GB2600699A

GB2600699A - Blank gun

Info

Publication number: GB2600699A
Application number: GB2017430.6A
Authority: GB
Inventors: Stuart Drysdale Neil; Dojin Miljan
Original assignee: Individual
Current assignee: Individual
Priority date: 2020-11-04
Filing date: 2020-11-04
Publication date: 2022-05-11
Also published as: GB202017430D0

Abstract

A blank gun 1 comprises a combustion chamber 3, a fuel storage tank 6 having a fuel valve, a gas compression means 8 and a trigger mechanism 9. The combustion chamber 3 has a fuel inlet, an oxidant inlet and an ignition means. The gas compression means 8 is adapted to provide compressed fuel and oxidant to form a volatile mixture in the chamber 3. The gun 1 is incapable of expelling a projectile when ignition occur such as by having no barrel or a mock barrel 2. The ignition means may comprise discharge terminals within the chamber. The blank gun 1 may be a handgun (i.e pistol). The fuel may be hydrogen.

Description

Blank gun This invention relates to a blank gun and in particular a blank gun that operates using a combustion chamber within the body of the gun.

Blank guns are in widespread use as starter guns in sporting events and in the film and stage industries. A conventional blank gun does not have a projectile, but contains a blank cartridge. A firing pin strikes a primer at one end of a cartridge, which ignites a propellant powder in the cartridge and creates an explosion. Although this technique has been generally accepted for many years, it does have the disadvantage that the cartridge must be ejected after each firing. It also requires moving parts.

The present invention relates to the type of gun that avoids the use of cartridges by providing a combustion chamber within the body of a gun. Compressed fuel and oxidant gas are introduced into the chamber to form a volatile mixture, which is ignited to when the trigger is depressed. No separate cartridges are necessary and there are no moving parts.

Guns having internal combustion chambers for ejecting a bullet are known. For example, US 8,826,792 discloses a projectile propulsion apparatus comprising a combustion chamber means and valve means enabling cartridge-free projectile propulsion. It employs liquid and/or gaseous propellants which can be injected into the device and combusted to provide the necessary pressures for propelling a projectile.

WO 2005119158 discloses a pistol in which the barrel contains a combustion chamber with a plug that produces sparks. Pellets are propelled from the barrel by means of pressure created by inflammable 30 gas and oxygen mixture, ignited by a spark. -2 -

In neither of those documents is there any disclosure or suggestion that the combustion mechanism can be used to in a blank gun. The guns described therein are designed to create an ignition sufficient to expel a bullet out of the gun.

Accordingly, the present invention provides a blank gun comprising a combustion chamber, a fuel storage tank having a fuel valve, a gas compression means and a trigger mechanism, the combustion chamber having a fuel inlet, an oxidant inlet, and an ignition means, the gas compression means being adapted to provide compressed fuel and oxidant gas to form volatile mixtures in the combustion chamber, and the trigger mechanism is adapted to ignite said volatile mixture in the chamber; characterized in that the gun is adapted to be incapable of expelling a projectile when the ignition occurs.

The blank gun of this invention is adapted to be incapable of expelling a projectile, such as bullet. Preferably, this is achieved by the absence of a barrel. Alternatively, the blank gun of this invention may comprise a nonfunctional barrel. Such a non-functional barrel is merely to provide the appearance of a firing gun, but ineffective to carry a bullet. Preferably the non-functional barrel may be blocked. It may comprise, for example, a piece of plastic pipe, shaped like a barrel.

In addition, the force generated by the ignition in the chamber is insufficient to expel a projectile. Nevertheless, the ignition is sufficient to create a sound that simulates the firing of a normal gun.

The pressure of the gas mixture that is initially introduced into the chamber is greater than 1 bar, but the pressure is significantly greater 30 when the gas expands as it is ignited. -3 -

A suitable pressure of gas mixture that is introduced into the chamber, which can be termed the load pressure, depends on the size of the gun. It is convenient to classify the size of gun in terms of the analogous firing gun for which the blank gun is a replica.

For example, for a blank gun that is a replica of hand gun firing a projectile of less than or equal to 0.38 calibre, the pressure of the gas mixture introduced into the combustion chamber of the blank gun of this invention is suitably from 4 bar to 7 bar (400-600 kPa), preferably about 5 bar (500 kPa), which provides a pressure of about 50 bar after ignition.

This is achieved by adjusting the proportions of oxidant and fuel in the mixture. Suitably the gas mixture contains about 15% of fuel, preferably hydrogen.

For comparison purposes, in a normal firing gun of this type, the pressure of gas mixture introduced into a chamber prior to ignition may be approximately 30 bar to 40 bar (300-400 kPa), which provides a pressure after ignition of over 300 bar, to eject a projectile.

For a blank gun that is a replica of a rifle firing a projectile of less than or equal to 0.22 calibre, the load pressure is suitably from 4 to 7 bar, with a gas mixture containing about 15% of fuel, preferably hydrogen.

