WO2024141369A1

WO2024141369A1 - Magazine unit and bolt unit for converting a firearm into a cartridge-free simulation firearm

Info

Publication number: WO2024141369A1
Application number: PCT/EP2023/086919
Authority: WO
Inventors: Danni Pharao MUNK
Original assignee: Cph Innotech Aps
Priority date: 2022-12-29
Filing date: 2023-12-20
Publication date: 2024-07-04
Also published as: DK202270654A1

Abstract

Magazine unit (1) and bolt unit (20) for reversibly converting a firearm (2) to a cartridge-free simulation firearm. The magazine unit (1) comprises a first compressed gas container (3) comprising a first gas and a second compressed gas container (4) comprising a second gas. A valve assembly (7) allows simultaneous flow of said first gas and said second gas to a combustion chamber (8) of said firearm (2). The bolt unit (6) comprises a moveable, hollow bolt carrier (21) and a stationary combustion chamber (8) arranged within an interior of said hollow bolt carrier (21), said combustion chamber (8) being configured to receive a combustible gas mixture. An ignition element (22) is configured to ignite said combustible gas mixture, and expansion of said combustible gas mixture generates linear movement of said hollow bolt carrier (21) from a first bolt position (P5) to a second bolt position (P6).

Description

MAGAZINE UNIT AND BOLT UNIT FOR CONVERTING A FIREARM INTO A CARTRIDGE-FREE SIMULATION FIREARM

TECHNICAL FIELD

The disclosure relates to a magazine unit and a bolt unit for converting a firearm to a cartridge-free simulation firearm, a method for converting a firearm to a cartridge -free simulation firearm, as well as a cartridge -free simulation firearm. The magazine unit comprises gas and a valve assembly. The bolt unit comprises a movable, hollow bolt carrier.

BACKGROUND

Firearm use has to be trained and combat situations have to be simulated as realistically as possible. Conventionally, live fire has been simulated by using blank rounds of ammunition. Blanks are not only expensive due to manufacturing, transport, and storage costs, but are also environmentally unfriendly.

There have also been made attempts to develop realistic weapon simulators, e.g. in the form of replicas or by retrofitting functional, live round firearms into simulators, utilizing lasers to provide instantaneous feedback indicating the effectiveness of the fire. However, these types of simulated firearms do not provide a realistic feel since they do not recoil in response to the simulated fire.

In order to simulate recoil, solutions utilizing CO2 or compressed air have been suggested. The gas is, in some solutions, provided via a compressed gas line coupled to the simulated weapon. Such solutions have the drawback that the gas line limits the user’s mobility and affects the aim. Other solutions require a part of the firearm, e.g. the original magazine, to be replaced with a component comprising a CO2 cartridge. Such solutions are usually non- reversible, i.e. the fireararm is no longer usable for live ammunition, or are difficult to implement, the conversion often requiring a specially trained technician to install the conversion components.

Hence, there is a need for solutions allowing simple and reversible conversion of a firearm into a simulation firearm which provides a realistic firing sensation by providing the same feel and balance as the original firearm, and which generates proper firing feedback to the user.

SUMMARY

It is an object to provide improved components, system, and method for reversibly converting a firearm to a cartridge-free simulation firearm. The foregoing and other objects are achieved by the features of the independent claims. Further implementation forms are apparent from the dependent claims, the description, and the figures.

According to a first aspect, there is provided a magazine unit for reversibly converting a firearm to a cartridge-free simulation firearm, the magazine unit comprising at least one first compressed gas container comprising a first gas; at least one second compressed gas container comprising a second gas; and a valve assembly configured to simultaneously allow flow of the first gas from the first compressed gas container and flow of the second gas from the second compressed gas container to a combustion chamber of the firearm.

Such a solution allows a gas mixture to be used for generating a recoil, a sound, and/or a muzzle flash of a firearm without requiring blanks. Furthermore, the magazine unit allows simple and direct replacement of an original cartridge-carrying magazine with a magazine unit solution integratable into the firearm and simulating gunfire using a gas mixture. In a possible implementation form of the first aspect, the magazine unit further comprises a first gas reservoir fluidly connected with the first compressed gas container; a second gas reservoir fluidly connected with the second compressed gas container; the valve assembly being configured to simultaneously allow flow of the first gas from the first compressed gas container to the first gas reservoir and flow of the second gas from the second compressed gas container to the second gas reservoir, and configured to simultaneously allow flow of the first gas from the first gas reservoir and flow of the second gas from the second gas reservoir to the combustion chamber of the firearm. This allows correct amounts of gases to be drawn in advance from the gas containers, ready for mixing in the combustion chamber at the exact time needed.

