GB2355056A

GB2355056A - Mechanism for firearms

Info

Publication number: GB2355056A
Application number: GB9919961A
Authority: GB
Inventors: David Ian Caig; Malcolm Douglas Cooper
Original assignee: ACCURACY INTERNAT Ltd
Current assignee: ACCURACY INTERNAT Ltd
Priority date: 1999-08-23
Filing date: 1999-08-23
Publication date: 2001-04-11
Also published as: GB9919961D0

Abstract

A mechanism comprising apparatus (19), (21) for use with noise-suppressed or silenced weaponry (1). Said apparatus being operable to allow the introduction of a dampening medium, such as an inert or noble gas or any other medium of reduced flammability, in to the barrel (25) and/or silencer (17) of the weapon (1) before firing.

Description

2355056 MECHANISM FOR FIREARMS This invention relates to a mechanism for

firearms such as a noise- suppressed or silenced rifle or handgun.

Noise suppressors, or silencers as they are more popularly known, are well known and a variety of different devices have previously been proposed. These devices have been proposed with the aim of reducing the noise or report of a firing firearm.

In a typical weapon barrel, a projectile such as a bullet is typically "fired" from a case by propelling the bullet through the barrel by a propellant, such as gunpowder. A tight seal is formed between the barrel and the bullet to prevent escape of propellant past the bullet.

When the bullet exits from the muzzle, gas escapes from the barrel which coincides with the "bang" emitted by the gun. The "bang" is caused by burning propellant entering the atmosphere at the muzzle at a very high pressure and temperature and this burning propellant also produces the luminous muzzle flash and muzzle blast typical of unsilenced weaponry.

Silencers function by providing a means whereby the pressure of the expanding propellant gas within the barrel is allowed to reduce slowly upon exiting the barrel behind the projectile. By reducing the pressure in this way, propellant exiting from the muzzle is significantly slowed and reduced in temperature (in comparison to unsilenced weaponry). As the propellant leaving the muzzle of the silencer is travelling that much more slowly and at cooler temperatures, the sound associated with the exiting propellant is reduced together with a corresponding reduction in the likelihood of muzzle flash and muzzle blast occurring.

United States Patent No. 3,776,093 (in the name of Leverance, et al.) discloses one such system that does indeed function to greatly reduce the sound 2 associated with a weapon being fired. This device, therefore, provides an effective solution, for the vast majority of situations, to the problem of reducing the firing noise of weaponry.

It has been noted, however, that even such a device as that disclosed in this United States patent may not sufficiently reduce firing noise for certain specialised situations. In such situations, such as may occur when a soldier is employed in a sniping role on the battlefield, it has been noted that noise associated with a first shot from an item of weaponry can be greater than that associated with further later shots.

Testing has shown that the first shot can be as much as two to five decibels louder than subsequent shots. This relative increase in noise can increase the risk of detection of a sniper's position. Clearly, therefore, addressing this problem could significantly improve the soldier's ability to remain undetected and thus improve the survivability of a given engagement.

It is therefore an aim of this invention to address these and other problems associated with conventional noise suppression devices.

In accordance with an aspect of the invention there is provided a mechanism for noise suppressed or silenced weaponry that is operable to introduce a dampening medium into the barrel and silencer of the weapon before firing.

The introduction of the medium into the weapon causes a corresponding reduction in an amount of combustible gas within the weapon and thus a reduction in noise associated with ignition of said combustible gas upon firing.

Accordingly, a further aspect of the invention provides a mechanism operable to cause a reduction in an amount of combustible gas within a weapon.

A further aspect of the invention provides a firearm comprising a mechanism as described herein.

3 A further aspect of the invention provides an item of silenced weaponry comprising a mechanism as described herein having a store of dampening medium attached or attachable thereto.

By introducing a dampening medium into the barrel and silencer of the weapon before firing, the operator (a soldier, marksman or sniper for example) can purge the weapon of (or at least reduce the amount of) combustible gas (which in most cases is oxygen rich air) that is typically trapped within the barrel and noise suppression device. Purging (or at least reducing) the weapon of combustible gas reduces the amount of gas that could be ignited by expanding propellant gas, and thus reduces the likelihood of noise being generated by the ignition of that combustible gas and the impact of the characteristic noise increase typically associated with the first shot.

For the avoidance of doubt, it is to be noted that it is not necessary to completely purge the weapon of combustible gas to reduce noise, and thus that purging of the weapon is to be construed simply as reducing the amount of combustible gas within the weapon.

