Gas Piston Compresses Breech Opening Spring Patents (Class 89/192)
  • Patent number: 10480876
    Abstract: A firearm including a barrel, receiver, indirect gas system and an adjustable gas block designed to interface with the indirect gas system is provided. Four indexable positions of adjustment are provided for on the adjustable gas block. Positions of adjustment are selected based on the use of a silencer, use of under-powered ammunition, the presence of un-burnt powder and debris in the host firearms operating system, or if the weapon is being fired under “ideal” circumstances. The provided gas block is designed to function with an indirect gas operating system. Excess gas from the operating system is not vented from the gas block thereby generating excess flash and sound. No tool is required to manipulate the adjustment mechanism of the gas.
    Type: Grant
    Filed: July 23, 2018
    Date of Patent: November 19, 2019
    Assignee: LWRC International LLC
    Inventor: Jesus S. Gomez
  • Patent number: 10036603
    Abstract: A gas operated firearm includes a barrel with an integrally formed gas block as one piece with the barrel. A barrel nut is assembled over the integral barrel and gas block, securing the rear barrel end to a firearm receiver. Gas tube or piston assembly and field replacement are enhanced, along with accommodation of increased size barrels and integral muzzle end devices, no longer limited by internal dimensions of separately added gas blocks.
    Type: Grant
    Filed: October 21, 2015
    Date of Patent: July 31, 2018
    Assignee: Maranli Automation, Inc.
    Inventor: Hasan Maranli
  • Patent number: 9303932
    Abstract: A firearm including a barrel, a bolt, a piston, a connecting arm, a rear gas port, a rear piston area, a forward gas port having a greater diameter than the rear gas port, a forward piston area, and an ammunition cartridge including a primer, powder and a bullet; the propellant gas from the explosion of the cartridge first exerting pressure from the rear piston area to keep the bolt in a forward position after firing of the bullet; when the bullet approaching the barrel exit, the forward gas port's larger diameter in comparison to the rear gas port allowing the propellant gas pressure from the forward piston area to overpower the propellant gas pressure from the rear piston area, forcing the piston and the bolt rearward, the bolt in its rearward movement functioning to extract and eject the empty cartridge from the firearm after barrel pressure returns to near ambient.
    Type: Grant
    Filed: November 6, 2014
    Date of Patent: April 5, 2016
    Assignee: The United States of America as represented by the Secretary of the Army
    Inventor: Paul T. Jackson
  • Patent number: 9282734
    Abstract: An adjustable shooting rail device retrofittable to a conventional hunting stand or hunting blind. The device includes an adjustment mechanism having an actuator that is pivotally secured between a shooting rail and a vertical member of the hunting stand. The device further includes a pair of support collars pivotally coupling the actuator between the shooting rail and the vertical member. A locking means is provided for releasably locking the shooting rail at a selectively-desired vertical position.
    Type: Grant
    Filed: May 13, 2014
    Date of Patent: March 15, 2016
    Inventor: Stanley M Clary
  • Patent number: 8813632
    Abstract: An adjustable firearm gas block has a gas channel intersected by a threaded bore. A set screw with longitudinal slots is driven through the bore until it enters and constricts the gas channel. A second bore, parallel to the first bore, is connected to the first bore by a passage. A spring and a detent plunger having a slanted notch are inserted in the second bore with a bearing located in the slanted notch and passage. When the detent plunger is in a resting position, it presses the bearing into a longitudinal slot, preventing the set screw from turning. When the detent plunger is urged away from the resting position, the bearing disengages the longitudinal slot, traveling into the slanted notch and allowing the set screw to rotate, thereby adjusting the gas pressure emitted by the gas block.
    Type: Grant
    Filed: July 19, 2012
    Date of Patent: August 26, 2014
    Inventor: Jason Mark Adams
  • Patent number: 8800423
    Abstract: A gas-operated semi-automatic rifle having a barrel group, a receiver group, a bolt group, a stock group, a trigger group, and a magazine group. The barrel group includes a gas-operated operating rod, the operating rod further including a follower rod, the operating rod being biased away from the follower rod. The receiver group includes a receiver body. A cavity is formed in a forward portion of the receiver body, the cavity being sized and shaped to receive and movably retain a proximal end of the follower rod.
