Battery Housing Reverse Polarity Protection

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Solution Overview

Problem

Conventional battery housings require additional machining time and cost due to integral ground posts and metal end caps, and involve complex soldering processes, as well as costly overmolding and inspection processes.

Innovation Solution

A battery housing design featuring a contact cage, a compressible spring forming a positive terminal, and an insulating cup, which reduces the number of parts, eliminates the need for metal end caps, and simplifies terminal formation through electric resistance welding and injection molding.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Strength

If conventional battery housings use integral ground posts and metal end caps, then structural strength and electrical grounding are improved, but manufacturing cost and complexity increase due to additional machining, soldering, and overmolding processes

Engineering Contradiction:

Improvestructural strengthVSAvoidmanufacturing complexity

Core Design Contradiction:

StrengthVSDevice complexity

Solution Approach 1:

The patent combines the ground post and end cap functions into a single molded plastic component. The contact cage assembly integrates the insulating cup, spring contact, and ground post structure into one unit that is molded directly into the battery housing, eliminating the need for separate metal end caps and reducing assembly steps.

Inventive Principle:

Principle #5Merging (Combining)

Solution Approach 2:

The patent replaces metal machining and soldering processes with injection molding and electric resistance welding. The ground post is formed through molding rather than machining, and electrical connections are made through resistance welding instead of traditional soldering, simplifying the manufacturing process.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

2Reliability

If conventional battery housings use integral ground posts and metal end caps, then electrical grounding and terminal formation are improved, but manufacturing time and cost increase

Engineering Contradiction:

Improveelectrical groundingVSAvoidmanufacturing efficiency

Core Design Contradiction:

ReliabilityVSProductivity

Solution Approach 1:

The patent performs preliminary action by forming the ground post and contact structures through injection molding before final assembly. The contact cage is pre-assembled with the spring and insulating cup, then molded into the housing in one operation, reducing subsequent assembly time and improving manufacturing efficiency.

Inventive Principle:

Principle #10Preliminary action

3Reliability

If conventional battery housings use complex soldering processes for terminal formation, then electrical connections are improved, but manufacturing cost and complexity increase

Engineering Contradiction:

Improveelectrical connectionsVSAvoidmanufacturing ease

Core Design Contradiction:

ReliabilityVSEase of manufacture

Solution Approach 1:

The patent replaces traditional soldering processes with electric resistance welding for forming electrical connections. The spring contact and ground post are welded directly to the battery terminals through molded contacts, eliminating the need for separate soldering operations and simplifying manufacturing.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

4Object-affected harmful factors

If conventional battery housings require overmolding and inspection processes, then environmental sealing is improved, but manufacturing cost and time increase

Engineering Contradiction:

Improveenvironmental sealingVSAvoidmanufacturing speed

Core Design Contradiction:

Object-affected harmful factorsVSProductivity

Solution Approach 1:

The patent combines the sealing function with the structural housing in a single injection molding operation. The contact cage assembly is molded directly into the battery housing with integrated sealing features, eliminating separate overmolding steps and reducing manufacturing complexity while maintaining environmental protection.

Inventive Principle:

Principle #5Merging (Combining)

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 design reduces manufacturing costs and time, simplifies terminal formation, and provides effective reverse polarity protection and environmental sealing while maintaining electrical contact during shock and vibration.

Implementation Method 1

a compressible spring forming a positive terminal

Methodology Applied

Scientific EffectElasticity: Elasticity

Implementation Method 2

simplifies terminal formation through electric resistance welding

Methodology Applied

Scientific EffectElectric resistance welding: Welding

Data Source

PatentUS9269943B1Battery housing with reverse polarity protection

Publication Date: 2016.02.23 ELBIT SYSTEMS OF AMERICA LLC

AI summary

A battery housing includes a contact cage forming a longitudinal cylindrical enclosure having a lateral opening. A leaf spring is included having first and second compressible ends, in which the first end is received by the contact cage through the lateral opening. A longitudinal insulating cup is also included having opposing cylindrical openings, in which the second compressible end of the leaf spring is received by the insulating cup through one of the cylindrical openings. The leaf spring forms a positive terminal in the battery housing and is held in position by the contact cage and the insulating cup.