WO2016087120A1

WO2016087120A1 - A gas powered gun and a pressure tube for a gas powered gun

Info

Publication number: WO2016087120A1
Application number: PCT/EP2015/074385
Authority: WO
Inventors: Fredrik Axelsson
Original assignee: Fx Airguns Ab
Priority date: 2014-12-02
Filing date: 2015-10-21
Publication date: 2016-06-09
Also published as: US20160153741A1; EP3227627A1

Abstract

A gas powered gun and a pressure tube for a gas powered gun each comprises a gas regulator between a pressure chamber and a source of compressed gas. The gas regulator comprises a body forming first and second cylindrical portions connected to each other. The first cylindrical portion is in fluid connection with the pressure chamber. A piston is mounted for sliding movement in the first and second cylindrical portions. A valve seat is in the second cylindrical portion. An intermediate chamber is in the second cylindrical portion between the piston and the valve seat and in fluid connection with the source of compressed gas. A passageway through the piston connects the pressure chamber with the intermediate chamber. A biasing member presses the piston resiliently away from the valve seat. A valve seat adjusting mechanism is accessible to a user for adjusting a position of the valve seat.

Description

A GAS POWERED GUN AND

A PRESSURE TUBE FOR A GAS POWERED GUN

Technical Field

The present disclosure relates to a gas powered gun, comprising a pressure chamber and a gas regulator, which is arranged between said pressure chamber and a source of compressed gas. It also relates to a pressure tube for a gas powered gun, comprising a pressure chamber and a gas regulator, which is arranged between said pressure chamber and a source of compressed gas.

Technical Background

Air guns are designed to have a controlled amount of high pressure air in a pressure chamber which is forwarded into the gun barrel behind a pellet in order to projectile the same out of the barrel. The air or the gas is usually provided from a reservoir of compressed gas at high pressure. In order to present the air or the gas to the pellet at a constant pressure a regulator can be used.

A regulator is a mechanical device, i.e. a valve that controls the air pressure and the volume available to the fire valve of a pre-charged airgun. This means that the pressure is always the same and hence an airgun with a regulator shoots with very consistent velocity. A further advantage is that it may get a few more shots on a fill.

When manufacturing the airgun the regulator is preadjusted to the desired pressure before it is arranged inside the airgun and if the pressure has to be adjusted after manufacturing the regulator has to be removed entirely from the air gun before it is adjusted. This is time consuming and usually requires a test rig in order to get exact values. Thus, there is a need to adjust the regulator in an easier way. Summary of the invention

The inventor has realized that by having a regulator which can be adjusted without removing the regulator time can be saved and the gun can be regulated in an easy way. The present disclosure relates to a gas powered gun comprising a pressure chamber and a gas regulator, which is arranged between said pressure chamber and a source of compressed gas. The gas regulator comprises:

- a body, forming a first cylindrical portion and a second cylindrical

portion, which are connected to each other, a diameter of said first cylindrical portion being greater than a diameter of said second cylindrical portion, said first cylindrical portion being in fluid connection with said pressure chamber;

- a piston mounted for sliding movement in said first and said second cylindrical portions;

- a first sealing member, which seals between a large diameter portion of said piston and said first cylindrical portion;

- a second sealing member which seals between a small diameter

portion of said piston and said second cylindrical portion;

- a valve seat sealingly arranged in said second cylindrical portion; - an intermediate chamber formed in said second cylindrical portion between said piston and said valve seat, said intermediate chamber being in fluid connection with said source of compressed gas;

- a passageway extending through said piston and connecting said

pressure chamber with said intermediate chamber;

- a biasing member for pressing said piston resiliently away from said valve seat; and

a valve seat adjusting mechanism for adjusting a position of the valve seat, wherein said valve seat adjusting mechanism is accessible to a user without removing said regulator from said gas powered gun; wherein said piston is subject to a first force created by pressure in said pressure chamber, and a second force created by pressure in said source of compressed gas, and said piston is movable against the action of the biasing member from a first position, in which said piston is separated from said valve seat so that said passageway is open to allow gas to flow from said source of compressed gas via said intermediate chamber into said pressure chamber, to a second position, in which said piston abuts said valve seat so that said passageway is closed, so that, when said piston is in its first position, pressure increases in said pressure chamber until said first force exceeds a sum of said second force and a spring force of said biasing member, to thereby move said piston to its second position, said spring force being dependant on the position of the valve seat.

Due to the sealing members the forces acting on the piston to urge it towards the pressure chamber are the high pressure gas from the source of compressed gas, i.e. the second force and the spring force of the biasing member acting on the small diameter portion of the piston. The force, i.e. the first force, acting on the piston towards the valve seat is the high pressure gas in the pressure chamber acting on the large diameter portion of said piston. When the pressure in the pressure chamber is sufficiently high, the first force will cause the piston to be urged towards the valve seat until the piston bears firmly against the valve seat to close the passageway in the piston. That is, the pressure inside the pressure chamber increases until the first force exceeds a sum of the second force and the spring force of the biasing member. Note that the pressure in the pressure chamber required to cause movement of the piston will be smaller than the pressure in the source of compressed gas, due to the difference in cross-sectional area between the large diameter portion and the small diameter portion of the piston.

By being able to adjust the position of the valve seat via a valve seat adjusting mechanism the regulator does not have to be removed to be able to adjust the pressure inside the regulator. When the valve seat adjusting mechanism moves the valve seat closer to or further away from the piston the biasing member has to be compressed a different distance. Thus a different force is necessary to move the piston towards the valve seat and

compressing the biasing member until the piston abuts the valve seat. Thereby the pressure inside the pressure chamber can be set and adjusted if necessary.

