GB2195421A - Weapon simulator - Google Patents

Abstract

High pressure is established in an annular reservoir 13 by feeding compressed air in through a port 30. The reservoir is closed off from a discharge chamber 16 by a sleeve piston 14 held closed by a spring 15 and the pressure of the air on a flange 22. When the pressure is high enough, compressed air is also admitted via a port 32 and lifts the piston 14 off a sealing ring 18 so that the air pressure in the reservoir 13 can act on the rear end of the piston 14 and shoot it forward very rapidly. The compressed air expands into the discharge chamber 16 and a bang is emitted through a horn 7. To simulate a complete weapon signature, the device may be operated in conjunction with an electronic flash unit and a smoke simulator with a venturi tube which sucks a puff of "smoke" from a vessel containing a powder. Air is also bled into the vessel to keep the powder loose. <IMAGE>

Description

SPECIFICATION Weapon simulator This invention relates to weapon simulators.

It is well known to simulate weapons using pyrotechnical devices, relying on explosives for their effect. These devices are, however, dangerous and are consequently subject to stringent regulations regarding their manufacture, transportation, storage and use. In addition, the nature of the devices means that they are consumable and cannot be reused.

The object of the present invention is to provide a simulator which does not suffer from these defects.

According to the present invention there is provided a weapon simulator for generating a noise resembling that of a weapon by the discharge of a pressurised fluid, comprising a fixed volume fluid discharge chamber having an inlet port and an outlet port, a means for supplying a pressurised compressible fluid to the inlet port and a valve rapidly movable between a closed position, in which the discharge chamber is isolated from the supply of pressurised fluid, and an open position in which the pressurised fluid can rapidly expand into the discharge chamber and be discharged through the outlet port.

The compressible fluid, for example air, expands upon decompression caused by the valve opening and rapidly fills the discharge chamber. The fluid escapes at a high velocity through the outlet port and, if the valve is opened rapidly enough, will emit a bang. The bang may be enhanced by restricting the outlet port to further increase the velocity of the discharging fluid, by the venturi effect. The outlet port is preferably through a horn.

In a preferred embodiment, the pressurised fluid is supplied to the inlet port from a pressurised reservoir. The valve remains in the closed position while pressurised fluid is supplied to the reservoir until the fluid pressure in the reservoir reaches a predetermined level.

At this point the valve is rapidly moved to the open position and a bang emitted. It is preferable to cut off the supply of pressurised fluid to the reservoir while the valve is in the open position.

Pyrotechnical devices create their own smoke. The simulator described above requires a supplementary device for simulating the smoke of the weapon and it is another object of the invention to provide a simple but effective device which can be operated off the same fluid supply as the weapon simulator for generating the noise.

According to the present invention there is further provided a simulator device for generating a cloud resembling the smoke pattern of a weapon, comprising a chamber for containing a powder, suction means for withdrawing powder from the chamber and discharging the powder to form a cloud and means for feeding fluid into the chamber to loosen the powder therein.

The cloud formation is significantly improved if the powder is agitated by the loosening flow of fluid, to overcome compaction of the powder.

In a preferred embodiment of this invention the chamber has an outlet connected to the throat of a venturi tube. When a smoke cloud is to be emitted, a flow of fluid is supplied to the venturi tube and induces suction in the connection from the throat of the tube to the chamber and thereby withdraws powder from the chamber to be ejected from the venturi.

The noise and smoke simulators may be used in combination with each other or independently. A complete simulator system may further comprise a means for producing a flash of light, thereby to simulate effectively all features of a weapon's signature. By allowing each of the simulators to be operated independently, a wide range of weapons may be simulated by a single apparatus. The simulators provide further advantages in that they can be reused repeatedly and in a rapid mode of operation. In addition none of the simulators requires the use of explosives to function effectively and use is not constrained by the regulations applying to pyrotechnic devices.