In a further possible implementation form of the first aspect, the valve assembly comprises at least one first reduction valve configured to fluidly connect the first compressed gas container with the first gas reservoir, at least one second reduction valve configured to fluidly connect the second compressed gas container with the second gas reservoir; a first check valve configured to fluidly connect the first gas reservoir with the combustion chamber of the firearm, and a second check valve configured to fluidly connect the second gas reservoir with the combustion chamber of the firearm; a first control valve configured to, in a first open position, allow the first gas to flow from the first reduction valve to the first gas reservoir, and, in a second open position, allow the first gas to flow from the first gas reservoir to the first check valve, and a second control valve configured to, in a first open position, allow the second gas to flow from the second reduction valve to the second gas reservoir, and, in a second open position, allow the second gas to flow from the second gas reservoir to the second check valve. The different valves allow the pressure of the compressed gas to be reduced automatically, as well as gas flow along two different paths using the same components. This facilitates a solution that is as simple, non-complex and with as few components as possible.

In a further possible implementation form of the first aspect, wherein the valve assembly further comprises a first gas line extending between each first reduction valve and the first gas reservoir, the first check valve being arranged within the first gas line, a second gas line extending between each second reduction valve and the second gas reservoir, the second check valve being arranged within the second gas line; a third gas line extending between the first gas reservoir and the first check valve, the first check valve being interconnected with the third gas line, a fourth gas line extending between the second gas reservoir and the second check valve, the second check valve being interconnected with the fourth gas line. This allows for a very simple, space-efficient, and reliable solution for storing and transporting gas.

In a further possible implementation form of the first aspect, the magazine unit further comprises a pivot arm configured to, when pivoting from a disengaged position and an engaged position, drive the first control valve and the second control valve from the first open position to the second open position. This allows a fully mechanical solution, avoiding the need for electronics which not only take up space but are also a risk when using combustible gas.

In a further possible implementation form of the first aspect, the first gas is O2 and the second gas is a biofuel, optionally CH4 or compressed natural gas. This allows for a combustible gas mixture that can generate recoil, sound, and muzzle flash when ignited and in cooperation with other components of the converted firearm.

According to a second aspect, there is provided a bolt unit for reversibly converting a firearm to a cartridge-free simulation firearm, the bolt unit comprising a hollow bolt carrier, the bolt carrier being configured to move linearly between a first bolt position and a second bolt position when arranged within the firearm; a stationary combustion chamber arranged within an interior of the hollow bolt carrier, the combustion chamber being configured to receive a combustible gas mixture; an ignition element configured to ignite the combustible gas mixture, expansion of the combustible gas mixture generating linear movement of the hollow bolt carrier from the first bolt position to the second bolt position.

Such a solution allows a recoil to be generated by means of a bolt unit which is a direct replacement of an original bolt unit. In a possible implementation form of the second aspect, the ignition element is fixed to the hollow bolt carrier and extends at least partially within the combustion chamber when the hollow bolt carrier is in the first bolt position, preventing the ignition element from becoming damaged as the gas in the combustion chamber expands.

In a further possible implementation form of the second aspect, the ignition element is a piezo element, facilitating simple and reliable ignition.

In a further possible implementation form of the second aspect, the bolt unit further comprises a gas evacuation line configured to evacuate expanding gas from the combustion chamber to an exterior, the gas evacuation line being fluidly connected with the interior of the hollow bolt carrier when the hollow bolt carrier is in the second bolt position. This allows the combustion chamber to be emptied and a muzzle flash to be simulated at the end of the gas evacuation line.

In a further possible implementation form of the second aspect, the gas evacuation line is fluidly disconnected from the interior of the hollow bolt carrier when the hollow bolt carrier is in the first bolt position, the combustion chamber forming a barrier between the interior of the hollow bolt carrier and the gas evacuation line. This allows the combustion chamber to be filled with gas.

In a further possible implementation form of the second aspect, the hollow bolt carrier and the ignition element are configured to return to the first bolt position from the second bolt position in response to a force applied by a resilient element of the firearm, utilizing existing parts of the firearm and hence avoiding the need for rebuilding the firearm.

In a further possible implementation form of the second aspect, expanding gas evacuating through the gas evacuation line generates an impression of a muzzle flash of the firearm.

In a further possible implementation form of the second aspect, the linear movement of the hollow bolt carrier and the ignition element from the first bolt position to the second bolt position generates an impression of a recoil in the firearm, and/or the expansion of the combustible gas mixture generates an audible impression of a discharge from the firearm.

