Patent Document

CROSS-REFERENCED TO RELATED APPLICATION 
     This application is a divisional of U.S. patent application Ser. No. 12/557,815 filed Sep. 11, 2009, which claims the benefit of U.S. Provisional Patent Application Ser. No. 61/096,710 filed Sep. 12, 2008 the contents each of which are incorporated herein by reference thereto. 
    
    
     BACKGROUND 
     The disclosed embodiments relate to firearms and, more particularly, to a firearm having a direct gas impingement operating system. 
     There are conventional semi-automatic or automatic firearms that are gas operated via a gas tube or operating rod in the case of an indirect gas operating system. In each case, gas ports are provided that can become fouled, for example, with carbon buildup or may suffer erosion over time with firing. As such, there is a desire to eliminate or clear such variances in gas ports that may adversely affect operation of the firearm. 
     SUMMARY 
     In accordance with one exemplary embodiment, a direct gas impingement operating system for an automatic or semi-automatic rifle having a barrel connected to a receiver is provided. The direct gas impingement operating system has a gas block fitted to the barrel, the gas block in communication with a bore in the barrel. A gas regulating sleeve removably is provided located in the gas block, the gas sleeve in communication with the bore through the gas block. A bolt assembly is provided having an integral impingement cylinder and a gas line is fixed to the sleeve in fluid communication with the bore through the sleeve and the gas block, the gas line further in fluid communication with the impingement cylinder. Gas discharged from a fired cartridge displaces the impingement cylinder displacing the bolt assembly relative to the receiver. The sleeve and the gas line are removable from the gas block without disconnecting the barrel and receiver and without removal of the gas block from the barrel. 
     In accordance with another exemplary an automatic or semi-automatic rifle is provided. The automatic or semi-automatic rifle has a receiver and a bolt carrier having an impingement cylinder, the bolt carrier and impingement cylinder being enclosed within the receiver. A barrel is provided having a bore, the barrel coupled to the receiver. A gas block is fixed to the barrel, the gas block in communication with the bore. A gas sleeve is removably located in the gas block in communication with the bore. A gas line is provided fixed to the sleeve fluid in communication with the bore through the sleeve and the gas block, the gas line further in fluid communication with the impingement cylinder. Gas discharged from a fired cartridge displaces the impingement cylinder displacing the bolt carrier relative to the receiver. The sleeve is configured so that it defines a gas flow regulator regulating gas flow volume through the bore and is removable from the gas block without removal of the gas block from the barrel and without removal of the barrel from the receiver. 
     In accordance with another exemplary embodiment, a black rifle type automatic or semi-automatic rifle is provided. The black rifle type automatic or semi-automatic rifle has a receiver assembly enclosing a bolt carrier and a barrel assembly having a bore, the barrel assembly removably coupled to the receiver. A gas block is provided mounted to the barrel, the gas block having a passage extending through the gas block in communication with the bore. A direct gas impingement operating system is provided having a gas sleeve located in the passage of the gas block, the gas sleeve in communication through the passage with the bore and a bolt assembly and an impingement cylinder disposed in the bolt carrier and enclosed within the receiver assembly A gas line is provided joined to the sleeve in communication with the bore through the sleeve and the passage, the gas line further in fluid communication with the impingement cylinder. Gas discharged from a fired cartridge displaces the impingement cylinder displacing the bolt assembly. The sleeve has an orifice arranged in the passage, so that it forms a gas flow regulator in the passage regulating gas flow volume from the bore through the passage to the gas line is removable from the gas block without removal of the gas block from the firearm. 
     In yet another embodiment, a method of removably securing a gas regulating sleeve and a gas line of a gas operating system to an automatic or semi-automatic rifle, the method including the steps of: fluidly coupling a gas block to a bore of a barrel of the rifle; removably locating and securing a gas regulating sleeve in the gas block, the gas regulating sleeve being in fluid communication with the bore of the barrel, a gas line fixed to the sleeve, the gas line being in fluid communication with the bore via the gas regulating sleeve and the gas block, and wherein a portion of the gas line is received within an impingement cylinder of a bolt assembly of the rifle when it is in a first position, and wherein the impingement cylinder moves away from the gas line as it moves from the first position to a second position due to gases passing through the gas line from the gas block; and wherein the gas regulating sleeve and the gas line are removable from the gas block without disconnecting the barrel from the receiver and without removal of the gas block from the barrel. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The foregoing aspects and other features of the exemplary embodiments are explained in the following description, taken in connection with the accompanying drawings, wherein: 
         FIG. 1  is a side view of an automatic firearm incorporating features in accordance with an exemplary embodiment; 
         FIG. 2  is a section view of an upper receiver section of the firearm shown in  FIG. 1 ; 
         FIG. 3  is a section view of an upper receiver section of the firearm shown in  FIG. 1 ; 
         FIG. 4  is a section view of an upper receiver section of the firearm shown in  FIG. 1 ; 
         FIG. 5  is an isometric view of a barrel and gas tube assembly; 
         FIG. 6  is an exploded isometric view of a barrel and gas tube assembly; 
         FIG. 7  is an exploded isometric view of a barrel and gas tube assembly; 
         FIG. 8  is a section view of a barrel and gas tube assembly; 
         FIG. 9  is a section view of a barrel and gas tube assembly; and 
         FIG. 10  is a section view of a barrel and gas tube assembly. 
