Zip Fastener Pull Tab Interlocking Mechanism
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing zip fasteners with two sliders lack sufficient security, as they can be easily opened by inserting fingers between the sliders, and prior solutions requiring special-purpose sliders with interlocking features are costly and complex.
Innovation Solution
A zip fastener design with first and second sliders and pull tabs that interlock via a male and female locking feature, allowing rotation about a pivot axis, and a detent mechanism to prevent separation, combined with a fastening device on luggage for enhanced security.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the distal ends of the pull tabs are locked in place or to one another, then security against unauthorized opening is improved, but the sliders cannot be readily moved together along the stringers
Solution Approach 1:
The pull tabs are designed to transition between two dynamic states: during normal operation, they rotate to an interlocked position that dynamically locks the sliders together; during maintenance or emergency, they can be rotated back to an unlocked position allowing slider movement. This dynamic switching resolves the contradiction between security and operational flexibility.
Solution Approach 2:
The locking function is segmented from the sliding function. The pull tabs serve as independent locking elements that can be rotated into position without interfering with the slider's ability to move along the stringers when not interlocked. This segmentation allows the system to achieve both security and ease of operation at different times.
2Reliability
If special-purpose sliders with interlocking features are provided, then security against slider separation is improved, but manufacturing cost and device complexity increase
Solution Approach 1:
Instead of modifying the sliders themselves to include interlocking features, the patent introduces pull tabs as intermediary elements. These pull tabs rotate to interlock with each other, providing the security function without requiring complex modifications to the slider structure. This intermediary approach maintains simplicity while achieving the desired reliability.
3Device complexity
If the pull tabs are aligned longitudinally and coplanar in interlocked position, then the interlocking mechanism is compact, but the pull tabs cannot be conveniently grasped for moving sliders
Solution Approach 1:
The pull tabs dynamically change their spatial configuration based on operational needs. In the interlocked position, they are compact and coplanar for security. When needing to move sliders, they can be rotated to protrude outward, making them convenient for grasping. This dynamic reconfiguration resolves the contradiction between compactness and graspability.
Data Source
Figure 1
Figure 2
Figure 3~4
AI summary
A zip fastener (20) includes two sliders (10, 11) for connecting elongate stringers (12, 13), each slider (10, 11) having a pull tab (15, 16). For improved security of the zip fastener (20) the pull tabs (15, 16) can be interlocked with one another by a slide-and-turn action, turning one pull tab (15) relative to the other about an axis (32) extending in the longitudinal direction of the stringers (12, 13). A luggage item includes a fastening device (25) for locking the pull tabs (15, 16) together.