Patent Publication Number: US-2023160648-A1

Title: Gas system of a firearm

Description:
TECHNICAL FIELD 
     The present invention relates generally to firearms, in particular to gas systems for firearms, especially for automatic and semi-automatic firearms. More precisely the present invention relates to a gas system of a firearm according to the preamble part of claim  1 . 
     BACKGROUND 
     In firearms, usually in semi-automatic or automatic firearms, a gas system is used for the autoloading cycle for loading the cartridge and removing the shells. In the gas system of the firearm, part of pressurized gas from the cartridge being fired is used to power the gas system to extract the spent case and chamber a new cartridge. Energy from the gas is transmitted through gas openings in the barrel of the firearm. This high-pressure gas impinges on a surface such as a piston head to provide motion for unlocking of the action, extraction of the spent case, ejection, cocking of the hammer and loading of a fresh cartridge. A short stroke gas piston operating system is common on modern rifles. It is defined as a gas piston which travels less than the distance of the bolt carrier. The present invention relates to gas systems operating based on the short stroke gas piston. 
     The gas systems of firearms known from prior art known as fixed gas systems take gas all the time from the barrel as long as there is pressure, which may lead to variations in acceleration to the bolt carrier assembly, which typically causes functional issues (reliability, cycling, feeding, extraction etc.). dependent on loading and type of used cartridge (bullet, powder etc.). In prior art gas system this is usually overcome by using a manually adjustable gas regulator. Disadvantage of the regulator being manual, is that the user can forget to use the regulator for example in stressing situations, which naturally may have technical and/or functional consequences. Especially difficult situation may be caused, when a suppressor is used as then a back-pressure phenomena might be caused and in worst case the firearm malfunctions and/or breaks down. Thus, in these types of firearms typically only one or a few types of ammunition is used. 
     In patent publication U.S. Ser. No. 10/222,151 B2 is disclosed an autoloader for a gas operated automated firearm, comprising a gas chamber including an inner diameter and constructed and arranged to receive pressurized combustion gas from a gas port of a barrel of the firearm when a round is fired from the firearm; a piston having a piston head in fluid communication with said gas chamber, said piston constructed and arranged to move away from a firing position to actuate at least a portion of a cycle of the firearm when urged by pressurized combustion gas received in said gas chamber and an expansion valve disposed within the gas chamber, the expansion valve constructed and arranged to move along the inner diameter of the gas chamber from a firing position to increase a volume of said gas chamber when pressure in the gas chamber exceeds a threshold level. 
     In patent publication U.S. Pat. No. 9,702,644 B2 is disclosed a regulator for a gas operated firearm auto loader, comprising a chamber constructed and arranged to receive pressurized combustion gas from a gas port of a barrel of the firearm when a round is fired from the firearm, a piston having a piston head in fluid communication with said chamber, the piston constructed and arranged to move away from a firing position to actuate at least a portion of a cycle of the firearm when urged by pressurized combustion gas received in said chamber, and a throttling valve in fluid communication with said chamber, the throttling valve having a first position in which pressurized combustion gas from the gas port of a barrel of a firearm can flow into the chamber, and a second position in which pressurized combustion gas from the gas port of a barrel of a firearm cannot flow into the chamber, and wherein the throttling valve is configured to move from the first position to the second position when pressure in the chamber exceeds a threshold level. 
     An object of the present invention is to create a gas system of a firearm by which the above described problems and disadvantages of gas systems known from prior art are eliminated or at least minimized. 
     Another object of the present invention is to create an improved gas system of a firearm, in which human error caused disadvantages are minimized. 
     Another object of the present invention is to provide an improved gas system of a firearm, which is not ammunition sensitive. 
     Yet, another object of the present invention is to provide an improved gas system, in which manual gas adjustment is not needed. 
     SUMMARY 
     In order to achieve the above objects and those that will come apparent later the gas system of a firearm is mainly characterized by the features of the characterizing part of claim  1 . 
     Dependent claims present advantageous features and embodiments of the invention. 
