Cap Inner Plug Expansion for Secure Sheet Retention

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Existing metal caps face issues with the metallic sheet member separating from the cap body under reduced pressure and requiring high stopper-opening torque, which complicates insertion and sealing.

Innovation Solution

A method for manufacturing a cap with a metallic sheet member that includes an annular flat region and a protruding portion, allowing for easy insertion and enlargement of the sheet member's outer diameter within the cap body, ensuring secure retention and reduced torque for opening.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If the outer diameter of the metallic sheet member is decreased to facilitate insertion into the cap body, then the ease of insertion is improved, but the sheet member separates from the cap body under reduced pressure

Engineering Contradiction:
Improveease of insertionVSAvoidretention of sheet member
Core Design Contradiction:
Ease of operationVSReliability

Solution Approach 1:

The metallic sheet member is divided into two functional zones: an insertion portion with a smaller outer diameter for easy insertion into the cap body, and a retention portion with a larger outer diameter that engages with the cap body to prevent separation under reduced pressure. This segmentation allows each portion to fulfill its specific function optimally.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

Different portions of the metallic sheet member are given different diameters to suit different functional requirements. The insertion portion has a smaller diameter for ease of insertion, while the retention portion has a larger diameter for secure engagement with the cap body, creating local quality variations that solve the contradiction.

Inventive Principle:
Principle #3Local quality

2Reliability

If the outer diameter of the metallic sheet member is increased to prevent separation under reduced pressure, then the reliability of retention is improved, but the sheet member or cap body deforms during insertion

Engineering Contradiction:
Improveretention of sheet memberVSAvoiddeformation during insertion
Core Design Contradiction:
ReliabilityVSManufacturing precision

Solution Approach 1:

The metallic sheet member is segmented into an insertion portion with smaller diameter and a retention portion with larger diameter. This allows the retention portion to prevent separation under reduced pressure while the insertion portion maintains a smaller diameter to avoid deformation during insertion into the cap body.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The sheet member exhibits local quality variations in diameter along its length. The insertion portion has a smaller diameter to prevent deformation during insertion, while the retention portion has a larger diameter to ensure reliable retention, thus avoiding deformation issues while maintaining retention reliability.

Inventive Principle:
Principle #3Local quality

3Reliability

If the metallic sheet member is securely retained in the cap body to prevent separation, then the reliability is improved, but the stopper-opening torque increases

Engineering Contradiction:
Improveretention of sheet memberVSAvoidstopper-opening torque
Core Design Contradiction:
ReliabilityVSForce

Solution Approach 1:

The metallic sheet member is segmented into an insertion portion and a retention portion with different diameters. The retention portion engages with the cap body to prevent separation, while the insertion portion maintains a smaller diameter that reduces friction and resistance during opening, thereby lowering the stopper-opening torque while ensuring reliable retention.

Inventive Principle:
Principle #1Segmentation

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 allows for secure insertion and retention of the metallic sheet member without deformation, maintaining the cap's gas barrier properties and reducing the stopper-opening torque, making it easier to open for users, including the elderly and children.

Implementation Method 1

the annular protruding portion is pressed in an axial direction of the cap body toward the top panel wall and deformed so as to become close to a flat shape, whereby the outer diameter of the sheet member is enlarged

Methodology Applied
Scientific EffectPlastic deformation: Plasticity

Data Source

PatentEP2832657B1Method for manufacturing cap
Publication Date: 2021.05.05 NIPPON CLOSURES
  • EP2832657B1 patent drawingFigure 1
  • EP2832657B1 patent drawingFigure 2~3
  • EP2832657B1 patent drawingFigure 4

AI summary

[Problems to be Solved] There is provided a method for manufacturing a cap, which can insert a sheet member easily into a predetermined position of an upper part inside a cap body, without causing deformation to the sheet member or the cap body, and in which the sheet member does not separate when a container is brought to reduced pressure. [Means to Solve the Problems] An annular protruding portion 50 protruding on a lower surface side is formed in an annular flat region 6c of a sheet member 6 of an inside plug 10. After or at the same time that the sheet member 6 is inserted into and installed at a predetermined position within a cap body 4, the annular protruding portion 50 is pressed axially toward a top panel wall 12 and deformed so as to become close to a flat shape, to enlarge the outer diameter of the sheet member 6. By so doing, the inside plug 10 is held to be inseparable from inside a skirt wall 14 and to be axially movable.