An embodiment of this invention will now be described, by way of example, with reference to the accompanying drawings, in which: Figure 1 is a sectional view of a device for simulating the noise of a weapon; Figure 2 is a schematic representation of a control system for controlling a weapon noise simulator and a weapon smoke simulator; and Figure 3 shows a modification of the device of Fig. 1.

The device shown in Fig. 1 comprises a hollow, cylindrical body 5 closed at its rear end by an end plate 6 and having a horn 7 attached to its front end, in each-case by machine screws 8. The horn is attached by way of a flange 9 partway along its length. In front of a flange 9 lies the flared mouth 10 of the horn. To the rear of the flange, the throat 11 of the horn extends back into the body 5, but with radial clearance such as to define an annular chamber 12, which will be called the spring chamber.

The rear part of the body 5 is counterbored to form an annular reservoir 13. A sleeve 14 slides in the spring chamber 12 and is biased by a compression spring 15 in that chamber to the illustrated position, in which it abuts the end plate 6, thereby partitioning the reservoir 13 from the discharge chamber 16 enclosed by the hollow body 5 and the horn 7.

The bore 17 of the horn forms an output port with a venturi constriction.

In order to isolate the reservoir 13 effectively from the discharge chamber 16, the rear end of the piston 14 cooperates with a rebate around the end plate 6 and with sealing rings in grooves round the walls of the rebate, namely a sealing ring 18 against which the rear end of the piston bears and a sealing ring 19 against which the inside surface of the piston slides. This surface also slides against a sealing ring 20 in a groove around the horn throat 11. The outside surface slides against a sealing ring 21 in the non-counterbored part of the bore in the hollow cylindrical body 5.

The piston 14 has a flange 22 at its rear end and when the piston is urged forward, as will be described below, against the bias of the spring 15, the flange strikes against a buffer washer 23.

Bores 30 and 30' extend through the end plate 6 to the reservoir 13. The bore 30 is used to supply compressed air to the reservoir. A high pressure can be built up therein without leakage because of the various seals 18 to 21 and the action of the air pressure on the flange 22 supplementing the closing force of the spring 15. The purpose of the second bore 30' will be explained below. A third bore 32 communicates directly with the rear end face of the piston 14, in between the seals 18 and 19. When compressed air is admitted to this port, it shifts the piston off the seal 18, whereupon the high pressure of the air in the reservoir 13 acts on the whole rear surface area of the piston 14. The piston therefore moves violently forward, air expands very suddenly into the dischamber 16 and a loud bang is emitted.

The energy of the piston is absorbed by the buffer washer 23 and, with the air pressure dissipated, the spring 15 returns the piston 14 to the closed position.

The schematic representation in Fig. 2 shows a noise simulator 4, symbolising the device of Fig. 1, and a weapon smoke simulator 40, which comprises a vessel 43 containing powder 42 for emission so as to form a cloud. The powder, for example talcum powder, may be coloured according to the use of the simulator or according to the weapon being simulated. The vessel 43 has an outlet 39 connected by a line 44 extending from the top of the vessel to a venturi tube 45, the line 44 entering the venturi at its throat. An inlet 47 in the lower region of the vessel 43 allows pressurised air to bleed into the vessel to keep the powder loose.

In operation, a puff of pressurised air is supplied tothe venturi tube 45 to create a flow of air along the tube. The air velocity increases as the air passes the throat of the venturi 45 and provides suction in the line 44, drawing powder 42 out of the vessel 43 to be discharged from the venturi tube 45 and form a cloud; A pneumatic control system for the noise and smoke simulators is shown in Fig. 2. A compressed air supply, for example an air bottle (not shown) is connected to a line 50. The air supply is controlled by a valve 51 which vents the control system to atmosphere when the air supply is off.

When the valve 51 is in the 'on' position, air is supplied along a line 52 to a solenoid valve 53, controlling the supply of air to the smoke simulator, and a solenoid valve 54, controlling the air supply to the noise simulator. Further simulators may be added to the system and are controlled by additional valves such as a solenoid valve 55.