     According to the invention the firearm comprises a barrel comprising gas openings, and a gas system, which gas system comprises a gas block, a gas piston, a force transmitter assembly, an indexing part and an indexing counterpart, gas openings, wherein the gas block is fixedly attached to the barrel, the gas piston is positioned by the indexing part, in the gas system gas is configured to pass through the gas opening of the barrel via the gas openings of the gas system into the gas block and to set the gas piston to movement and that in the gas system the gas piston during its movement backwards is configured to close the gas opening of the barrel for a defined time period and the gas piston is not transmitting power/energy from combustion gas to the force transmitter assembly unless the gas openings are closed. Thus, the gas system is connected to the gas of the barrel only during the defined time and the gas system is automatically controlled to prevent unlimited amount of gas entering from the barrel to the gas block. First the gas piston moves back, at the same time shutting the gas openings and finally making contact and transmitting energy/forces to the bolt carrier via the force transmitter assembly. 
     According to an advantageous feature of the invention the gas system is a short stroke gas piston system. 
     According to an advantageous feature of the invention the gas block is attached onto the barrel of the firearm. 
     According to an advantageous feature of the invention the gas block is attached around the barrel of the firearm. 
     According to an advantageous feature of the invention the gas system comprises an exhaust opening in the gas block and after a certain period of time the exhaust opening connected to ambient pressure is opened. 
     According to an advantageous feature of the invention the gas block and the gas piston together form a hollow encapsulation which is filled with gas from barrel. 
     According to the invention the gas piston is connected via a spring-loaded pin or bushing to at least one force transmitter of the force transmitter assembly. 
     According to an advantageous feature of the invention the force transmitter assembly comprises a helical return spring, which is configured to function as a return-spring returning the force transmitter assembly and the gas piston to its initial position. 
     According to an advantageous feature of the invention the indexing part comprises beveled surfaces and an indexing groove to keep the gas openings of the gas piston aligned with gas openings in the barrel and the gas block. 
     According to an advantageous feature of the invention the indexing part has an indexing counterpart with an indexing protrusion, which corresponds to the indexing groove of the indexing part of the gas piston. 
     According to an advantageous feature of the invention the gas system is located around the barrel of the firearm and comprises the gas block, the gas piston by which the energy of the gas is transmitted to mechanical movement inside the gas block, the indexing part and the force transmitter assembly and that the force transmitter assembly comprises a force transmitter sleeve, an extension part with a spring, spring-loaded pins with springs and a guide pin for keeping the gas openings in gas piston and barrel aligned. 
     According to an advantageous feature of the invention outer surface of the gas piston is provided with grooves for crust removal. 
     In this description the terms, back, front, upper, lower etc. are used as reference to the normal position of a firearm, when used for firing. They are not to have any as such limiting effect. 
     According to the invention in the autoloading cycle, the gas space within the gas block is filled for a determined time, the gas system is configured to close the gas connection between the gas openings of the gas system and the gas opening of the barrel and thus, only a certain, selected amount of gas is let into the gas space within the gas block to create the pressure behind the gas piston. 
     By the gas system according to the invention and its advantageous features many advantages are achieved: The gas system of the firearm according to the invention has an automatic function principle and thus, there is no need of human input and any disadvantages caused by human error are minimized. The gas system of the firearm according to the invention has a self-regulating function principle and thus, no manual gas adjustment is necessary. In the gas system of the firearm according to the invention the gas system shuts gas opening in the gas block once a specific amount of gas is taken for cycling the firearm. The user can safely operate the firearm with both a suppressor and without a suppressor. Further, the firearm is not ammunition sensitive as the gas system functions well with different kinds of loads. The risk of overloading the firearm system is eliminated and hence long-lifetime for the components (extractor, buffer etc.) is achieved. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       In the following the invention and its advantages are explained in greater detail below in the sense of example and with reference to accompanying drawing, where 
       In  FIG.  1    is schematically shown an advantageous example of a firearm. 
       In  FIGS.  2 - 21    is schematically shown an advantageous example of a gas system according to the invention with variations of details of the example, in which the gas system is arranged on top of the barrel of the firearm. 
       In  FIGS.  22 - 24    is schematically shown advantageous examples of operation of the gas system according to the invention. 
       In  FIGS.  25 - 32    is schematically shown another advantageous example of a gas system according to the invention, in which the gas system is arranged around the barrel of the firearm. 
