Projectile and method for distributing submunitions

Abstract

Summary The invention comprises a projectile (100), arranged with at least one submunition (10) wherein the projectile (100) is arranged with a rear portion (110) and a front portion (120), where at least one submuntion (10) is arranged 5 in the front portion (120) and where the submuntion (10) is arranged in a canister (12) and where the submunition (10) arranged in the canister (12) are arranged to be released from the front portion (120) and wherein the submunition (10) is arranged to be released from the canister (12) after at least five seconds since the submunition (10) arranged in the canister (12) are 10 released from the front portion (120). The invention furthermore comprises a method for distributing submunitions. Fig. 1.

Description

PROJECTILE AND METHOD FOR DISTRIBUTING SUBMUNITIONSTECHNICAL FIELD

[0001] The present patent application relates to a projectile comprising submunitions and a method for distributing submunitions.BACKGROUND OF THE INVENTION, PROBLEM AREA AND STATE OF THE ART

[0002] When combating ground targets, such as combat vehicles and / or tanks, with indirect fire, such as with artillery projectiles, rockets and / or missiles carrying subminitions, it is possible to make use of projectiles that include active components in order to achieve weapon effect against said ground targets. Examples of components include submunitions that are released from a projectile, such as an artillery projectile, rocket or missile, that are released above the ground targets. Submunitions are preferably outfitted with their own sensors, such as target identification systems, in order to detect any target objects in the effect area of the submunitions. The submunition preferably moves in a descending motion towards the ground after being released from the projectile. During the movement of the submunition towards the ground, the sensors arranged in the submunition can be used to detect ground targets, if any. Once a ground target has been detected, the submunition can position itself so as to allow the weapon effect to be directed towards the ground target, e.g. by means of a directed blast effect.

[0003] The submunitions are arranged in a projectile, e.g. a carrier projectile, and exits the projectile at a position where target objects are determined to be present or close to where the target objects are determined to be present. There are various methods of separating the submunition from the projectile, where one method involves ejecting the submunition from the aft portion of the projectile once a protective plate / hood / tray is removed from the projectile.When the submunition exits the projectile, large forces will be acting on the submunition, meaning that it is preferable to house it inside some form of protective device, for example a canister, also termed a can or a container.

[0004] Examples of projectiles arranged with submunitions for combating target objects are shown in patent specification US 5,760,330, which shows a projectile outfitted with submunitions, such as mines, housed inside a load carrier positioned on a rocket engine. The load carrier is arranged with a space, which also acts as the ogival / ogive on the projectile, where a parachute is arranged. When the load carrier is separated from the rocket engine, the load carrier exits the trajectory of the projectile, whereas the rocket engine, which is stabilized by fins, remains in the trajectory of the projectile. The load carrier ends up in an unstable path once it has been separated from the rocket engine, e.g. by means of a pyrotechnic charge. Once the rocket engine has passed, a parachute is released in the space arranged on the load carrier. The parachute dampens the fall speed of the load carrier as the load carrier falls towards the ground. The submunitions arranged in the load carrier are released from the load carrier by means of a pyrotechnic charge or as a result of the mass of the submunitions (gravity), whereupon the submunitions release a parachute and fall towards the ground.

[0005] The invention shown in US 5,760,330 differs from the invention described in the present patent application in that the canister is not housed in the projectile but rather makes up part of the projectile, and are thus not released from the projectile.

[0006] Additional problems which the present invention seeks to solve will become apparent in connection with the following detailed description of the various embodiments.PURPOSE AND FEATURES OF THE INVENTION

[0007] The present invention shows an improved projectile which is able to remove at least one submunition from a projectile in a manner which does not result in the submunition being unduly affected, and which places the submunition in a condition and / or a position which allows for further combating of ground targets.