According to a third aspect, there is provided a method of reversibly converting a firearm into a cartridge-free simulation firearm, the method comprising the steps of replacing an original bolt unit of the firearm with the bolt unit according to the above, and replacing an original cartridge-containing magazine of the firearm with the magazine unit according to the above.

This solution allows a firearm to be reversibly converted to a cartridge-free simulation firearm, by exchanging a limited number of original firearm components. Modern firearms are designed such that major parts can be easily removed for cleaning and maintenance, or for storage. Such standard disassembly procedures are provided by the manufacturer and are also part of the standard drill in the armed forces. Disassembly and reassembly of the bolt unit and magazine unit are skills entirely within the capabilities of an average user, and skills typically required for qualification in organized training or, in some jurisdictions, to be allowed to use the firearm.

In a possible implementation form of the third aspect, reversing the conversion of the firearm to the cartridge-free simulation firearm comprises the steps of replacing the bolt unit with the original bolt unit, and replacing the magazine unit with the original cartridgecontaining magazine.

According to a fourth aspect, there is provided an exchangeable gas system for reversibly converting a firearm to a cartridge-free simulation firearm, the exchangeable gas system being configured to generate an impression of a recoil, a fired shot, and/or a muzzle flash in the firearm, the exchangeable gas system comprising the magazine unit according to the above, and the bolt unit according to the above.

This allows reversible conversion of a firearm into a simulation firearm capable of reproducing tactile, visual, and acoustic signatures associated with firing a firearm. The solution is directly integrated into a firearm originally intended for live ammunition, allowing the user to utilize the original firearm mechanism yet allowing the cost advantages.

In a possible implementation form of the fourth aspect, the magazine unit and the bolt unit are configured to be scalable for use with a range of firearm platforms. This allows the invention to be utilized for any conceivable firearm, since no redesign other than adaptation to a select number of dimensions has to be done in order to fit the invention to a larger or smaller firearm.

According to a fifth aspect, there is provided a firearm reversibly converted to a cartridge- free simulation firearm, the firearm comprising an original frame of the firearm, an original trigger unit of the firearm, an original barrel of the firearm, and the exchangeable gas system according to the above.

This solution allows a firearm to be reversibly converted to a cartridge-free simulation firearm, by replacing a limited number of original firearm components. The present invention takes advantage of the remaining major components of the original firearm, in particular utilizing an unaltered trigger unit. This allows the user’s feel when pressing the trigger to be exactly the same in the simulation firearm as in the original firearm when firing live ammunition. This is very important for proper training and for becoming accustomed to one’s own firearm, trigger characteristics greatly affecting the accuracy of the firearm when firing.

In a possible implementation form of the fifth aspect, a hammer of the trigger unit is configured to simultaneously engage the ignition element of the hollow bolt carrier of the exchangeable gas system, the engagement generating a spark from the ignition element, and the pivot arm of the magazine unit of the exchangeable gas system, the engagement generating a pivoting action of the pivot arm. This allows an existing component of the original firearm to be used to open the control valves such that the combustion chamber can be filled with a combustible gas mixture and to ignite the combustible gas. In a further possible implementation form of the fifth aspect, a resilient element of the trigger unit is configured to apply a force onto an end of the hollow bolt carrier, the force being applied in a direction towards the combustion chamber of the exchangeable gas system. This allows an existing component of the original firearm to be used as part of the simulation operation.

In a further possible implementation form of the fifth aspect, the force is configured to force the hollow bolt carrier to return from the second bolt position to the first bolt position, allowing the original components of the firearm to move the bolt carrier back into its original position.

These and other aspects will be apparent from the embodiments described below.

BRIEF DESCRIPTION OF THE DRAWINGS

In the following detailed portion of the present disclosure, the aspects, embodiments, and implementations will be explained in more detail with reference to the example embodiments shown in the drawings, in which:

Fig. 1 shows a cross-sectional view of a firearm converted into a cartridge-free simulation firearm, in accordance with an example of the embodiments of the disclosure;

Fig. 2a shows a partial cross-sectional view of a firearm converted into a cartridge-free simulation firearm, in accordance with an example of the embodiments of the disclosure, wherein the trigger of the firearm is not actuated;

Fig. 2b shows the example of Fig. 2a, wherein the trigger of the firearm is being actuated;

Fig. 2c shows the example of Figs. 2a and 2b, after the trigger of the firearm has been actuated; Figs. 3a and 3b show partial cross-sectional views of a magazine unit in accordance with an example of the embodiments of the disclosure;

Figs. 4a and 4b show partial cross-sectional views of a bolt unit in accordance with an example of the embodiments of the disclosure, wherein the bolt unit is in a first bolt position;

Figs. 5a and 5b show the example of Figs. 4a and 4b, wherein the bolt unit is in a second bolt position.

