GAS SYSTEM FOR AUTOLOADING FIREARM

• US 3,592,101 A
• Filed: 04/21/1969
• Issued: 07/13/1971
• Est. Priority Date: 04/21/1969
• Status: Expired due to Term

• Current Assignee: US Repeating Arms Co (Government of France)
• Original Assignee: Edwin S. Vartanian, Jay P. Jarvis
• Inventors: Vartanian, Edwin S., Jarvis, Jay P.
• Application Number:
  US04/817,770
• Time in Patent Office: 813 Days
• US Class Current: 89/193
• CPC Class Codes: F41A 5/26 Arrangements or systems for bleeding the gas from the barrel F41A5/20 - F41A5/24 take precedence

Abstract

A gas system for an autoloading firearm wherein the gas piston is operative to seal the gas cylinder against high-pressure combustion gases during early stages of recoil of the firearm after firing thereof. As the force of recoil decreases, the seal is broken and lower pressure gases are bled into the gas cylinder to actuate the gas system.

Claims

1. In an autoloading firearm having a receiver and a barrel with a bore rigidly connected to the receiver, a gas system for operating the action of the firearm, said gas system comprising:

a. a gas cylinder rigidly secured to the barrel, said gas cylinder including a gas chamber having a cylindrical sidewall;

b. port means iNterconnecting said gas chamber and the barrel bore, said port means opening into said gas chamber in an area completely contained within said gas chamber sidewall, said port means being operative to bleed pressurized combustion gases from the barrel bore to said gas chamber;

c. shoulder means in said gas chamber and overlying a portion of said port means opening;

d. piston means having a working face and slidably mounted in said gas chamber, said piston means being movable into abutting contact with said shoulder means; and

e. inertia body means operative to force said piston means against said shoulder means during recoil to substantially seal said port means from said gas chamber.

2. The gas system of claim 2, further comprising passage means operative to continuously provide venting of said gas chamber to control energy input in said gas chamber.

3. The gas system of claim 1, wherein said gas cylinder further includes a void adjacent said port means opening, and bounded on one end by a transverse end wall of said gas chamber, and bounded on the other end by said working face of said piston.

4. In an autoloading firearm having a receiver and a barrel with a bore rigidly connected to the receiver, a gas system for operating the action of the firearm, said gas system comprising:

a. a gas cylinder rigidly secured to the barrel, said gas cylinder having a gas chamber with a cylindrical sidewall;

b. port means opening into said cylindrical sidewall and interconnecting said gas chamber with the barrel bore;

c. plug means rigidly secured to one end of said gas cylinder and extending into said gas chamber, said plug means including an inner portion overlying a part of said port means opening and defining a shoulder;

d. piston means slidably mounted in said gas chamber in sealing engagement with said cylindrical sidewall, said piston means being movable into abutting contact with said shoulder; and

e. inertia body means movably mounted on said firearm and operative to force said piston means against said shoulder during recoil to substantially seal said port means from said gas chamber.

5. The gas system of claim 4, wherein said plug means is hollowed out to form a void adjacent said port means opening and bounded on one end by said piston means.

6. The gas system of claim 4, further comprising passage means through said plug means operative to continuously vent said gas chamber to control energy input in said gas chamber.

7. In a system for operating the action of an autoloading firearm having a receiver, said system comprising:

a. a barrel having a bore rigidly secured to said receiver;

b. bolt means slidably mounted in said receiver for movement between a battery position and a retired position;

c. means operative to lock said bolt means to the receiver when said bolt means is in its battery position;

d. slide arm means connected to said bolt means;

e. gas cylinder means rigidly connected to said barrel, said gas cylinder means having a gas chamber with a cylindrical sidewall;

f. port means opening into said cylindrical sidewall and interconnecting said barrel bore with said gas chamber;

g. shoulder means in said gas chamber and overlying a portion of said port means opening;

h. piston means slidably mounted in said gas chamber, said piston means being movable into abutting contact with said shoulder means; and

i. inertia block means slidably connected to said slide arm means, said inertia block means being operative to force said piston means against said shoulder means during recoil to substantially seal said port means from said gas chamber.