CA2659573A1 - Gas removal arrangement and barrel and/or weapon with a gas removal arrangement - Google Patents

Abstract

The present invention relates to a gas removal arrangement (3) for a barrel (1), with the gas removal arrangement comprising a gas cylinder (12) which is connected for communication purposes via a connecting channel (8, 10, 10a; 10b) to the barrel bore (4). In this case, an inlet piece (30) is provided which matches the effective flow cross section (10a; 10b) and thus the operating pressure in the gas cylinder (12) to a specific weapon configuration. The invention also relates to a barrel assembly and to a weapon having a gas removal arrangement (3) such as this.

Description

Gas removal arrangement and barrel and/or weapon with a gas removal arrangement The invention is relating a gas removal arrangement for a barrel and /or a pipe of a self-loading, gas operated action weapon (e.g. a machine gun) with a gas cylinder which is connected for the purpose of interchange with the barrel bore. Such gas removal equipment is, for example, known from DE
196 15 181.

The expression "barrel" in the following refers to the barrel with its groves and lands as well as to a smooth weapon pipe. Directions such as on the top, bellow, in the front, behind, right and left are given from the view of the shooter for a weapon that is held in the firing position.

In so-called gas operated action weapons, where the loading mechanism is powered by the munitions' gas pressure, a gas piston is arranged in a gas cylinder. To a large extend the gas cylinder is closed on one end so that a pressure chamber is formed between the gas piston's frontal face and the gas cylinder's frontal face which forms a communicating connection with the interior parts of the barrel. During firing, the munitions' gas enters into this pressure chamber as soon as the projectile has passed the connection point between gas chamber and the barrel bore. The entering gases build up in the pressure chamber so that the pressure affects the frontal surface of the working piston.

Via a worlcing piston the resulting force operates an actuator rod, which is part of the loading mechanism of the weapon and which causes the cartridge feeding and removal, the loclcing, and if needed, the cocking of the trigger mechanism. In fully automatic weapons this mechanic is activated as long as the trigger is held in the shooting position. The detonation energy, which is released during shooting, is thus partially diverted for the powering of the weapon.

Customarily, the cross sections of the flow, the design of the gas piston, and the pressure chamber are adjusted to a weapon in a certain way so that the desired firing speed can be adjusted and overstress of the mechanical actuator can be omitted. For this purpose (besides the radial connection to the barrel) the pressure chamber is furnished on its frontal side with an axial gas release opening in order to regulate the pressure. Thus, the gas which enters from the barrel into the gas cylinder is partially released from the gas cylinder andlor the pressure chamber into the surroundings so that the pressure in the pressure chamber is relatively low compared to the barrel.
Such an embodiment is likewise known from DE 196 15 181.

There are also mechanisms where the amount of gas, which exits from the barrel, enters the pressure chamber axially on the frontal side (see, for example, DE 648 391). The amount of gas entering can be adjusted via a locking screw. The ventilation of the gas cylinder, however, is achieved here by the piston leaving the cylinder entirely and thus it is made possible for the gas to exist.

With changes on the weapon and/or on the munitions the gas pressure conditions in the barrel bore and/or the gas cylinder are also changing. For example, if a normally equipped weapon - with a flash compressor - is alternatively furnished with a silencer, the gas pressure increases in the barrel bore and thus in the gas cylinder and/or in the pressure chamber.
With that the speed of the working piston increases. This in turn leads to increased speed of the loading and/or repetition process of an automatic weapon. The same effect occurs if another type of munitions is used (larger propelling charge, higher bullet mass).

The loading process, which is accelerated in this way, also increases the firing speed. This is accompanied by an increased use of munitions and the mechanical stress on the parts of the weapon increases drastically. The unnecessary increase in munitions use can lead to logistic problems for the military use of such weapons. More munitions need to be brought along and need to be made available where the weapon is used without at the same time improving the performance of the weapon accordingly. The higher demand on the weapon results in an increase in wear and shorter intervals for maintenance and repair.

It is difficult and it cannot be put into practice under operating conditions to continuously adjust the flow and pressure conditions at the gas removal arrangement in order to stabilize the firing speed.

The object of the presented invention is to provide an improved gas removal arrangement which at least in part eliminates the above mentioned problems.
This object is addressed with the subject of claim 1. The invention is characterized in that the effective flow cross section is adjustable to a weapon configuration by means of a separate inlet piece.

In this context weapon configurations are a certain set-up of a weapon and/or the use of a certain kind of munitions with that weapon. With the use of an inlet piece in the connecting channel between the barrel bore and the gas cylinder in a very simple way an appropriate flow cross section can be achieved by means of an a appropriately designed inlet piece. Thus various inlet pieces with an appropriate flow cross section, which will be determined for certain weapon configuration, can be exchanged without the need for additional adjustments to the weapon.