DETAILED DESCRIPTION

Fig. 1 shows one type of firearm 2, a rifle, reversibly converted to a cartridge-free simulation firearm in the form of a simulation rifle. Figs. 2a to 2c shows a further type of firearm 2, a pistol, reversibly converted to a cartridge-free simulation firearm in the form of a simulation pistol.

Regardless of the type of firearm 2, the original, unconverted firearm comprises a number of features including an original frame 25, an original trigger unit 26 comprising a hammer 28 and a resilient element 29, an original barrel 27, an original bolt unit, and an original cartridge-containing magazine.

A converted firearm, according to the present invention and as illustrated in Figs. 1 to 2c, maintains the original frame 25, original trigger unit 26 including hammer 28 and resilient element 29, and original barrel 27. However, the original bolt unit (not shown) has been replaced with bolt unit 20 described further below. Furthermore, the original cartridgecontaining magazine has been replaced with magazine unit 1 also described further below.

The present invention relates to a method of reversibly converting the firearm 2, capable of firing live ammunition, into a cartridge-free simulation firearm, incapable of firing live ammunition or even blank ammunition. The method comprises the steps of replacing the original bolt unit of the firearm with the bolt unit 20 and replacing the original cartridgecontaining magazine of the firearm with the magazine unit 1. In other words, the original bolt unit and the original cartridge-containing magazine have been replaced by removing them from the firearm, in accordance with usual firearm disassembly procedures, and by fitting bolt unit 20 and magazine unit 1 in their place. No further disassembly, assembly or reconfiguration of the firearm is necessary. The firearm may be semi-automatic or automatic, and the converted firearm may simulate a semi-automatic or automatic function. Furthermore, the firearm may be a firearm utilizing an ammunition clip or an ammunition belt.

The conversion is reversed, i.e. the cartridge-free simulation firearm is converted back into a firearm for live ammunition, by a method comprising the steps of replacing the bolt unit 20 with the original bolt unit, and replacing the magazine unit 1 with the original cartridgecontaining magazine.

The present invention also relates to an exchangeable gas system 24 for reversibly converting a firearm 2 to a cartridge-free simulation firearm, the exchangeable gas system 24 comprising the above-mentioned magazine unit 1 and bolt unit 20. The exchangeable gas system 24 is configured to generate an impression of a recoil, i.e. a tactile result of firing a firearm, a fired shot, i.e. an audible result of firing a firearm, and/or a muzzle flash in the firearm, i.e. a visible result of firing a firearm.

By exchanging only the magazine unit 1 and bolt unit 20, standard assembly and disassembly procedures, skills entirely within the capabilities of an average user, can be used to convert a firearm capable of firing live ammunition into a simulation firearm incapable of firing live ammunition but capable of simulation the effects of firing live ammunition, and the reverse.

The magazine unit 1 and the bolt unit 20 may be configured to be scalable for use with a range of firearm platforms. This allows the invention to be utilized for any conceivable firearm, such as a rifle as illustrated in Fig. 1 or a pistol as illustrated in Figs. 2a to 2c, since no redesign other than adaptation to a select number of dimensions has to be done in order to fit the invention to a larger or smaller firearm.

Figs. 3a and 3b show a magazine unit 1 for reversibly converting a firearm 2 to a cartridge- free simulation firearm. The magazine unit 1 comprises at least one first compressed gas container 3 comprising a first gas and at least one second compressed gas container 4 comprising a second gas. The number of gas containers depends on the gases used and the applicable mixing ratio for these gases. The first gas may be O2 and the second gas may be a biofuel, optionally, the second gas may be CH4 or compressed natural gas. In an example wherein the first gas is O2 and the second gas is CH4, the gases are preferably mixed at a 2: 1 ratio. Preferably, such a ratio is achieved by simultaneously supplying O2 from two first compressed gas containers 3 and CH4 from one second compressed gas container 4. By adapting the number of gas containers 3, 4 to the desired gas mix ratio, the correct mixing ratio can be achieved by multiplying identical components and without using complex mixing arrangements. The pressure of the first gas and the second gas, when in the first and second compressed gas containers 3, 4 may be around 200 bar.

A valve assembly 7 is provided, the valve assembly 7 being configured to simultaneously allow flow of the first gas from the first compressed gas container 3 and flow of the second gas from the second compressed gas container 4 to a combustion chamber 8 of the firearm 2. The combustion chamber 8, in which the first gas and the second gas are mixed for the first time, is described further below.

