Tamper-Evident Closure With Irreversible Ratchet Locking
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Solution Overview
Problem
Existing tamper-evident closure systems can be defeated by reversing the tamper-evidence mechanism, and they often rely on obstructing members that can be cut to restore the original state, or they lack a reliable seal to preserve contents.
Innovation Solution
A tamper-evident closure system with a compressible stopper and a ratchet arrangement that irreversibly locks the closure in a second position after opening, forming an unobstructed gap, and incorporating a line of weakness that breaks if reverse rotation is attempted, ensuring the gap cannot be closed and providing an effective seal.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a gap is generated between two parts to indicate opening, then tamper-evidence is provided, but the gap can be closed by cutting the obstruction member or reversing the mechanism
Solution Approach 1:
The closure is divided into two separate parts (first part and second part) that can be relatively moved to generate a gap. The first part includes an inner part and outer part, while the second part is separate. This segmentation allows the gap to be generated without requiring a complex obstruction member, as the gap is created by the relative movement of the parts themselves.
Solution Approach 2:
The locking means is designed to automatically engage and lock the closure in the second position (with gap) once the opening action is completed. The ratchet arrangement is pre-configured to prevent reverse movement, so no additional locking action is needed after the gap is generated. This preliminary design of the locking mechanism ensures reliability without adding complexity.
2Reliability
If an obstructing member is used to hold parts apart, then the gap is maintained, but the member can be cut to allow gap closure
Solution Approach 1:
The traditional obstructing member is completely removed from the design. Instead of using a separate member to hold parts apart, the gap is maintained by the relative positioning of the first and second parts themselves, which are held in place by the locking means. This extraction of the obstructing member eliminates the vulnerability to cutting while maintaining gap integrity.
Solution Approach 2:
The locking means acts as an intermediary mechanism between the first and second parts, preventing them from returning to their original positions. The ratchet arrangement provides this mediating function, allowing the gap to be maintained without requiring a physical obstructing member that could be cut.
3Reliability
If a seal is added to preserve contents, then protection is improved, but the closure structure becomes more complex
Solution Approach 1:
The sealing function is merged with the existing first part of the closure. The stopper is integrated into the first part, which already contains the inner and outer parts with the ratchet arrangement. By combining the sealing function with the existing structure, no separate complex sealing mechanism is added, thus maintaining structural simplicity while improving content protection.
Solution Approach 2:
The first part serves multiple functions: it provides the structural framework for the gap generation, contains the locking means for maintaining the gap, and incorporates the stopper for sealing. This multi-functionality reduces the need for separate components, thereby reducing overall structural complexity while achieving comprehensive protection.
4Reliability
If a ratchet arrangement is used to prevent reverse rotation, then tamper-evidence is maintained, but sufficient torque can still overcome the ratchet
Solution Approach 1:
The line of weakness is pre-configured in the first part, specifically in the inner part. When reverse rotation is applied, this pre-placed line of weakness breaks at a controlled location, preventing the ratchet from being overcome. This preliminary design ensures that reverse operation is blocked not by strength, but by a predetermined failure point that activates under reverse torque.
Solution Approach 2:
The potential harm of reverse torque that could overcome the ratchet is converted into a beneficial tamper-evidence mechanism. The reverse torque that would normally be needed to defeat the ratchet instead triggers the break in the line of weakness, which is the desired tamper-evidence effect. The harmful reverse torque becomes the activating force for the security mechanism.
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 closure system effectively prevents re-filling by ensuring the gap remains open and provides a secure seal, making it tamper-proof and resistant to reverse operation, while maintaining the integrity of the container's contents.
Implementation Method 1
a compressible stopper for sealing the second portion and/or the container
Implementation Method 2
the first portion comprises locking means for irreversibly locking the closure in the second position upon first opening
Data Source
AI summary
A tamper-evident closure for a container. The closure comprises a first portion including inner and outer parts, and a second portion. The outer part is rotatable relative to the inner part from a first position in which at least part of the first and second portions are adjacent each other to a second position in which there is a gap therebetween. The first portion comprises a locking mechanism for irreversibly locking the closure in the second position upon first opening so that the gap cannot be closed, in which the first portion comprises a compressible stopper for sealing the second portion and/or the container. A tamper-evident closure in combination with a container.