Firearm and firearm conversion unit

A unit for use with a blowback autoloading pistol of the type consisting of a receiver, a barrel connected with said receiver, and a slide slidably supported on said receiver, said receiver containing a trigger and firing mechanism and a cartridge magazine and forming a hand grip, said slide containing a bolt with a firing pin, and said receiver and slide having cooperating sets of guide surfaces for restraining said slide to longitudinal sliding movement relative to said receiver, said unit being intended for use in converting such blowback autoloading pistol into a gas operated pistol by being connected to said receiver after said barrel and slide are removed therefrom, said unit comprising a shroud, a barrel carried by said shroud and immovable relative to said shroud during successive firings of said gas operated pistol, a gas piston operated bolt carried by said shroud and movable relative to said shroud between open and closed positions with respect to said barrel during successive firings of said gas operated pistol, and means for connecting said unit to said receiver which connecting means includes a set of guide surfaces cooperable with said set of guide surfaces on said receiver to restrain said unit to longitudinal sliding movement relative to said receiver during assemble therewith, and means for holding said unit in a given assembled position along its path of such longitudinal sliding movement relative to said receiver to render said shroud immovable relative to said receiver during successive firings of said gas operated pistol.

A unit for use in converting a blowback autoloading pistol, such as a U.S. caliber .45 model 1911A1, into a gas operated pistol, said unit being adapted to be connected with the receiver of said blowback pistol after its barrel, its slide and the components contained in said slide are removed from the receiver, said unit when so connected with said receiver generally replacing said barrel, said slide, and the components contained in said slide, of said blowback pistol, to form in combination with said receiver a gas operated pistol, said unit comprising a shroud, a barrel carried by said shroud and having forward and rear ends, means connecting said barrel to said shroud so that said barrel is immovable relative to said shroud during successive firings of said gas operated pistol, a bolt slidably supported by said shroud for movement between closed and open positions relative to said rear end of said barrel, said bolt having a forward end which in said closed position of said bolt is located near said rear end of said barrel and which in said open position of said bolt is located further from said rear end of said barrel, means for locking said bolt in its said closed position relative to said shroud and movable between an active condition in which said bolt is held against movement from said closed position and a release condition at which said bolt is free to move relative to said shroud, means providing a piston chamber extending along an axis generally parallel to the longitudinal axis of said barrel, a piston slidable in said piston chamber between forward and rear positions and having a forward end and a rear end, a spring means urging said piston forwardly toward its said forward position, means providing a gas passageway extending between the bore of said barrel and said piston chamber adjacent the forward end of said piston when said piston is in its forward position so that upon firing of a cartridge high pressure gas appearing in said barrel bore is applied to said forward end of said piston driving said piston rearwardly from its said forward position to its said rearward position against the force of said spring means with said spring means thereafter returning said piston to its said forward position, and mechanical drive means connected between said piston and said bolt and said locking means for producing such operation of said bolt and said locking means that as said piston moves rearwardly from said forward position to said rear position during a first part of said rearward piston movement said locking means is moved from its locked to its released condition and during the remainder of said rearward piston movement said bolt is moved from its forward to its rearward position and as said piston moves forwardly from said rear to said forward position during a first part of said forward piston movement said bolt is moved from its rear to its forward position and during the remainder of said forward piston movement said locking means is moved from said released to said locked condition.

A gas operated autoloading firearm comprising a frame, a barrel supported by said frame, a bolt supported on said frame for movement relative to said frame in a direction parallel to the longitudinal axis of said barrel between a closed forward position and an open rearward postion relative to said barrel, means for locking said bolt in said closed position including a locking member carried by said bolt and a locking recess in said frame, said locking member being movable relative to said bolt in a direction generally perpendicular to the path of movement of said bolt between a locking position at which it extends into said locking recess and locks said bolt against movement relative to said frame and a released position at which it is free of said locking recess and releases said bolt from movement relative to said frame, means defining a piston chamber extending along an axis generally parallel to said longitudinal axis of said barrel, a piston slidable in said piston chamber between forward and rear positions, a spring means urging said piston forwardly toward its forward position, means providing a gas passageway between the bore of said barrel and said piston chamber so that upon the firing of a cartridge high pressure gas appearing in said barrel bore is applied to said piston to move it rearwardly against the force of said spring means with said spring means thereafter returning said piston to said forward position, and mechanical drive means connected between said piston and said bolt for operating both said bolt and said locking means in response to movement of said piston.