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1. (WO2005066578) SYSTEME DE VERIFICATION D'ARMES A FEU
Note: Texte fondé sur des processus automatiques de reconnaissance optique de caractères. Seule la version PDF a une valeur juridique

Firearms Clearance System

The present invention relates to a firearms clearance system and in particular to a firearms clearance system that provides a safe and secure means for checking whether a firearm is loaded or unloaded.

It is known to those skilled in the art of firearms, whether it be in relation to recreational activities or on a professional basis, that a situation can arise when it is not known whether a particular firearm is loaded or unloaded. In such circumstances there is an obvious safety issue for the user, and any bystanders, as an accidental discharge of a firearm could be fatal. The situation is further aggravated when the user is unfamiliar with the particular make of firearm and so may not have the required knowledge in order to have it safely disabled. Therefore, it is of obvious benefit for firearms users to have access to a firearms clearance system that would allow them to safely discharge the firearm and/or ascertain that the firearm is unloaded..

A firearms clearance system known to those skilled in the art comprises a discharge tube that is filled with GranTex™, a granulated rubber material, that is employed to de-energise a round from a firearm. The granular nature of the rubber material is effective at stopping certain handgun and rifle rounds as these devices have a maximum accommodation rating for rounds with a velocity up to 3,600 feet per second (fps) (1098 rns-1) or with a muzzle energy of up to 3,600 feet per pound (ft/lbs) (4881 Joules) . However, these ratings are below the velocity/energy imparted to a round from a number of modern firearms, for example a .50 BMG, and so are limited with what firearms they may be deployed. Furthermore, this uncertainty factor prevents some firearm users, who are unsure of the rating of a firearm, from employing these devices, even if the particular firearm would fall within the safety specification of the device.

It is well known to those skilled in the art that granular based systems suffer from the effect of splash back. Splash back occurs when a fired round strikes solid matter. The impact force on the round as it strikes the solid matter often causes the casing of the round to break up and the lead within the round to melt. This results in fragments of the casing and molten lead being returned in the direction of the user resulting in a risk to the user and possible airborne pollution of lead.

It is therefore an object of aspects of the present invention to provide a firearms clearance system that obviates or at least mitigates one or more of the disadvantages associated with the prior art.

The term "rubber" used throughout this specification refers 'to natural rubber or any synthetic, elastomeric material with physical properties similar to those of natural rubber .

According to a first aspect of the present invention there is provided a firearms clearance system comprising a discharge tube and an infill located within the discharge tube, wherein the infill comprises two or more stacked layers of rubber that provide a means for stopping a round discharged into the discharge tube.

The employment of two or more stacked layers of rubber acts not only to stop the round discharged into the tube but also prevents splash back of fragments of the rounds from the round returning in the direction of the user.

Preferably the firearms clearance system provides an accommodation rating for rounds with a velocity up to 1,500 feet per second (455 s"1) .

Preferably the firearms clearance system provides an accommodation rating for rounds with a muzzle energy of up to 600 feet per pound (814 Joules) .

Preferably the infill further comprises one or more layers of a second material interspersed between the two or more layers of rubber selected from the group comprising poly-para-phenyleneterephthalamide, armoured steel, titanium, brass, aluminium, lead or any other base metal or alloy derived from a base metal .

Incorporation of layers of a second material interspersed between the two or more layers of rubber acts to increase the stopping accommodation rating of the system.

Preferably the firearms clearance system provides an accommodation rating for rounds with a velocity up to 4,000 fps (1220 ms"1) .

Preferably the firearms clearance system provides an accommodation rating for rounds with a muzzle energy of up to 12,000 ft/lbs (16,270 Joules).

Most preferably the firearms clearance system provides an accommodation rating for rounds with a muzzle energy of up to 23900 ft/lbs (32,400 J) .

Preferably the discharge tube comprises a firearms entrance aperture that provides access to the discharge tube for a barrel of a firearm.

Optionally the discharge tube further comprises a firearms entrance tube that acts to guide the barrel of a firearm into the discharge tube. Alternatively the layer of rubber adjacent to the firearms entrance aperture comprises a hollow so as to allow the barrel of a firearm to be partially inserted into the infill.

Preferably the discharge tube further comprises a plurality of firearms discharge apertures that provide an outlet for exhaust gases expelled when a firearm is discharged within the discharge tube.

