Single-Use Bullet Cartridge with Score Line Primer Bore

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

Reusable bullet casings pose a security risk in conflict zones as they can be collected and reloaded by enemy combatants, necessitating a single-use cartridge solution that cannot be reused.

Innovation Solution

A bullet cartridge design featuring an annular or segmented score line at the cartridge base, which distorts and renders the primer bore unusable upon attempted removal, combined with a heat-resistant adhesive to secure the primer, preventing replacement and ensuring the cartridge cannot be reloaded.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Duration of action of moving object

If brass casings are used to permit reuse of the casing, then the casing can be reused multiple times, but enemy combatants can collect spent shells and reload them to create new ammunition

Engineering Contradiction:

Improvecasing reuse capabilityVSAvoidsecurity risk from enemy reloading

Core Design Contradiction:

Duration of action of moving objectVSObject-affected harmful factors

Solution Approach 1:

The score line is pre-formed in the cartridge base before firing, creating a weakened zone that will fail when the primer is removed after firing. This preliminary structural modification ensures that once the primer is removed (either by enemy reloaders or during normal spent casing processing), the score line causes the cartridge base to fracture or deform, rendering the casing unusable for reloading while maintaining normal functionality during the single use

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The mechanical properties of the cartridge base are changed by introducing the score line, which creates a controlled weakness. The score line alters the structural integrity parameters of the base material, making it susceptible to failure under specific conditions (primer removal) while maintaining sufficient strength for normal handling and firing operations

Inventive Principle:

Principle #35Parameter changes

2Reliability

If polymer materials are used to create deformed single-use cartridges, then the cartridges cannot be reused, but the cost increases significantly making it economically unfeasible

Engineering Contradiction:

Improvesingle-use preventionVSAvoidmanufacturing cost

Core Design Contradiction:

ReliabilityVSEase of manufacture

Solution Approach 1:

The cartridge base is segmented by the score line into distinct zones with different structural integrity. The score line creates a predetermined fracture path that will separate or deform the base structure when triggered, providing single-use functionality through structural segmentation rather than material substitution

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

Instead of using expensive polymer materials to achieve single-use functionality, the invention uses a simple score line feature that can be implemented in conventional metal cartridge manufacturing. This approach creates a disposable cartridge system using inexpensive modifications to traditional metal casings, maintaining economic feasibility while achieving the single-use objective

Inventive Principle:

Principle #27Cheap short-living objects (Disposable)

3Reliability

If a score line is added to the cartridge base to prevent primer removal, then the cartridge cannot be reused, but the score line must not compromise structural integrity before firing

Engineering Contradiction:

Improvesingle-use enforcementVSAvoidcartridge base structural integrity

Core Design Contradiction:

ReliabilityVSStrength

Solution Approach 1:

The score line introduces a localized change in structural quality to the cartridge base, creating a specific weakened zone only where needed for single-use enforcement. The score line is positioned and dimensioned to affect only the primer removal process, while the rest of the cartridge base maintains its full structural integrity for withstanding firing pressures and handling loads

Inventive Principle:

Principle #3Local quality

Data Source

PatentUS11650032B2Single-use shell casing

Publication Date: 2023.05.16 GILMAN STEVEN A

AI summary

A modified bullet cartridge having a score line formed around a primer bore. The score line may be positioned symmetrically or asymmetrically about the primer bore. The score line may have a regular or irregular two-dimensional geometric shape. A modified bullet cartridge having a counter-bore formed superposed about a primer bore. The counter-bore may have a vertical counter-bore extension and/or a radial counter-bore extension. Adhesive is positioned in the counter-bore about a primer secured in the primer bore. The primer may have a radial flange extending radially from an exterior sidewall of the primer. The flange registers against a bottom surface of the counterbore, or within a radial flange extension if present. Adhesive is used to lock the primer flange against the counter-bore and/or radial counter-bore extension. The combination of the counter-bore, adhesive and optionally the flanged primer locks the primer to the bullet cartridge to render the cartridge unusable after one use. The bullet cartridge is rendered waterproof with the use of the adhesive.