     
    
    
     DETAILED DESCRIPTION 
     Referring to  FIG. 1 , there is shown, a side elevation view of a firearm  10  capable of automatic or semiautomatic fire incorporating features in accordance with an exemplary embodiment of the present invention. Although the present invention will be described with reference to the embodiments shown in the drawings, it should be understood that the present invention can be embodied in many alternate forms of embodiments. In addition, any suitable size, shape or type of elements or materials could be used. 
     Firearm  10  may be a rifle or carbine with a direct gas impingement operating system, like examples, such as the M-4™ or M-16 rifles available from Colt Defense, LLC, similar commercial variants thereof and may have features as disclosed in U.S. patent application Ser. No. 11/231,063 filed Sep. 19, 2005, U.S. patent application Ser. No. 11/352,036 filed Feb. 9, 2006 or U.S. patent application Ser. No. 60/772,494 filed Feb. 9, 2006 all of which are hereby incorporated herein by reference in their entirety. Firearm  10  is illustrated as generally having a black rifle configuration. The black rifle configuration being the family of rifles developed by Eugene Stoner, for example, such as an M4™ or M16 automatic firearm configuration. However, the features of the disclosed embodiments, as will be described below, are equally applicable to any desired type of automatic firearm. Firearm  10  may have features such as disclosed in U.S. patent application Ser. No. 11/672,189 filed Feb. 7, 2007, and U.S. patent application Ser. No. 11/869,676 filed Oct. 9, 2007, all of which are hereby incorporated by reference herein in their entirety. Firearm  10  may have operational features such as disclosed in U.S. Pat. Nos. 5,726,377, 5,760,328, 4,658,702, 4,433,610, U.S. Non Provisional patent application Ser. No. 10/836,443 filed Apr. 30, 2004, and U.S. Provisional Patent Application 60/564,895 filed Apr. 23, 2004, all of which are hereby incorporated by reference herein in their entirety. The firearm  10  and its sections described in greater detail below is merely exemplary. In alternate embodiments the firearm  10  may have other sections, portions or systems. Firearm  10  may have an upper receiver section  13  a barrel  24 , and hand guard portion. The hand guard portion is shown as being separate from receiver  13 . In alternate embodiments, the hand guard portion may be integral with upper receiver  13 . The hand guard section may have features such as disclosed in U.S. Pat. Nos. 4,663,875 and 4,536,982, both of which are hereby incorporated by reference herein in their entirety. Hand guard section  40  of upper receiver section  34  may be configured to support such rails as a “Picatiny Rail” configuration as described in Military Standard 1913, which is hereby incorporated by reference herein in its entirety. The rails may be made from any suitable material such as hard coat anodized aluminum as an example. A rear sight assembly is provided and mounted to upper receiver section  13 . Firearm  10  may incorporate stock  22 , lower receiver section  12 , magazine well  16 , a clip or magazine, rear and front sights, fire control selector  26 , trigger  14 , bolt assembly  20  and ejection port  18 . Upper receiver  13  having barrel  24 , lower receiver  12  and magazine well  14  may be modular and configurable such that firearm  10  comprises a modular rifle design. Further, the hand guard, and accessory mounting rails thereon, may be integral with the upper receiver and the integral upper receiver, hand guard and mounting rails may be of unitary construction. In alternate embodiments, the upper receiver and hand guard may be separate. 
