Tamper-Proof Seal Assembly Using Composite Rivet Locking

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Solution Overview

Problem

Existing meter seals, such as those used for gas, electricity, and water meters, face challenges in providing effective tamper protection while complying with RoHS directives and resisting environmental influences, as traditional lead seals are banned and plastic seals are vulnerable to tampering and degradation.

Innovation Solution

A tamper proof locking mechanism using a tubular rivet with a plastic-like material embedded in a rivet structure, which is embossed with a pattern to indicate tampering, and a flanged end to prevent removal, combined with a collar for added security, ensuring easy assembly and high tamper resistance.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If traditional lead seals are used, then tamper protection is effective, but RoHS compliance is violated

Engineering Contradiction:
Improvetamper protectionVSAvoidRoHS compliance
Core Design Contradiction:
ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The patent changes the material parameter from lead to a combination of metal rivet and plastic-like material, maintaining tamper protection while achieving RoHS compliance. The metal rivet provides structural strength and the plastic-like material provides tamper evidence, together replacing the functionality of lead seals without using hazardous substances.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent uses a composite structure combining metal rivet and plastic-like material. The metal rivet embedded in the plastic-like material creates a composite seal that leverages the strengths of both materials: metal provides durability and rigidity, while plastic provides tamper evidence and environmental resistance, achieving both security and compliance.

Inventive Principle:
Principle #40Composite materials

2Object-affected harmful factors

If plastic seals are used, then RoHS compliance is achieved, but tamper resistance and environmental durability deteriorate

Engineering Contradiction:
ImproveRoHS complianceVSAvoidtamper resistance
Core Design Contradiction:
Object-affected harmful factorsVSReliability

Solution Approach 1:

The patent combines metal rivet and plastic-like material to create a composite seal. The metal rivet embedded in the plastic-like material provides the structural strength and tamper resistance that pure plastic lacks, while the plastic component maintains RoHS compliance and environmental durability. This composite approach resolves the weakness of plastic seals.

Inventive Principle:
Principle #40Composite materials

Solution Approach 2:

The patent applies different material properties to different parts of the seal: the metal rivet is used in the critical load-bearing and tamper-resistant regions, while the plastic-like material is used in regions requiring environmental resistance and tamper evidence. This local differentiation of material quality optimizes both tamper resistance and compliance.

Inventive Principle:
Principle #3Local quality

3Reliability

If complex sealing mechanisms are used, then tamper protection is improved, but assembly difficulty increases

Engineering Contradiction:
Improvetamper protectionVSAvoidassembly ease
Core Design Contradiction:
ReliabilityVSEase of operation

Solution Approach 1:

The seal assembly is designed to be self-servicing through the hand-assembly capability. The rivet structure with its embedded plastic-like material allows workers to assemble the seal directly by hand without requiring specialized tools or complex procedures, simplifying the assembly process while maintaining strong tamper protection through the inherent design of the rivet-seal integration.

Inventive Principle:
Principle #25Self-service

Data Source

PatentEP3857006B1Tamper proof seal assembly
Publication Date: 2025.11.05 HONEYWELL INTERNATIONAL INC
  • EP3857006B1 patent drawingFigure 1
  • EP3857006B1 patent drawingFigure 2
  • EP3857006B1 patent drawingFigure 3

AI summary

A tamper proof locking mechanism incorporating a first fixture for attachment to an index protective cover, a second fixture for attachment to an instrument, and a third fixture for connecting the first fixture to the second fixture. The first fixture may have a receptacle, the second fixture may have a plate with an opening, and the third fixture may have a protrusive structure that fits into the receptacle of the first fixture and into the opening in the plate to connect the first fixture to the second fixture. The protrusive structure may have a rivet that is partially embedded with a plastic-like material that reveals tampering when an attempt is made to break a connection between the first fixture and the second fixture.