The air supply to all the solenoid valves 53, 54 and 55 is monitored by a pressure transducer 58 indicating if the pressure is adequate. The air passes through an adjustable throttle valve 59 to a pressure regulator 60.

The solenoid valve 53 controlling the smoke simulator vents the simulator to atmosphere when the valve 53 is in the 'off' position (as shown in Fig. 2). When the solenoid of the valve 53 is activated by an electrical pulse, a puff of air is supplied to the smoke simulator through a variable restrictor 61 and a line 62 directed to emit a puff of air through the venturi tube 45, thereby to draw powder 42 from the vessel 43 and discharge the powder to form a cloud. A bleed line 63 from the supply allows a puff of air also to be supplied via a variable restrictor 66 to the inlet 47 of the vessel 43 to provide the air flow necessary to loosen the powder.

The solenoid valve 54 controls the supply of air to the noise simulator 4 and vents the simulator to atmosphere when in the 'off' position, (as shown in Fig. 2). When the solenoid of the valve 54 is activated, air is supplied through a shut off valve 67 directly to the inlet 30 of the simulator 4 and charges the reservoir 13. A pneumatic feedback signal is taken from the bore 30' to a pilot operated valve 69. When the air pressure in the reservoir reaches a predetermined, value the valve 69 switches over from the position shown in Fig. 2 and pressurised air is supplied to the inlet 32 of the noise simulator 4 and to the shut off valve 67, which cuts off the air supply. At this point, with pressurised air supplied to the inlet 32, the noise simulator 4 is activated, releasing the charge of air very rapidly, as previously explained and emitting a loud bang.

Once the bang is emitted the air pressure in the reservoir 13 of the simulator 4 drops and the valve 69 closes and vents the air supply to the inlet 32 and the valve 67 to atmosphere. This re-establishes the air supply by opening the valve 67 and the charging process begins again. The piston 14 recloses as explained above. So long as the solenoid valve 54 is open, the noise simulator will continue to emit a series of bangs. The frequency of the bangs will depend upon how long it takes the valve 67 to re-open and then how long it takes the pressure in the reservoir 13 to build up to the level at which the valve 69 operates, in response to the pressure feedback signal from the port 30'.Re-opening of the valve 67 can be delayed (to reduce the frequency of the bangs, as well as providing time for the piston 14 to return to the closed position) by placing a restrictor 70 in the pilot line of the valve. In order to allow rapid closing, the restrictor 70 is by-passed by a oneway valve 71.

Once the valve 69 has returned to its normal state (as illustrated in Fig. 2), the only escape route for air in the reservoir 13 is via the port 32. Because of rapid return of the piston by the spring 15, there will be a tendency for air to be trapped between the seals 18 and 19 and because this can only escape via the port 32, the firing rate will be limited.

Fig. 3 shows a modified device which overcomes this problem. The port 32 no longer communicates directly with the end of the piston 14 but rather with a small piston 73 in a chamber 74 formed in the end plate 6. The pressure acts against a return spring 75. The piston rod 76 is screwed into a rebated plate 77 taking the place of the rebated part of the end plate 6b in Fig. 1. It will be noted that the sealing ring 19 is no longer present.

The piston 73 can apply a thrust to the piston 14 via the plate 77, lifting the main piston off the sealing ring 18 to initiate the rapid opening of the main piston by the pressure in the reservoir 13.The auxiliary piston 73 and plate 77 return very rapidly, once the port 32 is vented by the valve 69, under the action of the spring 75 and the reaction force of the air expanding violently in the discharge chamber 16. The return of the piston 14 is therefore unimpeded and very rapid firing is possible.

The solenoid valves 53, 54 and 55 may be operated at any time, independently or together to vary the effects according to the weapon being simulated. An electronic control unit (not shown) will be employed to determine the instants at which the solenoid valves are operated, and durations of closure and can also operate a flash unit for reproducing the flash of a weapon. The control unit will coordinate the timings so as to synchronize the flash, bang and smoke cloud.

