SMALL ARMS

Abstract: Small arm (10) includes a trigger, barrel assembly (11) and electronic firing controls mounted in handgrip (12). Barrel assembly (11) includes a plurality of axially disposed projectiles and discrete propellant charges for propelling respective projectiles, SMall arm (10) includes laaser beam (15) which terminates at target 816) to provide an instant reading of the target distance for adjusting the rate of fire to achieve a desired impact spread. The impact spread results from the recoiling action of small arm (10) inducing barrel climb. A single firing event activates the trigger and small arm (10) fires a predetermined number of projectiles at a rate selected to provide a desired impact spread on target (16). Where target (16) is a person, typically two or three projectiles are fired, and the rate of fire is between 10,000 and 60,000 rounds per minute, depending on the target distance.

Description: SMALL ARMS This invention relates to small arms and in particular personal firearms. Personal firearms such as revolvers are carried by military and law enforcement personnel for emergency use, such as to disable an attacker who threatens the life of the gun holder or the lives of others. Typically such firearms have poor accuracy and are used only for close range targets. Where the target is a person, users will often fire at the largest target zone, namely their chest. Given the relatively poor accuracy of the weapon, and the uncertainty of the lethality of the first shot, such a first shot may not be sufficient to stop the attacker from continuing the threat. In one embodiment of this invention, we have now found a handgun which will increase the potential for stopping an attacker with a single firing event. In a broader sense, we have now found a small arm that will permit a target to be hit with a plurality of projectiles in a selected impact spacing. According to the present invention there is provided a small arm capable of firing a plurality of projectiles at a target, said small arm including a trigger wherein a single firing event activates said trigger and said small arm fires a predetermined number of projectiles at a rate selected to provide a desired impact spacing on the target. The term "small arm" will, in the context of the present invention, be understood to include handguns, rifles, carbines, sub-machine guns and machine guns. The present invention has particular application to small arms of the single shot type that are employed to hit a target. In the context of sub-machine guns and machine guns, the present invention has application in single shot modes of use. Hereunder, the present invention will be described with reference to handguns, but it will be clear to the person skilled in the art that the present invention will be applicable to other small arms. The present invention may utilise barrel assemblies capable of firing a controlled rapid fire sequence of projectiles and being of the general type described and/or illustrated in our earlier International Patent Applications, including PCT/AU94/00124 and PCT/AU96/00459. However other configurations may be used to fire the projectiles such as by utilising double tap cartridges from conventional handguns or individual cartridges from respective barrels of a handgun having a plurality of clustered barrels. In a preferred embodiment, the projectiles may be contained in cartridges of the type described in International Patent Application Nos. PCT/AU94/00124 and PCT/AU96/00459. Such cartridges includes a shell; a plurality of projectiles axially disposed within the shell for operative sealing engagement with the bore of the tubular shell, and discrete propellant charges for propelling respective projectiles. The projectile may be round, conventionally shaped or dart-like and the fins thereof may be offset to generate a stabilising spin as the dart is propelled from a barrel that may be a smooth-bored barrel. The projectile charge may be form as a solid block to operatively space the projectiles in the shell or the propellant charge may be encased in metal or other rigid case which may include an embedded primer having external contact means adapted for contacting an pre-positioned electrical contact associated with the shell. For example the primer could be provided with a sprung contact which may be retracted to enable insertion of the cased charge into the shell and to spring out into an aperture upon alignment with that aperture for operative contact with its mating shell contact. If desired the shell may be consumable or may chemically assist the propellant burn. Each projectile may include a projectile head and extension means for at least partly defining a propellant space. The extension means may include a spacer assembly that extends rearwardly from the projectile head and abuts an adjacent projectile assembly. The spacer assembly may extend through the propellant space and the projectile head whereby compressive loads are transmitted directly through abutting adjacent spacer assemblies. In such configurations, the spacer assembly may add support to the extension means that may be a thin cylindrical rear portion of the projectile head. Furthermore the extension means may form an operative sealing contact with the bore of the shell to prevent burn leakage past the projectile head. The spacer assembly may include a rigid collar which extends outwardly to engage a thin cylindrical rear portion of the malleable projectile head inoperative sealing contact with the bore of the shell such that axially compressive loads are transmitted directly between spacer assemblies thereby avoiding deformation of the malleable projectile head. Complementary wedging surfaces may be disposed on the spacer assembly and projectile head respectively whereby the projectile head is urged into engagement with the bore of the shell in response to relative axial compression between the spacer means and the projectile head. In such arrangement the projectile head and spacer assembly may be loaded into the barrel and there after an axial displacement is caused to ensure good sealing between the projectile head and barrel. Suitably the extension means is urged into engagement with the bore of the barrel. The projectile head may