Embodiments described herein generally relate to gas operating systems for weapon systems, and more specifically to bolt carrier groups (BCGs) and related direct gas impingement system used in semi-automatic and/or full-automatic weapon systems, such as the AR15, M16, and M4 weapon systems.
The AR15, M16, and M4 weapon systems were originally designed to operate with a traditional direct gas impingement (DGI) system. The DGI system uses gases generated from the fired cartridge to operate the weapons action. Gases from the fired cartridge are tapped from a gas port in the barrel and directed back through a “gas tube” into the bolt carrier key and bolt carrier, pressurizing a small chamber between the rear of the bolt and the bolt carrier. Expanding gases drive the bolt carrier to the rear, unlocking the bolt from a barrel extension allowing the bolt and carrier to move to the rear and cycle the action of the weapon.
For the weapon to operate correctly and reliably, the action components of the AR15, M16, and M4 weapon systems should be kept well lubricated, specifically the bolt and bolt carrier components, to avoid malfunctions. Due to the way traditional DGI systems operate, a DGI system delivers heat and carbon from each fired cartridge back into the action of the weapon, most notability the bolt and bolt carrier and the inside of the upper receiver. The heat builds up quickly when the rifle is quickly fired fast in full-automatic mode or semi-automatic mode. The heat and carbon dries out the lubrication used on the action to keep the action operating, which requires adding more lubrication to maintain the weapons reliability. This process leads to the action of the weapon becoming “gummed up” or stuck and can lead to malfunctions. This repeated adding of lubrication to keep the weapon operational also attracts dust and dirt from desert type environments which can also lead to more frequent malfunctions. The rapid heat buildup from this design also has a negative impact on the weapons parts, contributing to early parts failure.
The traditional DGI system used in the AR15, M16, and M4 weapon systems was effective but very inefficient, and is a “leaky” and wasteful design, requiring much more of the propellant gasses to operate the weapon than what are actually needed. The traditional DGI system's “open design” contributes to its overheating and fouling of the weapons action. The area of the system where this is most apparent is the rear of the gas tube and the carrier key located on top of the bolt carrier. The carrier key slides over the rear of the gas tube and rests there until the weapon is fired. When the weapon is fired the carrier moves to the rear as the system is pressurized. As the bolt carrier moves to the rear the carrier key retracts from the gas tube and the carrier continues moving rearward approximately three inches to cycle the action. Pressurized gases from the fired cartridge continue to flow out of the gas tube even after the carrier key has separated from the rear of the gas tube, depositing hot dirty carbon laden gasses into the upper receiver of the weapon until the bolt carrier is again moved forward by the operating spring and the carrier key covers the exposed rear of the gas tube and the action closes. Pressurized gases from the fired cartridge continue to flow out the rear of the gas tube the entire time it is not covered by the carrier key.
The gas chamber of the traditional DGI system is made up of the rear of the bolt and back inside of the bolt carrier. The front of this chamber that is the rear of the bolt has three gas rings on a journal that forms a tight seal and contains the gases, the rear of the gas chamber formed by the bolt carrier has an open channel that the back or tail of the bolt sits in, there is a large gap in this location between the tail of the bolt and the bolt carrier channel, it is not sealed with gas rings like the front of the chamber. This open space allows the pressurized gases to flow freely out the back of the bolt carrier. This “loose fit open design” allows propellant gases to escape out of the rear of the carrier depositing hot, dirty propellant gasses into the upper receiver, contributing to fouling of the action and weapon malfunctions.
Another drawback to the DGI system for the AR15 type weapons, and more notably the military's current individual combat weapon, the M4 carbine, is the fact that the weapon cycles too fast due to its short carbine length gas system, and the cyclic rate of fire when fired on full automatic is excessively high because the weapon is “over gassed” or receives more gas volume than is necessary to ensure some reliability when the weapon becomes dirty. Several factors that contribute to the speed at which the weapon operates or cycles include the size of the gas port in the barrel, the gas port location (distance from the chamber), operating spring strength, and the weight of the buffer assembly. To keep the weapon functional and reliable, these different components must be balanced to operate with each other.
There have been many attempts to control the speed of the bolt carrier in the DGI system, most common of which attempt to control the amount of gas entering the system, such as adjustable gas keys and gas blocks with screws that allow adjustments of the flow of propellant gas into the system. Small assemblies like gas keys and gas blocks with screw type adjustments can become gummed up with carbon and/or unburned propellant making the devices difficult to adjust gas flow. Other ways to control the speed of the bolt carrier is with the use of hydraulic buffers and combination hydraulic and spring buffers, as well as, heavier buffer assemblies and buffer springs with greater k-value or additional coils over traditional mil-spec buffer springs.
