geometries allow the locking mechanism to engage positively and maintain stability during use, while still being manufacturable through injection molding at reasonable cost.
Data Source
AI summary
A fastener stringer is provided with a fixing section in which at least one of a first and second half sections is fixed to a fastener tape and a tapered extending section which extends from the fixing section toward the outside of the tape. A first side face and a second side face in the tape length direction in the fixing section have concave surfaces which curve in a concave shape so as to gradually increase from an element surface of a fastener element toward the fastener tape. Accordingly, each fastener element can exhibit an appearance close to a metallic fastener element and a locking mechanism of a slider can be made to function stably.