Asymmetric Locking Tabs for Secure Portable Case Stacking

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Solution Overview

Problem

Existing cases lack security against theft and tampering, and they do not stack stably, leading to instability and accessibility issues when stored or transported.

Innovation Solution

A portable case with asymmetric locking tabs, guide and stop ridges, and a stacking recess design that allows for secure engagement and stable stacking, preventing unauthorized access and facilitating easy handling and storage.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If conventional cases are used, then they are simple in structure, but they lack security against theft and tampering

Engineering Contradiction:
Improvesecurity against theft and tamperingVSAvoidstructure complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The locking tabs are designed with an asymmetric shape where the tabs extend perpendicular to the lid surface at a distance shorter than the container height. This asymmetric configuration prevents unauthorized removal while maintaining a relatively simple overall structure. The tabs have a grip portion and a hole for locking strips, creating security without excessive complexity.

Inventive Principle:
Principle #4Asymmetry

Solution Approach 2:

The locking mechanism is segmented into multiple locking tabs distributed along the sides of the lid, rather than a single complex lock. Each tab can engage independently with the container walls, providing distributed security. This segmentation allows the security function to be achieved through multiple simple elements rather than one complex mechanism.

Inventive Principle:
Principle #1Segmentation

2Stability of the object's composition

If conventional cases are stacked, then they can be stored efficiently, but they do not stack stably

Engineering Contradiction:
Improvestacking stabilityVSAvoidcase structure complexity
Core Design Contradiction:
Stability of the object's compositionVSDevice complexity

Solution Approach 1:

The stacking stability is achieved by utilizing the vertical dimension through the asymmetric locking tabs that extend downward from the lid. These tabs engage with the container walls to prevent lateral movement during stacking. The stacking recess in the bottom of the container further enhances vertical stacking stability by providing a mechanical interlock between stacked containers.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

Solution Approach 2:

The stacking recess is pre-formed in the bottom of the container at an optimized position, and the locking tabs are pre-positioned on the lid. This preliminary configuration ensures that when containers are stacked, the locking tabs automatically engage with the container walls and the stacking recess provides immediate mechanical support, eliminating the need for additional adjustment or complex assembly procedures.

Inventive Principle:
Principle #10Preliminary action

3Reliability

If the lid is made symmetric, then it is easier to manufacture, but it reduces security and stacking stability

Engineering Contradiction:
Improvesecurity and stacking stabilityVSAvoidlid manufacturing complexity
Core Design Contradiction:
ReliabilityVSEase of manufacture

Solution Approach 1:

The lid incorporates asymmetric locking tabs that extend perpendicular to the lid surface at a controlled distance. This asymmetric design provides both security against theft and stability during stacking. The asymmetry is implemented in a way that maintains manufacturability by using simple geometric forms rather than complex asymmetric shapes.

Inventive Principle:
Principle #4Asymmetry

Solution Approach 2:

The asymmetry is applied locally only where needed for security and stacking functions (the locking tabs and their positioning), while the rest of the lid maintains a simple, easy-to-manufacture structure. The lid body can be produced using standard processes, with the asymmetric features added as specific structural elements rather than requiring the entire lid to be complex.

Inventive Principle:
Principle #3Local quality

4Reliability

If locking tabs extend beyond container height, then they provide more locking engagement, but they increase device complexity and reduce compactness

Engineering Contradiction:
Improvelocking engagementVSAvoidoverall structure complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The locking tabs are designed with optimized parameters where the extension distance is specifically set to be shorter than the container height. This parameter optimization provides sufficient locking engagement for security and stacking purposes while maintaining a compact overall structure. The tabs have a grip portion and hole for locking strips, creating effective engagement without excessive length.

Inventive Principle:
Principle #35Parameter changes

Data Source

PatentEP3994073B1A case for storing articles and carrying articles by hand
Publication Date: 2024.07.10 HOFSTAD STEIN
  • EP3994073B1 patent drawingFigure 1A~1B
  • EP3994073B1 patent drawingFigure 2A~2B
  • EP3994073B1 patent drawingFigure 3A~3B

AI summary

Case (10) for storing articles and carrying articles by hand, comprising a square or rectangular container (200) having a front end wall (201),a rear end wall (202), side walls (203, 204) and a bottom (206). A lid(300) having surface (301), side edges (304, 305), a rear end edge (303)and a front side (302). The lid (300) comprises locking tabs (306, 307),arranged to establish a releasable locking engagement with container(200). The tabs (306, 307) exhibit a grip (310) and a hole (311) for a locking strip. The side edges (304, 305) exhibit numerous guide andstop ridges (309). An upper rim of the walls (202, 203, 204) exhibits alid guiding groove (210) defined by an outer wall (212), an inner ridge(213) and a horizontal guiding surface (211), arranged to serve as lidguiding means lid lock by establishing engagement between innerridge (213) and guide and stop ridges (309).