Preferably the discharge tube comprises a material selected from the group comprising plastic, armoured steel, titanium, brass, aluminium, lead or any other base metal or alloy derived from a base metal.

Preferably the firearms clearance system further comprises a base plate connected to the discharge tube wherein the base plate provides increased stability to the system.

Optionally the base plate is connected to the discharge tube via a hinge and one or more supporting arms such that the discharge tube can be orientated at an angle relative to the base plate.

Preferably the length of the one or more supporting arms can be varied so as to allow for the angle between the base plate and the discharge tube to be varied.

Optionally the base plate comprises one or more retractable wheels wherein when the one or more wheels are in an extended position they provide for increased mobility of the firearms clearance system.

According to a second aspect of the present invention there is provided an infill suitable for use with a firearms clearance system the infill comprising two or more layers of rubber arranged to form a stack.

Preferably the infill further comprises one or more layers of a second material interspersed between the two or more layers of rubber selected from the group comprising poly-para-phenyleneterephthalamide, armoured steel, titanium, brass, aluminium, lead or any other base metal or alloy derived from a base metal.

Embodiments of the invention will now be described, by way of example only, with reference to the accompanying drawings, in which:

Figure 1 presents a schematic representation of a firearms clearance system in accordance with an aspect of the present invention;

Figure 2 presents a side view of the firearms clearance system of Figure 1;

Figure 3 presents a cross sectional representation of:
(a) an infill; and
(b) an alternative infill
both being suitable for use within the firearms clearance system of Figure 1;

Figure 4 presents a schematic representation of an alternative embodiment of the firearms clearance system of Figure 1; and

Figure 5 presents a schematic representation of a further alternative embodiment of the firearms clearance system of Figure 1 that comprises the infill of Figure 3 (b) .

Referring to Figure 1 and Figure 2 a schematic representation and a side view, respectively, of a firearms clearance system 1 in accordance with an aspect of the present invention is presented. The firearms clearance system 1 can be seen to comprise a discharge tube 2, made from armoured steel, that is pivotally connected at a lower end, via a hinge 3, to a base plate 4. Two supporting arms 5 then act to secure the relative angle between the discharge tube 2 and the base plate 4 such that the discharge tube 2 is conveniently orientated for employment by a firearms user. The supporting arms 5 comprise adjustment means 5b that allow for the angle between the base plate 4 and the discharge tube 2 to be varied, as and when required by a user.

The discharge tube 2 can be seen to comprise a top plate 6 within which a firearms entrance aperture 7 has been formed. An infill 8 is contained within the discharge tube 2, the details of which are described below. Adjacent to the firearms entrance aperture 7 the infill 8 is hollowed so as to allow a firearms barrel to be inserted into the discharge tube 2. On the side walls 9 of the discharge tube 2 are located a number of firearm discharge apertures 10 whose function is to provide an outlet for exhaust gases expelled when a firearm is discharged within the system 1. Incorporation of the firearm discharge apertures 10 prevents a firearm recoiling back and injuring the user when the firearms clearance system 1 is employed to discharge a round from a firearm.

Figure 3 (a) presents a cross sectional representation of an infill 8a suitable for use within the firearms clearance system 1. The infill 8a can be seen to comprise six, stacked layers of rubber 11 each of which are approximately 14mm thick.

When required, a user deploys the firearms clearance system 1 in the following manner. The barrel of a firearm to be tested is inserted via the firearms entrance aperture 7 into the discharge tube 2. The trigger of the firearm is then activated. If the firearm is not loaded no round is discharged and the user knows the firearm is safe.

If however the firearm is loaded a round is discharged into the discharge tube 2 when the user activates the trigger. The round initially strikes the first layer of rubber 11 which acts to decelerate the round while simultaneously broadening the surface area of the tip of the round. The round then enters the second, and subsequent, layers of rubber 11 of the infill 8a that act on the round in a similar manner to that of the first layer i.e. decelerates the round as well as broadening the surface area of the tip of the round. This process continues on through the discharge tube 2 until the round is brought to rest.