       In  FIGS.  33 - 35    is schematically shown advantageous examples of operation of the gas system according to the invention. 
     
    
    
     DETAILED DESCRIPTION 
     During the course of the following description like numbers and signs will be used to identify like elements according to the different views which illustrate the invention and its advantageous examples. In the figures some repetitive reference signs may have been omitted for clarity reasons. 
     In the  FIG.  1    is shown an example of a firearm  100  comprising a barrel  101  and gas system  10 . The gas system  10  operates based on the short stroke gas piston system. 
     In  FIGS.  2 - 24    is shown one advantageous embodiment of the gas system according to the invention. 
     In the example of  FIG.  2    is shown an example of the gas system  10  of the firearm  100 . The gas system  10  comprises a gas block  11 , which is attached to a barrel  101  of the firearm  100  by spiral pins  33 , a gas piston  12  by which energy of the gas from barrel  101  is transmitted to mechanical movement, and a force transmitter assembly  13 . The gas block  11  and the gas piston  12  together form a hollow encapsulation which is filled with gas from barrel  101 . The gas piston  12  is connected via a spring-loaded pin  14  ( FIG.  3   ) to a force transmitter  15  ( FIG.  3   ) of the force transmitter assembly  13 . The spring  47  providing the spring-loading of the spring-loaded pin  14  is denoted by reference  47  in  FIG.  3   . The spring-loaded pin  14  is first compressed before contact is made to the force transmitter  15  of the force transmitter assembly. Once contact is made i.e. the gap  48  between the gas piston  12  and the force transmitter assembly  13  is closed, gas forces transmit to bolt carrier (not shown and cycling process of autoloading starts. Before that no acceleration happens to the bolt carrier assembly and a bolt (not shown) of the bolt carrier stays closed. At this position, the autoloading cycle begins. 
     In  FIG.  3    is shown an alternative of an assembly of the force transmitter assembly  13  comprising a force transmitter  15  as an exploded view. The force transmitter assembly  13  comprises by the spring  47  spring-loaded pin  14  at one end of the force transmitter  15  of the force transmitter assembly  13 . The force transmitter assembly  13  also comprises a cotter pin  49  and a spring pin  51  for fastening the components of the force transmitter assembly as shown in the  FIG.  3   . Further, the force transmitter assembly  13  comprises a helical, return spring  16 , which functions as a return-spring returning the force transmitter assembly  13  back into its initial position independent of bolt carrier movement. The helical, return spring  16  is located making contact with a spring bushing  52 . The force transmitter assembly  13  also comprises a bushing  53  for guiding the force transmitter  15 . 
     In  FIG.  4    is shown another alternative of an assembly of the force transmitter assembly  13  but instead the spring  47  loading the spring-loaded pin  14  ( FIG.  3   ) at one end of the force transmitter  15  of the force transmitter assembly  13  the spring  47  effects the spring-load to a bushing  14 B. 
     In  FIG.  5    is shown the force transmitter assembly  13  in accordance with the example of  FIG.  3    as an assembled view. At one end of the force transmitter  15  of the force transmitter assembly  13  is the spring-loaded pin  14 , which controls movements of the gas piston  12 . 
     In  FIG.  6    is shown in more detail the spring-loaded pin  14  of the force transmitter assembly  13  in accordance with the example of  FIG.  3   . The spring-loaded pin  14 , which controls movements of the gas piston  12 , is pressed in, when the gas piston  12  makes contact to the force transmitter  15 . 
     In  FIG.  7    is shown in more detail the gas piston  12  in accordance with the example of  FIG.  2   . Gas openings  18  are located on the gas piston  12 . Next to the gas openings  18  are located planar surface parts  19  for cleaner operation. Outer surface of the gas piston  12  is also provided with grooves  61  for crust removal. The gas piston  12  is provided with an indexing part  21  with bevelled surfaces  20  and an indexing groove  17  to keep the gas openings  18  of the gas piston  12  aligned with gas openings in the barrel  101  and the gas block  11 . If this would be in wrong position, no gas could flow into the gas piston  12 . The indexing groove  17  is to secure the gas piston  12  at correct position inside the gas block  11 , which moves the gas piston  12  that actuates the force transmitter  15  included in the force transmitter assembly  13 , which at the end pushes a bolt carrier. The force transmitter  15  is mounted to an opening  54  at one end of the gas piston  12 . 