    Type: Grant
    Filed: December 10, 2011
    Date of Patent: August 12, 2014
    Inventor: Mark Anthony Lammers
  • Patent number: 8783160
    Abstract: An indirect gas operating system for a semi-automatic or automatic rifle is provided, the indirect gas operating system having: a gas block secured to the rifle; a barrel secured to the rifle; a bolt carrier slidably received within a receiver of the rifle; a means for moving the bolt carrier within the receiver using gases discharged into a bore of the barrel of the rifle, wherein the means for moving is removably secured to the gas block such that the means for moving can be removed from the rifle through a forward end of the gas block without removing the gas block from the rifle; and an externally threaded barrel nut for securing the barrel to the receiver.
    Type: Grant
    Filed: August 12, 2013
    Date of Patent: July 22, 2014
    Assignee: Colt's Manufacturing Company LLC
    Inventors: Paul Hochstrate, Laurance Robbins, Arthur F. Daigle
  • Publication number: 20140076149
    Abstract: An adjustable firearm gas block has a gas channel intersected by a threaded bore. A set screw with longitudinal slots is driven through the bore until it enters and constricts the gas channel. A second bore, parallel to the first bore, is connected to the first bore by a passage. A spring and a detent plunger having a slanted notch are inserted in the second bore with a bearing located in the slanted notch and passage. When the detent plunger is in a resting position, it presses the bearing into a longitudinal slot, preventing the set screw from turning. When the detent plunger is urged away from the resting position, the bearing disengages the longitudinal slot, traveling into the slanted notch and allowing the set screw to rotate, thereby adjusting the gas pressure emitted by the gas block.
    Type: Application
    Filed: July 19, 2012
    Publication date: March 20, 2014
    Inventor: Jason Mark Adams
  • Patent number: 8505433
    Abstract: An indirect gas operating system for a semi-automatic or automatic rifle is provided, the indirect gas operating system having: a sleeve removably secured to a forward end of a gas block of the rifle; a piston slidably received within the gas block, wherein the gas block and the sleeve fluidly couple the piston to a bore of a barrel of the rifle; wherein an increase in pressure in the bore of the rifle causes the piston to move away from the sleeve; and wherein the sleeve and the piston are each capable of being removed from the rifle through the forward end of the gas block.
    Type: Grant
    Filed: February 17, 2012
    Date of Patent: August 13, 2013
    Assignee: Colt Defense, LLC
    Inventors: Paul Hochstrate, Laurance Robbins, Arthur F. Daigle
  • Patent number: 8307750
    Abstract: A gas operated autoloading firearm having an improved bolt carrier. The gas piston system may include a barrel defining a longitudinally-extending bullet pathway, a gas block defining a piston bore, a passageway fluidly connecting the bore with the bullet pathway for diverting combustion gas to the bore upon discharging the firearm, and a piston slidably disposed in the bore for reciprocating movement. The piston actuates a reciprocating bolt assembly including a bolt carrier slidably received in a receiver. The bolt carrier includes supporting and guiding surfaces configured to reduce receiver wear and bolt carrier drag.
    Type: Grant
    Filed: May 12, 2010
    Date of Patent: November 13, 2012
    Assignee: Sturm, Ruger & Company, Inc
    Inventors: Brian Vuksanovich, Todd Wilkinson
  • Patent number: 8117958
    Abstract: A semi-automatic or automatic rifle is provided the rifle having: a receiver having a hand guard portion; a barrel having a bore, the bore removably connected to the receiver, the hand guard portion surrounding at least a portion of the barrel; a gas block having a forward end and a rearward end aligned with the barrel; a sleeve removably secured to the forward end of the gas block; a piston slidably received within the gas block, wherein the gas block and the sleeve fluidly couple the piston to the bore of the barrel; wherein an increase in pressure in the bore of the barrel causes the piston to move away from the sleeve; and wherein the sleeve and the piston are each capable of being removed from the rifle through the forward end of the gas block without removing the gas block from the rifle.