Civilian competition shooters often adjust their individual weapons to operate reliably with specific ammunition, delivering just enough volume and pressure to cycle the weapon while at the same time minimizing recoil so they can remain on target for the next shot. These shooters are also limited to the existing options mentioned above. These adjustment options are more limited to law enforcement and military users who must use the issued weapon, usually a standardized weapon system that cannot be easily modified or may not be modified by the shooter or operator to maintain reliability as the “adjustable” component is not reliable when exposed to heavy or prolonged use in military or law enforcement situations. The use of a sound suppressor on such weapon also produces back-pressure that may negatively affect the cycling of the weapon unless one or more of the other variables in the weapon and ammunition systems are adjusted for the back-pressure.
Therefore, there is a need for a BCG that has better control of the cycle speed in a direct gas impingement system so to have more consistent cycling than a traditional BCG used in weapon systems having direct gas impingement.
Implementations described herein generally relate to gas operating systems for weapon systems, and more specifically to a bolt carrier group (BCG) and related direct gas impingement system used in semi-automatic and/or full-automatic weapon systems, such as the AR15, M16, and M4 weapon systems. In one or more embodiments, a BCG for a weapon system can include a carrier assembly, a bolt assembly, and a gas chamber disposed therebetween. The carrier assembly contains a carrier body that includes a shoulder, a piston surface, one or more inlet ports, and one or more exhaust ports. The shoulder is disposed within the carrier body and contains a channel therethrough and the piston surface is located on the shoulder at least partially encompassing the channel in the shoulder. The inlet port extends through the carrier body and is configured for receiving propellant gas into the carrier body. The exhaust port extends through the carrier body and is configured for removing the propellant gas from the carrier body. The bolt assembly is at least partially contained within the carrier assembly and includes a bolt head opposite of a bolt tail where the bolt tail is at least partially protruding into the channel in the shoulder. The gas chamber is disposed between the carrier body, the piston surface, the bolt tail, and two gas seals disposed on the bolt assembly.
In other embodiments, the bolt carrier group for a weapon system can include a carrier assembly, a bolt assembly, and a gas chamber disposed therebetween. The carrier assembly contains a carrier body that includes a shoulder, a piston surface, and one or more inlet ports. The shoulder is disposed within the carrier body and contains a channel therethrough. The piston surface is located on the shoulder at least partially encompassing the channel in the shoulder. The inlet port extends through the carrier body and configured for receiving propellant gases into the carrier body. The bolt assembly is at least partially contained within the carrier assembly and contains a bolt head opposite of a bolt tail. The bolt tail is at least partially protruding into the channel in the shoulder. The gas chamber is disposed between the carrier body, the piston surface, the bolt tail, and two gas seals disposed on the bolt assembly. In some examples, the two gas seals include a forward gas seal and a rear gas seal, the forward gas seal is disposed between the rear gas seal and the bolt head and the forward gas seal contains a forward chamber surface area. The forward chamber surface area is greater than a piston surface area of the piston surface, such that the piston surface area is about 98% or less of the forward chamber surface area.
In some embodiments, an upper receiver assembly for a weapon system can include an upper receiver containing a barrel, a gas block fluidly coupled to the barrel, and a BCG fluidly coupled to the gas block, where the BCG is described and discussed herein.
So that the manner in which the above recited features of the disclosure can be understood in detail, a more particular description of the disclosure, briefly summarized above, may be had by reference to implementations, some of which are illustrated in the appended drawings. It is to be noted, however, that the appended drawings illustrate only typical implementations of this disclosure and are therefore not to be considered limiting of scope, for the disclosure may admit to other equally effective implementations.
To facilitate understanding, identical reference numerals have been used, where possible, to designate identical elements that are common to the Figures. It is contemplated that elements and features of one implementation may be beneficially incorporated in other implementations without further recitation.
Implementations described herein generally relate to gas operating systems for weapon systems, and more specifically to direct gas impingement systems and bolt carrier groups (BCGs) used in automatic and/or semi-automatic weapon systems, such as the AR15, M16, and M4 weapon systems.
In one or more embodiments, a BCG for a weapon system can include a carrier assembly, a bolt assembly, and a gas chamber disposed therebetween. The carrier assembly contains a carrier body that includes a shoulder, a piston surface, one or more inlet ports, and one or more exhaust ports. The shoulder is disposed within the carrier body and contains a channel therethrough and the piston surface is located on the shoulder at least partially encompassing the channel in the shoulder. The inlet port extends through the carrier body and is configured for receiving propellant gas into the carrier body. The exhaust port extends through the carrier body and is configured for removing the propellant gas from the carrier body. The bolt assembly is at least partially contained within the carrier assembly and includes a bolt head opposite of a bolt tail where the bolt tail is at least partially protruding into the channel in the shoulder. The gas chamber is disposed between the carrier body, the piston surface, the bolt tail, and two gas seals disposed on the bolt assembly.