For a blank gun that is a replica of a handgun firing a projectile of greater than 0.38 calibre, the load pressure is suitably from 4 to 9 bar, with a gas mixture containing about 20% of fuel, preferably hydrogen.

For a blank gun that is a replica of a rifle firing a projectile of greater than 0.22LR calibre, the load pressure is suitably from 7 to 12 bar, with a gas 30 mixture containing about 20% of fuel, preferably hydrogen. -4 -

For a blank gun that is a replica of a larger gun firing a projectile of greater than 0.5 calibre, the load pressure is suitably from 10 to 19 bar, with a gas mixture containing about 40% of fuel, preferably hydrogen.

Preferably, the gun is designed so that it cannot readily be converted to a firing weapon. This may be achieved, for example, by the absence of a firing pin, the absence of a means to accommodate a cartridge, and/or the absence of a means to attach a barrel.

Suitably, the blank gun may be in the form of any normally explosive firing device, for example, a handgun, rifle, shotgun, an artillery shell gun, shoulder mounted bazooka, stinger, tank. The different forms of the gun may be used as starter guns in track and field races, competitive swimming events, military training exercises, military and public displays, and in the film and stage industries. For sporting events, the blank gun is preferably in the form of a handgun. It is generally operable in semiautomatic mode, so that the trigger can be depressed successively to produce sequential ignitions. For military and public displays, the blank gun can suitably be in the form of an artillery gun or a tank.

The body of the blank gun of this invention should be constructed of materials sufficient to withstand high temperatures produced during combustion. Suitable materials include advanced plastic additives, steel and high strength aluminium, titanium, or other metal alloys.

The blank gun suitably comprises one combustion chamber, but may comprise more chambers, for example from 2 to 4 chambers, to create an explosive sound in larger guns.

The blank gun of the present invention operates by using an expansion of gas in the combustion chamber to create the sound and recoil action of a firing gun. The expansion of gas is provided by the ignition of a volatile -5 -m ixtu re of fuel and oxidant in the chamber. The fuel employed may be any gaseous or volatile material that is combustible with an oxidant. Suitable fuels include hydrogen, natural gas, and hydrocarbons, such as methane propane, butane, or petroleum. A preferred fuel is hydrogen, as it produces an extremely high expansion when ignited.

The fuel is stored in a fuel storage tank, which is suitably situated within the gun, for example within the handle of the gun. The fuel storage tank may be connected via conduits, such as pipes, to provide a fuel inlet for the chamber. The flow of fuel into the chamber is controlled by a fuel valve. The fuel valve may be operated manually. Preferably, however, the fuel valve is operated by the trigger of the gun. For example, the trigger may be mechanically or electrically connected to the fuel valve, so that depressing the trigger first opens the fuel valve to allow a predetermined volume of fuel to enter the chamber; and further depression of the trigger ignites the volatile mixture in the chamber.

The oxidant may be, for example, oxygen or air. In this case, the extremely high temperatures caused by the ignition process produce wet and dry superheated steam, which provides additional expansion of gases within the combustion chamber. Preferably, the oxidant is air, which may be conveniently drawn into the chamber from the atmosphere through the oxidant inlet in the form of a one-way valve. When the oxidant is other than air, a separate oxidant storage tank may be provided, with oxidant inlets to the chamber.

A gas compression means is provided to compress the gas within the chambers. Suitably the gas compression means comprises a pump, connected to the chamber. In one embodiment of this invention, a pump is situated within the handle of the blank gun. The pump may be activated by means of an electrical or mechanical switch to compress the gas in the chamber. For example, the handle of the blank gun may also -6 -contain a slidable insert to operate a mechanical switch on the pump. A suitable such slidable insert is an empty magazine. Although the magazine is not required to dispense bullets or cartridges, the provision of a magazine can again create the illusion that the blank gun is a firing gun.

In this embodiment, the magazine may be located adjacent the pump, such that loading the magazine causes the pump to be activated.

Alternatively, the slidable insert in the handle may be a further fuel store or oxidant store. Again, loading of such a fuel or oxidant store will 10 activate the pump.

The gas compression means is required only when the magazine or fuel or oxidant store is loaded, prior to the first ignition. It can therefore be considered as a primer. Following the first ignition, the expansion of gas leaves a vacuum in the chamber, thus drawing further oxidant into the chamber.

When the trigger is pressed, compressed fuel from the fuel storage tank is released into the chamber and mixes with the compressed oxidant already in the chamber. The chamber is provided with a one-way valve, which is adjusted to allow a pre-ignition pressure to be maintained. For example, if the pre-ignition pressure needs to be from 4 to 7 bar, the one-way valve can be set to open only when the pressure in the chamber exceeds about 10bar. One suitable means to set the release pressure of the valve is a spring-loaded release mechanism. For example, a ball bearing may provide the closure in the valve, held in place by a spring. By adjusting the tension in the spring, it is possible to vary the release pressure of the valve. Suitably, the release pressure of the valve may be adjustable between 3 bar and 25 bar.