The smaller the difference in cross-sectional areas between the large diameter portion of the piston and the small diameter portion of said piston is, the lighter the spring force afforded by the biasing member may be.

By having the above described design it is possible to arrange the regulator in the gas powered gun in such a way that the valve seat can be adjusted without removing it from the regulator.

According to at least one exemplary embodiment the first and the second cylindrical portions forms a coaxial cylinder, which extends through the whole regulator body. The cylinder hence forms a through hole in said regulator body with the first cylindrical portion at one end and the second cylindrical portion at the other end.

According to at least one exemplary embodiment said valve seat adjusting mechanism is arranged in said second cylindrical portion. Since the first cylindrical portion is in fluid connection with the pressure chamber the other end of the cylinder, where the second cylindrical portion is arranged, can be arranged such that it is accessible from the outside of the body of the gas powered gun. This can, for example, be done by letting a part of the regulator body, which includes the opening of the second cylindrical portion, extend out over the body of the gun or arranging the opening of the second cylindrical portion in one plane with the outer gun body. Hence, the opening of the second cylindrical portion in the regulator body may be open to the atmosphere. The valve seat adjusting mechanism may hence be reached through the opening of the second cylindrical portion. This way the valve seat adjusting mechanism can be accessible to a user without removing the gun.

According to at least one exemplary embodiment the gas in the source of compressed gas is usually air, however any suitable gas may be used. According to at least one exemplary embodiment said valve pressure adjusting mechanism comprises a threaded portion and said second cylindrical portion comprises a matching threaded portion and said valve pressure adjusting mechanism is adapted to be screwed into and out of said threaded area in said second cylindrical portion. Threaded connections are easy to manufacture and the parts are easy to assembly and it is an easy way to adjust the valve seat position.

According to at least one exemplary embodiment said threaded portion of said valve pressure adjusting mechanism comprises a tool engaging portion, which is accessible to a user without removing the regulator from said gas powered gun. The tool engaging portion may be so arranged that is accessible through a hole in the body of the gun. The tool engaging portion may have the shape of the following type: slot, bolt, pozidriv, square,

Robertson, torx or secure torx, hex socket or alien key, security hex, Phillips, square double, triple double, polydrive, spline drive, double hex, Bristol or pentalobular or any other possible design. This way a standard tool, for example, a screw driver may be used.

According to at least one exemplary embodiment said threaded portion of said valve pressure adjusting mechanism is connected to a knob, which is accessible to a user without removing the regulator from said gas powered gun. By having a knob no extra tool is necessary to adjust the pressure.

According to at least one exemplary embodiment said valve seat moves to at least a first position when said valve pressure adjusting mechanism is moved in a direction into said second cylinder portion and said valve seat is adapted to move to at least a second position when said valve pressure adjusting mechanism is moved in an opposite direction. With the phrase "a direction into said second cylinder portion" it is meant that the valve pressure adjusting mechanism is moved closer to the piston. The valve seat adjusting mechanism is connected to the valve seat. The valve seat adjusting mechanism moves said valve seat between at least a first position and at least a second position such that said piston is adapted to move a first distance when said valve seat is arranged at said first position and to move a second larger distance when said valve seat is arranged at said second position. Hence a larger force has to act on said piston in order to move the piston to the second position of the valve seat than to the first position of the valve seat, this since the biasing member has to be pressed more together in order to close the passageway in said piston between said pressure chamber and said source of compressed gas.

According to at least one exemplary embodiment said valve seat comprises a piston abutting portion and a valve seat adjusting mechanism connection part.

According to at least one exemplary embodiment said piston abutting portion and said valve seat adjusting mechanism connection part are made in one piece.

According to at least one exemplary embodiment said piston abutting portion and said valve seat adjusting mechanism connection part are two different parts connected to each other. If one part breaks, it may be easier to replace it.

According to at least one exemplary embodiment said piston abutting portion is made of plastic. Plastic has the advantage of being adaptable. The area of the piston, which engages the piston abutting portion, and the piston abutting portion itself may not always match each other 100 percent, due to manufacturing tolerances. If the piston abutting portion is made of plastic, the plastic piston abutting portion will adapt to the piston and seal between the piston and the piston abutting portion. If the piston abutting portion has to be replaced it is advantageous that the piston abutting portion is a separate part from the valve seat adjusting mechanism connection part, then only the piston abutting portion has to be replaced.

According to at least one exemplary embodiment said biasing member is arranged in said first cylindrical portion between said large diameter portion of said piston and an annular portion between said first and said second cylindrical portions.

According to at least one exemplary embodiment said biasing member comprises of one or more spring discs. An advantage of using spring discs is that it is easy to adjust the force by adding or removing spring discs.

Alternatively, other springs suitable for the application may be used instead of spring discs. According to at least one exemplary embodiment said body further comprises an atmospheric passage extending between an opening to the atmosphere and said first and said second cylindrical portions between said first and said second sealing members.

According to at least one exemplary embodiment said source of compressed gas is a bottle or a tube comprising compressed gas.

According to at least one exemplary embodiment said gas powered gun further comprises a barrel adapted to receive a projectile, an open-close valve for exhausting compressed gas from said pressure chamber to discharge a projectile in the barrel.

In yet another embodiment, the valve seat is sealed against the inner wall of the body by two axially displaced sealing elements, and the fluid connection between the intermediate chamber and the source of compressed gas comprises a channel through the valve seat which channel has a first opening facing the piston and a second opening between the two sealing elements, and a channel through the body having an opening between the two sealing elements.