The gas channel carrier rail 120 extends through an adjustable tensioner 110 that is attached to and passes through an opening 102 passing through a wall of the upper receiver 104 of the firearm, as depicted in
In one or more embodiments, the adjustable tensioner 110 is a two-piece member which includes interlocking components 112a, 112b, which are installed from opposite sides of the wall of the upper receiver 104 so to engage one another. In such an embodiment, each of the two pieces includes tapered surfaces which engage one another to form an interference fit. Each of the two pieces include a base portion for contacting outer (and opposite) surfaces of the upper receiver front wall. In one example, each of the two components 112a and 112b of the adjustable tensioner 110 are positioned concentrically with respect to one another. In some examples, the adjustable tensioner 110 is a grommet having two or more segments or portions, such as components 112a and 112b. As shown in
The inlet end 124 of the gas channel carrier rail 120 is configured to couple to a gas block 103 disposed on a barrel 101 of the weapon system, as depicted in
The gas block 103 can be any gas block that meets or exceeds U.S. military specifications for the M16 or M4 weapon systems or any gas block used in the AR15 weapon system. The gas block 103 attached to the barrel 101 that directs the expanding gases from the gas port 105 in the barrel 101 into the inlet end 124 of the gas channel carrier rail 120. The gas channel carrier rail 120 may attach to the gas block 103 with a pin or screw. In some examples, the gas block 103 can be a standard, non-adjustable gas block. In other examples, the gas block 103 can be an adjustable or tunable gas block. The gas block 103 may be any height or profile (e.g., low or high profile gas blocks) to accommodate the gas channel carrier rail 120 with straight line profile or a bent or curved profile.
The gas channel carrier rail 120 also contains a slot 125 (depicted in
The BCG 140 contains a carrier assembly 150, a bolt assembly 170, and a gas channel carrier guide 180. The bolt assembly 170 is at least partially contained within the carrier assembly 150. The bolt assembly 170 and the carrier assembly 150 are axial to one another. A bolt head 171 of the bolt assembly 170 extends from the carrier assembly 150.
The gas channel carrier guide 180 is disposed on a carrier body 151 of the carrier assembly 150. In one or more embodiments, the gas channel carrier guide 180 and the carrier body 151 are monolithic, as such, are formed or otherwise produced as a single unit having a one piece design. In other embodiments, the gas channel carrier guide 180 and the carrier body 151 are separate parts that are fastened or combined together. For example, one, two, three, or more fasteners can be used to couple the gas channel carrier guide 180 and the carrier body 151 together. In one example, the gas channel carrier guide 180 and the carrier body 151 are coupled together with two bolts that pass through the gas channel carrier guide 180 and into threaded holes in the carrier body 151 and are each staked at the gas channel carrier guide 180. In other examples, the gas channel carrier guide 180 and the carrier body 151 are welded together. Each of the gas channel carrier guide 180 and the carrier body 151 can be made of or contain one or more metals, such as steel, stainless steel, titanium, or alloys thereof.
The gas channel carrier guide 180 contains a secondary gas channel 182 passing therethrough. The secondary gas channel 182 is disposed between and in fluid communication with the main gas channel 122 and an interior (e.g., gas chamber 152) of the BCG 140. The gas channel carrier guide 180 contains a lower segment 184 and an upper segment 186. The lower segment 184 is coupled to the carrier assembly 150. The upper segment 186 extends through the slot 125 and is at least partially disposed into the gas channel carrier rail 120. The gas channel carrier guide 180 contains an inlet port 188 and an outlet port 189. The inlet port 188 is in fluid communication with and coupled to the main gas channel 122 and the outlet port 189 is in fluid communication with and coupled to an inlet port 177 formed through the carrier body 151 of the BCG 140. The secondary gas channel 182 extends from the inlet port 188 to the outlet port 189 and to the interior of the BCG 140, such as into the gas chamber 152, via the inlet port 177. In one or more embodiments, the gas channel carrier guide 180 can include a gas tube or guide that is hollow or has a passageway in the center with the secondary gas channel 182 that passes from the top center at the inlet port 188, through the neck of the guide, out of the bottom at the outlet port 189, and into the inlet port 177 on the carrier body 151 and into the gas chamber 152.
