GB2138112A - Equipment for simulated shooting - Google Patents

Abstract

Equipment simulating the firing of projectiles from a gun at a target comprises a projector 11 for projecting a modulated beam 15 of electromagnetic radiation towards a target 28 in response to the operation of a trigger (not shown). The target 28 has a reflective surface operable to reflect the beam back along a path substantially parallel to the incident beam irrespective of the angle of incidence of the beam. The reflected beam is detected by a receiver 31 to 37 with means 38, 39 for signalling the reception of a reflected beam as a "hit". The equipment may include a score unit comprising a signal processor 42 and visual display means 44. The detection of a reflected beam is radiated to a detector 43 connected to the signal processor and the "hit" is displayed on the visual display means as well or instead of indication at the receiver. The target 25 may be in the shape of a clay pigeon, made from moulded plastics material with a number of reflective beads loaded into a fixing medium applied to its surface. <IMAGE>

Description

SPECIFICATION Equipment for simulated shooting The present invention relates to equipment for simulated shooting in which the use of a firearm is simulated by replacing bullets or cartridges by a beam of radiation.

Experimentsarecurrentlytaking place with a system in which bullets are replaced with a laser beam emitting device. The human target wears a jacket which incorporates sensors for indicating incidence of the laser beam on the jacket, and hence a "hit".

Problems have been encountered in this system with the accuracy of recording "hits".

U.K. Patent specification No 1,595,189 described an installation forsimulated shooting and illustrates an arrangement including a rifle and a stationary target.

The weapon is provided with a laser or L.E.D. pulse emitting device and optical provision is made for adjusting the width ofthe beam to the calibre of the weapon in the plane of the target. In this case the weapon is stationary during firing and the target is stationary and at a known distance away. The target includes sensors for detecting a "hit".

This prior disclosure does not provide a solution for the problems which arise in simulating a moving weapon and/or moving target, such as might be experienced, for example with clay pigeon shooting.

It is the object of the invention to provide equipment forsimulatedshooting in which itis possible to use a moving target, and/or a moving weapon.

According to the present invention there is provided equipmentforsimulated shooting comprising a projector having a trigger, means for generating a modulated beam of electromagnetic radiation and projecting ittowards a target in response to operation of the trigger, and receiver means for sensing incidence of the beam on the target and signalling a "hit", wherein the target comprises a reflective surface operable to reflect the beam back along a path substantially parallel to the incident beam irrespective of the angle of incidence of the beam; and the receiver means is adapted to detect radiation reflected from the target.

Advantageously the equipment includes means for timing and comparing the projected and received beams including means for detecting the operation of the trigger.

Preferably the equipment includes a score unit comprising a signal processor and visual display means, the equipment including meansforradiating signals form said receiving means to said score unit on receipt of a reflected beam, said score unit being adapted to increment the score reading on the visual display means in response to a signal from the receiver means.

The "hit" indicator may be electrically connected to the receiver or remote from the receiver but activated thereby.

Means may optionally be provided to cater for differences which may arise owing to the different nature of the radiation beam and the projectile which it is to simulate. For example the beam may be diverged to simulate the spread of pellets from the muzzie of a shot gun, or may be deflected to cater for the difference in the speed of travel of radiation and the projectile to be simulated.

Theequipmentcould bespecificallymadefor simulated shooting, or alternatively the projector could be mounted in a firearm which is normally used with ammunition, which is thus temporarily adapted for simulated shooting.

Figure lisa block diagram illustrating equipment forsimulated shooting according to one embodiment of the invention, Figure 2 is a cross-section of a barrel of a firearm fitted with a projector for use in the equipment of Figure 1, Figure 3 is a similarviewto Figure 2 of a second projectorfor use in the equipment of Figure 1, and Figure 4 is a perspective view of a target; being part of the equipment of Figure 1.

The equipment illustrated simulates the firing of one or more projectiles from a gun at a target such that a light beam replaces the projectile trajectory. Asolid state laser or pulsed light emitting source mounted in a barrel ofthe gun projects a narrow beam of light, in response to operation ofthe trigger, towards the target which is coated with reflective material. If the beam intersects the target reflected light is detected by a sensor located in the vicinity ofthe user, and preferably in or on the gun. An indication is then given that a "hit" has been made.