define a tapered aperture at its rearward end into which is received a complementary tapered spigot disposed on the leading end of the spacer assembly, wherein relative axial movement between the projectile head and the complementary tapered spigot causes a radially expanding force to be applied to the projectile head. The shell may be non-metallic and the bore of the shell may include recesses which may fully or partly accommodate the ignition means. In this configuration the shell houses electrical conductors which facilitate electrical communication between the control means and ignition means. This configuration may be utilised for disposable shell assemblies which have a limited firing life and the ignition means and control wire or wires therefor can be integrally manufactured with the shell. A cartridge may alternatively include ignition apertures in the shell and the ignition means are disposed outside the shell and adjacent the apertures. The shell may be surrounded by a non-metallic outer shell which may form the sleeve which may include recesses adapted to accommodate the ignition means. The outer shell may also house electrical conductors which facilitate electrical communication between the control means and ignition means. The outer shell may be formed as a laminated plastics shell which may include a printed circuit laminate for the ignition means. The cartridge may have adjacent projectiles that are separated from one another and maintained in spaced apart relationship by locating means separate from the projectiles, and each projectile may include an expandable sealing means for forming an operative seal with the bore of the shell. The locating means may be the propellant charge between adjacent projectiles and the sealing means suitably includes a skirt portion on each projectile which expands outwardly when subject to an in-shell load. The in-shell load may be applied during installation of the projectiles or after loading such as by tamping to consolidate the column of projectiles and propellant charges or may result from the firing of an outer projectile and particularly the adjacent outer projectile. The rear end of the projectile may include a skirt about an inwardly reducing recess such as a conical recess or a part-spherical recess or the like into which the propellant charge portion extends and about which rearward movement of the projectile will result in radial expansion of the projectile skirt. This rearward movement may occur by way of compression resulting from a rearward wedging movement of the projectile along the leading portion of the propellant charge it may occur as a result of metal flow from the relatively massive leading part of the projectile to its less massive skirt portion. Alternatively the projectile may be provided with a rearwardly divergent peripheral sealing flange or collar which is deflected outwardly into sealing engagement with the bore upon rearward movement of the projectile. Furthermore the sealing may be effected by inserting the projectiles into a heated shell which shrinks onto respective sealing portions of the projectiles. The projectile may comprise a relatively hard mandrel portion located by the propellant charge and which cooperates with a deformable annular portion may be moulded about the mandrel to form a unitary projectile which relies on metal flow between the nose of the projectile and its tail for outward expansion about the mandrel portion into sealing engagement with the bore of the shell. The projectile assembly may include a rearwardly expanding anvil surface supporting a sealing collar thereabout and adapted to be radially expanded into sealing engagement with the shell bore upon forward movement of the projectile through the shell. In such a configuration it is preferred that the propellant charge have a cylindrical leading portion which abuts the flat end face of the projectile. The projectiles may be adapted for seating and/or location within circumferential grooves or by annular ribs in the bore or in rifling grooves in the bore and may include a metal jacket encasing at least the outer end portion of the projectile. The projectile may be provided with contractible peripheral locating rings which extend outwardly into annular grooves in the shell and which retract into the projectile upon firing to permit its free passage through the barrel. The electrical ignition for sequentially igniting the propellant charges of a barrel assembly may preferably include the steps of igniting the leading propellant charge by sending an ignition signal through the stacked projectiles, and causing ignition of the leading propellant charge to arm the next propellant charge for actuation by the next ignition signal. Suitably all propellant charges inwardly from the end of a loaded shell are disarmed by the insertion of respective insulating ruses disposed between normally closed electrical contacts. Ignition of the propellant may be achieved electrically or ignition may utilise conventional firing pin type methods such as by using a centre-fire primer igniting the outermost projectile and controlled consequent ignition causing sequential ignition of the propellant charge of subsequent rounds. This may be achieved by controlled rearward leakage of combustion gases or controlled burning of fuse columns extending through the projectiles. In another form the ignition is electronically controlled with respective propellant charges being associated with primers which are triggered by distinctive ignition signals. For example the primers in the stacked propellant charges may be sequenced for increasing pulse width ignition requirements whereby electronic controls may selectively send ignition pulses of increasing pulse widths to ignite the propellant charges sequentially in a selected time order. Preferably however the propellant charges are ignited by a set pulse width signal and burning of the leading propellant charge arms the next propellant charge for actuation by the next emitted pulse. Suitably in such embodiments all propellant charges inwardly from the end of a loaded barrel are disarmed by the insertion of respective insulating fuses disposed between insertion of respective insulating fuses disposed between normally closed