[0008] The invention relates to a projectile, arranged with at least one submunition wherein the projectile is arranged with a rear portion and a front portion, where at least one submuntion is arranged in the front portion and where the submuntion is arranged in a canister and where the submunition arranged in the canister are arranged to be released from the front portion and wherein the submunition is arranged to be released from the canister after at least five seconds since the submunition arranged in the canister are released from the front portion.

[0009] According to additional aspects for a projectile, arranged so as to include at least one submunition, the following applies:

[0010] that additional submunitions are released form the front portion after 0, 1 seconds since the release of a prior submunition and before 10 seconds since the release of a prior submunition.

[0011] The invention further relates to a method for distributing submunitions arranged in a projectile, wherein the following method steps are included: i.) a rear portion of the projectil is released from the projectile, ii.) a canister, comprising at least one submunition, is separated from a front portion of the projectile, iii.) the canister is braked by means of an air brake, iv.) at least one submunition is separated from the canister after at least 5second since the separation of the submunition from the front portion of the projectile.

[0012] According to additional aspects for a method for distributing submunitions arranged in a projectile, the following applies:

[0013] that the canister, comprising at least one submunition, is separated from the aft of the front portion of the projectile.THE ADVANTAGES AND EFFECTS OF THE INVENTION

[0014] The advantage of the present invention is that submunition can be efficiently separated from a projectile to initiatiate the combat phase of the submunition, as the submunition is falling towards the ground. By reducing the rotational speed and the falling speed to a speed which is suitable for the sensors arranged on the submunition, the functionality of the submunition is improved. The submunition is able to influence the rotational speed and / or the fall speed to some extent, by means of bearing surfaces arranged on the submunition. Since it is advantageous not to provide large bearing surfaces on the submunition, the rotational speed and / or fall speed cannot be lower than the rotational speed and fall speed inherent in the projectile, meaning that a canister is required for purposes of reducing the rotational speed and fall speed prior to the combat phase of the submunition.LIST OF FIGURES

[0015] The invention will be described below by reference to the figures that are included there:Fig. 1 shows a schematic view of a projectile arranged with a submunition housed in a canister, according to one embodiment of the invention.Fig. 2 shows a schematic view of a cannister arranged with a submunition according to one embodiment of the invention.Fig. 3 shows an ejection process for submunitions from a projectile according to one embodiment of the invention.DETAILED DESCRIPTION OF EMBODIMENT

[0016] Distribution of submunitions can e.g. be achieved by dropping submunitions directly from a carrier projectile / projectile. This can e.g. involve firing off the submunitions, or otherwise transporting them out of the projectile. This can e.g. be achieved by means of a pyrotechnic charge that creates a gas pressure that ejects the submunition out of the projectile.

[0017] The term submunition refers to an effect device comprising means for acting against a specific target and may also be referred to as the combat component, the bomb or the warhead.

[0018] The submunitions are arranged so as to be separated from a fuselage, for example a carrier grenade or carrier missile, over a target area, whereas the submunition comprises an warhead, a target detector and optionally a device which imbues the submunition with a rotation within which the target area may be scanned, for example, in a helical pattern during the descending movement of the submunition towards the target area. Furthermore, the submunition may be outfitted with a parachute.

[0019] By ensuring that the submunition is designed in a suitably aerodynamic manner, and that a braking area is present on a carrier surface arranged on the submunition, the submunition is able to acquire a suitable fall speed. In a first embodiment, the submunition lacks rotation. In an alternative embodiment, the braking area may provide a driving momentum around thespin axis, which imbues the submunition with a rotation. This could be accomplished without the assistance of a parachute, which is advantageous since the parachute requires space. Within the available space inside a carrier grenade, additional space may instead be made available for the actual warhead or effect component.

[0020] Alternatively, the submunition can be arranged with a parachute, which provides the advantage that the braking effect and the rotation can be controlled with higher accuracy, albeit at the expense of the space of the parachute. With a parachute, the submunition, in a first embodiment, can be arranged without rotation or alternatively, the submunition, in a second embodiment, can be arranged with rotation.

