Patent ID: 7975596
Filing Date: 2011-07-12
Classification: F41A

Abstract:
1. In combination, a firearm having an upper receiver, an operating rod operably associated with said upper receiver for movement between a first position and a second position, a lower receiver connected to said upper receiver, a trigger mechanism carried by said lower receiver and a magazine connected to said lower receiver for carrying a plurality of ammunition cartridges, the improvement comprising: (a) a barrel connected to said upper receiver, said barrel having a rear portion having a guide slot and a curved bearing surface and an intermediate portion having a gas transfer passageway formed therein; (b) a generally semi-circular receiver bearing formed in said upper receiver; (c) a bolt slidably received within said upper receiver for movement between a first forward position and a second rearward position, said bolt having a longitudinally extending guide slot; (d) a firing pin carried by said bolt for movement between a first position and a second position; (e) a striker connected to said bolt for movement between a first position and a second position in engagement with said firing pin; (f) a locking member removably connected to said upper receiver for movement relative thereto between a first bolt engaging position and a second bolt disengage position, said locking member having a rearward portion, a central portion having a locking shoulder and a curved forward portion received within said generally semi-circular bore of said upper receiver and within said curved bearing surface of said barrel; (g) locking member biasing means carried by said upper receiver for urging said locking member into said first bolt engaging position; and (h) a disengage member slidably received within said longitudinally extending guide slot of said bolt and within said guide slot of said barrel for movement by said operating rod between a first position and a second position, said disengage member having a wall for engagement with said locking member to move said locking member into said bolt disengage position upon movement of said disengage member to said second position.