     Referring now to  FIG. 2 , there is shown a section view of an upper receiver section of the firearm shown in  FIG. 1 . Firearm  10  has a direct gas impingement operating system facilitating automatic or semi-automatic operation as will be described below. The direct gas operating system may have a gas feed regulator that may be configured to provide a substantially constant feed flow, independent of variances in barrel exhaust aperture, or may be configured to be adjustable, allowing the operator to vary cyclic rate as desired. As will be described in greater detail below, the system has a gas block assembly mounted or otherwise fitted to the barrel (see  FIG. 1 ) and in fluid communication with the bore of the barrel. The gas block assembly includes a gas block which has a passage formed through the gas block and a sleeve positioned in the passage in communication with the bore. Gas line  96  is provided fitted to the sleeve and also in communication with the bore through the sleeve and the gas block. As can be seen in  FIG. 2 , gas line  96  is further in fluid communication, via passage in key  30  with impingement cylinder  32  in bolt carrier  28  of bolt assembly  20 . As will be described below, the sleeve and the gas line are removable from a front portion of the gas block without removal of the gas block and without removal of the barrel from the receiver assembly. Bolt assembly  20  has bolt carrier  28 , within which are located bolt or bolt assembly  29  and firing pin  40  slidably mounted within the bolt  29 . The bolt  29  is slidably mounted within the bolt carrier  28 . Pin  36  is pressed into the bolt  29  and interfaces with corresponding camming slot  38  of bolt carrier  28 . Impingement key  30  has a cylinder portion  32  that slidably engages gas line  96 . Port  46  is provided between cylinder portion  32  and the expansion volume  34  of the impingement cylinder between a rear portion of the bolt and the bolt carrier. As can be seen in  FIG. 2 , hammer  42  strikes firing pin  40  discharging cartridge  44 . As can be seen below, gas from discharged cartridge  44  is routed from the barrel, to the gas block and sleeve and to gas line  96 . As can be seen in  FIG. 3 , gas discharged from fired cartridge  44  displaces the impingement cylinder  34  of key  30 , displacing bolt carrier  28  as gas expands in the larger expansion volume  48 . Camming slot  38  moves toward the rear of the firearm rotating the bolt until pin  36  bottoms out on slot  38 . As can be seen in  FIG. 4 , resulting momentum of bolt carrier  28  in combination with pressure in cylinder  34  also displaces the bolt thus displacing the bolt assembly  20  to eject cartridge  44  and displace hammer  42 . Here, impingement cylinder  32  disengages the gas line during operation. A gas regulator may be provided that interfaces with the pressurizing gas in the cylinder to provide a desired gas feed flow independent of variances arising from use of the firearm. The regulator may be incorporated into the gas block assembly or otherwise as will be described in greater detail below. A suitable example of a gas regulator is described in U.S. patent application Ser. No. 11/231,063, filed Sep. 19, 2005, and incorporated by reference herein in its entirety. In alternate embodiments, any suitable gas regulator may be provided. 
     Referring now to  FIG. 5 , there is shown an isometric view of a barrel and gas tube assembly. Referring also to  FIG. 6 , there is shown an exploded isometric view of a barrel and gas tube assembly. Referring also to  FIG. 7 , there is shown an exploded isometric view of a barrel and gas tube assembly. The direct gas impingement operating system interfaces with gas block  72  fitted to barrel assembly  24  where cylinder  32  of bolt carrier  28  is in fluid communication with gas block  72  via gas tube  96  and removable sleeve  70  (see also  FIGS. 6-7 ). In the exemplary embodiment, the removable sleeve  70  may include the gas regulator and may be removable from the front of gas block  72  (in the direction indicated by arrow F) and therefore removable from the front of the receiver or rail without further disassembly (e.g. without disconnecting barrel from receiver or removable of gas block from barrel). As can be seen in  FIGS. 6 and 7 , this further enables removal of the gas tube  96  from the firearm as a unit with the gas sleeve without further disassembly. In the exemplary embodiment, removable sleeve  70  is maintained captive with takedown pin  73  (see  FIG. 9 ) allowing for quick removal for reinitiation. A wave spring (not shown) may be provided under the head of sleeve  70  to bias sleeve  70  forward. The take down pin may be held captive. In alternate embodiments, the gas sleeve may be removable or installed in the gas block  72  in any other suitable manner. 