electrical contacts, the fuses being set to burn to enable the contacts to close upon transmission of a suitable triggering signal and each insulating fuse being open to a respective leading propellant charge for ignition thereby. Any convenient trigger may be used in the present invention. Conventional trigger mechanisms may be employed. In such conventional trigger mechanisms the single firing event may be a single squeeze or depression of the trigger for the predetermined number of projectiles to be fired. There is no requirement to maintain the trigger in a depressed state for the predetermined number of projectiles to be fired as would be the case with an automatic weapon such as a machine gun in automatic mode. Other trigger mechanisms may be employed provided that a single firing event initiated directly by the user, or remotely, activates the trigger and fires the predetermined number of projectiles. The predetermined number of projectiles will depend on the size and nature of the target. Where the target is an attacker or a person, preferably two and more preferably three projectiles are fired at a rate selected to provide the desired impact spacing on the target. The rate may be greater than 10,000 rounds per minute and preferably over 20,000 rounds per minute. When a handgun is supported for firing in a conventional manner its barrel climbs pivotally about the user's wrist upon firing. Typically we have found for a conventionally supported handgun absorbing firing recoil, the rapid rate of fire will provide a small angular separation between the trajectories of the predetermined number of fired projectiles, and thus a small vertical spacing between the target impact zones, particularly when the target is close to the firing position. When the handgun is held horizontally the impact spacing will be spread horizontally. Similarly when the handgun is fired from an other orientation the impact spacing will be spread at an angle equivalent to that orientation. For example, from a conventional firing position with a small calibre handgun having a barrel locked to the handgun frame such that the recoil of the barrel is transferred directly to the frame the vertical spacing between impact zones for two projectiles fired at a rate of 22,500 rounds per minute would be in the order of 220mm for a target at 7m from the firing position. This separation would be reduced to 150mm at a firing rate in the order of 45,000 rounds per minute. The impact spacing will also be effected by a number of parameters that effect the recoil of the handgun. The greater the inertia of the handgun the smaller the angular spacing between the trajectories and the smaller the impact spacing of the projectiles. The inertia of the handgun is effected by the weight of the gun and also by the strength and weight of the arm of the person firing the gun. The recoil, and hence impact spacing, will also be increased by the use of larger projectiles or greater charges of propellant. The number and rate of which that number of projectiles are fired may be selected to provide the desired impact spacing. The handgun or other small arm of the present invention may also incorporate a recoil abatement mechanism, such as a recoiling barrel(s). As a result of the very high rates of fire employed in the invention a number of projectiles, say two or three, can be fired before the barrel(s) has completed the recoil movement, and before the recoil of the barrel(s) is transferred to the handgun frame. Under such circumstances, the projectiles fired in a single firing event will travel along substantially the same trajectory and may provide an enhanced target penetration effect. Thus, such a handgun may be effective against a person wearing body armour. In a preferred embodiment the handgun may incorporate means for selectively engaging and disengaging the recoil abatement mechanisms so that it can be selectively used in either mode, for a desired impact spacing or for penetration. The handgun suitably has control means for adjusting the rate of fire so that it may be set automatically or manually to suit the conditions or the requirements of the operator. The handgun may also incorporate a control for selecting the number of projectiles to be fired in a single firing event. The handgun may also incorporate target distance sensor associated with the rate of fire control so that the rate of fire may be automatically adjusted to suit the sensed target distance and in order to achieve a desired target impact spacing. Various range finding devices, such as laser range finders, may be used. A control means, such as a microprocessor, may also be provided for selecting the desired impact spacing. In another aspect this invention resides in a method of operating a used small arm including:- providing a small arm capable of firing a plurality of projectiles at a target, said small arm including a trigger; selecting a rate of fire of a predetermined number of projectiles to provide a desired impacting spacing on the target; and activating the trigger with a single firing event. The method may further include providing control means for varying the rate of fire and, if desired providing target distance sensing means associated with the rate of fire control to automatically adjust the rate of fire to suit the sensed target distance and in order to achieve a desired target impact spacing. In order that this invention may be more readily understood and put into practical effect, reference will now be made to the accompanying drawings which illustrate a preferred embodiment of the invention, wherein:- FIG. 1 is a diagrammatic view of a pistol according to one embodiment of this invention, and FIG. 2 illustrates another embodiment of this invention. The handgun 10 illustrated in Fig. 1 has a barrel assembly 1 1 of the type described and electronic firing controls mounted in the handgrip 12. Together with touch pad adjusters, not illustrated for controlling the rate of fire, the number of projectiles fired with each trigger actuation and the desired impact spread. The handgun 10 also has an underslung distance sensing device 14 which utilises a laser beam 15 which terminates at the target 16 to provide an instant reading of target distance for adjusting the rate