May 20, 2025

US12305943 - Firearm operating mechanisms and bolt release

An operating system for a firearm includes a trigger, a hammer, a disconnector, a pivoting arm, and a lower member. The trigger includes a lower portion, an upper portion, and a trigger pivot. The disconnector includes a lower portion, an upper portion, and a disconnector pivot. The pivoting arm includes a forward protrusion, a pivoting arm opening, and a pin extending through the pivoting arm opening. The lower member includes a lower member opening and a pin hole that is coaxial with the trigger pivot and the disconnector pivot. At least a portion of the trigger and at least a portion of the disconnector are disposed within the lower member opening. Motion of the trigger causes the forward protrusion of the pivoting arm to engage a bolt carrier group and hold the bolt carrier group in an open position.

Inventors: James Matthew Underwood, Larry Cullen Underwood
Filing date: 2023-09-11

firearmmechanismtriggerbolt

This patent describes an innovative operating mechanism for firearms that includes a trigger, hammer, disconnector, and a pivoting arm designed to engage the bolt carrier group, holding it in an open position. The system is structured to fit within the receiver of the firearm, enhancing its operational efficiency and functionality.

Claim 1

An operating system disposed within a receiver of a firearm, the operating system comprising: a trigger; a hammer; a disconnector; a pivoting arm, wherein at least a portion of the pivoting arm is disposed rearward of the hammer; and a lower member, wherein at least a portion of the trigger and at least a portion of the disconnector are disposed adjacent to the lower member, wherein motion of the trigger causes a forward protrusion of the pivoting arm to engage a bolt carrier group of the firearm and hold the bolt carrier group in an open position. a trigger; a hammer; a disconnector; a pivoting arm, wherein at least a portion of the pivoting arm is disposed rearward of the hammer; and a lower member, wherein at least a portion of the trigger and at least a portion of the disconnector are disposed adjacent to the lower member, wherein motion of the trigger causes a forward protrusion of the pivoting arm to engage a bolt carrier group of the firearm and hold the bolt carrier group in an open position.

Google Patents

https://patents.google.com/patent/US12305943

USPTO PDF

https://image-ppubs.uspto.gov/dirsearch-public/print/downloadPdf/12305943