In the further modification according to claim 2 such an inlet piece, which can be inserted into the gas removal arrangement, is designed in an adjustable and/or removable form. To design the inlet piece into the gas removal arrangement is advantageous because here it is easy to implement the appropriate design and adaption for the use of such an inlet piece for structural and production reasons.

According to claim 3 such an inlet piece may feature a variety of different through bore-holes that then define the desired flow cross section according to the desired operating position of the inlet piece. Basically, in this manner it can be "switched" back and forth between several kinds of operation.
According to claim 4 the adjustment takes place by turning or moving the inlet piece in the gas removal arrangement.

The design according to claim 5, which locks into place, makes repeated adjustments of appropriate operating positions easier.

Claim 6 is in regard to a further modification where a specially designed indentation features effective surfaces which work together with a locking device so that the at least one of the characteristics of regulator stopper, resting surface, and mounting lock is achieved. Regulator stopper means in this context that the adjustment of the inlet piece is inhibited beyond a certain range; resting surfaces define the corresponding operating position in the gas removal arrangement; mounting lock means that unintentional removal is prevented by an appropriate locking effect between the locking unit and the indentation. The indentation itself can be produced with appropriate production methods (e.g. by turning, milling, grinding, precision casting, inject molding and so forth). According to claim 7 an indicator element is designed on the insertion through which the operation setting of the inlet piece can be seen andlor felt by touch.

Such an in indicator function is particularly important for weapons since this way the shooter can determine the adequate operational setting either "with one glance" or "with one touch".

The further modification according to claim 8 facilitates the operation of the inlet piece, whereby a inner hexagon profile can be operated with a regular tool and/or a slot can be operated with an easily available item (e.g. a coin).
The claims 9 and 10 are concerning a barrel component with a gas release arrangement according to the invention and/or a weapon with such a barrel component.

In the following the invention is closer described with the help of illustrations:

Figure 1 shows a longitudinal cut through the muzzle area of a barrel with the gas removal device according to the invention, Figure 2 shows an enlarged view of the gas removal area from figure 1, Figure 3 shows a side view (from the right) of the gas removal arrangement according to the invention, Figure 4 shows a side view (from the left) of the gas removal arrangement according to the invention, Figure 5 shows a cross cut through the gas removal arrangement according to the invention in the area of the gas channel, Figure 6 shows a longitudinal cut (sectional plane A-A in figure 5) which shows the locking and the safety mechanism.

Figure 7 shows a perspective view of an inlet piece for the gas removal arrangement according to the invention.

Figure 1 shows the muzzle area of a weapon with the barrel 1, where a flash compressor 2 is arranged at the frontal end. Behind the flash compressor a gas removal 3 is affixed to the barrel which is connected to the locking mechanism, which is not pictured, via rods, which are also not pictured.
When the munitions is fired the ignited propellant gas catapults the bullet out to the bullet casing through the barrel bore 4, which runs concentrically to the so-called bore axis 6, to the front of the barrel muzzle thought the flash compressor 2 in the direction of the target. As soon as the bullet has passed the area of the gas removal 3, part of the propellant gas enters into a tap bore hole 8, witch runs diagonally to the barrel bore 4 radial in the barrel 1, and it is directed into a pressure chamber 14, which is formed by the gas cylinder 12, and that via an adjacent gas channel 10 which runs in the gas removal 3.

This area is pictured enlarged in Figure 2. A gas piston 16 runs in the gas cylinder 12 which with appropriate fit rests in gliding form against the interior wall of the gas cylinder 12. The fit between the outer surface of the gas piston 16 and the cylindrical interior wall of the gas cylinder 12 is chosen in a way that the gas piston 16 is arranged in the gas cylinder 12 in movable and largely leak proof form. The surfaces which are gliding alongside each other are appropriately mechanically finished (turning, milling, grinding, and precision-grinding), and in order to increase durability they might be surface treated (hardened, chrome-plated, coated or such).
The design could also include compression rings.

The propellant gas, which has entered into the pressure chamber 14, builds up a working pressure between the frontal surface of the gas piston 16 and the frontal surface of the gas cylinder 12 and/or the pressure chamber 14.
This pressure moves the gas piston 16 and thus the rods to the back whereby the gas rods carries over the pressure impulse to the weapon actuator which activates the locking and loading mechanism (both are not pictured).