    Type: Grant
    Filed: May 9, 2011
    Date of Patent: February 21, 2012
    Assignee: Colt Defense LLC
    Inventors: Paul Hochstrate, Laurance Robbins, Arthur F. Daigle
  • Patent number: 7975595
    Abstract: A firearm having a bolt carrier comprising an operating rod slot that is open at an end of the bolt carrier. The bolt carrier also includes a cam slot extending from the operating rod slot. The firearm includes a bolt having a protrusion extending from the bolt which enters and is movable within the cam slot. The firearm further includes an operating rod comprising a piston and a foot. The foot is disposed within the operating rod slot to prevent the separation of the bolt from the bolt carrier and to connect the operating rod to the bolt carrier.
    Type: Grant
    Filed: October 6, 2008
    Date of Patent: July 12, 2011
    Assignee: RMDI, LLC
    Inventors: Alexander J. Robinson, Darin G. Nebeker, Jon C. Holway
  • Patent number: 7975596
    Abstract: An improvement to a firearm of the character having an upper receiver, an operating rod operably associated with the upper receiver for movement between a first position and a second position, and a lower receiver connected to the upper receiver. The improvement concerns a novel bolt and barrel lock and release mechanism carried by the upper receiver and a novel trigger mechanism carried by the lower receiver.
    Type: Grant
    Filed: April 21, 2009
    Date of Patent: July 12, 2011
    Inventor: Rubik Darian
  • Patent number: 7971518
    Abstract: A direct drive retrofit system for use with an M-16 or AR-15 rifle for conversion from an impingement system comprising: a gas block, the gas block having a barrel bore and a gas plug bore; a gas plug, the gas plug being inserted into the gas plug bore from the muzzle end; a bolt carrier key, the bolt carrier key being configured to mount directly to a bolt carrier; a rod, the rod being manufactured from a single continuous material stock; and a biasing means; wherein, the rod can be uninstalled without removal of a hand guard or the gas block by extracting the gas plug from the gas plug bore from the muzzle end, the actuating means releasing the rod, the rod being freely extracted thereafter by a user in a single piece.
    Type: Grant
    Filed: December 22, 2009
    Date of Patent: July 5, 2011
    Assignee: Adams Arms, Inc.
    Inventor: Jason Adams
  • Patent number: 7938055
    Abstract: A semi-automatic or automatic rifle is provided. The semi-automatic or automatic rifle includes a receiver having an integral hand guard portion, a barrel having a bore. The bore is removably connected to the receiver, the hand guard portion extending over and surrounding the barrel, an indirect gas operating system has a gas block and a piston. The gas block has a cylinder, the gas block is fitted to the barrel, the cylinder is in communication with the bore. The piston has a piston end and a striking end, the piston end is fitted to the cylinder and has a bolt carrier having a striking surface. When a cartridge is fired, gas displaces the piston end and causes the striking end to strike the striking surface displacing the bolt assembly, wherein, the cylinder and the piston are together removable as an assembly from the firearm without disassembly of the rifle.
    Type: Grant
    Filed: August 16, 2010
    Date of Patent: May 10, 2011
    Assignee: Colt Defense LLC
    Inventors: Paul Hochstrate, Laurance Robbins, Arthur F. Daigle
  • Patent number: 7938054
    Abstract: The characteristic of one or more of the gas springs themselves used in a revolver cannon or breech cannon is adjusted while the system is in operation. This is done by a separate, self-contained system, which can adjust the gas spring from hard to soft, for example, and back to harder/hard and can thus adjust the characteristic of the gas spring without the loss of gas. In the simplest embodiment, this system has two additional elements, preferably a reserve tank and a connecting line that connects the reserve tank to the gas spring via a valve.
    Type: Grant
    Filed: November 16, 2006
    Date of Patent: May 10, 2011
    Assignee: Rheinmetall Air Defence AG
    Inventors: Marcos Trigo, Michael Gerber
  • Publication number: 20100218671
    Abstract: A gas operating system for a firearm comprises a gas block defining a cylinder, a discharge gas vent coupled to the cylinder near a proximal end of the cylinder and a discharge gas inlet configured for pneumatic coupling with the barrel of a firearm near the proximal end of the cylinder. A piston in the cylinder is movable from a rest position distal of the discharge gas vent and the discharge gas inlet against the action of a return spring by discharge gas from a barrel of a firearm pneumatically coupled to the discharge gas inlet. A regulator is pneumatically coupled to the discharge gas vent to selectively control the flow of discharge gas from the discharge gas vent to modulate a volume of discharge gas advancing the piston. A diffuser may be provided pneumatically coupled to the regulator for diffusing any audible or visual report.