With this design, the fluid connection can be effectively sealed by the piston making contact with the valve seat and closing the first opening. This in turn requires a relatively small pressure on the piston to close the fluid connection, enabling a relatively weak biasing member.

As an example, the first opening may be located centrally on an upper surface of the valve seat, and the passage-way through teh piston may have an opening into the intermediate chamber at a distance from a central axis of the piston. This makes it possible for the central surface of the puiston to close the first opening.

The present disclosure also relates to a pressure tube for a gas powered gun, wherein the pressure tube comprises a pressure chamber and a gas regulator, which is arranged between said pressure chamber and a source of compressed gas. The gas regulator comprises:

- a body, forming a first cylindrical portion and a second cylindrical

- a second sealing member which seals between a small diameter

portion of said piston and said second cylindrical portion;

- a valve seat sealingly arranged in said second cylindrical portion;

- an intermediate chamber formed in said second cylindrical portion between said piston and said valve seat, said intermediate chamber being in fluid connection with said source of compressed gas;

- a passageway extending through said piston and connecting said

pressure chamber with said chamber;

- a biasing member for pressing said piston resiliently away from said valve seat, and

a valve seat adjusting mechanism for adjusting a position of the valve seat, wherein said valve seat adjusting mechanism is accessible to a user without removing said regulator from said pressure tube, wherein said piston is subject to a first force created by pressure in said pressure chamber, and a second force created by pressure in said source of compressed gas, and said piston is movable against the action of the biasing member from a first position, in which said piston is separated from said valve seat so that said passageway is open to allow gas to flow from said source of compressed gas via said intermediate chamber into said pressure chamber, to a second position, in which said piston abuts said valve seat so that said passageway is closed, so that, when said piston is in its first position, pressure increases in said pressure chamber until said first force exceeds a sum of said second force and a spring force of said biasing member, to thereby move said piston to its second position, said spring force being dependant on the position of the valve seat. The features related to the regulator described in relation with the air pressure gun relate also to the regulator in the pressure tube and will hence not be described again. However, said source of compressed gas is a chamber in said pressure tube, which is filled with gas. Further, the pressure chamber in the tube is connected to a chamber in the gas powered gun during use of the gun and hence they form together a pressure chamber.

Generally, all terms used in the claims are to be interpreted according to their ordinary meaning in the technical field, unless explicitly defined otherwise herein. All references to "a/an/the [element, device, component, means, step, etc.]" are to be interpreted openly as referring to at least one instance of said element, device, component, means, step, etc., unless explicitly stated otherwise.

Other objectives, features and advantages of the present invention will appear from the following detailed disclosure, as well as from the drawings. Brief Description of the Drawings

The above, as well as additional objects, features and advantages of the present disclosure, will be better understood through the following illustrative and non-limiting detailed description of exemplary embodiments of the present disclosure, with reference to the appended drawings, where the same reference numerals will be used for similar elements, wherein:

Fig. 1 a shows a gas powered gun according to a first embodiment in a cross-sectional view in a ready-to-shoot position.

Fig. 1 b shows the gas powered gun in Fig. 1 a when the hammer has been released.

Fig. 2a and 2b show the regulator in Figs. 1 a and 1 b in more detail and with the piston in the regulator in Figs. 1 a and 1 b in two positions.

Fig. 3 shows the regulator in Figs. 1 a and 1 b, 2a and 2b with the valve seat and the valve seat adjusting mechanism in a second position.

Fig. 4 shows a gas powered gun and a regulator according to a second embodiment in a cross-sectional view.

Fig. 5 shows a regulator according to a third embodiment in a cross- sectional view. All the figures are highly schematic, not necessarily to scale, and they show only parts which are necessary in order to elucidate the invention, other parts being omitted or merely suggested. Detailed Description of Exemplary Embodiments

Embodiments of the present disclosure will be described in more detail in the following with reference to the accompanying drawings.

Figs. 1 a and 1 b shows a gas powered gun 1 . The gun 1 is of the kind where a bottle 2 of compressed air or other gas is fitted to the body 3 of the gun 1 . The compressed gas is fed to a pressure chamber 1 1 and when the trigger 15 of the gun 1 is pulled, the compressed air is forwarded to a space 10 behind a bullet 12 which fires the bullet 12. In more detail, the bottle 2 is connected to the gun 1 at the front. A connector 95 is arranged between the bottle 2 and the gun 1 and it is used to fill the bottle 2 with gas. The gun 1 also comprises a gas regulator 20. A passage 16 in the gun body 3 forwards the gas from the bottle 2 into the regulator 20, which regulates the gas pressure in the pressure chamber 1 1 . The gun 1 further comprises a barrel 4, and a feeder pin 5 slidably arranged in a housing 6 behind the barrel 4. In a space between the barrel 4 and the feeder pin 5 is fitted a magazine (not shown) to an inlet 7 for providing projectiles, e.g., in the form of diabolo bullets 12. The feeder pin 5 is arranged to be slid back, thereby allowing a bullet to be provided from the magazine, and then to be slid forward, thereby feeding the bullet 12 into a firing position in the barrel 4, as shown in Figs. 1 a and 1 b.

The gun 1 further comprises an open-close valve 8, which is arranged in the pressure chamber 1 1 for allowing passage of compressed gas from the bottle 2 to the space 10 immediately behind the bullet 12 in the barrel 4, and a sliding hammer 9, which actuates the open-close valve 8 at the moment of firing. When the gun is in a loaded position the hammer 9 is biased towards the valve 8 by a biasing spring 13, and is held in a loaded position, against the force of the biasing spring 13, by a catch 14 (see Fig. 1 a). A trigger 15 is arranged to actuate the catch 14 in order to release the hammer 9. After firing the gun 1 the hammer 9 is brought back to its loaded position. The trigger- stopper-cooperation can be done in many different ways and will not be explained further since this is common knowledge to the person skilled in the art.