The outlet end 126 of the gas channel carrier rail 120 contains one or more baffles 130 within the main gas channel 122, as depicted in
The gas chamber 152 is formed or otherwise disposed within the interior of the BCG 140. The gas chamber 152 is in fluid communication with the main gas channel 122 via the secondary gas channel 182 disposed in the gas channel carrier guide 180. The gas chamber 152 is formed between the carrier assembly 150, the bolt assembly 170, and two or more gas seals 176, 178 therebetween. The two gas seals 176, 178 can include a first gas seal 176 and a second gas seal 178. The first gas seal 176 is contained on a journal or gas collar 172 disposed on the bolt assembly 170. The gas collar 172 can include one or more recesses or grooves 173 for containing one or more gas seals 176. The bolt assembly 170 has a bolt tail 174 that can include one or more recesses or grooves 175 for containing one or more gas seals 178. Alternatively, the boat tail 174 on the bolt assembly 170 does not have a recess or groove and therefore the second gas seal 178 can be contained directly on the surface of the bolt tail 174. Each of the gas seals 176, 178 can independently be or include 1, 2, 3, 4, or more rings, seals, gaskets, O-rings, or other devices used for gas sealing between two or more surfaces. In some examples, each of the gas seals 176, 178 can independently be metallic gas rings that meet or exceed U.S. military specifications for the M16 or M4 weapon systems. In one or more examples, the first gas seal 176 contains three metallic gas rings and the second gas seal 178 contains three metallic gas rings. In one or more embodiments, the bolt assembly 170 can be a bolt assembly that meets or exceeds U.S. military specifications for the M16 or M4 weapon systems, but has been modified by adding the second gas seal 178 on the bolt tail 174 and/or optionally modifying forming the recess or groove 175 on the bolt tail 174.
In
Although not shown in the Figures or described in the written description, the BCG 140 includes all other parts and components contained in a bolt carrier group that meets or exceeds U.S. military specifications for the M16 or M4 weapon systems. For example, exemplary parts or components used on or in the BCG 140 can be or include, but is not limited to, a firing pin, a firing pin retaining pin, a cam pin, an extractor, an ejector, all pins and springs used with the extractor and the ejector, and/or any combination thereof. In one or more embodiments, each of the gas channel carrier rail 120, the gas channel carrier guide 180, the carrier body 151, the bolt assembly 170, or any parts or portions thereof can independently have a coating or no coating. The coating can be or include an anodizing coating, a Parkerized coating, a phosphate coating (e.g., manganese phosphate), a nitride coating, a boride coating, a nickel coating (e.g., nickel boride or nickel nitride), a chromium coating, alloys thereof, or any combination thereof.
A portion of the outlet end 126 of the gas channel carrier rail 120 has the slot 125, that can have an open “C” shape (
At this time, the bullet has exited the barrel 101 (
In one or more embodiments, an upper receiver assembly for one or more weapon systems is provided and can include the upper receiver 104, the barrel 101, and the gas block 103, as depicted in
Assembly: The gas channel carrier rail 120 is installed in the upper receiver of the firearm and attached to the gas block at the front of the barrel. The gas channel carrier rail 120 extends from the gas block on the barrel, through the adjustable tensioner 110 and the upper receiver front wall, to just inside the rear of the upper receiver. The charging handle 190 is installed in the same manner as a standard DGI system (e.g., meets military specifications for the M16 or M4 weapon systems) such that the alignment tabs 193 on each side of the charging handle 190 are aligned with the cut outs in the upper receiver and lowered into place. The slot 194 allows the charging handle 190 to pass over the rear portion of the gas channel carrier rail 120 when installed in the upper receiver.
Once the charging handle 190 is installed, the gas channel carrier guide 180 attached to the bolt carrier is inserted into the rear of the gas channel carrier rail 120; the BCG 140 can then be pushed forward to the closed position.
DGI system Operation: The gas operating system 100, as described and discussed here, is pressurized via a gas block attached to the barrel. The pressurized propellant gas travels rearward through the gas channel carrier rail 120 and into the gas channel carrier guide 180 through the inlet port 188 in the gas channel carrier rail 120 that are in alignment with the main gas channel 122 on the gas channel carrier guide 180, and into the gas chamber 152 formed in the rear of the BCG 140. Once pressurized, the action unlocks and, the expanding propellant gases force the carrier assembly 150 to the rear unlocking the bolt head 171 on the bolt assembly 170 from the barrel extension (not shown) allowing the BCG 140 to move rearward and operate the action of the weapon.
In addition, in contrast to the piston systems described above, the individual parts of the action of the gas operating system 100 are designed to operate with the “balanced in-line” operation of the pressurized gas chamber at the rear of the bolt and carrier. This “balanced in-line” system does not induce any offset or out of alignment forces on the bolt and bolt carrier and allows for a smooth operation of the weapon.