    Type: Application
    Filed: December 30, 2009
    Publication date: September 2, 2010
    Applicant: MAGPUL INDUSTRIES CORPORATION
    Inventors: Michael T. Mayberry, Brian Nakayama, Mike Morgan, Eric Nakayama
  • Patent number: 7775150
    Abstract: An indirect gas operating system for an M4 type automatic or semi-automatic firearm. The indirect gas operating system has a gas block having a cylinder. The gas block is fitted to a barrel assembly having a bore with the cylinder in communication with the bore. A piston having a piston end and a striking end has the piston end fitted to the cylinder. A bolt assembly having a striking surface is provided. When a cartridge is fired, gas displaces the piston end and causes the striking end to strike the striking surface displacing the bolt assembly. The cylinder and the piston are together removable as an assembly from the firearm without removal of the gas block.
    Type: Grant
    Filed: February 7, 2007
    Date of Patent: August 17, 2010
    Assignee: Colt Defense LLC
    Inventors: Paul Hochstrate, Laurance Robbins, Arthur F. Daigle
  • Patent number: 7739939
    Abstract: A direct drive retrofit system for use with an M-16 or AR-15 rifle for conversion from an impingement system comprising: a gas block, the gas block having a barrel bore and a gas plug bore; a gas plug, the gas plug being inserted into the gas plug bore from the muzzle end; a bolt carrier key, the bolt carrier key being configured to mount directly to a bolt carrier; a rod, the rod being manufactured from a single continuous material stock; and a biasing means; wherein, the rod can be uninstalled without removal of a hand guard or the gas block by extracting the gas plug from the gas plug bore from the muzzle end, the actuating means releasing the rod, the rod being freely extracted thereafter by a user in a single piece.
    Type: Grant
    Filed: July 17, 2008
    Date of Patent: June 22, 2010
    Assignee: Adams Arms, Inc.
    Inventor: Jason Adams
  • Patent number: 7610843
    Abstract: An individual firearm with improved recock device comprising a casing (12), a barrel (13), a breech bolt (14), a breech bolt slide (15), wherein the barrel (13) has at least one hole (32), or gas bleeding port, communicating with a gas intake cylinder (19) which houses a piston gas intake assembly (20), which is connected to operating rods (31) integral to the breech bolt slide (15), comprises at least one first inertial spring (27, 27?) arranged between the breech bolt slide (15) and the gas intake cylinder (19), adapted for causing a variable, inertial and/or gas intake actuation.
    Type: Grant
    Filed: July 28, 2005
    Date of Patent: November 3, 2009
    Assignee: Fabrica d'Armi Pietro Beretta S.p.A.
    Inventor: Ugo Gussalli Beretta
  • Publication number: 20090223357
    Abstract: A kit for modifying a bolt carrier group actuating apparatus of a firearm manufacturer-configured with a gas-driven bolt carrier comprises a gas expansion assembly, an operating rod driven bolt carrier and an operating rod. The gas expansion assembly is configured for receiving combustion gases from an as-manufactured OEM gas block of the firearm and for facilitating expansion of said gases for generating a bolt carrier driving force. The operating rod driven bolt carrier includes an operating rod engaging lug. The operating rod driven bolt carrier is configured for being operably engaged within an as-manufactured OEM receiver body of the firearm with the operating rod engaging lug located in a gas tube lug receiving portion of the as-manufactured OEM receiver body. The operating rod is engagable between the gas expansion assembly and the operating rod engaging lug.
    Type: Application
    Filed: January 30, 2007
    Publication date: September 10, 2009
    Inventor: Geoffrey A. Herring
  • Patent number: 7469624
    Abstract: A direct drive retrofit system for use with an M-16 or AR-15 rifle for conversion from an impingement system comprising: a gas block, the gas block having a barrel bore and a gas plug bore; a gas plug, the gas plug being inserted into the gas plug bore from the muzzle end; a bolt carrier key, the bolt carrier key being configured to mount directly to a bolt carrier; a rod, the rod being manufactured from a single continuous material stock; and a biasing means; wherein, the rod can be uninstalled without removal of a hand guard or the gas block by extracting the gas plug from the gas plug bore from the muzzle end, the actuating means releasing the rod, the rod being freely extracted thereafter by a user in a single piece.