Although the embodiments described relate to the simulation ofthe use of a shot gun, itwill be -.

appreciatedthata similar system could equallywell be used to simulate other firearms.

A projector 11 has a cylindrical housing 12 which can befitted into one barrel 13 of a shotgun upto an abutment ring 14 on the housing which locates the projector in the barrel. In response to operation of a trigger (notshown),the projector 11 generates a beam of light 1 5from a source oremitter 16 intheform of a high density pulsed LED or semiconductor laser diode having a power of the order of 40mW. The source 16 is powered by dry cell batteries 17 and the output is.

modulated, for example to 20 KHz by a modulator 18.

The modulator 18 and the batteries 17 are located behind the source 16 in the housing 12. The beam 15 is collimated by a small diameter low power microscope objective lens, or an equivalent lens or lens system 19.

The lenses 19 are mounted in a cylindrical beam guide 21 and the source 16is mounted atthe back of a cylindrical beam guide 22, which is screwthreaded to the guide 21. Rotation of a ring 23 atthe outer end of the guide 21 thus alters the axial distance between the source and the lens system 19 and hence the focal point ofthe lens system. This adjustment may be effected to adjust two the choke of the barrel and to create a divergence of the beam 1 Sto simulate the spread of pellets from the muzzle of a shot gun. The beam angle adjustment required for a shot gun is between 0.76 and 1.050 two represent minimum and maximum chokes.

Alternativelythe arrangement of Figure 3 could be used. In this embodiment a single lens 19 is moved axially with respect to the source 16 by axial movement of a ring flange 20 connected to the lens.

A light beam actually travels faster than the shotthat it is to simulate. To enable the equipment more exactly to simulate a projectile trajectory, the optics will preferably incorporate compensation for this.

Although it would be possible to caterforthe difference in speed by delaying the firing of the light beam afterthe trigger has been operated so thatthe beam 15 reaches the target at the same time as the projectile would have done, this has a draw back in thatthe marksman would need to track the target steadilythrough throughoutthe delay time after firing. The present system is designed to deflectthe beam 1 5 so that the target is only illuminated by the light beam 15 if the projector is pointed the correct distance ahead of the targetto allow for projectile speed. In the case of a clay target there is a reasonably defined trajectory and speed profile therefore the angularvelocity ofthe projector could be used to determine the deflection required.The system described hereinafter is adapted to deflect the beam 15 by up to 4" behind the aim ofthe projector, a preferred deflection being 3.2" to 3.6 forsimulating shot.

The beam guides21,22 are mounted within a ball jointarrangement 24, which is itself attached tothe housing, such that angular acceleration would cause the guides 21,22 to twist slightly againstthe motion of the gun so that the guides 21, 22 are no longer coaxial with the housing 12. The twist or movement is resisted by springs 25 or an elastic compound fitted between the guide 22 and the housing 12 which causes the guides 21,22 to return to their normal position when movement ofthe gun had ceased. The ball joint 24 is lubricated with a light grease which would integrate the acceleration induced forces and provide deflection roughly proportional to velocity during the aiming period. In this arrangement the emitter 16 and the lens system 19wouldall movetogether.

Alternatively a separate lens or lens system could be used instead, as shown in Figure 3. In this embodi menta beam refractor in the form oftwothin deflecting prisms 26 are mounted in the path ofthe beam 15 in the housing 12. Both prisms are independently manually pivotable to create a deflection ofthe beam behind the aim of the gun according to the direction from which the target will travel. The mechanism for pivoting the prisms 26 consists of respective adjusting rings 27 located outsidethe barrel which are rotatable to an appropriate position in the same way that the lens aperture is adjusted on a camera. Another possible soiution is to provide a moveable aupportforthe emitter 16, the lens system 19,26 remaining stationary.By moving the emitter 16 by a small amount the incident angle of the beam 15 on the refractor 26 is adjusted without moving the lens system.

