Reinforced Folding Box Lid Assembly Against Deformation and Misopening

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Solution Overview

Problem

Existing containers, particularly folding boxes made of cardboard, are prone to irreversible deformation and unintentional opening, especially when subjected to frequent use, which compromises their closing function.

Innovation Solution

A container design featuring inner flaps and reinforcing elements that secure the lid assembly against unintentional opening, with locking tabs engaging with the lid assembly's inner surface and requiring two-handed operation for opening, and reinforced by multiple elements to prevent deformation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If locking tabs are hinged to the front wall for securing the lid, then the container can be securely closed and protected against unintentional opening, but the locking tabs and opening/closing mechanism become prone to irreversible deformation under pressure

Engineering Contradiction:
Improvesecurity against unintentional openingVSAvoidresistance to deformation of locking mechanism
Core Design Contradiction:
ReliabilityVSStrength

Solution Approach 1:

The lid construction is divided into multiple elements (lid body, lid flaps, reinforcing elements) that can move and lock independently. The locking mechanism is segmented into locking tabs on the lid and corresponding recesses on the front wall, allowing distributed stress and preventing concentrated deformation at a single point.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The container employs a composite structure combining the lid assembly with reinforcing elements that integrate multiple functional properties. The lid construction incorporates both flexible components (for locking/unlocking) and rigid components (for structural strength), creating a composite system that resists deformation while maintaining security.

Inventive Principle:
Principle #40Composite materials

2Productivity

If frequent opening and closing operations are performed, then the container remains accessible and usable, but the locking tabs and opening/closing mechanism suffer irreversible deformation leading to destruction of function

Engineering Contradiction:
Improvefrequency of opening/closing operationsVSAvoiddurability of opening/closing function
Core Design Contradiction:
ProductivityVSReliability

Solution Approach 1:

The lid construction incorporates dynamic elements including hinged lid flaps and movable locking tabs that can repeatedly transition between locked and unlocked states. The bending lines enable flexible movement during opening/closing while the reinforcing elements provide structural support that prevents permanent deformation even after frequent operations.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

Reinforcing elements are pre-installed in the lid construction to cushion and absorb stresses that occur during opening and closing operations. These elements are positioned to counteract deformation forces before they can cause irreversible damage to the locking mechanism, enabling repeated use without functional degradation.

Inventive Principle:
Principle #11Beforehand cushioning (Prior cushioning)

3Ease of operation

If the locking tabs rest against or project from the front wall for easy engagement, then automatic secure closure is achieved, but the areas around locking tabs become vulnerable to deformation under pressure

Engineering Contradiction:
Improveautomatic closure engagementVSAvoidstructural stability of front wall and locking area
Core Design Contradiction:
Ease of operationVSStability of the object's composition

Solution Approach 1:

The lid construction features localized reinforcing elements positioned specifically in the areas surrounding the locking tabs and bending lines. These reinforcing elements provide enhanced structural strength only where needed (at the locking mechanism and hinge areas) without adding unnecessary weight or complexity to the entire lid structure, maintaining both ease of operation and local structural stability.

Inventive Principle:
Principle #3Local quality

Data Source

PatentEP4365098B1Container and blank for forming a container
Publication Date: 2026.03.18 MAYR MELNHOF KARTON
  • EP4365098B1 patent drawingFigure 1
  • EP4365098B1 patent drawingFigure 2
  • EP4365098B1 patent drawingFigure 3

AI summary

The present invention relates to a container (10) for storing goods, in particular a folding box made of cardboard, paper or the like, comprising a front wall (12) and a rear wall (14), side walls (16, 18) connecting the front and rear walls (12, 14), at least a bottom wall (20) and a lid assembly (22), wherein the lid assembly (22) comprises at least an upper lid element (34) hinged to the end of the rear wall (14) opposite the bottom wall (20) via a bending line (86), a front lid flap (36) at the end of the upper lid element (34) opposite the rear wall (14), and side flaps (40, 42) laterally closing the lid assembly (22), and at least one locking tab (58, 60) at the end of the front wall (12) opposite the bottom wall (20) for locking the lid assembly (22) to the front wall (12) in the closed state. container (10) is hinged via a bending line (80) such that,that it abuts an outer surface of the front wall (12) or projects outwards from the container (10). At least one inner flap (38) is hinged to the end of the front lid flap (36) opposite the upper lid element (34), such that the inner flap (38) at least partially abuts and/or is connected to an inner surface of the front lid flap (36), and at least one first reinforcing element (32) is hinged to the inner flap (38), such that the first reinforcing element (32) at least partially abuts and/or is connected to an inner surface of the upper lid element (34). The invention further relates to a blank (128) for manufacturing a container (10) for storing goods.