    Type: Grant
    Filed: November 12, 2007
    Date of Patent: December 30, 2008
    Inventor: Jason Adams
  • Patent number: 7467581
    Abstract: A semi-automatic rifle includes a frame (2); a barrel (3); a sliding guide (9) mounted in the frame (2) and forming one piece with breech bolts (10) which make it possible to control the recocking and the locking of the rifle (1); an automatic recock device (12) includes a piston (13) mounted in a gas cylinder (14) whose chamber (15) is connected to the bore (7) of the barrel (3) via a vent hole (16), whereby the piston (13) makes contact with the head of a sliding guide (17) which is connected to the sliding guide (9) and which is mounted in a sliding manner on a guiding rod (19) which forms one piece with the frame (2) and which is mainly parallel to the axis of the barrel (3).
    Type: Grant
    Filed: October 24, 2006
    Date of Patent: December 23, 2008
    Assignee: Browning International, Societe Anonyme
    Inventor: Alain Botty
  • Patent number: 7461581
    Abstract: A self-cleaning gas operating system for a firearm having a conventional bolt carrier assembly is disclosed comprising: a nozzle assembly having a nozzle in direct communication with a port on the muzzle; said nozzle assembly nested within a piston cup having a vent, a connecting rod operationally linking the piston cup to a spring loaded operating rod which is substantially co-axial to a bolt carrier key having a striking portion, said striking portion having a concave strike face in contact with said operating rod, wherein gas discharged from a fired cartridge displaces the piston cup and causes the operating rod to strike the strike face displacing the bolt assembly.
    Type: Grant
    Filed: July 24, 2006
    Date of Patent: December 9, 2008
    Assignee: LWRCInternational, LLC
    Inventor: Paul Leitner-Wise
  • Patent number: 7240600
    Abstract: A charging handle for a rifle having a housing. The handle has a body with an elongated bar having a forward end and a rear end. The bar has a bolt engaging element at the forward end, and a crossbar having an intermediate portion connected to the rear end of the bar. The crossbar has opposed ends extending laterally of the bar. First and second latch elements are connected to the body. The first latch element has a housing-engaging element that engages the housing when the handle is in a forward position. The first and second latch elements are engaged to each other such that pivoting of the second latch element disengages the housing-engaging element from the housing.
    Type: Grant
    Filed: June 25, 2004
    Date of Patent: July 10, 2007
    Inventor: Martin J. Bordson
  • Patent number: 6868770
    Abstract: A gas porting structure for an autoloading gun, wherein the structure consists of an insert fitting within a slot cut laterally thru the gun barrel and wherein one or more slot like gas ports are formed thru the insert in a longitudinal direction generally axial of the barrel.
    Type: Grant
    Filed: May 31, 2003
    Date of Patent: March 22, 2005
    Inventor: Boje Cornils
  • Patent number: 6606934
    Abstract: Presented is a gas operated, semi-automatic rifle having a shortened barrel. For actuating a receiver to provide the semi-automatic feature, the rifle has a gas system including a gas cylinder assembly attached to the barrel at a second angular position relative to the barrel. For linking the gas cylinder assembly with the receiver, an operating rod is provided having a charging arm engaging the receiver and a distal end located at a first angular position relative to the barrel. The gas cylinder assembly and the distal end are hence coextensive to each other, eliminating the length of the barrel otherwise necessary to position the gas cylinder assembly and the distal end in a linear relationship. To provide for interaction between the gas cylinder assembly and the operating rod, an abutment block is attached to the operating rod and positioned at the second angular location.
    Type: Grant
    Filed: August 30, 2002
    Date of Patent: August 19, 2003
    Assignee: Rinky Dink Systems, Inc.
    Inventors: Michael B. Rock, James E. Ribordy
  • Patent number: 6508160
    Abstract: This is a gas-flow device for semiautomatic or automatic shotguns, which consists of a gas-flow cylinder, closed at the front part by a flange with gas discharge ports (17) around the ammunition magazine, opposite the cylinder, a circular valve (18) that moves axially for controlled opening and closing of the discharge ports. The valve is kept in the closed position by a pre-stressed spring (19) and it moves to the open position when the gas pressure in the expansion chamber increases beyond a set value.