The combustion chamber is provided with an ignition means, to ignite the volatile mixture therein. The ignition means is suitably a set of discharge -7 -terminals situated in the chamber, which create a spark therein. The electricity for the sparks is produced by an electricity generating ignition source, for example a pieso-electric generator. Alternatively, the ignition source could be a battery.

The trigger mechanism is adapted to ignite the volatile mixture in the chamber, preferably by activating the ignition source. An electrical circuit between the ignition source and the ignition means, such as discharge terminals, then creates a spark in the chamber. The effect of that ignition is to create an expansion of gas, and create the sound of a fired gun.

The resulting rapid expansion of gases in the combustion chamber causes the pressure in the chamber to exceed the release pressure of the one-way valve, thus opening the valve. The expanded gas is thereby rapidly released from the chamber through the valve and an exit hole in the gun. That rapid release creates a vacuum in the chamber, which in turn draws oxidant, such as air, into the chamber to re-start the cycle.

A specific embodiment of the present invention will now be described with 20 reference to the accompanying drawings in which: Fig. 1 is a cross sectional view of one embodiment of a blank gun of this invention.

Referring to Fig. 1, the body of a blank gun 1 contains a mock barrel 2 and a combustion chamber 3 having an air inlet 4. The barrel 2 is blocked, so that no projectile can be expelled. The handle 5 of the gun contains a fuel storage tank 6, a slidable insert in the form of an empty magazine 7, and a gas compression means in the form of a pump 8, which is connected to the combustion chamber 3. The fuel storage tank 6 contains hydrogen and is also connected to the combustion chamber 3. The body of the gun also contains a trigger mechanism 9. -8 -

The combustion chamber 3 is provided with a one-way valve mechanism 10 which comprises a ball bearing 11 and a spring 12. By adjusting the tension in the spring 12, the valve mechanism 10 is set to open at a pressure of 10-bar. An exit hole 13 communicates from the rear of the valve mechanism 10 to the exterior of the gun.

When the empty magazine 7 is loaded into the handle of the gun, it operates the pump 8 to pass compressed air via a one-way valve 8A into the combustion chamber 3, to a pressure of about 7 bar. That pressure is maintained, as it is below the release pressure of the valve mechanism 10.

In operation, the trigger of the gun is depressed and opens the fuel valve on the hydrogen storage tank 6 to release compressed hydrogen into the chamber 3, which then contains a compressed mixture of hydrogen and air. Further depression of the trigger causes the upper part of the mechanism 9 to push against an ignition source 14, creating an electric current in a circuit which terminates in two discharge terminals (not shown) located in the combustion chamber 3. That creates a spark between the terminals which ignites the compressed hydrogen and air in the chamber, causing a rapid expansion of the gas mixture, thereby creating a sound which simulates a firing gun.

The resulting rapid expansion of gases in the combustion chamber causes the pressure in the chamber 3 to exceed the release pressure of the one-way valve mechanism 10, thus opening the valve. The expanded gas is thereby rapidly released from the chamber 3 through the valve mechanism 10 and the exit hole 13 in the gun. That rapid release creates a vacuum in the chamber, which in turn draws air into the chamber 3 through the air inlet 4, which is connected via a further one-way valve to the exterior of the gun. In this way, the blank gun is in a position for the next ignition.

Claims

CLAIMS1. A blank gun comprising a combustion chamber, a fuel storage tank having a fuel valve, a gas compression means and a trigger mechanism, the combustion chamber having a fuel inlet, an oxidant inlet, and an ignition means, the gas compression means being adapted to provide compressed fuel and oxidant gas to form volatile mixtures in the combustion chamber, and the trigger mechanism is adapted to ignite said volatile mixture in the chamber; characterized in that the gun is adapted to be incapable of expelling a projectile when the ignition occurs.
2. A blank gun as claimed in claim 1, wherein the inability to expel a projectile is provided by the absence of a barrel.
3. A blank gun as claimed in claim 1 or 2, wherein the pressure of the gas mixture introduced into the combustion chamber, prior to ignition, is from 4 bar to 7 bar (400-600 kPa).
4. A blank gun as claimed in any one of claims 1 to 3, wherein the ignition means comprises a set of discharge terminals within the chamber.
5. A blank gun as claimed in any one of claims 1 to 4, wherein the blank gun is in the form of a handgun.
6. A blank gun as claimed in any one of claims 1 to 5, wherein the fuel is hydrogen.
7. A blank gun as claimed in any one of claims 1 to 6, wherein the gas compression means is a pump situated in the handle of the gun. -10 -
8. A blank gun as claimed in any one of claims 1 to 7, wherein the handle of the gun contains a slidable insert, such that loading the slidable insert causes the pump to be activated.