Easy-Open Container Lid Bead Flattening for Safer Score Lines
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Solution Overview
Problem
Easy open ends for containers, such as cans, often leave sharp edges after opening, posing a safety risk and requiring additional sheet material for manufacturing, which increases costs due to the need for complex tools and dies.
Innovation Solution
A method involving a preform with a bead that is thinned and elongated, then flattened to form projections underneath the score line, reducing material usage and simplifying tool requirements, while maintaining safety features.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If double-folding of the lid is performed in the region of the score line to create protective shoulders, then user safety is improved by preventing contact with sharp edges, but the amount of sheet material required increases and manufacturing complexity increases
Solution Approach 1:
The patent applies local quality by creating variable wall thickness in specific regions of the lid. The side wall portions of the bead are thinned to a lesser thickness than the bridge portion, allowing the thinned material to collapse and form protective shoulders when the bead is flattened. This localized thinning enables the safety feature to be created from the existing material rather than requiring additional sheet material.
Solution Approach 2:
The patent changes the physical parameter of wall thickness in the bead structure. By thinning the side wall portions of the bead while maintaining or increasing the thickness of the bridge portion, the patent creates a material distribution that enables the side walls to collapse inward and form protective shoulders during flattening, thereby providing safety protection without increasing overall material consumption.
2Object-affected harmful factors
If double-folding of the lid is performed to create protective shoulders, then user safety is improved, but device complexity increases due to requirements for complex tools and dies
Solution Approach 1:
The patent applies preliminary action by pre-thinning the side wall portions of the bead during the forming process before the flattening operation. This preliminary thinning prepares the material so that when the bead is subsequently flattened, the thinned side walls naturally collapse and form protective shoulders without requiring additional complex forming tools or multi-step operations, thereby simplifying the overall manufacturing process.
Solution Approach 2:
The patent changes the wall thickness parameter of the bead side walls during forming, creating a material structure that will naturally collapse to form protective shoulders during flattening. This parameter change eliminates the need for complex subsequent forming operations and specialized tools, simplifying the manufacturing equipment requirements while still achieving the safety function.
3Quantity of substance
If the bead side wall portions are thinned and elongated, then material usage is reduced and protective projections are formed, but the manufacturing precision requirements increase
Solution Approach 1:
The patent applies local quality by selectively thinning only the side wall portions of the bead while maintaining the thickness of the bridge portion. This localized material removal or displacement creates the necessary condition for the side walls to collapse and form protective shoulders, optimizing material usage in the critical regions while maintaining sufficient material in other areas.
Solution Approach 2:
The patent changes the wall thickness parameter of the bead side walls to a lesser value than the bridge portion thickness. This parameter change creates a material gradient that enables the thinned side walls to collapse inward during flattening, forming protective projections. The controlled parameter change ensures adequate material remains in the bridge portion while creating the safety feature from the thinned side walls.
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 method reduces the risk of user injury by creating protective projections and minimizes material consumption, lowering manufacturing costs and simplifying the production process.
Implementation Method 1
thinning the side wall portions of the bead at least partially, thereby elongating the side wall portions
Implementation Method 2
flattening the bead such that the two thinned side wall portions collapse
Data Source
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AI summary
The invention relates to a method for producing a lid for closing a container, the lid reduces the risk of a user's injury when opening the container while being producible at relatively low costs. The method comprising the steps of providing a preform of the lid (10), wherein the preform of the lid (10) has opposing first and second sides (11, 12), wherein the first side (11) faces towards the inside of the container when the lid (10) is affixed to the container; forming a bead (20) in the preform of the lid (10), wherein the bead (20) extends out of said second side (12) in an axial direction from said first side (11) towards said second side (12), wherein the bead (20) comprises two radially spaced apart side wall portions (22, 24) and a bridge portion (26) connecting the side wall portions (22, 24); thinning the side wall portions (22, 24) of the bead (20) at least partially, thereby elongating the side wall portions (22, 24); forming a score line (30) in the bridge portion (26) of the bead (20) on said second side (12); and flattening the bead (20) such that the two thinned side wall portions (22, 24) collapse, thereby providing the lid (10).