     In  FIG.  8    is shown in more detail one end of the gas piston  12  in accordance with the example of  FIG.  7   . The indexing groove  17  for securing the gas piston  12  has the beveled surface parts  20 . 
     In  FIG.  9    is shown in more detail front side of the gas piston  12  in accordance with the example of  FIG.  7   . As can be seen from the figure the gas piston  12  has a tubular form. 
     In  FIG.  10    is shown in more detail front side of an indexing counterpart  22  located below the gas piston  12  in accordance with the example of  FIG.  2   . The indexing part  21  comprises thus the indexing counterpart  22 . The indexing counterpart  22  has an indexing protrusion  23 , which corresponds to the indexing groove  17  of the indexing part  21  of the gas piston  12 . A form-fitting joint is formed by the indexing groove  17  of the indexing part  21  and the indexing protrusion  23  of the indexing counterpart  22  and thus, the gas piston  12  is located at the correct position. The indexing protrusion  23  guides by the indexing groove  17  the gas piston  12  to its correct location. 
     In  FIG.  11    is shown the force transmitter assembly  13  in accordance with the example of  FIG.  4    as an assembled view. In this example the force transmitter assembly  13  comprises by the spring  47  ( FIG.  4   ) spring-loaded bushing  14 B at one end of the force transmitter  15  of the force transmitter assembly  13 . The spring  47  effects the spring-load to the bushing  14 B. Further, the force transmitter assembly  13  comprises the helical, return spring  16 , which functions as the return-spring returning the force transmitter assembly  13 , when the bolt carrier has returned back. The helical, return spring  16  is located at a spring bushing  52 . The force transmitter assembly  13  also comprises a bushing  53  for guiding the force transmitter  15 . 
     In the  FIG.  12    is shown a more detailed example of the outer circumference with crust removal grooves  61  of the force transmitter  15  of the force transmitter assembly  13  in accordance with the example of  FIG.  4   . The spring-loaded bushing  14 B does the same function as the spring-loaded pin  14 . The spring  47  is located inside bushing  14 B and is a helical spring and the forces are transmitted using the helical spring  47  inside to the force transmitter  15 . 
     In the  FIG.  13    is shown a more detailed example of an example of an end  25  of the force transmitter assembly  13  in accordance with the example of  FIG.  4   . In this example the end  25  of the force transmitter assembly  13  is tapered for controlling the position of the force transmitter assembly  13  in conjunction with a gas piston  12  ( FIG.  16   ). 
     In the  FIGS.  14  and  15    are shown more detailed examples of further examples for controlling the position of the force transmitter assembly  13  by the end  25  of the force transmitter assembly  13  in accordance with the example of  FIG.  4   . In these examples one end  25  of the force transmitter  15  is turnable to selected positions. 
     In  FIG.  16    is shown a more detailed example of an alternative of the indexing part  21  of the gas piston  12 . The indexing part  21  of the gas piston  12  has a protrusion  27 , which corresponds to the indexing groove  27  of the indexing counterpart  22  ( FIG.  17   ). A form-fitting joint is formed by the indexing groove  26  and the indexing protrusion  27  and thus, the gas piston  12  is located at the correct position. The indexing protrusion  27  guides by the indexing groove  26  the gas piston  12  to its correct location. 
     In  FIG.  17    is shown the example of  FIG.  16    yet in greater detail. Additionally, in the figure is shown the gas piston  12  at the position, where it has travelled to contact the force transmitter  15 . In this position no more gas passes from the barrel  101  of the firearm  100  to the gas piston  12  and charging is finished. Only the gas encapsulated inside the gas block/gas piston  12  volume is contributing to the cycling of the weapon now. 
     In  FIGS.  18  and  19    is shown the example of  FIG.  10   . The press button assembly  28  is pressed down and the indexing counterpart  22  is unlocked and the gas piston  12  is released as shown in  FIGS.  7 - 9   . The positioning tag  57  positions the barrel  101  and the gas block  11 . 
