FR2724221A1 - Projectile with payload designed to be launched at set altitude - Google Patents

Abstract

The projectile has a payload (10), e.g. an infrared, electromagnetic or jamming decoy, with deployable stabilising (12) and braking (14) parachutes, each equipped with its own time delay system to actuate it at the required altitude. The projectile has a separable propulsion stage (20), and the two parachutes have surface areas of under 2 sq m and over 10 sq m respectively.

Description

 The present invention relates to the field of projectiles comprising a payload used at altitude.

 The present invention applies in particular to the implementation of decoys, in particular passive infrared and / or electromagnetic decoys (reflectors, for example in the form of flakes, or retroreflectors, for example cube corner type) or active decoys (electronic jammers ).

 More precisely, the present invention relates to the field of projectiles braked on a trajectory.

 This particular field of braked projectiles has given rise to an abundant literature.

Many parachute braked projectile systems in particular have been proposed. We can refer for example to documents FR-A-2619441, FR-A-2623897, FR-A-2478297, FR-A-2613824, FR-
A-2634453, FR-A-2635381, FR-A-2642159 and FR-A-2657157. Certain documents have proposed specific means of deploying such a parachute. Reference may be made, for example, to documents FR-A 2595810, FR-A-2581750, FR-A-2595811, FR-A-2679642, FR-A-2546477 and FR
A-2679643.

 The document FR-A-2654505 describes for example a munition which can be transported by an artillery projectile and comprising a release device for a braking parachute stored in its rear part. The release device can be activated by a delay element released when the munition leaves the envelope of a carrier projectile.

 Various documents have described main parachute systems associated with extractor parachutes. See for example documents FR-A-2317171, FR-A-2573385 and FR-A-2502580.

 In addition, various braking and / or stabilization devices other than parachutes have been proposed. Reference may be made, for example, to documents FR-A-2595809, FR-A-2679641 and FR-A-2682753.

 All these systems are not entirely satisfactory for the implementation of payloads at altitude. Those skilled in the art therefore tend to move towards solutions of the type described in documents FR-A-2519134 and FR-A-2602861. These documents describe means capable of maintaining a load at a substantially constant distance from the ground, comprising a rope on which a load is fixed, connected on one side to a balloon or parachute type of lifting means and on the other side to an anchor or equivalent.

 The object of the present invention is to improve the projectiles comprising a payload intended to be used at altitude.

 An auxiliary object of the present invention is to propose simple means making it possible, from the same basic structure, to choose the altitude for implementing the payload.

 These objects are achieved according to the present invention thanks to a projectile of the type comprising a payload intended to be implemented at a controlled altitude and a deployable braking system for this, in a descent phase of its trajectory, characterized in that 'it further comprises: - deployable stabilizing means, - first time delay means capable of controlling the deployment of the stabilization means after a predetermined time consecutive to the sending of the projectile, and this before deployment of the braking system, and - second timing means capable of controlling the deployment of the braking system when the payload is located at the desired altitude.

 Other characteristics, objects and advantages of the present invention will appear on reading the detailed description which follows, and with reference to the appended drawings given by way of non-limiting example and in which FIGS. 1 and 2 respectively represent the various main sequences of implementation of a projectile in accordance with two variants of the present invention.

 The projectile P according to the present invention shown in the appended figures mainly comprises a body 10 and a propellant 20.

 The propellant 20 can be the subject of numerous variant embodiments known to those skilled in the art. I1 advantageously comprises at least one pyrotechnic engine.

 Preferably, the engine stage 20 comprises own stabilizers, for example in the form of fins 22.

 Preferably, according to the invention, the motor stage 20 is removably fixed on the rear part of the body 10 and there are provided separation means capable of separating the motor stage 20 from the body 10, when this motor stage 20 has completed its propulsion mission.

 Means can be provided to then separate the engine stage 20 and the body 10. These spacing means can be formed for example of an asymmetrical wing linked to the engine stage 20 and allowing a divergence between the trajectories of the motor stage 20 and body stage 10.

 The body 10 mainly houses a payload, for example a load of lures as indicated above, deployable stabilizing means 12, first delay means, main braking means 14 and second delay means.