     Referring now to  FIG. 8 , there is shown a section view of a barrel and gas tube assembly. Referring also to  FIG. 9 , there is shown a section view of a barrel and gas tube assembly. Referring also to  FIG. 10 , there is shown a section view of a barrel and gas tube assembly. The cylinder  32  of the direct gas impingement operating system interfaces with gas block  72  fitted to barrel assembly  24  via gas line  96  and sleeve  70 . Barrel  24  has bore  6  with the gas block being in fluid communication with the bore through a port  76  in barrel  24 . The gas block  72 , may include a passage that extends through the block (as seen best in  FIG. 9 ) and is in fluid communication with the bore through a corresponding port disposed on a surface of the gas block facing the barrel. The sleeve may be located within the passage in the gas block, and may be installed and removed through a front opening of the passage as may be realized from  FIG. 6 . The sleeve is in fluid communication with the bore through a corresponding port  74  disposed on a surface of the sleeve facing the barrel. As seen in  FIG. 10 , in the exemplary embodiment the barrel port  76 , block port  90  and sleeve port  74 , may have different sized openings respectively, arranged so that the gas sleeve port  74  effects gas regulation of feed gases exhausting from the barrel bore  6 , via port  70 , into the gas line  96  feeding cylinder  32 . In the exemplary embodiment, sleeve port  74  is sized and arranged so that changes in either or both the barrel port  76  and gas block port  90  (such as from erosion or fouling) have little perceivable effect on cyclic rate of the firearm. In the exemplary embodiment, gas block  72  is in communication with bore  6  through the first gas port  90  in the gas block and sleeve  70  is in communication with bore  6  through the regulating or second gas port  74  of sleeve  70  inside the passage in the gas block where second gas port  74  is smaller than first gas port  90  and gas port  76 . The tube  96  is in fluid communication with the bore through a corresponding port  77 , for example disposed on a surface of the tube facing the barrel though such port for the gas tube may be located in any other suitable position in the barrel. Hence, cylinder  32  of bolt carrier  28  is in fluid communication with bore  6  via gas block  72 , sleeve  70  and gas tube  96 . Tube  96  may have a keyed feature (not shown) that prevents rotation of tube  96  relative to sleeve  70  during operation and alignment of the ports. In alternate embodiments, a recess may be made in the bore of sleeve  70  or housing  72  allowing rotation of tube  96 . Holes  82 ,  84  may be provided on the head of sleeve  70  whereby a tool may be used to rotate sleeve  70  for removal in the event of carbon buildup preventing removal. Chamfer  86  is shown provided on the bore of sleeve  70  to allow for easy assembly and disassembly of rod  96  to sleeve  70 . A plug  88  having recesses is provided in tube  96  where the outer surface of tube  96  is formed over the recesses to retain the plug. A hole  90  through tube  96  and plug  88  is shown for proper orientation. In the exemplary embodiment removable sleeve  70  is maintained captive with takedown pin  73  above sleeve  70  engaging slot  102 . Slot  102  in the upper portion of sleeve  70  in the upper portion of sleeve  70  provides a cam surface for pin  73  to cam sleeve  70  to seal gas sleeve  70  opening to the gas port in sight block  72 . In this manner, pin  73  engages takedown notch  102  such that pressure reacting on sleeve  70  causes pin  73  to cam sleeve  70  down to the exhaust hole and making a tighter seal. Wave spring  104  is provided under the head of sleeve  70  to bias sleeve  70  forward, removing play and actuating the cam surface  102  by lock pin  73 . In this manner, the sleeve  70  is coupled to the gas block  72  with removable pin  73 , where pin  73  provides a camming surface to seal sleeve  70  to a gas port in gas block  72 . The take down pin may be held captive, for example, by a spring and detent ball, or by a pin or otherwise. In alternate embodiments, the sleeve may also have exhaust ports. Relief  80  in the outside diameter of sleeve  70  may facilitate cutting gum or carbon and act as a scrapper and may also be relieved in the back to clear any carbon buildup. In the exemplary embodiment, external annular groove(s)  98  are provided on sleeve  70  for cutting carbon buildup in gas block bore housing cylinder sleeve  70 . The annular grooves  98  in the outside diameter of sleeve  70  facilitate cutting gum or carbon that may have impacted on the inside and act as a scraper and may also be relieved in the back to clear any carbon buildup. Grooves  98  may form a labyrinth seal for trapping exhaust blow by and to minimize carbon build up. Although grooves  98  are shown radially cut, in alternate embodiments, grooves  98  may have any suitable shape, for example, grooves  98  may be helically cut. Here, slots or grooves  98  are adapted to remove carbon build up during operation. Grooves  98  may be provided with rings  100 , with the rings adapted to enhance sealing of the sleeve to gas block interface (minimizing exhaust blow by through the interface) and may remove carbon build up during operation and removal of sleeve  70  from gas block  72 . In the exemplary embodiment, different interchangeable gas sleeves (similar to gas sleeve  70 ) may be provided, each with different sized gas regulating ports (similar to port  74 ). The bores of the regulating ports may be varied in size, for example in accordance with different barrel lengths or other predetermined characteristics of the barrel or firearm. The gas sleeves may be selected for installation from the different interchangeable gas sleeves in accordance for example, with barrel length. In alternate embodiments, a gas sleeve may be provided with more than one gas regulating port, each port having a different bore size and resulting in a different gas feed flow when positioned in communication via gas block port  90  with the barrel exhaust port  76 . 
     It should be understood that the foregoing description is only illustrative of the invention. Various alternatives and modifications can be devised by those skilled in the art without departing from the invention. Accordingly, the present invention is intended to embrace all such alternatives, modifications and variances which fall within the scope of the exemplary embodiments.

Technology Category: 2