It should be noted that on striking the first rubber layer 11 some of the force of the round is transferred through the rubber creating a compression effect throughout the column of stacked layers of rubber 11. This compression effect provides distinct advantages for the infill 8a. In the first instance the compression increases the density of the subsequent layers of rubber 11 so increasing the drag and retardation effect subsequently placed upon the round. As a result the stopping time is dramatically increased allowing the displacement of the energy over an extended period of time therefore reducing the forces exerted on the external parts of the discharge tube 2.

The above described process can then be repeated by the firearms user until they are satisfied that the firearm in fully unloaded. It should be noted that continuous use of the firearms clearance system 1 results in rounds being collected at various points along the length of the discharge tube 2, dependent on their particular type and velocity. As these rounds are made mainly from lead or tungsten they act to further increase the stopping power of the firearms clearance system 1 for subsequent rounds that strike these fragments.

The above described firearms clearance system 1 has been calibrated and is therefore known to exhibit an accommodation rating for rounds with a velocity up to 1,500 feet per second (fps) (455 ms-1) or with a muzzle energy of up to 600 feet per pound (ft/lbs) (814 Joules) . This rating is maintained for at least one hundred rounds discharged into the firearms clearance system 1.

A major advantage of employing the layers of rubber 11 is that they act to remove the problematic features of splash back experienced by those systems described in the prior art. Since the layers of rubber are solid this allows for the deceleration of the round prior to striking any solid body within the discharge tube 2 e.g.

earlier cleared rounds. Thus when a round does strike these solid bodies any fragments are prevented from returning in the direction of the user by the layers of rubber 11. As a result the firearms clearance system 1 is self sealing so acting to contain all the lead and casing fragments.

Figure 3 (b) presents a cross sectional representation of an alternative infill 8b suitable for use within the firearms clearance system 1. The infill 8b can be seen to comprise four repeated sections 12, each of which comprise six layers of rubber 11 (14mm thick) stacked upon a layer of Kevlar® 13 having a thickness of approximately 5mm.

Kevlar® 13 is the common trade for poly-para-phenyleneterephthalamide, which is also commonly referred to as a para-aramid. It is a material whose properties are known to provide for high strength with low weight, high chemical resistance, and high cut resistance. Kevlar® is also flame resistant, does not melt, soften, or flow, and is unaffected by immersion in water. These physical properties make Kevlar® an ideal material for use within the infill 8b of the firearms clearance system 1.

The layers of rubber 11 within the infill 8b act in a similar manner as previously described in relation to infill 8a. Inclusion of the layers of Kevlar® 13 within the infill 8b act to provide further means for decelerating the round as it passes downwards through the discharge chamber 2. When a round strikes the Kevlar® 13 layer dependant on calibre, velocity and bullet type the following may occur:

A The bullet strikes the Kevlar® 13 and fails to penetrate - Due to the force being exerted on the Kevlar® 13 the compression of the rubber sections behind allow the Kevlar® 13 layer to travel circa 4- 15 millimetres . As a result the force of the round is further dissipated providing controlled deceleration of the round bringing it to an eventual stop;

B The bullet strikes and penetrates the Kevlar® 13 layer - If the bullet is travelling at sufficient velocity and is of a sufficiently powerful calibre the round will penetrate the first Kevlar® 13 layer. However, penetration of this layer provides for rapid deceleration of the round and further expansion of the point of the bullet. This increases the cross sectional area of the point of the round further so increasing the deceleration and drag on the bullet within subsequent layers of the discharge tube 2.

The firearms clearance system 1 employing the infill 8a has also been calibrated and is therefore known to exhibit an accommodation rating for rounds with a velocity up to 4,000 fps (1220 ms"1) or with a muzzle energy of up to 12,000 ft/lbs (16,270 Joules). This rating is maintained for at least one hundred rounds discharged into the firearms clearance system 1 before the infill 8b is required to be replaced.

Various other alternative materials can also be employed to construct the firearms clearance system 1. In particular the layers of Kevlar® 13 can be replaced with armoured steel, titanium, brass, aluminium, lead or any other base metal or alloy derived from them. Similarly, the discharge tube 2 may be constructed from any of the above materials or even from a plastic material since the discharge tube 2 is not directly employed in the process of stopping a round.