In the illustrated example, the open-close valve 8 has a main body oriented essentially in the longitudinal direction of the gun 1 , and comprises a valve head 8a adapted to cooperate with an opening of the pressure chamber 1 1 in front of the valve 8, the opening thus acting as a valve seat 8b. The pressure inside the pressure chamber 1 1 keeps the valve head 8a in place against the valve seat 8b, thus effectively sealing the pressure chamber 1 1 . The valve head 8a is additionally biased against the valve seat 8b by a biasing spring 18. Another channel 19 connects a passage 16 behind the valve seat 8b with the space 10 behind a bullet 12 in the barrel 4. When the hammer 9 is released it is forced by the spring 13 into contact with a portion 96, to which said valve head 8a is a part of. This is shown in Fig. 1 b. The hammer 9 pushes the valve head 8a out of sealing contact with the valve seat 8b (not shown) to thereby allow an exhaust of gas through the channel 19 to the space 10 behind the bullet 12. However, many other solutions for an open-close valve 8, to be actuated by the hammer 9, are possible.

Figure 1 a shows the gun in a ready-for-f ire-position. In this condition, the feeder pin 5 has been slid into the barrel 4, and fed the bullet 12 into the firing position. The hammer 9 is in a loaded position and the valve 8 seals the pressure chamber 1 1 . When the hammer 9 is in a loaded position it is held in place by the catch 14, against the force of the biasing spring 13. The pressure chamber 1 1 has not yet been filled with high pressure air from the bottle 2.

Fig. 2a and 2b show the regulator 20 in Figs. 1 a and 1 b in more detail and will be described together. The illustrated regulator 20 comprises a body 21 , a piston 30, and a biasing member 40, where the biasing member 40 is a set of spring discs 40. Fig. 2a shows the piston 30 in a first position. Fig. 2b shows the piston 30 in a second position. Also shown in Fig. 2a and 2b are 0- rings 41 , 42, 43, 44 and a valve seat 50 and a valve pressure adjusting mechanism 60. Typically, the body 21 is machined of stainless steel and the piston 30 is machined of brass, the spring discs 40 are of spring steel, the 0- rings 41 , 42, 43 and 44 are of elastomeric materials and the valve seat 50 is at least partly made of plastic.

The body 21 has an outer cylindrically stepped shaped form. The body 21 is provided with an externally threaded portion 22, which allows the regulator 20 to be screwed into the gas powered gun 1 until it reaches an annular flange 71 on the regulator body 21 , since the gun 1 is provided with a corresponding bore with which the externally threaded portion 42 engages. Part of the regulator is arranged inside the body 3 of the gun, and part of the regulator is arranged outside the body 3. However, this is not necessary. The body 21 comprises a first cylindrical portion 24 with a first opening 23 and a second cylindrical portion 25, which is arranged coaxial with the first cylindrical portion, which together define an inner cylinder in which the piston 30 is mounted for sliding movement. The first cylindrical portion 24 extends from said first opening 23 in a predetermined distance into said body 21 and the second cylindrical portion 25 extends from the bottom of the first cylindrical portion into said body 21 and through to the other end of the regulator body 21 , forming a second opening 73. It is noted that part of the body 21 may be formed directly in the material of the body 3 of the gun. For example, the first cylindrical portion 24 may be fiormed in the gun body 3, and the second cylindrical portion 25 in the regulator body 21 , as shown e.g. in the embodiment in figure 5 below.

The first cylindrical portion 24, which is in connection with the pressure chamber 1 1 in Figs. 1 a and 1 b, has a diameter D1 which is larger than the diameter D2 of the second cylindrical portion 25. Hence, the first piston portion 24 is a large diameter portion of the piston and the second piston portion is a small diameter portion of the piston. By way of example, the first cylindrical portion 24 may have a diameter D1 of 8 mm +/- 2 mm. By way of example, the second cylindrical portion 25 may have a diameter D2 of 4 mm +/- 2 mm. By way of a second example, the first cylindrical portion 24 may have a diameter D1 between 6-14mm. By way of a second example, the second cylindrical portion 25 may have a diameter D2 between 3-6 mm, as long it is smaller than the diameter of the first cylindrical portion 24 he piston 30 is arranged in the first and the second cylindrical portions 24, 25 and it has two correspondingly stepped portions, i.e. a first piston portion 31 and a second piston portion 32 which engage within the cylindrical portions 24 and 25 respectively. Hence, the first piston portion 31 has a diameter which is larger than the second piston portion 32. The piston portions 31 and 32 engage the respective cylindrical portions 24 and 25 with a close fit, and the 0-rings 41 , 42 provide sealing between the two portions 31 , 32 of the piston 30 and the cylindrical portions 24 and 25.The piston 30 is formed with a central, longitudinal bore 33, which forms a passageway for communication between the opposite ends of the piston 30. By way of example, the longitudinal bore 33 may have a diameter D1 of 1 ,5 mm +/- 0,5mm. Biasing means in the shape of spring discs 40 are arranged in the first cylindrical portion 24 between the first piston portion 31 of the piston 30 and the bottom of the first cylindrical portion 24, i.e. between the first piston portion 31 and an annular portion 26 between the first and the second cylindrical portions 24, 25. The spring discs 40 are compressed to a desired degree when the regulator 20 is fitted into the gun 1 . The strength and the number of the spring discs 40, and the degree to which they can be compressed decides the operating pressure of the assembly.

