Paper Container Bottom with Locking Slot and Coupling Tabs

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Solution Overview

Problem

Existing paper material containers for pharmaceutical and cosmetic products lack sufficient strength to securely hold heavy items like glass bottles or jars, risking accidental displacement or spillage.

Innovation Solution

A container with a locking closure system featuring a locking slot and pair of coupling tabs on the bottom flaps, along with contrasting tabs for stable engagement, ensuring the bottom remains securely closed and resistant to opening.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Strength

If a simple bottom structure is used in paper material containers, then manufacturing is easier and cost is lower, but the bottom strength is insufficient to securely hold heavy items like glass bottles or jars

Engineering Contradiction:
Improvebottom strengthVSAvoidbottom structure complexity
Core Design Contradiction:
StrengthVSDevice complexity

Solution Approach 1:

The bottom structure is segmented into multiple functional components including closing flaps, coupling tabs, locking slots, and contrasting tabs. Each segment performs a specific function: closing flaps provide structural coverage, coupling tabs enable interlocking, locking slots secure the assembly, and contrasting tabs prevent misalignment. This segmentation allows the bottom to achieve high strength through distributed load bearing while maintaining manufacturability through standardized component formation from paperboard sheets.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The bottom structure employs a nested arrangement where coupling tabs are inserted into locking slots, and contrasting tabs are positioned within recesses of the closing flaps. This nested configuration creates multiple layers of mechanical interlocking, where each nested component reinforces the overall structure. The nested design allows compact assembly while providing cumulative strength through layered support, effectively holding heavy contents without requiring excessive material thickness.

Inventive Principle:
Principle #7Nested doll (Nesting)

2Reliability

If a locking closure system with multiple tabs and slots is implemented, then bottom strength and security are improved, but manufacturing complexity and assembly difficulty increase

Engineering Contradiction:
Improvebottom closure reliabilityVSAvoidmanufacturing ease
Core Design Contradiction:
ReliabilityVSEase of manufacture

Solution Approach 1:

The coupling tabs, locking slots, and contrasting tabs are pre-formed as integral features of the paperboard bottom structure during the molding or die-cutting process. This preliminary action ensures precise geometric accuracy of interlocking features without requiring separate machining or assembly steps. The tabs and slots are created with exact dimensions and positions in the flat sheet before folding, guaranteeing reliable engagement while simplifying manufacturing by eliminating post-forming operations.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The bottom closure system is designed to be self-assembling through its interlocking tab and slot mechanism. When the container is folded into its three-dimensional form, the coupling tabs automatically align with and insert into the locking slots, while the contrasting tabs engage with the closing flaps. This self-service assembly requires no additional fastening operations, adhesives, or external tools, thereby maintaining ease of manufacture despite the complex appearance of the closure system. The structure relies on its own geometry to achieve reliable closure.

Inventive Principle:
Principle #25Self-service

Data Source

PatentEP3898433B1Container with bottom resistant to opening
Publication Date: 2024.03.27 ZAMBON SPA
  • EP3898433B1 patent drawingFigure 1a
  • EP3898433B1 patent drawingFigure 1b
  • EP3898433B1 patent drawingFigure 2~3

AI summary

A container with a bottom resistant to opening comprising a locking closure system for the bottom is described. The locking closure system comprises a locking slot and a pair of coupling tabs, wherein the locking slot is formed on a bottom closing tab of the container and is suitable for being engaged, when the container is closed, by the pair of coupling tabs. The coupling tabs are formed on an edge of two bottom closing flaps of the container which are suitable for overlapping at least partially so as to close the container at the bottom.