Claims (18)

1. A weapon simulator for generating a noise resembling that of a weapon by the discharge of a pressurised fluid, comprising a fixed volume fluid discharge chamber having an inlet port and an outlet port, a means for supplying a pressurised compressible fluid to the inlet port and a valve rapidly movable between a closed position, in which the discharge chamber is isolated from the supply of pressurised fluid, and an open position in which the pressurised fluid can rapidly expand into the discharge chamber and be discharged through the outlet port.

2. A simulator according to claim 1, wherein the fluid discharge chamber is a tube closed at one end, the other end being open and forming the outlet port.

3. A simulator according to claim 1 or 2, wherein the means for supplying the pressurised fluid to the discharge chamber comprises a pressurised fluid reservoir connected to the inlet port, means for selectively supplying pressurised fluid to the reservoir with the valve in the closed position, and means for moving the valve to the open position when the fluid in the pressurised fluid chamber reaches a predetermined pressure.

4. A simulator according to claim 3, wherein the valve comprises a slidable member which, when in a closed position is urged by the pressure in the reservoir against a seal, means for applying force to the slidable member to lift it off the seal and permit the reservoir pressure to act on an area of the slidable member beyond the seal and thereby shoot the slidable member to an open position.

5. A simulator according to claim 4, comprising a spring acting on the slidable member to bias it towards the closed position.

6. A simulator according to claim 4 or 5, wherein the means for applying force to the slidable member comprise a second inlet port for applying fluid pressure directly to the said area of the slidable member.

7. A simulator according to claim 4 or 5, wherein the means for applying force to the slidable member comprise an auxiliary piston, a second inlet port for applying fluid pressure to the auxiliary piston, and an element coupled to the auxiliary piston and contacting the slidable element in its closed position, without connection thereto, whereby the said element can apply a thrust to the slidable element when pressure is applied to the auxiliary piston.

8. A simulator according to claim 6 or 7, comprising a pilot operated valve responsive to pressure in the reservoir to communicate that pressure to the second inlet port when the pressure reaches the said predetermined pressure.

9. A simulator according to any of claims 3 to 8, further comprising means for preventing the supply of pressurised fluid to the reservoir when the valve is in the open position.

10. A simulator according to claims 8 and 9, wherein the pilot operated valve vents the reservoir in the position in which it communicates pressure to the second inlet port.

11. A simulator according to any of claims 6 to 10, comprising a further valve controlling the supply of fluid to the inlet port and biased to a first position permitting the supply, the further valve being resposive to the pressure applied to the second inlet port to move to a second position cutting off the supply.

12. A simulator according to claim 11, wherein the further valve has means retarding its return from the second position to the first position under the action of the bias on the valve.

13. A simulator according to any of claims 1 to 12, wherein the output port comprises a venturi.

14. A simulator according to any of claims 1 to 13, comprising a chamber for containing a powder and means for discharging the powder to form a cloud.

15. A simulator according to any of claims 1 to 13, further comprising a chamber for containing a powder, suction means for withdrawing the powder from the chamber and discharging the powder to form a cloud and means for feeding fluid into the chamber to loosen the powder therein.

16. A simulator device for generating a cloud resembling the smoke pattern of a weapon, comprising a chamber for containing a powder, suction means for withdrawing the powder from the chamber and discharging the powder to form a cloud and means for supplying a flow of fluid into the chamber to loosen the powder therein.

17. A simulator or simulator device according to claim 15 or 16, wherein the means for withdrawing and discharging the powder comprises a venturi tube, means for providing a flow of fluid along the tube, the chamber connected to the throat of the venturi, whereby powder is drawn into the venturi tube by the fluid flow.

18. A weapon signature simulator as hereinbefore described with reference to the accompanying drawings.