Another problem with simulating the use of a shot gun is that there is stringing timeforthe the shot, i.e.

the shot is spread out over a finnite distance in length.

To caterforthis, eitherthe light emission is of a predetermined period, or alternatively actuation ofthe trigger will modulate the light emission for the same period. At a range of 45m, the shot cloud passes the target in approximately 60msecs. The duration ofthe emission is designed to represent this passage time.

The proposed 20KHz modulation catersforthis.

All the beam projection mechanism and optics is designed to be removeablyfitted into a barrel ofthe shot gun. A receiverforthe reflected beam may be located in the other barrel.

Atarget 28 which is in the shape of a clay pigeon, and is designed for ejection by similar launching equipment, is made of a tough and durable plastics material which is injection moulded to the required shape. To be useful as a target the clay must remain a dark colour so that it is silhouetted againstthe sky.

Therefore the reflective coating applied to the clay mustbeonethatreflectsthe beam 15 without significantly altering whatthe markesman sees.

To create a reflective surface to the projected signal beam 15, reflective elements in the form ofsubstan- tially spherical or polygonal reflective beads 29 loaded into a fixing medium are applied to the surface of the target. These beads mainly reflect light back along the path from which it came irrespective of the angle of the reflecting surface to the incident light. Because of this property, the paint has a dark mattfinish when observed under diffuse lighting conditions and therefore appears as a black objectto the marksman when viewed againstthe sky. A reflective paint such as that sold underthe Trade Mark"Scotchlite" is considered suitable.

Such targets can be reused, and could be fitted with means assisting recovery after use.

A receiverforthe reflected lightfrom the target 28 is mounted in or on the gun. Where the beam projector is in one barrel and the receiver in the other a link bridge for power and signal wires connects across the open ends of the barrels. The receiver comprises an optical band passfilter(notshown) which may be placed before or after a focusing lens 31, which filter limits the light entering the receiverto a limited wave-band, thus improving the signal to noise ratio.

The beam is focused bythe lens 31 on to a small photodetectorsuch as a pin photodiode 32. The lens 31 is of maximum practical aperture such thatthe maximum transmitted beam deflection angle is catered for. Afield effect transistor 33 amplifies the received signal at the detector 32 and a synchronous demodulatorsuchasaphaselocked loop detector34 allows passage only of signals synchronous with the transmitted beam, in this case 20KHz. As a further insurance against receiving stray signals, a small piezo electric microphone 35 mounted in the receiver barrel ofthe gun detects the operation ofthetrigger and in response activates a timer36.Thetimer36 opens a gate 37 for a period sufficient for the simulated shot cloud travel time, for example 60msecs. Receivedsignals passingthroughthede- modulator34will only be able to pass the gate 36 during this time. The received signal, having passed the gate 36 may be used to activate either or both of a piezo electricsounder38 and a visible indicator39.

The signal once through the gate 36 can also be used to activate an electrical or radio controlled linkto a score unit whereby automatic scoring can be achieved. An encoding integrated circuit 40 is provided forthis purpose. The indicators 38,39 would be positioned at the open end of the barrel. Optionally a low noise detectorcircuit (notshown) could be included immediately afterthe photodetector32.

The signal detecting capacity of the receiver can futher be improved by blooming all the optical components to have minimum reflection coefficient For a single marksman or in a friendly match no score unit is necessary. But in a competitive environment it is advantageous to provide a score unit including visual display means 44 on which the number of "hits" attained by a person or team is automatically displayed, together with any other information that may be required. While this can be achieved using a direct receiving aerial, this would entail the use of a higher power emitter 16. Amore reliable display would be recorded be creating a link with each gun so thatthe result of any successful shot detected at the gun can be incremented on the score unit automatically.

To avoid the chance of confusion as to the identification ofthe gun that scored the "hit", it would be possible for different guns to use emitted signals of different frequencies or characterisations.

It is envisaged that the occurrence of a "hit" would be radiated to the score unit by a second light emitting source 41 emitting an infrared light signal on detection of a "hit". This source 41 would be mounted on the underside of the barrels pointing roughly downwards.