[0021] The rocket grenade can be an missile, or an artillery rocket system of the caliber 22,7 cm or an artillery projectile, e.g. have a caliber of 15.5 cm, which is fired off from an artillery piece in a ballistic trajectory towards a target area.

[0022] A projectile is arranged with at least one submunition, where the submunition is arranged in a canister. At a certain time or geographical point, or based on sensor information, the canister, arranged with at least one submunition, may be separated from the projectile. Sensor information may include information from sensors arranged in the projectile, for example optical, thermal or electromagnetic sensors arranged in the projectile, e.g. for the purpose of detecting vehicles in a certain position. When the sensor detects target objects, such as vehicles, the canister is separated from the projectile. Alternatively, the canister can be separated when a positioning device detects that the projectile is in a certain position. Furthermore, the canister can be separated from the projectile at a certain time when the projectile is determined to be in a position where submunitions housed in the canister are able to combat target objects on the ground. The position and time of the projectile can both be programmed prior to the projectile being fired offfrom the artillery piece or rocket launcher, but can also be programmed by sending information to the projectile, e.g. by means of a radio.

[0023] One method of separating the submunitions from the canister from the projectile involves triggering a pyrotechnic charge that creates a gas pressure that ejects or otherwise moves the submunition out of the projectile. The submunition is preferably moved out of the aft portion of the projectile. A rear portion arranged in the aft of the projectile can be arranged on the projectile. The rear portion can be removed prior to the submuntion being ejected out of the projectile, but can also be removed in connection with the submunition being ejected out of the projectile. The rear portion is preferably arranged so as to exit the trajectory of the projectile and thus not to stand in the way of the submunitions, which initially, having been separated from the projectile, travels in the trajectory of the projectile. If the rear portion is removed, there is minimal risk of the rear portion colliding with the submunition, preferably since the release of the first subminition is released with a delay since the rear portion is separated from the projectile. An embodiment which causes the rear portion to be moved out of the trajectory of the projectile involves designing the rear portion so that its speed is reduced in the trajectory, for example by having a non aerodynamic shape, which causes the rear portion to be moved out of the projectile trajectory since the rear portion is moving in a separate trajectory. The rear portion could also be arranged with a brake, such as a parachute, to brake the rear portion and also to contro the decent of the rear portion to the gorund.

[0024] Once the submunition arranged with a canister has exited the projectile, an air brake may be deployed in order to reduce the speed of the canister. Examples of air brakes include various forms of parachutes, different forms of braking belts or wings / flaps. Furthermore, a rotation brake may be deployed in order to decrease the canister’s rotational speed. By reducing the rotational speed, the canister will continually position itself closer to a vertical position relative to the ground and the ground targets, as a result of a gravitational pullacting upon the submunition. When the speed and the rotational speed are damped to a level at which the submunition is able to be separated from the canister, a device such as a pyrotechnic charge is triggered in order to eject the submunition out of the canister. Since the submunition has higher weight, mass, and a smaller braking surface compared to the empty canister, which could be outfitted with a folded-out parachute or other braking device, the submunition is able to travel faster from the canister towards the ground surface. After exiting the canister, the submunition can fold / unfold brake surfaces and / or a parachute in order to create an increased brake surface or to induce a specific peferable movement of the submunition.

