Lead Acid Battery Strap Molding Well Design

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Solution Overview

Problem

Conventional lead acid batteries are limited by the vertical tombstone structure, which restricts the height of the battery plates and increases manufacturing complexity and cost due to additional steps like punching tombstone holes and welding.

Innovation Solution

A lead acid battery design that eliminates the vertical tombstone by using a mold with strap molding wells to form lead straps and terminal posts, allowing for increased battery plate height and reduced manufacturing steps by embedding tabs in molten lead within the mold.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If a vertical tombstone structure is used to connect cells, then cell-to-cell connection is achieved, but the vertical height of battery plates is restricted and manufacturing complexity increases

Engineering Contradiction:
Improvecell-to-cell connectionVSAvoidvertical height of battery plates
Core Design Contradiction:
Ease of operationVSLength of stationary object

Solution Approach 1:

The invention extracts and eliminates the vertical tombstone structure from the battery assembly, replacing it with horizontal lead straps that connect cells at the plate level. This removal of the tombstone component directly resolves the height restriction problem while maintaining cell connectivity through the strap configuration

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

Instead of connecting cells vertically through tombstones as in conventional designs, the invention inverts the connection approach by using horizontal lead straps that connect cells at the plate level. This inversion of the connection geometry eliminates the vertical height constraint while achieving the same cell-to-cell connectivity function

Inventive Principle:
Principle #13The other way round (Inversion)

2Ease of operation

If a vertical tombstone structure is used for cell connection, then connectivity is achieved, but manufacturing steps and production cost increase

Engineering Contradiction:
Improvecell-to-cell connectionVSAvoidmanufacturing steps
Core Design Contradiction:
Ease of operationVSDevice complexity

Solution Approach 1:

The invention merges the functions of cell connection and plate support into a single integrated lead strap structure. This consolidation eliminates the separate tombstone component and its associated manufacturing steps (punching holes, welding), reducing overall device complexity while maintaining connectivity functionality

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The lead straps are pre-formed and positioned during the plate assembly process itself, eliminating the need for subsequent tombstone installation steps. The connection structure is established in advance during plate formation, reducing the number of discrete manufacturing operations required

Inventive Principle:
Principle #10Preliminary action

3Ease of operation

If vertical tombstone is used in battery design, then cell connection is achieved, but battery plate height is limited reducing energy storage capacity

Engineering Contradiction:
Improvecell connectionVSAvoidenergy storage capacity
Core Design Contradiction:
Ease of operationVSQuantity of substance

Solution Approach 1:

By extracting and removing the vertical tombstone structure, the invention frees up vertical space within the battery housing. This additional space allows for increased battery plate height and volume, directly enabling greater energy storage capacity while maintaining cell connectivity through alternative strap configurations

Inventive Principle:
Principle #2Taking out (Extraction)

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 enhances energy storage capacity in the same-sized battery housing by increasing the vertical height of battery plates and simplifies manufacturing by eliminating tombstone-related steps, thereby reducing production costs.

Implementation Method 1

The cast-on mold is cooled, and the lead freezes, encapsulating the tabs 111 of the cell of battery plates 110

Methodology Applied
Scientific EffectFreezing: Freezing

Data Source

PatentEP3149788B1Lead acid battery having a strap molding well
Publication Date: 2020.02.12 EAST PENN MANUFACTURING CO INC
  • EP3149788B1 patent drawingFigure 1
  • EP3149788B1 patent drawingFigure 2
  • EP3149788B1 patent drawingFigure 3

AI summary

A lead acid battery has a housing having a plurality of adjacently positioned battery plate receiving compartments. A cell of battery plates is positioned in each battery plate receiving compartment. Each cell has a plurality of positive plates, each having a positive lug, and a plurality of negative plates interleaved with the positive plates, each having a negative lug. A mold positioned on a top edge of each group of battery plates, and has two strap molding wells, each having a lead receiving space, a well base, and a plurality of lug receiving openings positioned in the well base. The positive lugs of the cell extend through the lug receiving openings in one of the strap molding wells, and the negative lugs of the cell extend through the lug receiving openings in the other strap molding well.