The magazine unit 1 may further comprise a first gas reservoir 5 fluidly connected with the first compressed gas container 3 and, correspondingly, a second gas reservoir 6 fluidly connected with the second compressed gas container 4. The valve assembly 7 is configured to simultaneously allow flow of the first gas from the first compressed gas container 3 to the first gas reservoir 5 and flow of the second gas from the second compressed gas container 4 to the second gas reservoir 6. Furthermore, the valve assembly 7 is configured to simultaneously allow flow of the first gas from the first gas reservoir 5 and flow of the second gas from the second gas reservoir 6 to the combustion chamber 8 of the firearm 2. In other words, the first compressed gas container 3 is fluidly connected to the first gas reservoir 5 and the first gas reservoir 5 is, in turn, fluidly connected to the combustion chamber 8. The second compressed gas container 4 is fluidly connected to the second gas reservoir 6 and the second gas reservoir 6 is, in turn, fluidly connected to the combustion chamber 8. The gas containers 3,4, gas reservoirs 5, 6, and combustion chamber 8 are fluidly connected via gas lines, 15, 16 , 17, 18 and valves 9, 10, 11, 12, 13, 14, as described below.

The valve assembly 7 comprises at least one first reduction valve 9 configured to fluidly connect the first compressed gas container 3 with the first gas reservoir 5, and at least one second reduction valve 10 configured to fluidly connect the second compressed gas container 4 with the second gas reservoir 6. The first and second reduction valves 9, 10 may be configured to reduce the pressure of the first and second gases from around 200 bar to around 20 bar as the gases exit gas containers 3, 4.

A first check valve 11 may be configured to fluidly connect the first gas reservoir 5 with the combustion chamber 8 of the firearm 2, and a second check valve 12 may be configured to fluidly connect the second gas reservoir 6 with the combustion chamber 8 of the firearm 2. The first and second check valves 11, 12 ensure mixed gas does not travel in the opposite direction, into the gas reservoirs 5, 6.

A first control valve 13 may be configured to, in a first open position Pl as illustrated in Fig. 2a, allow the first gas to flow from the first reduction valve 9 to the first gas reservoir 5, and, in a second open position P2 as illustrated in Fig. 2b, allow the first gas to flow from the first gas reservoir 5 to the first check valve 11. The first control valve 13 is configured such that only one gas flow is possible at a time. In other words, when the first control valve 13 is in the first open position Pl, first gas can travel only from the first gas container 3, via first reduction valve 9, and into the first gas reservoir 5. When the first control valve 13 is in the second open position P2, first gas can travel only from the first gas reservoir 5 into the combustion chamber 8 via the first check valve 11. This allows the first gas reservoir 5 to be filled separately, immediately, and constantly when the first control valve 13 is in the first open position Pl, which is the position used when not firing the firearm. Correspondingly, a second control valve 14 may be configured to, in a first open position Pl, allow the second gas to flow from the second reduction valve 10 to the second gas reservoir 6, and, in a second open position P2, allow the second gas to flow from the second gas reservoir 6 to the second check valve 12. The second control valve 14 is configured such that only one gas flow is possible at a time. In other words, when the second control valve 14 is in the first open position Pl, second gas can travel only from the second gas container 4, via second reduction valve 10, and into the second gas reservoir 6. When the second control valve 14 is in the second open position P2, second gas can travel only from the second gas reservoir 6 into the combustion chamber 8 via the second check valve 12. This allows the second gas reservoir 6 to be filled separately, immediately, and constantly when the second control valve 14 is in the first open position Pl, which is the position used when not firing the firearm. When the first and second control calves 13, 14 are in the second open position P2, the first and second gas located in the first and second gas reservoir 5, 6 is allowed to travel, via separate gas lines, into the combustion chamber 8 where the first and second gases mix to allow combustion.

The valve assembly 7 may further comprise a first gas line 15 extending between each first reduction valve 9 and the first gas reservoir 5, the first check valve 11 being arranged within the first gas line 15. A second gas line 16 may extend between each second reduction valve 10 and the second gas reservoir 6, the second check valve 12 being arranged within the second gas line 16. A third gas line 17 may extend between the first gas reservoir 5 and the first check valve 11, the first check valve 11 being interconnected with the third gas line

17. A fourth gas line 18 may extend between the second gas reservoir 6 and the second check valve 12, the second check valve 12 being interconnected with the fourth gas line