[0025] Fig. 1 shows a projectile 100, also called a rocket, missile, grenade or a carrier grenade, comrpising a rear portion 110 and a front portion 120. The front protion 120 is arranged with a projectilecanister 1 , outfitted with at least one submunition, in the shown embodiment four submunitions are shown 10, 10', 10", 10"'. Each submunition is arranged in an individual canister. Furthermore, pyrotechnic kits 102, 102', 102", 102'" are arranged in the projectile between each submunition 10, 10', 10", 10'". The fuze 104 of the projectile, preferably disposed in the tip or ogival of the projectile, includes control electronics for triggering the pyrotechnic charges 102, 102', 102", 102'". The fuze 104 may include radio communication equipment 106 for receiving external radio communication and / or for transmitting information from the projectile 100. Triggering of the pyrotechnic kit 102, 102', 102", 102'" can e.g. take place at a certain programmed time, or otherwise be arranged in the fuze before the projectile is fired off from a launching device or triggered / programmed / adapted during the movement of the projectile by means of the radio communication equipment 106. The pyrotechnic kit 102, 102', 102", 102'" can also be triggered at a certain position which may e.g. be determined on the basis of a positioning system arranged in the projectile (for instance a satellite navigation system such as GPS / GLONASS, or an inertial navigation system), where the position is programmed or otherwise arranged in the fuze prior to the projectile being fired off from a launchingdevice or during the movement of the projectile by means of information received from the radio communication equipment 106. The pyrotechnic kits 102, 102', 102", 102"' can also be triggered individually by means of the fuze 104 being outfitted with a sensor 108, such as a target finder, which detects a relevant ground target able to be combated by a submunition 10, and thus triggers the charges 102, 102', 102", 102'" in order to release the submunitions 10, 10', 10", 10'". The projectilecanister 1 is arranged in the front potion 120 and is protected by the rear portion 110, which may comprise a rocket engine and / or a base flow unit. The projectile 100 may be provided with shear pins or other devices for retaining the rear portion 110 of the projectile 100, and the rear portion 110 may be pushed away by the front portion 120 at a certain point in the projectiles trajectory. Alternatively, the front portion 120 may be removed by means of a different mechanical / pyrotechnic device which detaches the rear portion 110 prior to the pyrotechnic charge 102 being initiated and causes the first submunition 10 to be ejected out of the projectilecanister 1. The rear portion 110 is designed to exit the trajectory of the projectile. The rear portion 110 could be provided with an air brake 22, such as a parachute, attached to a rolling / siding bearing 3, such as a ball bearing for controlling the rear portions decent to ground after propelling the projectile to the desired point of separation between the rear portion 110 and front portion 120. The submunition 10 is preferably arranged in an additional canister arranged with at least one air brak and / or rotation brake in order to reduce the submunitions fall speed and / or rotation after the submunition 10 exits the projectilecanister 1 . The rotation brake may be a fold-out fin / flap / panel, which can e.g. be ejected radially from the canister, or the rotation brake may be a fin which is arranged so that it abuts the outer radius of the canister, and is spring-loaded so that it is unfolded as the submintion arranged in a canister exits the projectilecanister 1 of the projectile 100.