The payload contained in the body 10 can be the subject of numerous variants. It is advantageously a charge of decoys, in particular as indicated above of passive infrared and / or electromagnetic decoys (reflectors, for example in the form of flakes, or retroreflectors, for example cube corner type) or active decoys (electronic jammers)
The deployable stabilizing means 12 are preferably provided in the rear part of the body 10, in a compartment located in front of the engine stage 20. These stabilizing means 12 are thus designed to take over from the stabilizers 22 linked to the engine stage 20, after separation of the latter.

 In addition, according to the invention, the stabilizing means 12 are designed to be used preferably on the ascending part of the trajectory of the projectile, in order to control the reversal of the projectile. As a variant, however, provision can be made to deploy the stabilizing means 12 only on the descending phase of the trajectory of the projectile.

 For this purpose, preferably, the deployable stabilization means 12 are preferably formed of a small auxiliary parachute.

 In the context of the invention, the auxiliary parachute making up the stabilization means 12 typically has a bearing surface of less than 2 m 2, for example a diameter of the order of 500 to 600 mm.

 The first delay means are designed to control the deployment of the stabilizing means 12 after a predetermined time consecutive to the sending of the projectile, and this before deployment of the braking system 14. Such delay means can be the subject of many variants . It can be a pyrotechnic, electronic, mechanical delay, or any other equivalent means.

These first timing means are preferably adapted to ensure the reversal of the body 10 containing the payload at an altitude HO greater than the maximum altitude desired for the implementation of the payload.

 Typically and without limitation, the first delay means can ensure the deployment of the auxiliary parachute 12 after a time of less than six seconds after the projectile is sent.

 The main braking means 14 are designed to brake the payload in its descent phase. These braking means 14 are preferably formed of a conventional parachute. This parachute 14 is advantageously placed in the rear part of the body 10. The braking parachute 14 can be placed for example between the rear part of the body 10 and the stabilizing means 12. Thus, as can be seen in the appended figures, the lines of the parachute stabilizer 12 can be attached to the top of the main parachute 14.

 Typically and without limitation, in the context of the invention, the main parachute 14 has a bearing surface greater than 10 m 2, for example of the order of 30 m 2.

 It should be noted that when the payload underlying the parachute 14 generates hot gases, these are recovered by the parachute 14 which makes it possible to significantly slow down the descent of the system, since these hot gases tend to follow an upward movement.

 It should also be noted that the initial deployment of the stabilization parachute 12 makes it possible to reduce the speed of the body 10 before the deployment of the main braking parachute 14 and consequently makes it possible to limit the deceleration due to the opening of the latter. This provision is particularly important when the payload is sensitive to decelerations, as is the case for example for electromagnetic decoys formed from jammers based on electronic circuits.

 The second timing means are intended to control the deployment of the braking system 14 when the payload is located at a desired altitude.

 In practice, the first and second time delay means can act, for example, by cutting off at least one halyard holding the stabilizing parachute 12 and the braking parachute 14 respectively, to authorize the deployment thereof.

 In a manner comparable to the first time delay means, the second time delay means can be formed by pyrotechnic, electronic, mechanical, or any other equivalent means.

 In addition, these first and second time delay means can be adjustable before sending the projectile, or even selectable by module.

 We will now describe the implementation of the projectile according to the present invention with reference to Figures 1 and 2 attached.

 In these figures, it is assumed that the projectile P contains a payload formed by an infrared decoy for the protection of a building with surface B.

 Projectile P is launched from this building B, using a fixed mount.

 Phase I represented in FIGS. 1 and 2 corresponds to a propulsion phase of the projectile 10 using the motor stage 20. During this stage I the motor stage 20 is always linked to the rear part of the body 10.

 Phase II represented in FIGS. 1 and 2 corresponds to the instant TO of deployment of the stabilizing parachute 12 initiated by the first time delay means.

 Of course, between phases I and II, the stage 20 has been separated from the body 10.

 More precisely, it is assumed in FIGS. 1 and 2 that the first time delay means ensure the deployment of the stabilizing parachute 12 after a time TO following the sending of the projectile P identical for the two figures, for example of the order of 6 seconds after sending the projectile.

 The instants of deployment of the stabilizing parachutes 12 being identical for the two figures 1 and 2, the phases III which illustrate the body 10 after reversal (and initiation of the descent phase) under the effect of the stabilizing means 12, are therefore also identical . By way of example, this phase III after turning can be obtained on the order of one to two seconds after the deployment of the stabilizing means 12 in step II.