A bore 90 in the body 21 is connected to a passage in the regulator body (not shown) which affords communication between the ambient atmosphere (or any other external reference pressure) and the cylinder portion, at a point between the 0-rings 41 , 42.

The regulator 20 also comprises a valve seat 50, which is arranged in the second cylindrical portion 25. The valve seat 50 comprises an end surface 55 which will abut the piston 30 and its end surface 34. In Fig. 2a the end surface 55 of the valve seat 50 is arranged at a first distance (L1 ) from the end surface 34 of the piston 30. In Fig. 2b the end surfaces of the valve seat and the piston are abutting each other and hence the distance L1 =0. An intermediate chamber 51 is formed in the second cylindrical portion 25 between the piston 30 and the valve seat 50. A passage 27 is formed In the body 21 and connects the internnediate chamber 51 with a connection point to which a bottle 2 is connectable (not shown). The passage 27 comprises a third opening 28 in the regulator body, which is connected to the passage 16 in the body 3 of the gun 1 (see also Figs. 1 a and 1 b.) The passage 16 is connected to the connection point. By way of example, the passage 27 may have a diameter D1 of 2 mm +/- 1 mm.

The piston 30 is mounted for sliding movement in the two cylinder portions 24, 25, and the passageway 33 in the piston connects the first opening 23 and the third opening 28 in the body 21 . At the same time it connects the pressure chamber 1 1 with the intermediate chamber 51 in the regulator 20. The function of the spring discs 40 are to bias the piston 30 resiliently into the intermediate chamber 51 and towards the valve seat 50. The valve seat 50 is made of two parts connected to each other. The first part 52 is a piston abutting portion, which comprises the end surface 55. The piston abutting portion is made of plastic, which the piston 30 will abut. The second part 53 is a valve seat adjusting mechanism connection part. These two parts may be fixedly connected to each other, for example screwed together, or loosely connected to each other. The valve seat 50 is provided with an O-ring 54, which seals between the valve seat 50 and the second cylindrical portion 25. The O-ring 54 is arranged to the valve seat adjusting mechanism connection part 53. A valve pressure adjusting mechanism 60 is connected to the valve seat 50. The valve pressure adjusting mechanism 60 comprises a threaded portion 61 which is screwed into a threaded portion 29 in the second cylindrical portion 25 of the regulator 20. The threaded portion 61 is at the end facing the valve seat 50 provided with a valve seat contacting protrusion 62. On the other end the threaded portion has a tool engaging portion 63 of type: slot, bolt, pozidriv, square, Robertson, torx or secure torx, hex socket or alien key, security hex, Phillips, square double, triple double, polydrive, spline drive, double hex, Bristol or pentalobular or any other possible design, which allows, for example, a screw driver to connect to the tool engaging portion. The screwdriver is then inserted into the second opening 73 of the regulator 20. The regulator 20 operates as follows. The forces acting on the piston to urge it upwards are the spring force of the spring discs 40 and the high pressure gas from the bottle 2 in Figs. 1 a and 1 b acting on the second smaller piston portion 32. The force acting on the piston downwardly as seen in Figs. 1 a and 1 b is the high pressure gas in the pressure chamber acting the first larger piston portion 31 . When the pressure in the high pressure chamber 1 1 is sufficiently high, the force will cause the piston 30 to be urged downwardly until the piston 30 bears firmly against the valve seat 50 to close the passageway 33 in the piston 30. That is, high pressure gas from the gas bottle 2 passes through the passage 16 in the gun 1 and through the third opening 28 and through the passage 27 in the regulator 20 and into the chamber 51 (seen in Fig. 2a) in the regulator body 21 and due to the sealing provided by the 0-rings 42, 41 , the high pressure air passes through the longitudinal bore 33 of the piston 30 into the pressure chamber 1 1 where the pressure increases (see also Figs. 1 a and 1 b). The pressure increases in the pressure chamber 1 1 (see Figs. 1 a and 1 b) until the force created by the pressure in the pressure chamber 1 1 , and which acts of the larger piston portion 31 , exceeds a sum of the force of the high pressure gas from the bottle 2 in Figs. 1 a and 1 b acting on the second smaller piston portion 32 and the spring force of the spring discs 40. The piston 30 starts to move from its position shown in Figs. 1 a and 1 b and Fig. 2a to a second position shown in Fig. 2b. The spring discs 40 are being compressed. This continues until the end 34 of the piston 30 abuts the end surface 55 of the valve seat 50 and shuts the flow of gas off (see Fig. 2b). A predetermined amount of gas is now arranged in the pressure chamber 1 1 having a predetermined pressure inside the pressure chamber 1 1 . When the trigger 15 is pulled the compressed gas is forwarded to the space 10 behind the bullet 12 which fires the bullet 12.