[0026] Fig. 2 shows a canister 12 arranged with a submunition 10 in a phase where the canister 12 with the folded-out air brake 2 has exited the projectile 100 and is falling towards the ground. The air brake 2, which may be in theform of a fin, as shown in fig. 2, or in the form of a parachute, is arranged to the canister 12. The air brake 2 brakes the fall speed of the canister 12. The canister 12 includes a space within which at least one submunition 10 has been arranged. The submunition 10 is retained in the canister 12, e.g. by means of shear pins which are broken in the event that the submunition 10 is ejected from the canister 12 by means of a pyrotechnic charge. In an alternate embodiment, the submunition 10 is retained with a mechanical / electromechanical lock which when the lock opens, and thus releases the submunition 10 so that the submunition 10 exits the canister 12 through falling out of the canister 12, as the mass of the submunition 10 causes the submunition 10 to exit the canister 12. In the case that the projectile 100 has a high rotational speed, which means that the projectile is rotation- stabilized during its trajectory, the canister 12, after exits from the projectile 100, will continue to have a high rotational speed, since the projectile 100 had a high rotational speed 100 prior to the canister 12 with a submunition 10 exiting from the projectile. In order to prepare the combat phase of the submunition 10, the rotational speed of the canister 12 is decreased by means of unfolding rotation brakes 4 arranged on the canister 12. In the case that the projectile has low rotational speed, such as when the projectile is a rocket or missile, there in no need for rotation brakes 4. The air brakes 2 and / or the rotation brakes 4 can e.g. be unfolded by means of braking flaps / rotation brakes being unfolded radially from the canister 12. The air brakes 2 and / or rotation brakes 4 can also be arranged so that the surface of the brake flap abuts the outer surface of the projectilecanister 1 in the projectile 100 and unfolds from the surface after the canister 12 has exited the projectile 100, e.g. by means of the air brakes and / or brake flaps being spring-loaded and so that, when the projectile 100 no longer holds the canister 12 in the projectile 100, the air brakes and / or brake flaps are released automatically and are locked in the unfolded position. In such cases, the air brakes and / or brake flaps may be made from a material which is reshaped when the brake flaps abut the surface of the projectilecanister 1 , in order to conform to the shape of the projectilecanister 1 , but straightens and no longer retains the shape of theprojectilecanister once the air brakes and / or brake flaps unfold. The air brake 2 and / or rotation brake / brake flap 4 can be partly situated in the rear portion of the canister 12, with respect to the longitudinal direction of the canister 12, meaning the aft portion, as shown in figure 2, where the rear portion is the area where the air brake 2 of the canister is arranged, but can also be situated in the front portion of the canister, not shown in figure 2. The fins, also termed rotation brake or brake flaps, are in an unfolded position, radially outwards relative to the canister, and unfolded in the range of between 50% and 80% of the diameter of the canister. The axial length of the fins, chord, is in the range of 10% to 40% of the diameter of the canister. The number of fins / break flaps preferably ranges from 4 to 8.

[0027] Fig. 3 shows an ejection process for a projectile 100 comprising the release of at least one submunition 10 arranged with a canister 12 from the projectilecanister 1 arranged in the front portion 120 of the projectile 100. Initially, while in position A, the projectile 100 exits an ejection device, such as an artillery piece or rocket or missile launcher. In a certain position B in the trajectory, the rear portion 110 is separated from the front portion 120. In position B, an arrangement is arranged in the projectile which enables the rear portion 110 to separate from the projectile 100 by means of the rear portion 110 being detached from the projectile 100 leaving the front portion 120 to continue in the projectiles trajectory. The rear portion 110 can e.g. be separated by means of a mechanical lock which unlocks at a certain point, so that the rear portion 110 is no longer attached to the projectile 100. In an alternative embodiment, the rear portion 110 may be separated by use of a pyrotechnic charge arranged between front portion 120 of the projectile 100 and the rear portion 110, so that the rear portion 110 is separated from the projectile 100. In a third embodiment, the rear portion 110 can be arranged so that the rear portion exits the projectile 100 once a rocket engine / base flow unit has burned out. Once the rear portion 110 has exited the projectile 100, and is no longer in the trajectory of the projectile, a submunition 10 can be separated from projectilecanister 1 arranged in the front portion 120 in the projectile 100. Thesubmunition 10, as shown in position C, exit the projectilecanister 1 in the aft of the front portion 120. In a first embodiment, the submuntion 10 exits the front portion 120 of the projectile 100 as a result of a pyrotechnic charge arranged in the projectile 100 pressing on submunition 10 or otherwise causing it to exit the front portion 120 of the projectile 100. In a second embodiment, an air brake / brake device, for example a parachute, arranged in or on the submunition 10 arranged in the projectilecanister 1 , is unfolded, thus pulling the submuntion 10 out of the projectilecanister 1 arranged in the front portion 120 of the projectile 100. Once the submunition 10 arranged in a canister 12 exits the projectilecanister 1 of the projectile 100, an air brake 2 slows down the speed of the canister 12, as shown in position D. Examples of an air brake 2 is a brake flap or a parachute. Furthermore, the rotation of the canister 12 could be reduced by means of a rotation brake 4 arranged on the canister 12, preferably in the rear portion of the canister. When the fall speed and, when necessary, the rotational speed is reduced the submunition 10 is separated from the canister 12, in a preferable embdoiment the separation is initiated after at least 5 (five) seconds since the canister 12 was released from the projectilecanister 1 arranged in the front portion 120 of the projectile. Preferably the submunition 10 separated from the canister 12 in a time interval between 0,1 s (one hundred milliseconds) to 10 s (ten seconds) since the canister 12 was released from the projectilecanister 1 arranged in the front portion 120 of the projectile. In a most preffered emobodiment the submunition 10 is separated from the canister 12 at 7 (seven) seconds since the canister 12 was released from the projectilecanister 1 arranged in the front portion 120 of the projectile. Additional submunitions 10', 10" are released from the projectilecanister 1 of the front portion 120 after 5 seconds since the release of a prior submunition and before 30 seconds since the release of a prior submunition. The submunition 10 is preferably separated from the canister 12 when the rotational speed is less than 150 revolutions per minute (rpm) and the fall speed is less than 115 meters per second (m / s). In a first embodiment, the submunition exits the canister 12 as a result of a lock between the canister 12 and the submunition 10 being unlocked. The mass of the submunition 10then causes the submunition 10 to exit the air-braked canister 12. In an alternative second embodiment, the submunition 10 may be ejected out of the canister 12 by means of a pyrotechnic charge arranged between the canister 12 and the submunition 10. When the submunition 10 has exited the canister 12, the submunition 10 will initiate a combat phase against ground targets, which are not described any further in the present application as shown in position E where four submunitions 10, 10', 10" and 10"' are released from their respective canisters 12, 12', 12" and 12'".ALTERNATIVE DESIGN TYPES