Once the BCG 140 has moved rearward completely to unlock the bolt from the barrel extension, the front gas rings 176 on the carrier assembly 150 have moved forward of the exhaust ports 107 on the right side of the carrier assembly 150, opening the exhaust ports 107 and allowing the propellant gases to be discharged out through the exhaust ports 107. In such a manner, propellant gas is directed through the exhaust port 107 in the gas operating system 100, rather than permitting exhausted propellant gas from escaping through the rear of the bolt carrier and into the action, as occurs with traditional DGI systems. The BCG 140 continues rearward until the operating or buffer spring is fully compressed, the compressed buffer spring then forces the BCG 140 forward and closes the action, with the BCG 140 locking the bolt head 171 into the barrel extension and the weapon is ready to be fired again.
Benefits of the Direct Gas Impingement (DGI), gas operating system 100: The gas operating system 100 maintains the balanced “in-line” pressurized chamber design that utilizes the expanding gases from the fired cartridge to operate the weapon and contains the gases in a “closed” system that minimizes exposure of the operating parts of the weapon to the hot carbon laden gases that overheat and foul the weapon's action.
The closed system of the gas operating system 100 requires less amount (e.g., volume) of propellant gas to operate than the traditional DGI system because the gas operating system 100 is more efficient, therefore allowing the use of a smaller diameter gas port in the barrel from which the gases are obtained. Because the system requires less volume to operate, less heat and carbon fouling is directed into the system with each shot fired, this results in a cleaner and cooler operating system compared to the traditional DGI system.
The gas operating system 100, as described and discussed herein, is a closed design that keeps the gases that are required to operate the action in a “sealed channel” from the time they enter the system at the gas port in the barrel, until they are discharged out through the right side of the bolt carrier, minimizing exposure of the other components of the weapons action to the propellant gases.
The gas tube 220 extends through an opening 102 passing through a wall of the upper receiver 104 of the firearm, as depicted in
The gas block 103 can be any gas block that meets or exceeds U.S. military specifications for the M16 or M4 weapon systems or any gas block used in the AR15 weapon system. The gas block 103 attached to the barrel 101 that directs the expanding gases from the gas port 105 in the barrel 101 into the inlet end 224 of the gas tube 220. In some examples, the gas block 103 can be a standard, non-adjustable gas block. In other examples, the gas block 103 can be an adjustable or tunable gas block. The gas tube 220 may attach to the gas block 103 with a pin or screw. The gas block 103 may be any height or profile (e.g., low or high profile gas blocks) to accommodate the gas tube 220 with straight line.
The BCG 240 contains a carrier assembly 150, a bolt assembly 170, and a gas key 280. The bolt assembly 170 is at least partially contained within the carrier assembly 150. The bolt assembly 170 and the carrier assembly 150 are axial to one another. A bolt head 171 of the bolt assembly 170 extends from the carrier assembly 150. The carrier assembly 150 contains a carrier body 151 and a gas key 280. One, two, three, or more exhaust ports 107 (two exhaust ports are drawn in phantom in
The gas key 280 is disposed on the carrier body 151 of the carrier assembly 150. In one or more embodiments, the gas key 280 and the carrier body 151 are monolithic, as such, are formed or otherwise produced as a single unit having a one piece design. In other embodiments, the gas key 280 and the carrier body 151 are separate parts that are fastened or combined together. For example, one, two, three, or more fasteners can be used to couple the gas key 280 and the carrier body 151 together. In one example, the gas key 280 and the carrier body 151 are coupled together with two bolts that pass through the gas key 280 and into threaded holes in the carrier body 151 and are each staked at the gas key 280. In other examples, the gas key 280 and the carrier body 151 are welded together. Each of the gas key 280 and the carrier body 151 can be made of or contain one or more metals, such as steel, stainless steel, titanium, or alloys thereof.