18. Each gas line 15, 16, 17, 18 is a separate line, though gas lines configured to accommodate identical gas may be connected to the same gas reservoir 5, 6. Nevertheless, it is conceivable that each gas line is connected to an individual gas reservoir. As illustrated in Figs. 2a to 3b, the magazine unit 1 may further comprise a pivot arm 19 configured to, when pivoting from a disengaged position P3, as illustrated in Fig. 2a and an engaged position P4, as illustrated in Fig. 2b, drive the first control valve 13 and the second control valve 14 from their respective first open positions Pl to their respective second open positions P2. Preferably, the magazine unit 1 comprises only one pivot arm 19 driving all first and second control valves 13, 14. A hammer 28 of the trigger unit 26 of the firearm may be configured to engage, or strike, the pivot arm 19, this engagement generating the pivoting action of the pivot arm 19 shown in Figs. 2a and 2b. After the engagement of the hammer 28, as the hammer returns to its initial position, the pivot arm 19 pivots back to the disengaged position P3 as shown in Fig. 2c allowing the hammer 28 to strike the pivot arm 19 once again as the trigger is squeezed.

Figs. 4a to 4d show a bolt unit 20 for reversibly converting a firearm 2 to a cartridge -free simulation firearm. The bolt unit 6 comprises a hollow bolt carrier 21, the bolt carrier 21 being configured to move linearly between a first bolt position P5 and a second bolt position P6 when arranged within the firearm. This linear movement is illustrated in Figs. 2b and 2c, respectively. The linear movement is also illustrated in Figs. 4a and 5a, as well as in Figs. 4b and 5b.

A stationary combustion chamber 8 is arranged within an interior of the hollow bolt carrier 21, the combustion chamber 8 being configured to receive a combustible gas mixture. The combustible gas mixture may comprise the previously mentioned first gas and second gas.

Ignition element 22 is configured to ignite the combustible gas mixture, such that an expansion of the combustible gas mixture generates linear movement of the hollow bolt carrier 21 from the first bolt position P5 to the second bolt position P6. The ignition element 22 may be a piezo element. The ignition element 22 may be fixed to the hollow bolt carrier 21 and extend at least partially within the combustion chamber 8 when the hollow bolt carrier 21 is in the first bolt position P5, as shown in Figs. 2a, 2b, 4a and 4b. The ignition element 22 may be arranged outside of the combustion chamber 8 when the hollow bolt carrier 21 is in the second bolt position P6, as shown in Figs. 2c, 5a, and 5b.

The hollow bolt carrier 21 and the ignition element 22 may be configured to return to the first bolt position P5 from the second bolt position P6 in response to a force Fl applied by a resilient element 29 of the firearm, such as a spring. The force Fl is applied in a direction toward the combustion chamber 8, as illustrated in Fig. 1.

The bolt unit 20 may further comprise a gas evacuation line 23 configured to evacuate expanding gas from the combustion chamber 8 to an exterior, the gas evacuation line 23 being fluidly connected with the interior of the hollow bolt carrier 21 when the hollow bolt carrier 21 is in the second bolt position P6, as illustrated in Figs. 2c, 5a, and 5b. The gas evacuation line 23 may be fluidly disconnected from the interior of the hollow bolt carrier 21 when the hollow bolt carrier 21 is in the first bolt position P5, such that the combustion chamber 8 forms a barrier between the interior of the hollow bolt carrier 21 and the gas evacuation line 23 as illustrated in Figs. 2a, 2b, 4a, and 4b.

The expanding gas, evacuating through the gas evacuation line 23, may generate an impression of a muzzle flash of the firearm. Furthermore, the linear movement of the hollow bolt carrier 21 and the ignition element 22 from the first bolt position P5 to the second bolt position P6 may generate an impression of a recoil in the firearm. Also, the expansion of the combustible gas mixture may generate an audible impression of a discharge from the firearm. In a preferred embodiment, recoil, sound, and muzzle flash are generated simultaneously in response to pulling the trigger of the converted firearm.

The present invention also relates to a firearm 2 reversibly converted to a cartridge-free simulation firearm, as illustrated in Fig. 1 The firearm 2 comprises an original frame 25 of the firearm, an original trigger unit 26 of the firearm, and an original barrel 27 of the firearm. Furthermore, the converted firearm comprises the above-mentioned exchangeable gas system 24. A hammer 28 of the trigger unit 26 may be configured to simultaneously engage the ignition element 22 of the hollow bolt carrier 21 of the exchangeable gas system 24, the engagement generating a spark from the ignition element 22, and the pivot arm 19 of the magazine unit 1 of the exchangeable gas system 24, the engagement generating a pivoting action of the pivot arm 19. This is best illustrated in Fig. 2b. The hammer 28 may engage the pivot arm 19 via linkage arranged within the magazine unit 1 (not shown).