    Type: Grant
    Filed: May 25, 2001
    Date of Patent: January 21, 2003
    Assignee: Fabbrica D′Armi Pietro Beretta S.p.A
    Inventor: Ugo Gussalli Beretta
  • Patent number: 6311603
    Abstract: A charging handle for a firearm having a receiver, a bolt and bolt carrier reciprocating within the receiver and a gas tube for directing powder gases to cause operation of the bolt carrier and bolt within the receiver. The charging handle is a generally elongated member having a forward end portion and a rearward end portion with the rearward portion having a portion that extends outside of the receiver that is sized, shaped and adapted to be grasped by a hand of a shooter using the firearm. The charging handle has grooves and gas deflecting surfaces for diverting and deflecting powder gases to protect the shooter from powder gases that may develop around the charging handle when the firearm is fired.
    Type: Grant
    Filed: October 15, 1999
    Date of Patent: November 6, 2001
    Inventor: Norman D. Dunlap
  • Patent number: 5886281
    Abstract: The invention concerns a firearm for receiving and firing a projectile. The firearm includes an integral casing having a barrel and a breech block receiving area to the rear of the barrel. A breech block is guided through the breech block receiving area by separated guide pins which project from the breech block into respective longitudinal track sections in the barrel. The guide pins are axially separated at opposite ends of the breech block and are circumferentially separated. The longitudinal track sections meet circumferential track sections. The guide pins in the circumferential track sections permit the breech block to be rotated. The breech block has a forward closed barrel position and a rearward open loading position. A breech mount around the breech block has a cam slot that extends longitudinally and into which a cam follower pin from the breech block projects. The breech mount is drawn forward by a spring and driven rearwardly by the gas pressure from detonation of a projectile leaving the barrel.
    Type: Grant
    Filed: November 7, 1997
    Date of Patent: March 23, 1999
    Assignee: Waltraud Bucher-Kirstein
    Inventor: Gerhard Kirstein
  • Patent number: 5824943
    Abstract: A gas-pressure loading arrangement for a self-loading rifle includes a gas cylinder fluidly connected to the bore of the rifle barrel and a gas piston received in the gas cylinder to define a gas chamber. The gas piston has piston ring members seated thereon in engagement with the inner surface of the gas cylinder under tension. The piston ring members allow the gas piston to be loosely received in the gas cylinder while preventing gas leakage around the piston. The piston ring members also scrape gas deposits off the inner wall of the gas cylinder during piston movement so that the inner wall remains clean.
    Type: Grant
    Filed: April 16, 1997
    Date of Patent: October 20, 1998
    Assignee: Heckler & Koch GmbH
    Inventors: Manfred Guhring, Helmut Weldle
  • Patent number: 5429034
    Abstract: An improved semi-automatic shotgun of the type contains a magazine tube (8) around which is provided a cylinder (9) whose interior part communicates with an interior part of a barrel (2) of the invention. In this cylinder (9) and around the magazine tube (8), a piston (10) can be shifted by propulsion gases. The piston cooperates with a sleeve (12) provided with a rod (13) which can act upon the whole of the moving parts (14) on the one hand, and a control or pressure control valve (11) on the other hand is situated in the piston block (10).
    Type: Grant
    Filed: July 15, 1994
    Date of Patent: July 4, 1995
    Assignee: Browning S.A. societe anonyme
    Inventors: Joseph A. Badali, Joseph F. N. Rousseau
  • Patent number: 5388500
    Abstract: Applicant's device improves rapidly firing guns. When such a gun fires, applicant's device delays departure of the gun bolt from the chamber or barrel zone holding a spent round's casing until barrel pressure drops to a safe level. The device has a hollow piston which is translatable fore and aft along the barrel and which has an orifice communicated to a duct from an inner barrel diameter to an outer barrel diameter. The duct slants forward toward the gun muzzle in a radially outward direction so as to direct expanding propellant gas from the barrel against a forward internal surface of the piston. Momentum of the gas keeps the piston in its most forward position and the piston solidly connects to the bolt so that the bolt stays at the chamber when the piston is pressurized.