[0028] The invention is not limited to the types of design specifically shown, but can be varied in different ways within the framework of the claims.

[0029] For instance, it is clear that the number of projectiles, submunitions and canisters, along with the included elements and details, are to be adapted to the one or several weapons systems, platforms and other construction-related properties which are applicable in each individual case.

[0030] Furthermore, the invention is not limited to certain types of target objects, but can also be applied to other types of targets, such as surface targets, ground targets or air targets.

[0031] Furthermore, the invention encompasses all types of projectiles, including grenades, high-explosive shells, robots, missiles and rockets.

[0032] Furthermore, the invention is not limited to a certain number of projectiles or target objects, but can be adapted to the number of target objects or projectiles presently at issue.

[0033] It could be observed that it is preferable to measure time instead of speed or velocity, or other physical quantity. Measurement of time is easaliy accomplished by time measurement circuits compared to speed that, most commonly, requires a sensor.

Claims

Claims1. Projectile (100), arranged with at least one submunition (10) characterized in that the projectile (100) is arranged with a rear portion (110) and a front portion (120), where at least one submuntion (10) is arranged in the front portion (120) and where the submuntion (10) is arranged in a canister (12) and where the submunition (10) arranged in the canister (12) are arranged to be released from the front portion (120) and wherein the submunition (10) is arranged to be released from the canister (12) after at least five, 5, seconds since the submunition (10) arranged in the canister (12) are released from the front portion (120).

2. Projectile according to claim 1 , characterized in that additional submunitions (10', 10", 10"') are released form the front portion (120) after at least 0,1 seconds since the release of a prior submunition and before 10 seconds since the release of a prior submunition.

3. Method for distributing submunitions arranged in a projectile, characterized in that the following method steps are included: i.) a rear portion (110) of the projectil (100) is released from the projectile (100). ii.) a canister (12), comprising at least one submunition (10), is separated from a front portion (120) of the projectile (100), iii.) the canister is braked by means of an air brake (2), iv.) at least one submunition (10) is separated from the canister (12) after at least 5 second since the separation of the submunition from the front portion (120) of the projectile (100)4. Method for distributing submunitions from a projectile according to claim 3, characterized in that the canister (12), comprising at least one submunition (10), is separated from the aft of the front portion (120) of the projectile (100).

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