Some specifically designed armour piercing rounds are designed for Anti-Material purposes (e.g. .50 Cal BMG AP, .50 Cal BMG API, 14.5 * 114 AP and 14.5 * 114 API.). These rounds have typical energies between 12,000 ft/lbs (16,270 Joules) and 20,000 ft/lbs (27,117 Joules) and are designed to penetrate armoured military vehicles. The penetrative ability of these weapons are such that they can successfully penetrate 30mm plus of armoured steel. However the firearms clearance system 1 comprising the infill 8b, with armoured steel layers (of approximately 4mm thickness) replacing the layers of Kevlar® 13, is capable of dealing with such armour piercing rounds.

In particular, the system deals with these rounds through an initial deceleration and compression of the layers of rubber 11 so as to dramatically elongate the flight time of the round. When the round strikes the first layer of armoured steel the outer copper/ lead jacket is stripped off, allowing only the steel penetrator to continue to travel onwards. This has the effect of dramatically reducing the momentum of the round so allowing the drag and compression effect of the layers of rubber 11 to further decelerate the round before until it strikes the second armoured steel layer. The steel penetrator then pass through the second armoured steel layer but incurs significant damage to its front point allowing , as described in B above, increased drag and deceleration until it finally comes to rest before the armoured steel layer. With such an arrangement the firearms clearance system 1 is consistently able to stop 990 grains (64g) rounds exhibiting velocities of 3,300 fps (1000 ms"1) and muzzle energies of 23900 ft/lbs (32,400 J) .

In an alternative embodiment, shown in Figure 4, the firearms clearance system lb, incorporates a firearms entrance tube 14, employed to .aid the insertion of a firearm into the device. The firearms entrance tube 14 is lined with rubber so as to prevent scratching of any firearm when located within the tube.

Figure 5 presents a yet further alternative embodiment firearms clearance system lc . In this embodiment the discharge tube is connected directly to the base plate by any suitable means e.g. welding. This embodiment includes the infill 8b located so as to provide a void 15 at the lower end of the discharge tube 2 wherein the lower plate 16 comprises hardened armoured steel. In this arrangement when a round directly strikes the hardened armoured steel with sufficient energy this layer drops towards the base plate 4 so providing a safeguard to the user indicating that the system is no longer safe for use. At this stage a replacement system is required.

In a further alternative embodiment (not shown) the firearms clearance system may further comprise retractable wheels associated with the base plate 4 so as to increase the mobility of the device. When the system is to be deployed the wheels are retracted so as to prevent unwanted movement of the system when a round is discharged within the discharge tube 2.

It is envisaged that the firearms clearance systems la, lb and lc would be provided as a sealed unit so as to avoid any unwanted tampering of the infill 8. However, it will be apparent to those skilled in the art that by simply incorporating a removable section on the discharge tube 2 the system can be made re-usable whereby the infill 8 is simply replaced when required. Examples of a removable section include a hinged top plate 6 or firearms entrance aperture 7.

Although particular dimensions for the various layers of the infills 8 have been provided it is not intended that the aspects of the invention should be limited by these values. For example infills 8 have been produced by the applicant that comprise layers of rubber 11 within the range of 10mm to 30mm, layers of Kevlar® 13 within the range of 3mm to 9 mm and layers of armoured steel within the range of4mm to 10mm.

The above invention has several advantages over those systems described in the prior art. Most significantly it negates the detrimental effects of splash back experienced by those systems described in the prior art. Furthermore, the system is designed to exhibit accommodation ratings that are suitable for receiving a round discharged from a range of firearms i.e. from .22 RF up to and including a .50 BMG. Thus the system provides a means for safely stopping a round so allowing a user to safely check on whether the firearm is loaded or unloaded. Employing the system also reduces the requirements on the user to have skilled knowledge of the firearm.

The described system is mobile and so allows it to be used either internally or externally. It is also capable of being adapted so as to allow it to be mounted on a vehicle or a wall. The described system is therefore ideal for the test firing of firearms and for the preparation and testing of new prototype weapons as well as allowing for captured weapons to be quickly and easily tested.

The foregoing description of the invention has been presented for purposes of illustration and description and is not intended to be exhaustive or to limit the invention to the precise form disclosed. The described embodiments were chosen and described in order to best explain the principles of the invention and its practical application to thereby enable others skilled in the art to best utilise the invention in various embodiments and with various modifications as are suited to the particular use contemplated. Therefore, further modifications or improvements may be incorporated without departing from the scope of the invention as defined by the appended claims.