An embodiment of the invention will now be described with reference to the accompanying drawings, in which:

Figure I is an elevation of a weapon to which a noise suppression device has been fitted; Figure 2a is a plan view of the barrel of the weapon shown in Figure 1; Figure 2b is a cross-sectional view along the line A--A of Figure 2a; Figure 3 is an end view partly in section of the noise suppression device along the line B--B of Figure 1; Figure 4 is plan view partly in section of the noise suppression device along the line C--C of Figure 2; and Figure 5 is a plan view partly in section of the noise suppression device along the line D--D of Figure 4.

4 Figure 1 is an elevation of a weapon to which a noise suppression device including a mechanism according to an embodiment of the invention has been fitted. In this example, the weapon is a rifle 1 of the type that might be provided to soldiers, snipers or the like.

As shown, the rifle comprises a butt 3, a stock 5 within which the gun mechanism is contained, and a barrel assembly 7. A trigger 9 projects from the stock 5 and is protected by a trigger guard 11 in the normal way. The barrel end of the rifle 1 is fitted in this example with a tripod 13 that can be extended to provide a support for the rifle when in use. The stock 5 comprises an opening into which a magazine 15 may be fitted.

In the example shown, the barrel assembly 7 comprises a noise suppression device (i.e. a silencer) 17 mounted over a barrel 23 (see Figure 2) through which ordnance is fired in use, and an adaptor 19 to which is fastened a valve mechanism 21 for introducing a dampening medium into the weapon. In the embodiment shown, the silencer 17 and mechanism 21 comprise separate components fittable to one another, but it will be appreciated of course that they could instead be an integral item. Such an arrangement would be disadvantageous, however, as maintenance of the mechanism 21 would then be unduly difficult.

As shown in Figures 2a and 2b, the barrel 23 comprises a tube 25 having a bore 27 formed therethrough. The tube 25 is formed with a notch 29 that extends through the tube 25 to the bore 27. The tube's outside surface is formed with a screw thread in the region 31 to enable the silencer 17 to be screwably engaged with the barrel 23. Before engaging the silencer 17 with the barrel 23, the adapter 19 is slid over the barrel 23 until it abuts against a raised edge 33. Once the adapter 19 has been correctly located, the silencer 17 can be screwed onto the barrel 23 to securely hold the adapter 19 and mechanism 21 in place on the barrel 23. The notch 29 provides an entry point into the weapon, and in particular into the bore 27 and silencer 17, for the dampening medium.

Figure 3 is an end view partly in section of the adapter 19 and mechanism 21 that together with the silencer comprise a noise suppression device. As shown, the adapter 19 includes an aperture 35 through which the barrel may be passed. The adapter 19 is provided with a locating lug 37 that engages with the notch 29 on the barrel 23 to correctly locate the adapter 19 on the barrel. The adapter 19 is connected to a primary housing 38 that has an actuating lever 39 pivotally mounted thereon.

As shown in Figure 4, the lever 39 is operable to move a pin 41 that operates to open a first valve 43. The first valve 43 comprises a valve body 45 that is biased (in this embodiment by a spring 49) against a valve seat 47 to close the first valve 43.

The first valve 43 is connected to a storage vessel 51 for dampening medium by way of a suitable adapter (not shown).

When the lever 39 is depressed (i.e. when it is moved towards the muzzle as shown in Figure 1) the pin 41 is driven to move the valve body 45 away from the valve seat 47 against the spring 49 to open the first valve 43. Once the first valve 43 has been opened, dampening medium may flow under pressure from the storage vessel 51 to a second valve 53. The second valve 53 comprises a further valve body 55 that may be driven away from an associated valve seat 57 against the action of a resilient bias 59 (which in this embodiment is another spring) by the pressurised flow of the dampening medium. When the second valve body 55 is driven away from the second valve seat 57 the second valve 53 is open and pressurised dampening medium can flow from the storage vessel 51 through the first valve 43, through the second valve 53 and into the aperture 35 of the adapter 19. From the aperture 35, the dampening medium may flow via a groove 61 through the notch 29 and into the bore 27 and attached silencer 17. The second valve 53'acts; as a non-return valve that seals the first valve and storage vessel from the bore when the weapon is fired.

Figure 5 is an elevation partly in section along the line D--D of Figure 4.

Figure 5 shows the particular way in which the storage vessel 51 communicates with 6 the first valve 43, and the particular way in which the lever 39 is operable to drive the pin 41 to open the first valve 43. As shown in Figure 5, the vessel 51 and attached adapter 63 communicate with the first valve 43 by way of a passageway 65. The passageway 65 is closed at one end by a bung 67 that may be removed to allow for cleaning of the passageway 65. In the preferred embodiment, the bung 67 comprises a flat bottomed screw.