    Type: Grant
    Filed: March 7, 1994
    Date of Patent: February 14, 1995
    Inventor: Paul A. Petrovich
  • Patent number: 4409883
    Abstract: A gas operated firearm having means for initially storing energy from the gases released during discharge of a bullet is disclosed. The firearm includes a piston and cylinder arrangement which receives such gases, with the piston moving forwardly to compress a spring and operate a latch mechanism to maintain the spring in the compressed condition. The latch mechanism may be released by the operator when it is desired to reload the firearm, with reloading being accomplished by operation of an interengaging piston connecting rod and slide connecting rod.
    Type: Grant
    Filed: June 3, 1981
    Date of Patent: October 18, 1983
    Inventor: Edouard Nyst
  • Patent number: 4270437
    Abstract: A belt-fed, gas operated automatic weapon of a type in which the gas pressure developed in the bore is ported just forward of the chamber and utilized to compress a system of opposing spring sets which in turn operate the various mechanisms involved in the automatic or semi-automatic functioning of the weapon. Symmetrically arranged dual power cylinders operated by the gas pressure compress all of the springs in the opposing spring sets by engagement with a sliding carriage. Bolt locking is carried out by a separate oscillating cam-operated bolt latch element cooperating with a shoulder recess formed in the periphery of the bolt, with an arrangement for reducing the bolt locking mechanism forces during the unlocking interval. Manual actuation is enabled by movement of a slider. The bolt is automatically latched open in some modes of operation. A particular interlinked ammunition belt construction is disclosed to separate each link from the belt after passing beyond the bolt.
    Type: Grant
    Filed: March 15, 1979
    Date of Patent: June 2, 1981
    Inventor: John S. Donovan
  • Patent number: 4253378
    Abstract: A belt-fed, gas-operated automatic weapon of a type in which the gas pressure developed in the barrel bore during firing is ported just forward of the barrel chamber to be utilized to compress a system of opposing spring sets which in turn operate the various mechanisms involved in the automatic or semi-automatic functioning of the weapon, including ammunition feeding and ejection, bolt locking and unlocking, and reciprocation. Dual power cylinders with symmetrically arranged pistons operated by the gas pressure compress all of the springs in the opposing spring sets by engagement with a sliding carriage. The forces exerted on the bolt locking mechanism by the spring sets are greatly reduced during the interval in which the locking mechanism is operated to reduce wear on the mating surfaces and to properly sequence the unlocking after discharging a round.
    Type: Grant
    Filed: June 11, 1979
    Date of Patent: March 3, 1981
    Inventor: John S. Donovan
  • Patent number: 4210060
    Abstract: A belt-fed, gas-operated automatic weapon of a type in which the gas pressure developed in the barrel bore during firing is ported just forward of the barrel chamber to be utilized to compress a system of opposing spring sets which in turn operate the various mechanisms involved in the automatic or semi-automatic functioning of the weapon, including ammunition feeding and ejection, bolt locking and unlocking, and reciprocation. Dual power cylinders with symmetrically arranged pistons operated by the gas pressure compress all of the springs in the opposing spring sets by engagement with a sliding carriage. The forces exerted on the bolt locking mechanism by the spring sets are greatly reduced during the interval in which the locking mechanism is operated to reduce wear on the mating surfaces and to properly sequence the unlocking after discharging a round.
    Type: Grant
    Filed: February 1, 1978
    Date of Patent: July 1, 1980
    Inventor: John S. Donovan
  • Patent number: 4015512
    Abstract: A gas-operated firearm is disclosed in which the gas port is located in the forward part of the chamber, in the part of the barrel bore wall which surrounds the portion of the bullet projecting from the case of a chambered cartridge. In the disclosed firearm the bolt remains locked in its breech-closing position until the gas pressure resulting from the detonation of a cartridge drops to practically zero (gauge). The bolt, which rides on guide rails in the receiver, is provided with a pivotable locking member constructed and arranged to engage locking recesses in the guide rails when it is pivoted into one of its extreme positions. The locking member can be withdrawn from engagement with the locking recesses in the guide rails, and the bolt impelled rearwardly, when a lug projecting from the locking member is struck by a cam which is pivotably mounted in the receiver.
    Type: Grant
    Filed: October 29, 1974
    Date of Patent: April 5, 1977
    Inventor: Jay J. Feerick