Polygonal Cartridge Case for Non-Lethal Projectile Spin
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Solution Overview
Problem
Existing non-lethal firearms and cartridges face issues such as unintentional lethality, lack of precision, ineffectiveness against protected subjects or multiple threats, and logistical challenges, including reliability and maintenance issues with air or gas-based systems, as well as complexities with live ammunition loading.
Innovation Solution
A low energy cartridge design featuring a case with a polygonal interior to impart spin to a non-circular projectile, combined with a propellant system and actuator, ensuring consistent and controlled propulsion, and a mechanism to prevent accidental chambering of live ammunition, utilizing a custom firing pin or electronic activation to enhance safety and precision.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If air or gas based systems are used to propel projectiles, then the system can achieve non-lethal velocity, but the system becomes unreliable due to seals and O rings drying out and performance varying with ambient temperature
Solution Approach 1:
The patent replaces air/gas based propulsion systems with a solid propellant system. The cartridge uses a propellant charge contained in a propellant receptacle that generates gas pressure through combustion to propel the projectile, eliminating seals and O rings that dry out. This mechanical substitution resolves the reliability issue while maintaining controlled velocity through propellant formulation.
Solution Approach 2:
The patent changes the physical and chemical parameters of the propulsion system by using solid propellant with controlled burn rates. The propellant's energy release characteristics are engineered to provide consistent muzzle velocity across varying ambient temperatures, resolving the temperature sensitivity issue of gas-based systems.
2Ease of operation
If conventional cartridges are used in firearms, then the firearm can fire projectiles, but there is risk of inadvertent loading of live rounds when the user believed they were loading a less-lethal cartridge
Solution Approach 1:
The patent employs asymmetric case design where the cartridge case has a polygonal cross-section (e.g., hexagonal) rather than the conventional circular shape. This asymmetric geometry provides visual and physical differentiation from live ammunition, allowing users to quickly identify less-lethal cartridges and preventing inadvertent loading. The asymmetric case shape is maintained throughout the cartridge assembly.
Solution Approach 2:
The patent implements preliminary protective measures by designing the cartridge with inherent safety features including the asymmetric case shape that prevents misidentification, and a primerless construction that eliminates the risk of accidental discharge. These preliminary anti-actions prevent the harmful effect of unintentional lethality before it can occur.
3Manufacturing precision
If a projectile is fired without rotational engagement features, then the cartridge structure is simpler, but the projectile may tumble in flight resulting in reduced accuracy and effectiveness
Solution Approach 1:
The patent uses the asymmetric polygonal case cross-section to rotationally engage the projectile, which has a matching asymmetric cross-section. This engagement feature imparts spin to the projectile during firing, preventing tumbling and improving accuracy. The asymmetric geometry serves dual purposes: identification and rotational stabilization.
Solution Approach 2:
The patent merges the identification function (asymmetric case shape) with the rotational engagement function (polygonal interior surfaces). This combination eliminates the need for separate spin-imparting mechanisms while achieving both user identification and projectile stabilization, reducing overall device complexity.
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
The solution provides a consistent, controlled non-lethal projectile velocity with improved accuracy and reliability, addressing the limitations of existing systems by preventing tumbling and enhancing ballistic stability, while ensuring safety through prevention of accidental live ammunition discharge.
Implementation Method 1
a propellant charge in a propellant receptacle with a passage communicating with the projectile receptacle
Implementation Method 2
a case having a sidewall with an interior surface defining a projectile receptacle... a projectile having an exterior sidewall closely received in the projectile receptacle... At least one of the projectile and the sidewall interior surface may have a helical surface feature, such that spin is imparted to the projectile upon propulsion from the case
Data Source
AI summary
A low energy cartridge has a case having a sidewall with an interior surface defining a projectile receptacle along a bore axis and having a forward open case mouth, a projectile having an exterior sidewall closely received in the projectile receptacle and defining a rotational axis, a propellant receptacle defined by the case and having a passage communicating with the projectile receptacle, the projectile exterior sidewall being non-circular in cross section across the rotational axis, and the case sidewall interior surface having a rotational engagement feature configured to rotationally engage the non-circular projectile exterior sidewall. The projectile may be slidably received in the projectile receptacle for propulsion from the forward open case mouth. At least one of the projectile and the sidewall interior surface may have a helical surface feature, such that spin is imparted to the projectile upon propulsion from the case.