When the shot is fired the air pressure in the pressure chamber 1 1 drops and the biasing springs 40 lift the piston 30 off its seat allowing high pressure air to flow into the pressure chamber 1 1 once again and the cycle is repeated. In order to change the force on the piston 30 created by the pressure inside the pressure chamber 1 1 the valve seat 50 is movable by using the valve seat adjusting mechanism 60. When the valve seat adjusting

mechanism 60 is screwed into the second cylinder portion 25, the valve seat 50 is pushed and hence moved closer to the piston 30 and its piston end 34. Fig. 3 shows the seat adjusting mechanism 60 arranged closer to the piston 30, than in Fig. 2a, i.e. when the piston 30 is in the first position. In Fig. 3 the end surface 55 of the valve seat 50 is arranged at a second distance L2 from the end 34 of the piston 30, which second distance L2 is shorter than the distance L1 between the end surface 55 of the valve seat 50 and the end 34 of the piston 30 in Fig. 2a. When the valve seat adjusting mechanism 60 is screwed out of the second cylinder portion 25 the valve seat 50 is allowed to move further away from the piston 30. The valve seat 50 can be pushed back until it abuts the valve seat adjusting mechanism 60 by the high pressure gas or it can be connected to the valve seat adjusting mechanism 60 so that it moves with the valve seat adjusting mechanism 60. Due to the different distances which the piston 30 is allowed to move, the biasing springs 40 have to be compressed much differently, and hence different forces are necessary to compress the springs until the end of the piston 30 abuts the valve seat 50. In order to check the pressure inside the pressure chamber 1 1 a pressure gauge may be connected to the pressure chamber 1 1 (not shown in Figs. 1 a and 1 b). By way of example, it has been found that a regulator constructed as illustrated may regulate an air bottle of 200-300 bar rapidly and effectively to a working pressure of 60-160 bar, to within an accuracy of +/- 1 bar. This affords a high degree of accuracy in shooting, by ensuring that each shoot is taken at a substantially constant air pressure.

Fig. 4 shows a gas powered gun 1 which is similar as the gun 1 in Figs. 1 a and 1 b and hence the same reference numbers have been used and the function of the gun will not be further explained. However, instead of a bottle 2, is a pressure tube 80 arranged at the same position as the bottle 2 in Figs. 1 a and 1 b. The regulator 20^' is here arranged in a piece 3' of the pressure tube 80 instead of in the body 3 of the gun 1 and it works the same way. The regulator 20^' is still connected to the pressure chamber 1 1 , which now is larger than in Figs. 1 a and 1 b since the volume 82 in the pressure tube 80 is part of the pressure chamber 1 1 , and hence also has to be filled. On the other end the regulator 20^' is connected to the source of pressure 85.

The regulator 20^' has a slightly different design and is connected to the tube 80 a bit differently than to the body of the gun 1 as explained and shown in Figs. 1 a and 1 b. More specifically, the regulator body 21 ' is screwed into the piece 3' through an opening 94 in the tube 80. The regulator body 21 ' and the piece 3' form the an inner shape of the regulator 20' in a similar way as the regulator 20 in figure 2a is formed by the regulator body 20 and the gun body 3. Here, however, the regulator body part 21 ' only forms the second cylindrical portion 25, while the first cylindrical portion 24is formed by the piece 3'.. The regulator body 21 ' is sealed to the piece 3' by O-rings 43.

The regulator body 21 ' also comprises the passage 27 and the bore 90 (not shown in Fig. 4). Both are arranged at the same place as in the regulator 20 in Figs. 2a and 2b and they have the same function.

A piston 30 having the same design as the piston shown in Fig. 2a and 2b is sealingly arranged in the two cylindrical portions just like in Fig. 2a and 2b. Spring discs 40 having the same design as the spring discs in Fig. 2a and 2b are arranged in the same place as described and shown in Fig. 2a and 2b. The piston 30 and the spring discs 40 are inserted into the piece 3' before the regulator body 21 ' is screwed into the piece 3'.

The valve seat 50 and the valve seat adjusting mechanism 60 are made in one single part 64, however the function is the same as the valve seat 50 and the valve seat adjusting mechanism 60 shown in Figs. 2a and 2b. The regulator 20^' works in the same way as the regulator 20 shown in Figs. 1 a, 1 b, 2a, 2b and 3 and will hence not be described further.

Further, an insert 91 is arranged in the opening 93 in the gun 1 and seals the opening. A pressure gauge 92 is arranged in order to check the pressure in the pressure chamber 1 1 . The pressure gauge 92 is used to check the pressure inside the pressure chamber 1 1 , for example, when the regulator is being adjusted. Fig. 5 shows a regulator 20^", according to a further embodiment of the invention, having a different piston 30' and valve seat 50'.

The regulator 20" is here illustrated as arranged in the body 3 of the gun and connected to the pressure chamber and the source of compressed gas in the same way as the regulator in Fig. 1 . The regulator 20^" may, however, also be integrated in a piece 3' of a pressure tube 80 as described in connection with Fig. 4. All three embodiments of the regulator 20, 20^', 20^" work in the same way and will not be further described. Same reference numbers have been used for the parts having the same functions. The shapes and the dimensions of the parts are the same as described in connection to the regulator in Figs. 1 -3, if not anything else is stated.

The regulator 20^" in fig. 5 comprises a regulator body 21 ', here similar to the regulator body in figure 4, in that the body 3 of the gun forms the first cylindrical portion 24, while the regulator body part 21 ' only forms the second cylindrical portion 25. The regulator body 21 ' is sealed to the body 3 by means of O-rings 43. The dimensions and the shapes are similar to the dimensions and shaped described in connection with Figs 2a and 2b.

The regulator body 21 ' comprises the passage 27, which connects the intermediate chamber 51 with the passage 16, which connects with the gas source. The body 3 also comprises the bore 90 (not shown in Fig. 5). The passage 16^" and the bore 90 are arranged at the same place as in the regulator 20 in Figs. 2a and 2b and they have the same function.

A piston 30' having a similar design as the piston shown in Fig. 2a and 2b is sealingly arranged in the two cylindrical portions just like in Fig. 2a and 2b. It is sealed with an O-ring 41 against the first cylindrical portion 24, and an O-ring 42 against the second cylindrical portion 25. Spring discs 40 having the same design as the spring discs in Fig. 2a and 2b are arranged in the same place as described and shown in Fig. 2a and 2b. The piston 30 and the spring discs 40 are inserted into the body 3 before the regulator body 21 ' is screwed in place.