An infra-red detector43 mounted within a small enclosure, say 1 Omm diameter, and lying on the ground in front of the marksman would receive the radiated signal and, provided that the pattern fitted a pre-set arrangement, a signal would be sent fro the enclosure bya signal wire 45 to the score unit to be received by a microcomputer 42 or other signal processor. The m icrncom puter would associate with an infra-red detector, a high gain amplifier chip, a decoding integrated circuit and a circuitfortransmitting the signal back th rough a current loop connection to the microcomputer.If more than one detector is required they may be connected either separately to the micro-computer 42 in a star configuration, or by means of a ring circuit Once processed, the score is displayed or printed out on the visual display unit 44, which forms partofthescoreunit.

The system described not only reduces the running costs normally incurred in the sport of clay pigeon shooting by obviating the need for cartridges and disposable clays, butwill also create little noise, therefore allowing thesportto take place in urban areas, and perhaps even indoors.

Although it would be possible to use a light source remote from the projector with a cable to the projector and a gate connected tothetrigger, by using a low power source in the projector and by radiating signals to the score unit the projector is completely free of connecting cables. This makes the system more flexible, and there is less chance of accidents occurring from tripping overwires.

Claims (16)

1. Equipementforsimulated shooting comprising a projector having a trigger, meansfor generating a modulated beam of electromagnetic radiation and projecting it towards a target in response to operation ofthe trigger, and receiver means for sensing incidence ofthe beam ofthe target and signalling a "hit"; wherein the target comprises a reflective su rface operable to reflect the beam back along a path substantially parallel to the incident beam irrespective ofthe angle of incidence ofthe beam; and the receiver means is adapted to detect radiation reflected from the target.

2. Equipmentaccording to claim 1 wherein the target incorporates a plurality of relective elements.

3. Equipmentaccording toclaim 1 or 2 including meansfortiming and comparing the projected and received beams including mean for detecting the operation ofthe trigger.

4. Equipment according to claim 3 wherein the meansforcomparing the projected and received beams includes a synchronous demodulator.

5. Equipment according to any of the preceding claims wherein optical meansfor adjusting the spread ofthe beam is located in the path ofthe beam.

6. Equipment according to any of the preceding claims wherein means is provided for deflecting the beam behind the aim of the projector by an amount to caterforthe difference in the speeds of travel ofthe radiation and the projectile that is to be simulated.

7. Equipment according to claim 6wherein the deflecting means is adjustable automatically in response to movement of the projector before operation ofthe trigger.

8. Equipment according to claims Sand 7 wherein the optical means is resiliently mounted in such a way that movement of the projector immediately before firing automatically moves the optical means so as to deflectthe beam; the resilience acting to return the optical means to its original position after the projec tileisstill.

9. Equipment according to any of claims 6 to 8 wherein the projector comprises a housing and a beam guide in the housing for guiding the beam, the deflecting means comprising means for adjusting the relative positions ofthe guide and the housing.

10. Equipment according to any of claims 6 to 9 wherein the deflection in the beam path produced by the deflecting means is notgreaterthan 4 .

11. Equipment according to claim 6 wherein the deflecting means includes a refrator mounted in the path of the beam and rotatable to adjustthe deflection ofthe beam.

12. Equipment according to any ofthe preceding claims wherein the duration of emission of the modulated radiation in response to a single operation of thetrigger is adapted to represent the stringing time of a shot cloud.

13. Equipmentaccording to claim 3whereinthe meansfortiming and comparing the projected and received beams includes an electrical gate which is opened for a predetermined time following operation of the trigger.

14. Equipment according to any ofthe preceding claims wherein the projector is associated with a shot gun, one of the projecting equipment and the receiver means being mounted in the barrel of the gun and the other being mounted on the gun or in a second barrel.

15. Equipment according to any ofthe preceding claims including a score unit comprising a signal processor and visual display means, the equipment including meansforradiating signalsfromthe receiv- erto the score unit and the score unit being adapted to incrementthescore reading on the visual display means in response to a signal from the receiver.

16. Equipmentforsimulated shooting substantially as herein described with reference to the accompanying drawings.