The gas removal 3 and the gas cylinder 12, which are here pictured in one piece, are closely connected to the barrel 1 by means of a collar 18. The collar 18 can be shrunk-on with the appropriate fitting on a corresponding outer casing area of the barrel 1. The axial position on the barrel 1 is hereby defined by an offset 20, against which the collar 18 rest with its end face.
The collar 17, and thus also the gas removal 3, are additionally axial and in circumferential direction affixed to the barrel 1 by means of pins 22. These pins can, for example, be dowel pins or conical pins which pull the collar 18 downwards in the area of the gas channel 10 (diagonal to the bore axis) to the outer surface of the barrel 1, so that the outer opening of the tap bore-hole 8 merges closely with the opening of the gas channel 10. This seal prevents the loss of gas between the barrel 1 and the collar 18.

In the pictured embodiment the gas piston 16 is furnished on its frontal end with an auxiliary piston 16a which in the basic position of the gas cylinder 16 (pictured in figure 2) partially enters the ventilation bore- hole 24. Some of the gas propellant exits thought the ventilation bore-hole 24 to the front thought the discharge nozzle 26 when the gas piston 16 has moved a little backwards (under the effect of the propellant gas) so that the auxiliary piston 16a uncovers the ventilation bore-hole hole 24. With this the pressure in the pressure chamber 14 is reduced and the effect of the gas on the gas piston 16 (and thus to the rods with are attached to the back) is reduced. Thus a "softer" pressure flow on the gas piston is achieved. With it the forces on the adjacent rods and on the loading and/or locking mechanism are reduced as well.

In the gas channel 10 itself an inlet piece is 30 designed which is inserted into a through-bore-hole 32, which runs diagonally to the gas channel 10 and to the bore axis 6 (see also figure 5). In the illustrated embodiment the inset piece 30 features two bore-holes 10a and l Ob which cross at an angle of about 90 , penetrate each other, and which feature different diameters.

In the position, which is illustrated in figure 2, the bore-hole 10a connects the end of the gas channel 10, which is facing the barrel with its end which in turn is facing the gas cylinder. By turning the inlet piece 30 by 90 it can be adjusted in a way so that the bore 10b connects the two ends of the gas channel 10. Depending on the chosen through bore-hole l0a and/or l Ob the flow cross section between the tap bore-hole 8 and the gas cylinder 12 changes and thus also the amount of overflowing gas changes. Between inlet piece 30 and through bore-hole 32 a tight fit is designed, so that the bore hole 10a or lOb, which is not activated and which does not align with the gas channel, is sealed.

The option to adjust the flow cross section between the tap bore-hole 8 and the gas cylinder 12 and/or the pressure chamber 14 in a fixed predefined way permits to adjust the weapon to various operation modes in order to achieve in both modes the optimum firing speed.

For example, the use of a silencer (not picture) instead of the use of a flash suppressor 2 increases the gas pressure in the barrel bore 4. This increased pressure would lead with the unchanged gas channel cross section 10; 10a, or l Ob to an increase in gas pressure built up in the pressure chamber 14 with in turn would lead to higher acceleration of the gas piston 16.

This in turn would increase the firing speed and thus would lead to increased stress or wear on the locking and reloading mechanism. In the worst case scenario it can lead to malfunctioning of the ejection mechanism and that the time for reloading a new cartridge from the magazine is too short so that it could reliably be transferred from the locking arrangement to the cartridge chamber.

In order to keep the pressure increase in the pressure chamber 14 at a constant level even with an increase in gas pressure in the barrel bore 4 the inlet piece can be adjusted in a way so that a bore-hole l0a or l Ob connects the tap bore 8 with the pressure chamber 14 with a smaller cross section.
The corresponding bore-hole l0a or 10b reduces in this way the overflowing gas so that the pressure increases slowly and so that the firing speed remains constant.

In the illustrated embodiment for munitions of NATO caliber 7.62 a bore diameter of the bore-hole 10a and/or 10b is designed at 1.7 mm for the use with a flash suppressor and a bore diameter of 1.2 mm for the use with silencer. For other common calibers, which are used with assault rifles, the diameters can lie between 0.5 and 2 mm. For other weapons and other calibers, however, the corresponding diameters need to be adjusted and can also range differently.

A combined positioning and locking mechanism is designed for the locking of the inlet piece 30 in the through bore-hole 32 in the gas removal 3. Its function can be seen in the sectional view in figure 6 as well as in figure 3, 4,5and7.

Figure 7 shows an enlarged perspective view of the inlet piece 30. On one end the inlet piece features an adjusting head 34 which has on the side a protruding indicator and a control blade 36.

An inner hexagon profile 38 and a slot for operation40 is located on the frontal surface of the adjusting head 34 (figure 3). Both serve the purpose to insert appropriate tools or devices (e.g. a coin) in order to turn the inlet piece in the through bore-hole 32 for positioning the desired connecting bore-hole l0a or lOb.

