US12535306 - Polymer cartridge with snapfit metal insert
The patent describes a high-strength polymer cartridge that incorporates a metal insert designed to enhance structural integrity, with specific thickness relationships among the polymer case and insert components. The design aims to optimize performance by ensuring the case thickness and insert dimensions are tailored to accommodate the projectile’s caliber and ballistic characteristics.
Claim 1
1 . A high strength polymer-based cartridge, comprising: a polymer case, comprising: a first end having a mouth; a neck extending away from the mouth; a shoulder extending below the neck and away from the first end; a body formed below the shoulder and having a case thickness (Tc), comprising: a flat portion comprising a pull thickness (Tp); and a dip, closer to the shoulder than the flat portion and comprising a dip thickness (Tb); an insert directly attached to the polymer case at a second end opposite the first end, comprising: a flat section contacting the flat portion and comprising an insert wall thickness (Ti); and a bulge engaging the dip to maintain the insert on the polymer case; and a projectile disposed in the mouth having a particular caliber; wherein the case thickness, the pull thickness, the dip thickness, and the insert wall thickness are related as follows: Tp+Tb+Ti=Tc; wherein Tp is at least 0.010 inches in thickness; wherein Tb is greater than or equal to Tp; and wherein Tc is a function of the projectile and a ballistic performance for the projectile. a polymer case, comprising: a first end having a mouth; a neck extending away from the mouth; a shoulder extending below the neck and away from the first end; a body formed below the shoulder and having a case thickness (Tc), comprising: a flat portion comprising a pull thickness (Tp); and a dip, closer to the shoulder than the flat portion and comprising a dip thickness (Tb); an insert directly attached to the polymer case at a second end opposite the first end, comprising: a flat section contacting the flat portion and comprising an insert wall thickness (Ti); and a bulge engaging the dip to maintain the insert on the polymer case; and a projectile disposed in the mouth having a particular caliber; a first end having a mouth; a neck extending away from the mouth; a shoulder extending below the neck and away from the first end; a body formed below the shoulder and having a case thickness (Tc), comprising: a flat portion comprising a pull thickness (Tp); and a dip, closer to the shoulder than the flat portion and comprising a dip thickness (Tb); a flat portion comprising a pull thickness (Tp); and a dip, closer to the shoulder than the flat portion and comprising a dip thickness (Tb); an insert directly attached to the polymer case at a second end opposite the first end, comprising: a flat section contacting the flat portion and comprising an insert wall thickness (Ti); and a bulge engaging the dip to maintain the insert on the polymer case; and a flat section contacting the flat portion and comprising an insert wall thickness (Ti); and a bulge engaging the dip to maintain the insert on the polymer case; and a projectile disposed in the mouth having a particular caliber; wherein the case thickness, the pull thickness, the dip thickness, and the insert wall thickness are related as follows: Tp+Tb+Ti=Tc; Tp+Tb+Ti=Tc; wherein Tp is at least 0.010 inches in thickness; wherein Tb is greater than or equal to Tp; and wherein Tc is a function of the projectile and a ballistic performance for the projectile.
Google Patents
https://patents.google.com/patent/US12535306
USPTO PDF
https://image-ppubs.uspto.gov/dirsearch-public/print/downloadPdf/12535306