The gas key 280 contains a secondary gas channel 282 passing therethrough. The secondary gas channel 282 is disposed between and in fluid communication with the main gas channel 222 and an interior (e.g., gas chamber 152) of the BCG 240. The gas key 280 contains a lower segment 284 and an upper segment 286. The lower segment 284 is coupled to the carrier assembly 150. The gas key 280 contains an inlet port 288 and an outlet port 289. The inlet port 288 of the gas key 280 is in fluid communication with and coupled to the main gas channel 222 via the outlet end 226 of the gas tube 220. The inlet port 288 of the gas key 280 receives the outlet end 226 of the gas tube 220 which extends partially into the gas key 280. The outlet port 289 of the gas key 280 is in fluid communication with and coupled to an inlet port 277 formed through the carrier body 151 of the BCG 240. The secondary gas channel 282 extends from the inlet port 288 to the outlet port 289 and to the interior of the BCG 240, such as into the gas chamber 152, via the inlet port 277. In one or more embodiments, the gas key 280 can include a gas tube or guide that is hollow or has a passageway in the center with the secondary gas channel 282 that passes from the top center at the inlet port 288, through the neck of the guide, out of the bottom at the outlet port 289, and into the inlet port 277 on the carrier body 151 and into the gas chamber 152. The gas chamber 152 is formed or otherwise disposed within the interior of the BCG 240. The gas chamber 152, as well as other parts, portions, and/or components of the BCG 240 are the same as the similarly numbered parts, portions, and/or components of the BCG 140 and therefore are further discussed above.
In
The carrier assembly 350 has a carrier body 351 and an inlet port 377 formed within and passes through the carrier body 351. A gas chamber 352 is contained within the carrier body 351. Neither a gas channel carrier guide (e.g., the gas channel carrier guide 180, as illustrated in
The gas chamber 352 is formed between the carrier assembly 350, the bolt assembly 370 having a bolt tail 374, and one or more gas seals 376. The gas seal 376 is contained on a journal or gas collar 372 disposed on the bolt assembly 370. The gas collar 372 can include one or more recesses or grooves 373 for containing one or more gas seals 376. The gas seal 376 can be or include 1, 2, 3, 4, or more rings, seals, gaskets, O-rings, or other devices used for gas sealing between two or more surfaces. In some examples, the gas seals 376 can be 1, 2, or 3 metallic gas rings that meet or exceed U.S. military specifications for the M16 or M4 weapon systems. In one or more examples, the gas seal 376 contains three metallic gas rings.
The carrier body 351 includes a shoulder 357 disposed within the carrier body 351. The shoulder 357 can support or help align the bolt tail 374 of the bolt assembly 370. An inner surface 356 of the shoulder 357 defines an opening 355 in which the bolt tail 374 disposed therein. The diameter of the bolt tail 374 is smaller than the opening 355, therefore the remaining portion of the opening 355 forms a gap or space disposed between the bolt tail 374 and the inner surface 356. This gap or space within the opening 355 is part of the gas chamber 352 and provides an exhaust port for propellant gas, received from the inlet port 377, to pass through and exit into the rear of the bolt carrier 340 and into the action of the weapon, as occurs with traditional DGI systems. In one or more examples, such as for AR15, M16, M4, AR10, LR308, SR25, and other weapon systems, the opening 355 is about 0.2535 inches to about 0.2540 inches in diameter and the diameter of the bolt tail 374 is about 0.250 inches.
The gas chamber 352 also has a pressure surface 354 disposed on an inner surface of the carrier body 351 opposite from the journal or gas collar 372 on the bolt assembly 370. The pressure surface 354, as illustrated in
Because the gas chamber 352 uses pressurized propellant gas from the fired cartridge to pressurize the gas chamber 352 and cycle the weapon, the BCG 340 operates in a pneumatic fashion. As such, the force and speed with which the bolt carrier 350 is pushed to the rear (away from the bolt assembly 370) is directly related to the difference between the pressure surface 354 in the rear the gas chamber 352 and the pressure surface 364 in front of the gas chamber 352 (e.g., the gas collar 372 and the gas seal 376).
The bolt tail 374 extends most of the length of the gas chamber and passes through the opening or space 355 in the rear of the carrier body 351 resulting in both ends of the gas chamber 352 having the same surface area or substantially the same surface area. This configuration in which both sides (e.g., the pressure surfaces 354 and 364) of the gas chamber 352 having the same surface area or substantially the same surface area is the standard in the industry, regardless of the size of the weapon or the carrier and bolt assemblies. Although the pressure surface 354 is different between various sizes of the weapon or the carrier and bolt assemblies and the pressure surface 364 is different between various sizes of the weapon or the carrier and bolt assemblies, within any particular size of weapon, the pressure surfaces 354 and 364 are the same surface area or substantially the same.