     In  FIGS.  20 - 21    is shown the gas block  11  of the gas system  10 . Inside the gas block  11  a space  29  is provided for the gas piston  12 . Towards the space  29  inside the gas block  11  grooving  30  is provided for crust removal and gas sealing. At least one bore  31  is provided also in the gas block  11  for the indexing counterpart  22 . Additionally, one exhaust opening  32  is provided on the front of the gas block  11 . The gas block  11  will be attached onto the barrel  101  of the firearm  100  by attachment means, for example by spiral locking pins  33 . 
     In the following the operation of the gas system  10  is described with reference to  FIGS.  22 - 24    and to the example of the  FIGS.  2 - 21   . 
     In  FIG.  22    is shown stage  1 , when a shot is fired and the bullet B has not yet reached the gas openings  18  and no gas passes yet into the gas block  11 . In this stage openings of the gas piston  12  are aligned with the gas openings  18  and the exhaust opening  32  is closed by the gas piston  12 . Thus, the gas system  10  is still in its initial setting. Once the bullet B passes beyond the first of the gas openings  18 , gas will start streaming into the gas block  11 . The pressure inside the gas block  11  rises and the gas piston  12  starts moving, while the bullet B continues its travelling towards the end of the barrel  101 . The gas piston  12  acts on the bushing  14 B or the spring loaded pin  14  respectively ( FIGS.  4 - 6   ) integrated into the force transmitter assembly  13  ( FIGS.  2 - 7 ,  11 - 15   ) and the force transmitter  15  ( FIGS.  2 - 7 ,  11 - 12 ,  17   ), which do not move at this point and hence do not transmit momentum onto the bolt carrier. At this stage the cycling operation has not yet begun. 
     In  FIG.  23    is shown stage  2 , when the bullet B has reached the end of the barrel  101 . The gas piston  12  has moved to rest against the force transmitter assembly  13  ( FIGS.  2 - 7 ,  11 - 15   ) and the force transmitter  15  ( FIGS.  2 - 7 ,  11 - 12 ,  17   ), which are still stationary and have not yet accelerated the bolt carrier. At this stage no more gas from barrel  101  can flow into the gas openings  18  and the exhaust opening  32  is still closed. Additionally, to the bushing  14 B or the spring-loaded pin  14  ( FIGS.  4 - 6   ) pressure inside the gas block  11  acts onto the bolt carrier by means of the force transmitter assembly  13  ( FIGS.  2 - 7 ,  11 - 15   ) and the force transmitter  15  ( FIGS.  2 - 7 ,  11 - 12 ,  17   ). After the bullet B has passed through the end of the barrel  101 , movement of the bolt carrier is initiated. As this happens only after the bullet B has left the barrel  101 , any harmful vibrations cannot influence accuracy of the trajectory of the bullet B anymore. After this stage, the movement of the bolt carrier will unlock the bolt and finally start the cycling operation, which has altogether been delayed up till this stage. It should be noted that in the gas operating systems according to prior art the cycling starts immediately once gas reaches the gas piston. 
     In  FIG.  24    are shown stages  3  and  4 , when the bullet B is long gone and travels towards its target along its trajectory. In the meantime the pressurized gas enclosed within the internal volume of the gas openings  18  has carried out work and by means of the gas piston  12  pushed the force transmitter assembly  13  ( FIGS.  2 - 7 ,  11 - 15   ) and the force transmitter  15  ( FIGS.  2 - 7 ,  11 - 12 ,  17   ) backwards for a certain distance and therewith transmitted momentum to the bolt carrier. The force transmitter assembly  13  ( FIGS.  2 - 7 ,  11 - 15   ), the force transmitter  15  ( FIGS.  2 - 7 ,  11 - 12 ,  17   ) and the gas piston  12  stop at some point and the bolt carrier and the bolt continues moving on its own in accordance to “the short-stroke system”—principle. Shortly before the gas piston  12  reaches its rest position after having accelerated the bolt and the bolt carrier, the exhaust opening  32  is opened. At this point the still pressurized working gas inside the gas block  11  is streaming through the exhaust opening  32  forward away from the shooter and the gas is released to the environment. The openings of the gas piston  12  are still shut so that no remaining combustion gases can flow into the gas block  11  through the gas openings  18 . After the pressure inside the gas block  11  has sunk sufficiently, the spring-actuated force transmitter assembly  13  including the force transmitter  15  and the spring-loaded bushing  14 ,  14 B will together with the gas piston  12  return into their initial position i.e. stage  1  shown in  FIG.  22   . 