From the above discussion, it may be seen that the operator of the weapon, for example a soldier, can depress the lever 29 for a given period of time to allow dampening medium to enter from the storage vessel 51 into the bore 27. The dampening medium then permeates through the bore 27 towards the muzzle end of the barrel 23, and also enters the silencer 17 as it progresses. Once dampening medium has been introduced into the weapon (typically by depressing the lever 39 for two or more seconds) the operator may then fire the weapon whereupon the dampening medium resists burning by expanding propellant gases within the silencer. In this way, the first shot fired by the operator is quieter than the first shot of other previously proposed silenced weaponry, and is typically of a shnilar loudness of that of subsequent shots. In the preferred embodiment, that dampening medium is carbon dioxide, but it will be appreciated that a large variety of alternative mediums may instead be provided. In order to enjoy the benefits of the present invention, it is only necessary for the dampening medium to resist burning by the propellant gases within the silencer. Accordingly, any non- flammable medium or any medium of reduced flammability would be suitable. For example, the dampening medium could be one of the inert or noble gases (such as Argon, Neon etc), Nitrogen or any other elements, compounds or mixtures that are of reduced flammability. A large number of suitable elements, compounds and mixtures will be apparent to persons skilled in the art.

One advantage of the particular arrangements described is that the dampening medium may be supplied from a pressurised vessel that may easily be removed and replaced when empty. A soldier in the field can therefore carry spare vessels

7 together with his normal kit to allow for prolonged silenced use of the weapon.

It will be understood, of course, that the present invention has been described herein by way of example only, and that modifications may be made within the scope thereof. For exwnple, whilst the invention has been described herein with respect to a silencer that fits over the barrel of the weapon, it will be understood that the teachings of the invention could usefully be employed in conjunction with a silencer for mounting to the muzzle of the weapon. It should also be noted that the teachings of the invention are equally applicable to handguns and rifles, as well as to other forms of weaponry. Furthermore, whilst the mechanism is mounted externally in the example shown, it could alternatively be mounted internally in either the silencer and barrel system or the weapon structure itself.

Claims

I Apparatus for noise-suppressed or silenced weaponry, said apparatus being operable to allow the introduction of a dampening medium into the barrel and/or silencer of the weapon before firing.
2. Apparatus according to claim 1, wherein the apparatus is removably attached or attachable to the weapon.
3. Apparatus according to claim 1, wherein the apparatus forms an integral and/or 10 internal part of the weapon.
4. Apparatus according to claim 2, comprising an adapter for attachment to the weapon and a valve body.
5. Apparatus according to claim 4, wherein the valve body includes a socket by means of which a store of dampening medium may be attached thereto.
6. Apparatus according to claim 5, wherein the store of dampening medium comprises a store of pressurised dampening medium.
7. Apparatus according to claim 5 or 6, wherein the valve body includes a pathway from the socket to the adapter.
8. Apparatus according to claim 7, comprising a first valve resiliently biased 25 against a valve seat to close said pathway.
9. Apparatus according to claim 8, comprising a lever movable to displace the first valve from the valve seat and open the pathway.
10. Apparatus according to any of claims 4 to 9, wherein the adapter comprises an annular body fittable over the barrel of the weapon.

9
11. Apparatus according to claim 10, wherein the adapter comprises a locating projection locatable in a groove in said barrel.
12. Apparatus according to claim 10 or 11, wherein the adapter comprises a non return valve for obstructing return flow of dampening medium during firing of the weapon.
13. Apparatus according to claim 12 and claim 7, wherein the non-return valve is located in said pathway 13. Apparatus according to claim 11, 12 and 13, wherein the adapter comprises a pathway in communication with the groove and non-return valve by means of which dampening medium may be supplied to the groove and hence to the barrel of the weapon.
14. Apparatus according to any preceding claim which may be disassembled for cleaning.

15. An assembly comprising:

an item of noise-suppressed or silenced weaponry; a store of pressurised dampening medium; and apparatus according to any of claims I to 13, said apparatus being operable to allow the introduction of at least a portion of the dampening medium into the barrel and/or silencer of the weapon before firing.
15. An assembly according to claim 14, wherein said dampening medium comprises a non-flammable medium or a medium of reduced flammability.
16. An assembly according to claim 14 or 15, wherein the dampening medium is selected from the group consisting of carbon dioxide; an inert or noble gas; nitrogen or any other element, compound or mixture of reduced flammability.
17. An item of noise-suppressed or silenced weaponry such as a rifle or a handgun comprising apparatus according to any of claims 1 to 14.
18. Apparatus for noise-suppressed or silenced weaponry substantially as hereinbefore described with reference to the accompanying drawings.
19. An assembly substantially as hereinbefore described with reference to Figure 1.
20. An item of noise-suppressed or silenced weaponry such as a rifle or a handgun substantially as hereinbefore described with reference to the accompanying drawings.