For example, such as for an AR15, M16, and/or M4 type weapon systems, the diameter of the bolt tail 374 is about 0.250 inches and the pressure surfaces 354 and 364 are about 0.147 square inches, as depicted in
In other examples, such as for an AR10, LR308, and/or SR25 type weapon systems, the diameter of the bolt tail is about 0.250 inches and the pressure surfaces 354 and 364 are about 0.293 square inches, which is twice the surface area as in the AR15, M16, and/or M4 type weapon systems. The gap or space between the bolt tail 374 and the outer surface of the opening 355 is about 1.25×10−5 square inches for an AR10, LR308, and/or SR25 type weapon systems, which is a very small value relative to the pressure surfaces 354 and 364 having an area of about 0.293 square inches. As such, regardless of the larger size of the AR10, LR308, and/or SR25 type weapon systems, the pressure surfaces 354 and 364 have the same surface area or substantially the same surface area as each other. Therefore, the carrier body 351 moves backwards away from the bolt assembly 370 at a standardized rate relative to the amount of pressure applied by the propellant gas, although the standardized rate may be the same or different in various weapons systems.
Also, one, two, three, or more exhaust ports 307 (two exhaust ports are drawn in phantom in
When the bolt assembly 470 is in a contracted position relative to the carrier assembly 450, fluid communication between the gas chamber 452 and the exhaust port 407 is closed for removal of the propellant gas from the gas chamber 452. That is, the gas seal 476 maintains no fluid communication between the gas chamber 452 and the exhaust ports 407 so that the propellant gas builds pressure within the gas chamber 452 until the carrier assembly 450 moves into the extended position. Therefore, the bolt assembly 470 is in an extended position relative to the carrier assembly 450 (which moves away from the bolt assembly 450) when fluid communication between the gas chamber 452 and the exhaust ports 407 is opened or established for removal of the propellant gas from the gas chamber 452.
Also, one, two, three, or more exhaust ports 407 (two exhaust ports are drawn in phantom in
The carrier assembly 450 has a carrier body 451 and an inlet port 477 formed within and passes through the carrier body 451. A gas chamber 452 is contained within the carrier body 451. Neither a gas channel carrier guide (e.g., the gas channel carrier guide 180, as illustrated in
The gas chamber 452 is formed between the carrier assembly 450, the bolt assembly 470 having a bolt tail 474, and two or more gas seals 476, 478. The gas seals 476, 478 extend independently from the bolt tail 474. In one configuration, as depicted in
The carrier body 451 includes a shoulder 457 disposed within the carrier body 451. The shoulder 457 can support or help align the bolt tail 474 of the bolt assembly 470. An inner surface 456 of the shoulder 457 defines an opening or channel 455, such as a boat tail channel, in which the bolt tail 474 and the gas seal 478 are disposed within. The diameter of the gas seal 478 is the same or less than as the channel 455. In one embodiment, as shown in
The gas chamber 452 also has a piston surface 454 disposed on an inner surface of the carrier body 451 opposite from the journal or gas collar 472 on the bolt assembly 470. The piston surface 454, as illustrated in
The gas chamber 452 uses pressurized propellant gas from the fired cartridge to pressurize the gas chamber 452 and cycle the weapon, therefore, the BCG 440 operates in a pneumatic fashion. As such, the force and speed with which the bolt carrier 450 is moved to the rear away from the bolt assembly 470 is directly related to the area difference between the piston surface 454 in the rear of the gas chamber 452 and the pressure surface 464 in front of the gas chamber 452 (e.g., the gas collar 472 and the gas seal 476). The BCG 440 has better control of the cycle speed in a DGI system so to have more consistent cycling than a traditional BCG used in weapon systems having DGI.
The opening or space 455 in the rear of the carrier body 451 has a larger diameter compared to the corresponding opening in a traditional or military specification carrier body. The combination of the bolt tail 474 and the gas seal 478 has a larger diameter compared to the corresponding bolt tail on a traditional or military specification bolt assembly. However, the piston surface area, which is the area of the piston surface 454 in the rear portion of the gas chamber 452, is less than the forward chamber surface area, which is the area of the pressure surface 464 in forward portion of the gas chamber 452.
Since the area of the piston surface 454 in the rear of the gas chamber 452 (e.g., the piston surface area) is less than the area of the pressure surface 464 in front of the gas chamber 452 (e.g., the forward chamber surface area), the carrier body 451 moves backwards away from the bolt assembly 470 at a slower rate proportional to the area differential between the piston surface 454 and the pressure surface 464. The surface area of the pressure surface 464 is about 0.147 square inches for an AR15, M16, and M4 weapon systems. This configuration in which the surface area of the piston surface 454 in the rear of the gas chamber 452 is less than the surface area of the pressure surface 464 in front of the gas chamber 452 can be scaled regardless of the size of the weapon or the carrier and bolt assemblies.
