Rimless Shotshell Hull Design for Reliable Feeding
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Solution Overview
Problem
Conventional shotshell ammunition has a rimmed design that can lead to inconsistent loading and firing issues due to the protruding rim, causing jamming and requiring specific barrel configurations for different types of ammunition, which complicates the use of both lethal and less-lethal rounds in firearms.
Innovation Solution
The development of rimless shotshell ammunition with a hull design featuring a seat surface and a cylindrical side surface extending from the rimless end, allowing for consistent stacking and feeding, and the use of a firearm chamber configured to prevent longitudinal movement, enabling the use of various projectile types without barrel modifications.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If a rimmed hull design is used, then the hull can be mechanically deformed and crimped to close the end, but the protruding rim causes inconsistent loading and firing issues and requires specific barrel configurations
Solution Approach 1:
The patent removes the protruding rim from the hull design, extracting the problematic feature that caused inconsistent loading and firing. The hull is designed with a rimless configuration where the end is closed by deforming the cylindrical portion itself, eliminating the need for a separate rim structure and enabling consistent operation across different barrel configurations.
Solution Approach 2:
The rimless hull design enables the ammunition to be universally compatible with different barrel configurations and firearm types. The standardized rimless structure allows the same hull design to work across multiple applications (lethal and less-lethal rounds) without requiring specific barrel modifications, achieving multi-functionality.
2Reliability
If a rimmed design is used, then the rim can prevent longitudinal forward movement of the hull, but the protruding rim causes jamming and complicates the use of both lethal and less-lethal rounds
Solution Approach 1:
The patent extracts the rim structure that caused positioning issues and jamming problems. Instead of relying on a protruding rim to prevent longitudinal movement, the invention uses a rimless design where the hull's cylindrical portion is deformed to close the end, eliminating the source of adaptability problems while maintaining positioning reliability.
Solution Approach 2:
The patent changes the geometric parameters of the hull by transitioning from a rimmed configuration to a rimless configuration. This parameter change allows the same hull design to accommodate different projectile types (lethal and less-lethal) by varying other parameters like seat surface distance, achieving versatility without compromising positioning.
3Reliability
If the seat surface is located closer to the rim, then the hull is more securely positioned, but the rimless design requires precise control of the cylindrical side surface extension distance
Solution Approach 1:
The patent establishes a specific parameter relationship where the cylindrical side surface extends a predetermined distance from the rimless end to the seat surface. This parameter control enables reliable positioning without requiring a rim, as the precise dimensional control of the cylindrical portion ensures consistent seating and firing performance.
Data Source
AI summary
Shotshell type ammunition includes a hull, a sabot disposed within the hull, and at least one projectile disposed within the sabot. The hull has a rimless first end that includes a primer for firing the ammunition. The hull also has a seat surface for seating the hull against a complementary seat surface in a firing chamber of a firearm. The seat surface is located a distance from an outer end surface of the hull at the rimless first end. The hull further includes an outer cylindrical side surface extending from the rimless first end of the hull to the seat surface of the hull. Methods of fabricating such ammunition include forming such a hull, providing one or more projectiles within a sabot, and disposing the sabot with the one or more projectiles therein at least partially into the hull. Shotgun type firearms are configured for firing such ammunition.