Also like the piston 30 in fig. 2a, the piston 30' has a bore 33 extending through the piston to form a passageway for communication between the opposite ends of the piston 30. However, in this embodiment, the bore has a first portion 33a facing the passage 100, and a second portion 33b, facing the chamber 51 . The first portion 33a extends along the central axis A1 of the piston, while the second portion 33b deviates from the central axis A1 , i.e. the centre axis A2 of the second portion 33b is in an angle to the centre axis A1 . As a consequence, the opening 38 of the second portion into chamber 51 is at a distance from the central axis A1 . The end surface 34 of the piston 30' is thus solid.

The diameter of the second portion 33b is here smaller than the diameter of the first central portion 33a. By way of example, first central portion 33a may have a diameter D1 of 1 ,5 mm +/- 0,5mm.

The regulator 20" has a valve seat 50' arranged in the second cylindrical portion 25, which valve seat is adjustable by means of a adjusting mechanism 60. Similar to the embodiment in figure 4, the valve seat 50' and the adjusting mechanism 60 are here formed in one piece.

In this embodiment, however, the valve seat has a channel 56 having a first opening 56a centrally in the upper end surface, and a second opening 56b in the side wall. The channel 56 is here L-shaped, but may have any suitable shape. The channel 56 ensures a fluid connection between the with the passage 27 (leading to the passage 16 in the gun body 3) and the channel 100.

Sealing elements, here in the form of O-rings 54a, 54b, are arranged above and below the second opening 56b, so as to seal a section of the valve seat 50 against the inner walls of the body 21 '. This ensures a pressure tight connection from the channel 27, via the channel 56, to the intermediate chamber 51 . It should be noted that this connection is ensured as long as the channel 27 meets the valve seat 50' at a position between the two O-rings 54a, 54b. In particular, it is not necessary that the opening 56b faces the channel 27, as indicated in figure 5.

In use, when the pressure in the high pressure chamber (not shown in

Fig. 5) is sufficiently high, the force will cause the piston 30^' to be urged downwardly until the piston 30^' bears firmly against the valve seat 50^'. As the opening 56a of the channel 56 is centrally located, while the opening 38 of is off centre, the solid end surface 34 of the piston 30' will thus close the channel 56, thereby interrupting the flow of gas from the gas source 2.

As the opening 56a is much smaller than the total cross section of the intermediate chamber 51 , the force required to be applied to the piston in order to close the fluid connection is smaller, and the biasing arrangement 40 may be less powerful.

On the opposite end to the end surface 55 of the valve seat a tool engaging portion 63^" is arranged. The tool engaging portion 63^" may be of the type: slot, bolt, pozidriv, square, Robertson, torx or secure torx, hex socket or alien key, security hex, Phillips, square double, triple double, polydrive, spline drive, double hex, Bristol or pentalobular or any other possible design, which allows, for example, a screw driver to connect to the tool engaging portion. In order to move the valve seat 50^', i.e. to regulate the gun in a similar way as described in connection with Figs. 1 -4.

The disclosure has mainly been described above with reference to a few embodiments. However, as is readily appreciated by a person skilled in the art, other embodiments than the ones disclosed above are equally possible within the scope of the present disclosure, as defined by the appended patent claims.

Claims

1 . A gas powered gun comprising:

- a pressure chamber (1 1 ); and

- a gas regulator (20), which is arranged between said pressure chamber and a source (2) of compressed gas;

said gas regulator comprising:

- a body (3, 21 ), forming a first cylindrical portion and a second cylindrical portion, which are connected to each other, a diameter of said first cylindrical portion being greater than a diameter of said second cylindrical portion, said first cylindrical portion being in fluid connection with said pressure chamber (1 1 );

- a piston (30) mounted for sliding movement in said first and said second cylindrical portions;

- a first sealing member (41 ), which seals between a large diameter portion of said piston and said first cylindrical portion;

- a second sealing member (42) which seals between a small diameter portion of said piston and said second cylindrical portion;

- a valve seat (50) sealingly arranged in said second cylindrical portion, - an intermediate chamber (51 ) formed in said second cylindrical portion between said piston and said valve seat, said intermediate chamber being in fluid connection with said source of compressed gas;

- a passageway (33) extending through said piston and connecting said pressure chamber (1 1 ) with said intermediate chamber (51 );

- a biasing member (40) for pressing said piston resiliently away from said valve seat; and

- a valve seat adjusting mechanism (60) for adjusting a position of the valve seat, wherein said valve seat adjusting mechanism is accessible to a user without removing said regulator from said gas powered gun;

wherein said piston is subject to a first force created by pressure in said pressure chamber, and a second force created by pressure in said source of compressed gas, and said piston is movable against the action of the biasing member from a first position, in which said piston is separated from said valve seat so that said passageway is open to allow gas to flow from said source of compressed gas via said intermediate chamber into said pressure chamber, to a second position, in which said piston abuts said valve seat so that said passageway is closed, so that, when said piston is in its first position, pressure increases in said pressure chamber until said first force exceeds a sum of said second force and a spring force of said biasing member, to thereby move said piston to its second position, said spring force being dependant on the position of the valve seat.

2. A gas powered gun according to claim 1 , wherein said valve seat adjusting mechanism is arranged in said second cylindrical portion.

