Electrochemical Device Crimp Ring Closure

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Solution Overview

Problem

Conventional button cell batteries and similar electrochemical devices are limited by their circular shape, making them inefficient for non-circular applications where space is premium, and the use of metallic housings can create electrical shorts due to the need for radial force and friction fits, which are costly and not easily adaptable.

Innovation Solution

The use of a crimp ring to secure housing portions with a compressive force, eliminating the need for radial force and incorporating grommets for electrical and fluid isolation to prevent shorts, allowing for non-circular shapes and reduced material strength and cost.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If radial force and friction fit are used to secure housing portions, then electrical contacts are provided and sealing is achieved, but the device is limited to circular shapes and requires strong housing materials

Engineering Contradiction:
ImproveShape adaptabilityVSAvoidHousing material strength
Core Design Contradiction:
Adaptability or versatilityVSStrength

Solution Approach 1:

A crimp ring is introduced as an intermediary component between the first and second housing portions. The crimp ring applies compressive force to secure the housing portions together, replacing the need for radial force between housing portions. This allows the housing portions to be made of less strong, less costly materials while maintaining secure assembly.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The sealing and securing function is divided into separate components: the crimp ring provides compressive force to secure housing portions, while grommets provide sealing and electrical isolation. This segmentation allows each component to be optimized for its specific function, with housing portions needing less strength.

Inventive Principle:
Principle #1Segmentation

2Reliability

If metallic housing portions are used for electrical contacts, then electrical conductivity is provided, but electrical shorts may occur due to contact between housing portions

Engineering Contradiction:
ImproveElectrical isolationVSAvoidEnclosure structure complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

Grommets are used as intermediary components positioned between the first and second housing portions. These grommets provide both sealing and electrical isolation, preventing electrical shorts between the conductive housing portions while maintaining the metallic housing for electrical contacts.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The housing portions maintain metallic conductivity at contact points with the electrochemical module, while grommets are strategically placed at specific locations where electrical isolation is needed. This local differentiation allows electrical conductivity where needed and isolation where required.

Inventive Principle:
Principle #3Local quality

3Adaptability or versatility

If welding is used to secure housing portions, then non-circular shapes are enabled, but manufacturing cost and process complexity increase

Engineering Contradiction:
ImproveShape adaptabilityVSAvoidManufacturing cost
Core Design Contradiction:
Adaptability or versatilityVSEase of manufacture

Solution Approach 1:

The welding process is replaced with a mechanical crimping system. The crimp ring applies compressive force through mechanical action to secure the housing portions, eliminating the need for laser welding or other complex welding processes. This reduces manufacturing cost and process complexity while maintaining shape adaptability.

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

Solution Approach 2:

The method of applying force changes from thermal/welding parameters to mechanical compressive force parameters. The crimp ring system uses mechanical compression rather than heat and fusion, fundamentally changing the manufacturing parameter space to simpler, less costly processes.

Inventive Principle:
Principle #35Parameter changes

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

This solution enables the creation of non-circular electrochemical device enclosures that are more adaptable and cost-effective, with improved electrical and fluid isolation, reducing material strength requirements and manufacturing costs while maintaining effective sealing and electrical contact.

Implementation Method 1

the crimp ring provides a compressive force on the housing portions rather than a radial force

Methodology Applied
Scientific EffectCompressive force: Compression

Implementation Method 2

the use of a metallic crimp ring to secure the housing portions with respect to one another may create a short between the housing portions if the crimp ring is in contact with both housing portions. The enclosure disclosed herein incorporates grommets to provide electrical isolation between both housing portions and between the housing portions and the crimp ring.

Methodology Applied
Scientific EffectElectrical isolation: Electrical Resistance

Implementation Method 3

In addition to electrical isolation, the grommets may also provide fluid isolation between the interior and exterior of the enclosure.

Methodology Applied
Scientific EffectFluid isolation: Semipermeable Membrane

Data Source

PatentEP2915200B1Electrochemical device with crimp ring closure and method
Publication Date: 2019.10.09 MEDTRONIC INC
  • EP2915200B1 patent drawingFigure 1
  • EP2915200B1 patent drawingFigure 2~3
  • EP2915200B1 patent drawingFigure 4a~4b

AI summary

Electrochemical device and method. The electrochemical device has an electrochemical module and an enclosure configured to enclose the electrochemical module. The enclosure has an electrically conductive first housing portion forming a first rim and an electrically conductive second housing portion forming a second rim, the first housing portion and the second housing portion, when the first rim of the first housing portion substantially abuts the second rim of the second housing portion, forming, at least in part, a volume configured to enclose the electrochemical device. The enclosure further has a substantially non-conductive grommet positioned between the first rim and the second rim, and a crimp ring engaging the first rim and the second rim, the crimp ring being configured to secure the first housing portion with respect to the second housing portion. The grommet is further positioned between the crimp ring and the first rim and the second rim.