RFID Ear Tag Transponder Locking Mechanism

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Solution Overview

Problem

Ear tag manufacturers face challenges in producing RFID tags due to complexity and the need for new injection machines, particularly those with horizontal injection machines, as they struggle to maintain quality and competitiveness while minimizing investment, and existing assembly processes risk damaging transponders during the overmolding process.

Innovation Solution

The design incorporates a separate washer with special dents or extensions that acts as a locking mechanism to maintain the transponder in the housing without glue, allowing for stress-free assembly and compatibility with conventional injection machines, enabling manual or automated production without additional investment.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the transponder is squeezed inside the housing during assembly, then the transponder is maintained in position, but the coil may be damaged and production yield becomes unstable

Engineering Contradiction:
Improvetransponder positioning stabilityVSAvoidcoil damage risk
Core Design Contradiction:
ReliabilityVSObject-affected harmful factors

Solution Approach 1:

A separate washer is introduced as an intermediary component between the transponder and the housing. The washer features locking extensions that engage with slots in the transponder, providing a mechanical locking mechanism that secures the transponder in position without applying damaging compression forces to the coil.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The housing is divided into functional segments: a main housing body, a separate washer component with locking extensions, and a cover. This segmentation allows the washer to specifically handle the transponder positioning function while the housing provides structural support, enabling precise positioning without compromising the transponder.

Inventive Principle:
Principle #1Segmentation

2Reliability

If a separate washer with locking extensions is used to maintain the transponder, then the transponder is secured without damage risk, but the device complexity increases

Engineering Contradiction:
Improvetransponder positioning stabilityVSAvoidnumber of components
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The washer is designed to combine multiple functions: it serves as both a positioning element and a locking mechanism. The locking extensions integrate the securing function directly into the washer structure, eliminating the need for separate fasteners or additional positioning components.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The washer serves multiple purposes: it positions the transponder, locks it in place through engaging extensions, and provides a mounting interface for the cover. This multi-functionality reduces the overall component count compared to using separate elements for each function.

Inventive Principle:
Principle #6Universality (Multi-functionality)

3Reliability

If ultrasonic welding and gluing processes are used for assembly, then the transponder can be attached to the housing, but additional equipment investment and quality maintenance difficulties arise

Engineering Contradiction:
Improvetransponder attachment strengthVSAvoidassembly equipment requirements
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The invention replaces chemical bonding (glue) and ultrasonic welding processes with a purely mechanical locking system. The locking extensions of the washer engage with slots in the transponder through simple mechanical insertion, eliminating the need for dispensing equipment, ultrasonic welders, and associated quality control systems.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

4Object-affected harmful factors

If the transponder is left loose in the housing during overmolding, then the coil is not damaged, but the transponder may fall down or move during injection

Engineering Contradiction:
Improvecoil stressVSAvoidtransponder position stability
Core Design Contradiction:
Object-affected harmful factorsVSReliability

Solution Approach 1:

The washer with locking extensions is installed in the housing before the overmolding process. This preliminary action secures the transponder in the correct position beforehand, preventing it from moving or falling during the subsequent injection process while avoiding direct contact between the molten material and the transponder.

Inventive Principle:
Principle #10Preliminary action

Data Source

PatentEP2848116B1RFID ear tag
Publication Date: 2020.04.22 ASSA ABLOY AB
  • EP2848116B1 patent drawingFigure 1~2
  • EP2848116B1 patent drawingFigure 3~4

AI summary

The RFID tag part comprises at least a housing (2) to house a transponder (1), and a washer (3) to maintain said transponder in said housing first part.