3. A gas powered gun according to claim 1 or 2, wherein said valve pressure adjusting mechanism comprises a threaded portion and said second cylindrical portion comprises a matching threaded portion and said valve pressure adjusting mechanism is adapted to be screwed into and out of said threaded portion in said second cylindrical portion.

4. A gas powered gun according to claim 3, wherein said threaded portion of said valve pressure adjusting mechanism comprises a tool engaging part, which is accessible to a user without removing the regulator from said gas powered gun.

5. A gas powered gun according to claim 2, wherein said valve seat moves to at least a first position when said valve pressure adjusting mechanism is moved in a direction into said second cylinder portion and said valve seat is adapted to move to at least a second position when said valve pressure adjusting mechanism is moved in an opposite direction.

6. A gas powered gun according to any one of the preceding claims, wherein said valve seat comprises a piston abutting portion and a valve seat adjusting mechanism connection part.

7. A gas powered gun according to claim 6, wherein said piston abutting portion is made of plastic.

8. A gas powered gun according to any one of the preceding claims, wherein said biasing member is arranged in said first cylindrical portion between said large diameter portion of said piston and an annular portion between said first and said second cylindrical portions.

9. A gas powered gun according to any one of the preceding claims, wherein said biasing member comprises one or more spring discs.

10. A gas powered gun according to any one of the preceding claims, wherein said body further comprises an atmospheric passage (90) extending between an opening to the atmosphere and said first and said second cylindrical portions between said first and said second sealing members.

1 1 . A gas powered gun according to any one of the preceding claims, wherein said source of compressed gas is a bottle or a tube comprising compressed gas.

12. A gas powered gun according to any one of the preceding claims, wherein said gas powered gun further comprises a barrel adapted to receive a projectile and an open-close valve for exhausting compressed gas from said pressure chamber to discharge a projectile in the barrel.

13. A gas powered gun according to any one of the preceding claims, wherein the valve seat (50') is sealed against the inner wall of the body (21 ') by two axially displaced sealing elements (54a, 54b), and wherein the fluid connection between the intermediate chamber (51 ) and the source (2) of compressed gas comprises:

a channel (56) through the valve seat (50') which channel has a first opening (56a) facing the piston (30') and a second opening (56b) between the two sealing elements, and

a channel through the body (21 ') having an opening between the two sealing elements (54a, 54b).

14. A gas powered gun according to claim 13, wherein the first opening (56a) is centrally located on an upper surface of the valve seat (50'), and said passage-way (33) has an opening (38) into the chamber (51 ) at a distance from a central axis (A1 ) of the piston (30').

15. A pressure tube for a gas powered gun comprising:

- a volume (82) adapted to be connected to a pressure chamber; and

- a gas regulator (20'), which is arranged between said volume (82) and a source of compressed gas (85);

said gas regulator comprising:

- a body (3', 21 '), forming a first cylindrical portion and a second cylindrical portion, which are connected to each other, a diameter of said first cylindrical portion being greater than a diameter of said second cylindrical portion, said first cylindrical portion being in fluid connection with said pressure chamber;

- a valve seat (50) sealingly arranged in said second cylindrical portion; - an intermediate chamber formed in said second cylindrical portion between said piston and said valve seat, said intermediate chamber being in fluid connection with said source of compressed gas;

- a passageway (33) extending through said piston and connecting said pressure chamber with said intermediate chamber;

- a valve seat adjusting mechanism (60) for adjusting a position of the valve seat, wherein said valve seat adjusting mechanism is accessible to a user without removing said regulator from said pressure tube;

16. A pressure tube according to claim 15, wherein said valve seat adjusting mechanism is arranged in said second cylindrical portion.

17. A pressure tube according to claim 15 or 16, wherein said valve pressure adjusting mechanism comprises a threaded portion and said second cylindrical portion comprises a matching threaded portion and said valve pressure adjusting mechanism is adapted to be screwed into and out of said threaded portion in said second cylindrical portion

18. A pressure tube according to claim 17, wherein said threaded portion of said valve pressure adjusting mechanism comprises a tool engaging part, which is accessible to a user without removing the regulator from said pressure tube.

19. A pressure tube according to claim 16, wherein said valve seat moves to at least a first position when said valve pressure adjusting mechanism is moved in a direction into said second cylinder portion and said valve seat is adaptive to move to at least a second position when said valve pressure adjusting mechanism is moved in an opposite direction.

20. A pressure tube according to any one of claims 15 - 19, wherein said valve seat comprises of a piston abutting portion and a valve seat adjusting mechanism connection part.

21 . A pressure tube according to claim 20, wherein said piston abutting portion is made of plastic.

22. A pressure tube according to any one of claims 15 - 21 ,, wherein said biasing member is arranged in said first cylindrical portion between said large diameter portion of said piston and an annular portion between said first and said second cylindrical portions.

23. A pressure tube according to any one of claims 15 - 22, wherein said biasing member comprises one or more spring discs.

24. A pressure tube according to any one of claims 15 - 23, wherein said body further comprises an atmospheric passage extending between an opening to the atmosphere and said first and said second cylindrical portions between said first and said second sealing members.

25. A pressure tube according to any one of the claims 15 - 24, wherein the valve seat (50') is sealed against the inner wall of the body (21 ') by two axially displaced sealing elements (54a, 54b), and wherein the fluid connection between the intermediate chamber (51 ) and the source (2) of compressed gas comprises:

26. A gas powered gun according to claim 25, wherein the first opening (56a) is centrally located on an upper surface of the valve seat (50'), and said passage-way (33) has an opening (38) into the chamber (51 ) at a distance from a central axis (A1 ) of the piston (30').