Can Lid Score Line Geometry for Reliable Opening
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Solution Overview
Problem
Existing can lids for beverage cans often face issues with panel breakage along score lines being inconsistent, leading to reduced user workability and the possibility of unintended opening due to external forces, along with difficulties in bending the piece-like portion and simplifying the tab operation.
Innovation Solution
A can lid design featuring a tab with one end section and another end section, where the portion between them is fastened to the panel by a rivet, with score lines configured to facilitate tongue-shaped portion formation and bending, reducing the need for tab operation and preventing unintended openings.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If score lines are formed on the panel surface to enable opening formation, then the opening can be formed by panel breakage along the score lines, but the panel breakage may not proceed consistently along the score lines in some cases, reducing workability
Solution Approach 1:
The score lines are pre-formed on the panel surface at predetermined locations before the opening formation operation. These score lines create predetermined breakage paths that guide the panel breakage to proceed consistently along the intended trajectory when the tab is pulled, ensuring reliable and repeatable opening formation.
Solution Approach 2:
The score lines are designed to pass outside the outer peripheral edge of the tab, creating a segmented pattern that ensures breakage occurs in a controlled sequence. This segmentation of the breakage path into defined segments (first portion, second portion, third portion) guarantees consistent panel separation along the score lines regardless of variations in pulling force.
2Ease of operation
If the tab is pulled up to form an opening, then the opening is formed successfully, but the tab projects from the surface requiring additional operation to lay it down
Solution Approach 1:
Instead of the tab remaining on the outer surface after pulling (conventional design), the score lines are configured to pass outside the tab's outer peripheral edge, causing the tab to be pulled through to the inner surface of the panel. This inversion of the tab's final position eliminates the need for a separate laying-down operation, as the tab naturally ends up on the inner surface where it does not interfere with drinking.
3Ease of operation
If the piece-like portion is formed by panel breakage, then the opening structure is created, but the piece-like portion may not bend inward easily, reducing workability
Solution Approach 1:
The score lines are positioned to pass outside the outer peripheral edge of the tab, creating a specific local geometry where the piece-like portion (tongue-shaped portion) is formed. This localized configuration of the score lines relative to the tab position creates a geometric structure that naturally facilitates inward bending of the piece-like portion while maintaining sufficient strength for handling.
4Ease of operation
If the score lines pass close to the tab to enable easy breaking, then opening formation is simplified, but external forces may cause unintended opening formation
Solution Approach 1:
The score lines are pre-formed at optimized positions that pass outside the tab's outer peripheral edge, creating a predetermined breakage path that requires significant force to activate. This preliminary configuration ensures that casual external forces (such as drops or accidental impacts) are insufficient to initiate breakage, while deliberate tab pulling operations successfully form the opening.
Data Source
Figure 1A~1B
Figure 2
Figure 3A~3C
AI summary
A can lid 300 comprising: - a panel 400 attached to an aperture of a can barrel; - a tab 500 including one end section 505 and other end section 510, a portion of which positioned between the one end section and the other end section being fastened to the panel by a rivet 900, and pressing a predetermined pressed location of the panel with the other end section; and - a score line 440 formed on the panel, which includes a first portion 440A that passes one side 581 of the tab to head toward the one end section 505 side of the tab, a second portion 440B that passes other side 582 of the tab to head toward the one end section 505 side of the tab, and a third portion 440C that is formed to connect the first portion 440A and the second portion 440B and passes outside of an outer peripheral edge of the tab on the other end section 510 side of the tab, - wherein each of the first portion 440A and the second portion 440B heading toward the one end section 505 side is formed to reach any of a location beyond the one end section 505, a location where the one end section 505 is positioned, and a location positioned beside the one end section 505.