of fire to achieve the preset impact spread. For example in the illustration a user, who has set the gun controls to achieve a three shot burst with an impact separation between the first and last fired projectiles of 450mm, will aim the pistol 10 at the chest 17 of the target and upon squeezing the trigger 18, the target will be lased to provide the distance to the target, and at seven metres the firing circuit will automatically trigger firing of the three outer projectiles at a rate of 45,000 rounds per minute. It is considered that when the first shot is fired the barrel will begin to climb, and when the second shot is fired, the combined energy of the first and second shots will combine to increase the rate of climb, so that when the third shot is fired, the vertical separation between the third and second shots will be greater than the vertical separation between the second and first shots. This outcome may be provide a vertical separation of advantage, or if deemed preferable the increasing separation may be reduced by increasing the rate of fire between rounds two and three to say 60,000 rpm. Provided the aim is on target, the first impact will be the chest of the target 16, followed at millisecond intervals by impacts in the upper chest and head. Thus either the lethality per firing event will be increased or the chance of hitting the target with at least one projectile will be increased. The impact spread may be in an upward, downward or sideward array, selected by holding the pistol 10 with its barrel 19 either above, below or to either side of the wrist. The handgun 20 illustrated in Fig. 2 utilises a recoiling barrel assembly 21 of the type described and provided with latching means 22 for preventing recoil of the barrel assembly 21 , if a spread of impact zones is required. The recoiling action of the barrel assembly 21 is set to enable three projectiles to be fired at a rapid rate of between 20,000 and 60,000 before the recoil action terminates and thus before recoil acts to induce barrel climb. Accordingly when the handgun is set in the barrel recoil mode, a single event actuation of the handgun 20 by pulling the trigger 24 will result in the firing of a three shot burst with each shot travelling substantially along the same trajectory so as to hit the target repeatedly at the same location and in rapid succession enabling the rounds to penetrate armour which would not be penetrated by a single shot fired from a conventional pistol In the illustration the position of the recoiling barrel assembly 21 relative to the stock 25 is shown for the three successive shots occurring over a period of about three milliseconds and activated by a single trigger action. It is envisaged that the barrel assembly 21 will recoil approximately 50mm in that time. Should a user wish to utilise the gun 20 in the mode illustrated in Fig. 1 , the latching means is utilised to lock the barrel assembly 21 to the stock 25. The gun 20 may also incorporate the controls as per the gun 10 as well as the target distance sensing means. It will of course be realised that the above has been given by way of illustration of the present invention and that all such modifications and variations thereto as would be apparent to persons skilled in the art are deemed to fall within the broad scope and ambit of this invention as is herein set forth.

Claims: THE CLAIMS DEFINING THE INVENTION ARE AS FOLLOWS: 1 . A small arm capable of firing a plurality of projectiles at a target, said small arm including a trigger wherein a single firing event activates said trigger and said small arm fires a predetermined number of projectiles at a rate selected to provide a desired impact spacing on the target. 2. A small arm according to claim 1 wherein the predetermined number of projectiles is 2. 3. A small arm according to claim 1 or claim 2 wherein the predetermined number of projectiles is 3. 4. A small arm according to any one of claims 1 to 3 wherein the predetermined number of projectiles are fired at a rate of greater than 10,000 rounds per minute. 5. A small arm according to any one of claims 1 to 4 wherein the predetermined number of projectiles are fired at a rate of greater than 20,000 rounds per minute. 6. A small arm according to claim 1 wherein the predetermined number of projectiles is 3 or more and the predetermined number of projectiles are fired at an increasing rate such that the delay between the firing of a subsequent projectile is less than the delay in firing the previous projectile. 7. A small arm according to any one of claims 1 to 6 wherein the single firing event is one squeeze of a trigger mechanism. 8. A small arm according to any one of claims 1 to 6 wherein the single firing event is remote from the small arm. 9. A small arm according to any one of claims 1 to 8 wherein the projectiles are contained in a cartridge wherein said cartridge includes a shell, a plurality of projectiles axially disposed within the shell for operative sealing engagement with the bore of the tubular shell and discrete propellant charges for propelling respective projectiles. 10. A small arm according to any one of claims 1 to 9 wherein the small arm is a handgun. 1 1. A small arm according to any one of claims 1 to 10 wherein the small arm includes a target distance sensor integrated with a controller for selecting the rate at which the projectiles are fixed to provide the desired impact spread. 12. A small arm according to any one of claims 1 to 11 further including a recoil abatement mechanism whereby the predetermined number of projectiles may be fired prior to substantive recoil of the frame of the small arm and the impact spacing is minimised. 13. A method of operating a used small arm including, providing a small arm capable of firing a plurality of projectiles at a target, said small arm including a trigger, selecting a rate of fire of a predetermined number of projectiles to provide a desired impacting spacing on the target and activating the trigger with a single firing event.

Inventors: O'DWYER JAMES MICHAEL, O'DWYER, JAMES, MICHAEL
Applicants: DWYER JAMES MICHAEL O, METAL STORM LTD, METAL STORM LIMITED, O'DWYER, JAMES, MICHAEL
Application year: 2000
Main classification: F41A19
IPC codes: F41A19, F41C3, F41G3, F42B5