Molded Keel Zipper Structure for Automated Case Assembly
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Solution Overview
Problem
Existing zipper cases face high production costs due to manual stitching, high labor costs, high defective rates, and poor aesthetics due to manual assembly, with the zipper structure affecting the case's strength and appearance.
Innovation Solution
A zipper structure comprising two zipper bodies with a keel fixed to the case body, allowing for automated assembly, reduced labor costs, and enhanced aesthetics through recess integration, while maintaining strength.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If manual stitching is used to attach the zipper to the case body, then the zipper can be securely fixed, but the production cost increases and labor efficiency decreases
Solution Approach 1:
The patent replaces the manual mechanical stitching system with an automated injection molding process. The keel is integrated into the case body through injection molding, eliminating the need for manual stitching operations while maintaining secure fixation. This substitution of mechanical manual stitching with automated molding process directly addresses the contradiction by enabling high-speed production while ensuring reliable zipper attachment.
Solution Approach 2:
The patent merges the keel and case body into a single integrated component through injection molding. The keel is molded directly as part of the case body structure, combining two separate elements (keel and case body) into one unified piece. This merging eliminates the need for separate stitching operations and enables automated production, resolving the contradiction between reliability and productivity.
2Reliability
If manual stitching is used to attach the zipper, then the zipper can be fixed, but the labor cost increases
Solution Approach 1:
The patent replaces manual mechanical stitching with automated injection molding technology. The keel is molded directly into the case body using injection molding machines, eliminating the need for skilled stitchers and manual labor. This substitution dramatically reduces labor costs while maintaining the reliability of zipper fixation through the integrated molded structure.
Solution Approach 2:
The injection molding process is a self-service manufacturing method where the mold automatically forms the keel and case body integration without requiring manual intervention. The process is automated, consistent, and does not depend on skilled laborers, thereby reducing manufacturing costs while ensuring reliable fixation through precise molded geometry.
3Reliability
If manual stitching is used, then the zipper can be attached, but the defective rate increases
Solution Approach 1:
The patent replaces manual stitching with automated injection molding, which provides precise and consistent geometric control. The molded keel-case body integration ensures uniform thickness, proper positioning, and consistent bonding surfaces, eliminating the variability inherent in manual stitching. This substitution significantly reduces defective rates by ensuring high manufacturing precision through automated molding processes.
Solution Approach 2:
The patent changes the manufacturing parameters from manual stitching variables (needle penetration depth, thread tension, operator skill level) to controlled injection molding parameters (mold temperature, injection pressure, cooling time). These parameter changes enable precise reproduction of the keel structure and its integration with the case body, ensuring consistent quality and reducing defects.
4Ease of manufacture
If the leather strip or frame is used with the zipper, then the zipper can be assembled, but the case body appearance is affected due to height difference
Solution Approach 1:
The patent merges the keel and case body into a single integrated component through injection molding, eliminating the height difference problem. Since the keel is molded as part of the case body rather than being a separate attached component, the surface achieves a flush, aesthetically pleasing appearance without protrusions. This merging resolves the contradiction by maintaining assembly feasibility while improving appearance.
Solution Approach 2:
The patent extracts the problematic height difference issue by redesigning the keel structure to be flush with the case body surface. The keel is molded to extend only as much as necessary for zipper functionality, with its outer surface aligned with the case body outer surface. This extraction of the height difference problem eliminates the aesthetic defect while preserving the zipper assembly capability.
5Device complexity
If traditional straight-sided opening is used, then the case structure is simple, but the opening strength is reduced and deformation occurs
Solution Approach 1:
The patent applies curvature to the opening structure by molding the case body with rounded, curved transitions at the opening rather than sharp straight edges. The curved geometry distributes stress more effectively around the opening, preventing deformation while maintaining structural integrity. This curvature modification resolves the contradiction by enhancing opening strength without significantly increasing overall structural complexity.
Solution Approach 2:
The patent incorporates reinforcement features directly into the molded case body structure at the opening area. The injection molding process includes pre-formed reinforcing ribs, thickened sections, or geometric reinforcements at the opening that proactively prevent deformation before it occurs. This preliminary structural preparation strengthens the opening without requiring additional complex assembly steps.
Data Source
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AI summary
A zipper structure, a case body, a mold for manufacturing a case body, and a mold operation method. The zipper structure is for connecting an upper housing and a lower housing of a case body. The zipper structure includes two zipper bodies, each zipper body including a zipper fabric and a keel; an end of the zipper fabric is arranged with first zipper teeth, and the other end of the zipper fabric is configured to be connected to a lining fabric of the case body; the first zipper teeth of one of the two zipper bodies are configured to be engaged with the first zipper teeth of the other of the two zipper bodies; the keel is connected to the zipper fabric; each zipper body is fixed to the case body by fixedly connecting the keel to the case body.