For the BCG 440, the area of the piston surface 454, such as the piston surface area, is less than the area of the pressure surface 464, such as the forward chamber surface area. Particular percentages of the piston surface area relative to the forward chamber surface area can be adjusted to better control the cycle speed and have more consistent cycling. Smaller value percentages are proportionally related to slower cycle speeds. Regardless of the type of weapon system, the area of the piston surface 454, such as the piston surface area, is about 99%, about 98%, about 97%, about 96%, about 95%, about 90%, about 85%, or less of the area of the pressure surface 464, such as the forward chamber surface area. In some examples, the piston surface area is about 10%, about 20%, about 25%, about 30%, about 35%, about 40%, about 45%, about 48%, or about 50% to about 55%, about 60%, about 65%, about 68%, about 70%, about 75%, about 80%, about 85%, about 90%, about 95%, about 97%, about 98%, or about 99% of the forward chamber surface area. For example, the piston surface area is about 20% to about 99%, about 20% to about 98%, about 20% to about 97%, about 20% to about 95%, about 25% to about 97%, about 25% to about 95%, about 25% to about 90%, about 25% to about 85%, about 25% to about 80%, about 25% to about 70%, about 25% to about 60%, about 25% to about 50%, about 40% to about 85%, about 40% to about 75%, about 40% to about 65%, about 40% to about 55%, about 48% to about 85%, about 50% to about 85%, or about 60% to about 85% of the forward chamber surface area.
In one or more embodiments, such as for AR15, M16, M4, AR10, LR308, SR25, and other weapon systems, the diameter of the gas seal 478 on the bolt tail 474 is greater than 0.250 inches, such as from about 0.260 inches, about 0.270 inches, about 0.280 inches, or about 0.300 inches to about 0.320 inches, about 0.350 inches, about 0.370 inches, about 0.400 inches, about 0.420 inches, about 0.440 inches, or greater. In some examples, the diameter of the gas seal 478 on the bolt tail 474 is greater than 0.250 inches to about 0.440 inches, greater than 0.250 inches to about 0.420 inches, greater than 0.250 inches to about 0.400 inches, greater than 0.250 inches to about 0.380 inches, greater than 0.250 inches to about 0.360 inches, greater than 0.250 inches to about 0.340 inches, about 0.260 inches to about 0.440 inches, about 0.260 inches to about 0.420 inches, about 0.260 inches to about 0.400 inches, about 0.260 inches to about 0.380 inches, about 0.260 inches to about 0.360 inches, about 0.260 inches to about 0.340 inches, about 0.300 inches to about 0.440 inches, about 0.300 inches to about 0.420 inches, about 0.300 inches to about 0.400 inches, about 0.300 inches to about 0.380 inches, about 0.300 inches to about 0.360 inches, about 0.300 inches to about 0.340 inches, about 0.35 inches to about 0.44 inches, about 0.35 inches to about 0.42 inches, about 0.35 inches to about 0.40 inches, about 0.35 inches to about 0.38 inches, about 0.33 inches to about 0.37 inches, about 0.34 inches to about 0.36 inches, about 0.38 inches to about 0.42 inches, or about 0.39 inches to about 0.41 inches.
In some embodiments, the piston surface 454, as depicted in
In other embodiments, the piston surface 454, as depicted in
Although not shown in the
While the foregoing is directed to implementations of the disclosure, other and further implementations may be devised without departing from the basic scope thereof, and the scope thereof is determined by the claims that follow. All documents described herein are incorporated by reference herein, including any priority documents and/or testing procedures to the extent they are not inconsistent with this text. As is apparent from the foregoing general description and the specific embodiments, while forms of the present disclosure have been illustrated and described, various modifications can be made without departing from the spirit and scope of the present disclosure. Accordingly, it is not intended that the present disclosure be limited thereby. Likewise, the term “comprising” is considered synonymous with the term “including” for purposes of United States law. Likewise whenever a composition, an element or a group of elements is preceded with the transitional phrase “comprising”, it is understood that we also contemplate the same composition or group of elements with transitional phrases “consisting essentially of,” “consisting of”, “selected from the group of consisting of,” or “is” preceding the recitation of the composition, element, or elements and vice versa.
Certain embodiments and features have been described using a set of numerical upper limits and a set of numerical lower limits. It should be appreciated that ranges including the combination of any two values, e.g., the combination of any lower value with any upper value, the combination of any two lower values, and/or the combination of any two upper values are contemplated unless otherwise indicated. Certain lower limits, upper limits and ranges appear in one or more claims below.
This application is a continuation-in-part of U.S. application Ser. No. 16/005,381, filed Jun. 11, 2018, which claims benefit of U.S. Appl. No. 62/518,166, filed Jun. 12, 2017, which are herein incorporated by reference in their entirety.
Number | Date | Country | |
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62518166 | Jun 2017 | US |
Number | Date | Country | |
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Parent | 16005381 | Jun 2018 | US |
Child | 16179557 | US |