As mentioned above, a resilient element 29 of the trigger unit 26 may be configured to apply a force Fl onto an end of the hollow bolt carrier 21, the force Fl being applied in a direction towards the combustion chamber 8 of the exchangeable gas system 24, as best illustrated in Fig. 1. The force Fl may be configured to force the hollow bolt carrier 21 to return from the second bolt position P6 to the first bolt position P5.

The various aspects and implementations have been described in conjunction with various embodiments herein. However, other variations to the disclosed embodiments can be understood and effected by those skilled in the art in practicing the claimed subject-matter, from a study of the drawings, the disclosure, and the appended claims. In the claims, the word “comprising” does not exclude other elements or steps, and the indefinite article “a” or “an” does not exclude a plurality. The mere fact that certain measures are recited in mutually different dependent claims does not indicate that a combination of these measured cannot be used to advantage.

The reference signs used in the claims shall not be construed as limiting the scope. Unless otherwise indicated, the drawings are intended to be read (e.g., cross-hatching, arrangement of parts, proportion, degree, etc.) together with the specification, and are to be considered a portion of the entire written description of this disclosure. As used in the description, the terms “horizontal”, “vertical”, “left”, “right”, “up” and “down”, as well as adjectival and adverbial derivatives thereof (e.g., “horizontally”, “rightwardly”, “upwardly”, etc.), simply refer to the orientation of the illustrated structure as the particular drawing figure faces the reader. Similarly, the terms “inwardly” and “outwardly” generally refer to the orientation of a surface relative to its axis of elongation, or axis of rotation, as appropriate.

Claims

1. A magazine unit (1) for reversibly converting a firearm (2) to a cartridge -free simulation firearm, said magazine unit (1) comprising:

-at least one first compressed gas container (3) comprising a first gas;

-at least one second compressed gas container (4) comprising a second gas;

-a valve assembly (7) configured to simultaneously allow flow of said first gas from said first compressed gas container (3) and flow of said second gas from said second compressed gas container (4) to a combustion chamber (8) of said firearm (2).

2. The magazine unit (1) according to claim 1, further comprising

-a first gas reservoir (5) fluidly connected with said first compressed gas container (3);

-a second gas reservoir (6) fluidly connected with said second compressed gas container (4); said valve assembly (7) being configured to simultaneously allow flow of said first gas from said first compressed gas container (3) to said first gas reservoir (5) and flow of said second gas from said second compressed gas container (4) to said second gas reservoir (6), and configured to simultaneously allow flow of said first gas from said first gas reservoir (5) and flow of said second gas from said second gas reservoir (6) to said combustion chamber (8) of said firearm (2).

3. The magazine unit (1) according to claim 2, wherein said valve assembly (7) comprises: —at least one first reduction valve (9) configured to fluidly connect said first compressed gas container (3) with said first gas reservoir (5),

—at least one second reduction valve (10) configured to fluidly connect said second compressed gas container (4) with said second gas reservoir (6);

—a first check valve (11) configured to fluidly connect said first gas reservoir (5) with said combustion chamber (8) of said firearm (2), and

—a second check valve (12) configured to fluidly connect said second gas reservoir (6) with said combustion chamber (8) of said firearm (2); —a first control valve (13) configured to, in a first open position (Pl), allow said first gas to flow from said first reduction valve (9) to said first gas reservoir (5), and, in a second open position (P2), allow said first gas to flow from said first gas reservoir (5) to said first check valve (11), and

—a second control valve (14) configured to, in a first open position (Pl), allow said second gas to flow from said second reduction valve (10) to said second gas reservoir (6), and, in a second open position (P2), allow said second gas to flow from said second gas reservoir (6) to said second check valve (12).

4. The magazine unit (1) according to claim 3, wherein said valve assembly (7) further comprises:

—a first gas line (15) extending between each first reduction valve (9) and said first gas reservoir (5), said first check valve (11) being arranged within said first gas line (15), —a second gas line (16) extending between each second reduction valve (10) and said second gas reservoir (6), said second check valve (12) being arranged within said second gas line (16);

—a third gas line (17) extending between said first gas reservoir (5) and said first check valve (11), said first check valve (11) being interconnected with said third gas line (17), —a fourth gas line (18) extending between said second gas reservoir (6) and said second check valve (12), said second check valve (12) being interconnected with said fourth gas line (18).

5. The magazine unit (1) according to claim 3 or 4, further comprising a pivot arm (19) configured to, when pivoting from a disengaged position (P3) and an engaged position (P4), drive said first control valve (13) and said second control valve (14) from said first open position (Pl) to said second open position (P2).