 On the other hand, the instants of implementation of the braking parachute 14 differ between FIGS. 1 and 2.

 More precisely, the second time delay means, according to FIG. 1, deploy the braking parachute 14 faster than according to FIG. 2.

 By way of nonlimiting example, according to FIG. 1, the second delay means can ensure the deployment of the braking parachute 14 approximately four seconds after the deployment of the stabilizing parachute 12 controlled by the first delay means, whereas according to the figure 2, the second time delay means ensure the deployment of the braking parachute 14 approximately ten seconds after the deployment of the stabilizing parachute 12.

 Thus, according to FIG. 1, the braking parachute 14 is deployed in step IV at a high altitude H1. On the other hand, an intermediate stage III ′ has been illustrated in FIG. 2 during which the body 10 containing the payload descends in the stabilized position by the parachute 12 according to a substantially vertical trajectory, that is to say with substantially reach constant in horizontal projection of building B to be protected.

 Found in Figure 2 in step IV, the deployment of the braking parachute 14, this time at a low altitude H2.

 Preferably, in the context of the invention, the second delay means which ensure the deployment of the braking parachute 14 are also adapted to initiate the payload.

 Those skilled in the art will readily understand that the structure of the projectile in accordance with the present invention thus makes it possible to obtain, with a substantially constant range L, an implementation of the payload at an altitude varying over a wide range by simple modification of the delay controlling the opening of the braking parachute 14.

 In addition, those skilled in the art can of course play on the combination of the two timers respectively controlling the deployment of the stabilizing parachute 12 and the braking parachute 14, in order to define the desired operating altitude for the payload.

 Of course the present invention is not limited to the particular embodiment which has just been described but extends to any variant in accordance with its spirit.

 In particular, the present invention may find application in non-self-propelled projectiles, that is to say projectiles devoid of the propellant stage 20, but containing a payload to be implemented at controlled altitude.

Claims (14)

 1. Projectile comprising a payload intended to be implemented at a controlled altitude and a deployable braking system (14) thereof in a phase of descent from its trajectory, characterized in that it further comprises - deployable stabilizing means (12), - first delay means capable of controlling the deployment of the stabilizing means (12) after a predetermined time consecutive to the sending of the projectile (P), and this before deployment of the braking system (14) , and - second timing means capable of controlling the deployment of the braking system (14) when the payload is located at the desired altitude.  2. Projectile according to claim 1, characterized in that it comprises a separable propellant stage (20).  3. Projectile according to one of claims 1 or 2, characterized in that the deployable stabilizing means (12) are adapted to further ensure the reversal of the payload (10) between an ascending phase and a descending phase of its path.  4. Projectile according to one of claims 1 to 3, characterized in that the deployable stabilizing means (12) comprise a parachute.  5. Device according to claim 4, characterized in that the parachute (12) forming the deployable stabilizing means have a bearing surface of less than 2m2.  6. Projectile according to one of claims 4 or 5, characterized in that the parachute (12) forming deployable stabilizing means has a diameter between 500 and 600mm.  7. Projectile according to one of claims 1 to 6, characterized in that the first timing means are adapted to ensure the deployment of a stabilizing means (12) at an altitude at least equal to the maximum desired altitude of implementation of the payload.  8. Projectile according to one of claims 1 to 7, characterized in that the deployable braking means (14) comprise a parachute.  9. Projectile according to claim 8, characterized in that the parachute composing the braking means (14) has a bearing surface greater than 10m2  10. Projectile according to one of claims 8 or 9, characterized in that the parachute (14) composing the braking means has a bearing surface of the order of 30m2.  11. Projectile according to one of claims 1 to 10, characterized in that the payload comprises a charge of decoys, such as a charge of passive or active infrared and / or electromagnetic decoys.  12. Projectile according to one of claims 1 to 11, characterized in that the second timing means are further adapted to initiate the payload.  13. Projectile according to one of claims 1 to 12, characterized in that it comprises a propellant stage (20), means capable of separating the propellant stage from the body (10) containing the payload, and means , such as an asymmetrical wing, able to separate the engine stage (20) from the body (10) containing the payload.  14. Projectile according to one of claims 1 to 13, characterized in that the first and second timing means are adapted to cut a halyard initially holding respectively a parachute forming stabilizing means (12) and a parachute forming braking means ( 14).