     It should be noted that in the above description referring to the  FIGS.  22 - 24    the operation of the gas system  10  has been explained in view of an example comprising two gas openings  18 . The gas system  10  can comprise one or more gas openings  18 . 
     In  FIGS.  25 - 35    is shown one advantageous embodiment of the gas system according to the invention. 
     In the example of  FIG.  25    is shown another example of a gas system  10  of the firearm  100 . The gas system  10  is located around the barrel  101  of the firearm  100 . 
     In  FIG.  26    is shown as an exploded view the example of  FIG.  25    of the gas system  10  located around the barrel  101  of the firearm  100 . The gas system  10  comprises a gas block  11 , a gas piston  12  by which the energy of the gas is transmitted to mechanical movement inside the gas block  11 , an indexing part  21  and a force transmitter assembly  13 . A force transmitter assembly comprises a sleeve  15 , an extension part  55  with spring (not shown), spring-loaded pins  14  with springs  47  and guide pin  42  for keeping the gas openings in gas piston  12  and barrel  101  aligned. 
     In  FIG.  27    is shown the gas block  11  of the example of  FIGS.  25 - 26   . 
     In  FIG.  28    is shown the gas piston  12  of the example of  FIGS.  26 ,  33 - 35   . 
     In  FIG.  29    is shown the force transmitter assembly  13  of the example of the  FIGS.  26 ,  33 - 35   . A force transmitter assembly comprises a sleeve  15 , an extension part  55  with a spring (not shown), spring-loaded pins  14  with springs  47  and a guide pin  42 . 
     In  FIG.  30    is shown the force transmitter assembly  13  of the example of the  FIG.  26    in greater detail. The force transmitter sleeve  15  comprises three pins  14 , which are spring-loaded with springs  47  and one guide pin  42 . 
     In  FIGS.  31 - 32    is shown the force transmitter extension part  55  and the indexing part  21  of the example of the  FIGS.  25 - 26   . 
     In the following the operation of the gas system  10  is described with reference to  FIGS.  33 - 35    and to the example of the  FIGS.  25 - 32    but it should be noted that the examples presented in  FIGS.  2 - 24    operate correspondingly by substantially same functions and basis. In  FIG.  33    is shown the basic situation and in  FIG.  34    the situation, when the gas piston  12  and spring-loaded pins  14  move and in  FIG.  35    the situation, when the gas piston  12  and the force transmitter assembly  13  move. 
     The gas block  11  and the indexing part  21  are not moving parts but instead stay at their locations. In the basic situation the force transmitter assembly  13  has pushed the gas piston  12  to its front position and thus, the spring-loaded pins  14  have pushed the gas piston  12  to its front position and the gas can flow through the gas openings  18  to the space in between the gas piston  12  and the gas block  11 . Pressure of the gas in the space between the gas piston  12  and the gas block  11  moves the gas piston  12  and from the gas opening  18  no further gas can enter the space between the gas piston  12  and the gas block  11 . The spring-loaded pins  14  of the force transmitter sleeve  15  have been pressed in to pressed position. When the pressure of the gas between the gas piston  12  and the gas block  11  has moved the force transmitter assembly  13  against the indexing part  21  the gas can flow off through the openings  32  in the gas block  11 . At the end, the force transmitter assembly  13  and the gas piston  12  are pushed to the front position and the spring-loaded pins  14  push the gas sleeve to its front position and the gas system  10  is back in the basic situation. 
     In the description in the foregoing, although some functions and elements have been described with reference to certain features and examples, those functions and elements may be performable by other features and examples whether described or not. Although features have been described with reference to certain embodiments or examples, those features may also be present in other embodiments or examples whether described or not. 
     Above only some advantageous examples of the inventions have been described to which examples the invention is not to be narrowly limited and many modifications and alterations are possible within the invention.