In figure 7 the two openings of the bore-holes l0a and l Ob can be seen in the cylindrical shank area 42. At the end of the shank area 42 an indentation 44 is designed into which the locking device 46 can interlock. (Figure 6) For the interconnection with the locking device 46 the indentation 44 works the following way: The frontal end 52 of the locking device 46 engages in a springy manner with the indentation 44. The appropriate spring force is pretensioned via a pressure spring 48, which is arranged together with a locking device 46 in a conductor 49, over a locking pin 50.

The two radial sides 54 and 56 of the indentation 44 (see figure 7) with which the end 52 engages are determining the axial position of the inlet piece in the through bore 32 and prevent the unintentional removal. The two radial sides 54 and 56 are connected to each other by corner arcs 58 and 60.
The indentation 44 and the bore-holes 1 0a and l Ob are arranged in a way to each other so that the corner arcs 58 and 60 each form a stopper in circumferential direction, which together with the end 52 determine the final turning position of the inlet piece 30 by aligning the bore-holes 10a, l Ob, respectively, with the gas channel 10.

Finally, the indentation features two more stopping surfaces 62 and 64 which interact with the frontal surface 66 on the end 52 of the locking device 46.

With the turning of the inlet piece 30 the edge 63 which separates the two stopping surfaces 62 and 64 moves across the frontal surface 66 and hereby presses the locking device against he spring force backwards. If a certain turning point is passed, the frontal surface 66 presses under the effect of the feather 48 against the edge 63 and turns the inlet piece 30 further into its final position where the appropriate bore 10 a or lOb is aligned with the gas channel 10.

For the removal of the inlet piece 30 the locking device 46 has an actuating pin 68 which can be reached from the outside via a channe170 (figure 4).
Above the actuating pin 68 the locking device (46) can be moved out of the grip of the indentation 44 so that the inlet piece 30 can be pushed out of the though bore-hole 32. A shoulder 72 at the locking device 46 and a corresponding step 73 in the conductor 49 prevent the locking device from sliding into the through bore-hole 32 when the actuating pin is completely released (when the inlet piece 30 is removed).

In the embodiment described above the inlet piece 30 is designed with two through bore-holes l0a and l Ob. In other embodiments, however, several crosswise arranged through bore-holes could be designed so that more then two different through bore-hole settings can be possible. There are also embodiments were a respective inlet piece 30 only features one bore-hole and where the apportioning of gas can take place by a respective exchange of such inlet pieces.

In yet another embodiment the through bore-holes can be arranged next to each other, that is in different axial positions on the shank 42. These bore-holes can then be aligned with the gas channel 10 by appropriate in or out movements of the inlet piece 30.

The inlet piece 30 is then designed as a slider. Such a mechanism is to be furnished with a respective loclcing device.

Additional embodiments and variations of the presented invention are resulting for the expert in the context of the following patent claims.

Claims (10)

1. Gas removal arrangement (3) for a barrel (1) with a gas cylinder (12) that communicates with the barrel bore (40) via a connection channel (8, 10, 10a, 10b), whereby the effective flow cross section (10a, 10b) can be adjusted to a weapon configuration by means of an inlet piece (30).

2. Gas removal arrangement (3) according to claim 1, where the inlet piece (30) is designed to be inserted into the gas removal arrangement (3) in an adjustable and/or removable way.

3. Gas removal arrangement (3) according to claim 1 or 2 in which the inlet piece features several different bore-holes (10a, 10b) which define the flow cross section according to a certain operating position of the inlet piece (30).

4. Gas removal arrangement (3) according to claim 3, in which the operating position takes place by turning and/or moving of the inlet piece (30) in the gas removal arrangement (3).

5. Gas removal arrangement (3) according to claim 3 or 4, in which the inlet piece (30) is designed in a way that it can be locked in the respective operating position.

6. Gas removal arrangement (3) according to claim 4 or 5, in which a regulating and locking device (46) is designed in a way so that in spring-loaded form it engages with a indentation (44) which is designed on the inlet piece (30), whereby the indentation is formed with at least one of the following effective surfaces: Corner Arc (54, 60), locking surface (62, 64), inlet lock (54, 56) which engages with the locking device (46).

7. Gas removal arrangement (3) according to one of the previous claims, for which an indicator element (36) is designed on the inlet piece (30) which indicates the operational mode of the inlet piece (30) optically or manually.

8. Gas removal arrangement (3) for which the inlet piece (30) features at least one cut surface for the positioning of an operation tool whereby the surface design advantageously takes the form of a inner hexagon profile (38) and/or of a slot (40).

9. Barrel component with a gas removal arrangement (3) according to one of the previous claims.

10.Weapon with a barrel component according to claim 9.