6. The magazine unit (1) according to any one of the previous claims, wherein first gas is O2 and said second gas is a biofuel, optionally CH4 or compressed natural gas.

7. A bolt unit (20) for reversibly converting a firearm (2) to a cartridge -free simulation firearm, said bolt unit (6) comprising:

-a hollow bolt carrier (21), said bolt carrier (21) being configured to move linearly between a first bolt position (P5) and a second bolt position (P6) when arranged within said firearm;

-a stationary combustion chamber (8) arranged within an interior of said hollow bolt carrier (21), said combustion chamber (8) being configured to receive a combustible gas mixture;

-an ignition element (22) configured to ignite said combustible gas mixture, expansion of said combustible gas mixture generating linear movement of said hollow bolt carrier (21) from said first bolt position (P5) to said second bolt position (P6).

8. The bolt unit (20) according to claim 7, wherein said ignition element (22) is fixed to said hollow bolt carrier (21) and extends at least partially within said combustion chamber (8) when said hollow bolt carrier (21) is in said first bolt position (P5)

9. The bolt unit (20) according to claim 7 or 8, wherein said ignition element (22) is a piezo element.

10. The bolt unit (20) according to any one of claims 7 to 10, further comprising a gas evacuation line (23) configured to evacuate expanding gas from said combustion chamber (8) to an exterior, said gas evacuation line (23) being fluidly connected with said interior of said hollow bolt carrier (21) when said hollow bolt carrier (21) is in said second bolt position (P6).

11. The bolt unit (20) according to claim 10, wherein said gas evacuation line (23) is fluidly disconnected from said interior of said hollow bolt carrier (21) when said hollow bolt carrier (21) is in said first bolt position (P5), said combustion chamber (8) forming a barrier between said interior of said hollow bolt carrier (21) and said gas evacuation line

12. The bolt unit (20) according to any one of claims 7 to 11, wherein said hollow bolt carrier (21) and said ignition element (22) are configured to return to said first bolt position (P5) from said second bolt position (P6) in response to a force applied by a resilient element of said firearm.

13. The bolt unit (20) according to any one of claims 10 to 12, wherein expanding gas evacuating through said gas evacuation line (23) generates an impression of a muzzle flash of said firearm.

14. The bolt unit (20) according to any one of claims 7 to 13, wherein said linear movement of said hollow bolt carrier (21) and said ignition element (22) from said first bolt position (P5) to said second bolt position (P6) generates an impression of a recoil in said firearm, and/or said expansion of said combustible gas mixture generates an audible impression of a discharge from said firearm.

15. A method of reversibly converting a firearm (2) into a cartridge-free simulation firearm, said method comprising the steps of:

-replacing an original bolt unit of said firearm with the bolt unit (20) according to any one of claims 7 to 14, and

-replacing an original cartridge-containing magazine of said firearm with the magazine unit (1) according to any one of claims 1 to 6.

16. The method according to claim 15, wherein reversing the conversion of the firearm to the cartridge-free simulation firearm comprises the steps of:

-replacing said bolt unit (20) with said original bolt unit, and

-replacing said magazine unit (1) with said original cartridge-containing magazine.

17. An exchangeable gas system (24) for reversibly converting a firearm (2) to a cartridge-free simulation firearm, said exchangeable gas system (24) being configured to generate an impression of a recoil, a fired shot, and/or a muzzle flash in said firearm, said exchangeable gas system (24) comprising

-the magazine unit (1) according to any one of claims 1 to 6, and

-the bolt unit (20) according to any one of claims 7 to 14.

18. The exchangeable gas system (24) according to claim 17, wherein said magazine unit

(1) and said bolt unit (20) are configured to be scalable for use with a range of firearm platforms.

19. A firearm (2) reversibly converted to a cartridge-free simulation firearm, said firearm

(2) comprising

-an original frame (25) of said firearm,

-an original trigger unit (26) of said firearm,

-an original barrel (27) of said firearm, and

-the exchangeable gas system (24) of claim 13 or 14.

20. The firearm (2) according to claim 19, wherein a hammer (28) of said trigger unit

(26) is configured to simultaneously engage

-the ignition element (22) of the hollow bolt carrier (21) of said exchangeable gas system (24), said engagement generating a spark from said ignition element (22), and

-the pivot arm (19) of the magazine unit (1) of said exchangeable gas system (24), said engagement generating a pivoting action of said pivot arm (19).

21. The firearm (2) according to claim 19 or 20, wherein a resilient element (29) of said trigger unit (26) is configured to apply a force (Fl) onto an end of said hollow bolt carrier (21), said force (Fl) being applied in a direction towards the combustion chamber (8) of said exchangeable gas system (24).