Resealable Cap With Bistable Locking Flap for Impact Resistance

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Solution Overview

Problem

Existing resealable caps for containers face issues with strength and ease of use, as snap-caps are easily dislodged by shocks and impacts but require little force to open, while screw-on caps are difficult to open and close, especially for children and the elderly, and are costly due to precision requirements.

Innovation Solution

A cap design featuring a disc-shaped top section with an annular side section and a locking flange, including a bistable locking flap that enhances sealing and retention force, and a frangible tab for tamper evidence, allowing for easy opening and closing while resisting impacts and abrasion.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If a snap-cap is used, then the cap is easy to open and close, but the joint strength is weak and the cap may be easily dislodged by external shocks and impacts

Engineering Contradiction:

Improveease to open and closeVSAvoidjoint strength

Core Design Contradiction:

Ease of operationVSStrength

Solution Approach 1:

The locking flap is designed to be mobile between different positions (engaged and disengaged states) to provide dynamic locking and unlocking functionality. This allows the cap to transition from a static snap-fit to a dynamic system that can actively lock onto the container neck, resolving the contradiction between ease of operation and joint strength.

Inventive Principle:

Principle #15Dynamics

Solution Approach 2:

The cap is divided into distinct functional segments: the locking flap, the locking flange, the annular side section, and the disc-shaped top section. This segmentation allows each component to perform its specific function optimally - the locking flap provides the locking mechanism while the annular side section provides structural support, thereby achieving both ease of operation and strong joint.

Inventive Principle:

Principle #1Segmentation

2Strength

If a screw-on cap is used, then the joint strength is high and the seal is tight, but a large amount of force is required to open and close

Engineering Contradiction:

Improvejoint strengthVSAvoidease to open and close

Core Design Contradiction:

StrengthVSEase of operation

Solution Approach 1:

The threading mechanism is extracted and replaced with a snap-fit locking mechanism. The locking flap and locking flange provide the necessary joint strength without requiring rotational threading, thereby eliminating the need for large forces to open and close while maintaining high joint strength.

Inventive Principle:

Principle #2Taking out (Extraction)

Solution Approach 2:

The locking flap is designed as a simple, inexpensive plastic component that can be easily molded into the cap. This disposable-like simplicity in design allows for easy manufacturing and replacement while providing sufficient locking strength, avoiding the complexity and cost of threaded connections.

Inventive Principle:

Principle #27Cheap short-living objects (Disposable)

3Reliability

If screw-on cap with threads is used, then the seal is tight and leakage-resistant, but the manufacturing cost increases due to precision requirements

Engineering Contradiction:

Improveseal qualityVSAvoidmanufacturing cost

Core Design Contradiction:

ReliabilityVSEase of manufacture

Solution Approach 1:

The locking flap and sealing structures are made from flexible plastic material that can be easily molded. This flexibility allows for effective sealing through elastic deformation and contact pressure rather than precision-threaded connections, significantly reducing manufacturing complexity and cost while maintaining reliable seals.

Inventive Principle:

Principle #30Flexible shells and thin films

Solution Approach 2:

The sealing mechanism transitions from relying on precise dimensional control of threaded interfaces to relying on elastic deformation and contact pressure of flexible plastic components. This parameter change from rigid precision fitting to flexible elastic sealing simplifies manufacturing while maintaining seal quality.

Inventive Principle:

Principle #35Parameter changes

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

The cap provides a secure seal resistant to shocks and impacts, is easy to open and close, and is cost-effective, with the frangible tab serving as a tamper-evident indicator, improving usability and reliability.

Implementation Method 1

The locking flap, when moved from the first position to the second position, will multiply the force applied to it by the user, permitting a greater sealing and retaining force to be realized between the cap and the container

Methodology Applied

Scientific EffectMechanical Advantage: Mechanical Advantage

Implementation Method 2

At this point, the elasticity of the cap causes the groove to close around the seated bead, retaining the cap on the container

Methodology Applied

Scientific EffectElasticity: Elasticity

Data Source

PatentEP3233650B1A cap for a container and a package comprising such a cap

Publication Date: 2020.01.29 SOCIETE DES PRODUITS NESTLE SA

Figure 1A~1B
Figure 2A~2B
Figure 3

AI summary

A cap (100) for a container comprises a disc-shaped top section (102), an annular side section (104) projecting from said disc-shaped top section (102), and a locking flange (111) disposed at an extremity of said annular side section (104) opposite said disc-shaped top section (102), and further comprises a locking flap (116) extending from said annular side section (104), which is mobile between a locked first position wherein a portion (114) of the locking flange (111) extends inwardly from the annular side section (104), and an unlocked second position wherein the locking flange (111) is at least partially recessed relative to the annular side section (104).