May 12, 2026

US12624910 - Reduced weapon system blowback

A reloading firearm featuring a mechanism to reduce the blowback of toxic propellant gasses towards the warfighter. The reloading assembly acts in plural segments to increase the firing chamber-closed dwell time, while limiting adverse impact to the overall nominal rate of fire. Greater dwell time corresponds with reduced exposure of the warfighter to propellant gasses. Moreover, increasing the dwell time without otherwise altering the firing cycle has the additional effect of delaying the breech opening after the cartridge is fired. This delay in breech opening permits gas pressure at the muzzle, which may be elevated and/or constrained by flash and/or sound suppression, to dissipate before the breech is opened. Accordingly, when the breech opens later in the firing cycle, there is a reduced pressure gradient across the combination of barrel and firing chamber, which reduces a driving force of propellant gasses towards the warfighter via the open breech.

Assignee: The United States of America as Represented by the Secretary of the Army
Inventors: Adam L. Foltz, Francis J. Battersby, Michael W. Brown
Filing date: 2024-12-13

firearmblowbackreloadingmechanism

The patent describes a reloading firearm mechanism designed to minimize blowback of toxic propellant gases towards the user by increasing the dwell time of the firing chamber. This is achieved through a multi-segmented reloading assembly that delays breech opening, allowing gas pressure to dissipate before the breech is opened, thereby reducing the exposure of the warfighter to harmful gases.

Claim 1

1 . An operating rod apparatus for a reloading firearm, the operating rod apparatus being translatable from a first forward position corresponding with a closed and locked condition of the firearm breech bolt, to a second rearward position corresponding with an open condition of the firearm breech bolt, the operating rod apparatus comprising: a rod stem, the rod stem being operatively connected at a first forward end thereof to a piston for driving the operating rod apparatus, the rod stem having a second end thereof substantially opposite said first end; a cam associated with the second end of the rod stem; a cylinder having a passage that is in fluid communication with a pressure port located along a barrel of the firearm between a first muzzle end thereof, and a second firing chamber end thereof, the fluid communication being operative to admit propellant gasses of the firearm into the cylinder forward of the piston; an operating tube that is in sliding engagement with the rod stem, the operating tube having a forward first end and a second end substantially opposite the first end, the second end of the operating tube being operatively connected to a bolt carrier mechanism of the reloading firearm; a rod sear that is movable between a first position that constrains movement of the operating tube, and a second position that frees the operating tube to translate; an elastic bias that urges the rod sear into the first position thereof, and is overcome by the action of the cam associated with the second end of the rod stem, said cam displacing the rod sear into the second position thereof; and a return spring biasing the operating rod apparatus towards the first forward position thereof. a rod stem, the rod stem being operatively connected at a first forward end thereof to a piston for driving the operating rod apparatus, the rod stem having a second end thereof substantially opposite said first end; a cam associated with the second end of the rod stem; a cylinder having a passage that is in fluid communication with a pressure port located along a barrel of the firearm between a first muzzle end thereof, and a second firing chamber end thereof, the fluid communication being operative to admit propellant gasses of the firearm into the cylinder forward of the piston; an operating tube that is in sliding engagement with the rod stem, the operating tube having a forward first end and a second end substantially opposite the first end, the second end of the operating tube being operatively connected to a bolt carrier mechanism of the reloading firearm; a rod sear that is movable between a first position that constrains movement of the operating tube, and a second position that frees the operating tube to translate; an elastic bias that urges the rod sear into the first position thereof, and is overcome by the action of the cam associated with the second end of the rod stem, said cam displacing the rod sear into the second position thereof; and a return spring biasing the operating rod apparatus towards the first forward position thereof.

Google Patents

https://patents.google.com/patent/US12624910

USPTO PDF

https://image-ppubs.uspto.gov/dirsearch-public/print/downloadPdf/12624910