The present invention relates to the field of exterior ballistics and more particularly to the stabilization of projectiles moving in space. More specifically, the invention relates to a projectile and its associated wing or fin deployment device.
During a projectile firing, several parameters are to be taken into account for said projectile to reach a designated target. During the flight phase, the projectile is subjected to aerodynamic forces that can deflect it from its trajectory. One of the important parameters is thus the stabilization of said projectile.
For their stabilization, several projectiles are, to this end, provided with wings or fins deployment mechanisms or devices. The association of such a mechanism or device with the projectile, however, should not cause a significant variation in the dimensions of the architecture of the projectile at the risk of either aggravating the aerodynamic disturbances or preventing the addition of on-board electronic devices with a view to improving, for example, the performances of the projectile.
Document U.S. Pat. No. 6,761,331 teaches a missile and a fin deployment mechanism, the arrangement of which does not reduce the useful volume of the projectile, said deployment mechanism pivots automatically by rotating a fin from a stowed orientation to a deployed orientation. The deployment mechanism comprises a spring that provides a thrust force allowing the fin to move quickly, simply and reliably from the stowed orientation to the deployed orientation. The deployment mechanism, which is carried out in three steps, also comprises one or more cam(s) or the like for guiding the fin from the stowed orientation to the deployed orientation. This mechanism therefore requires space and its complexity can cause malfunctions or incomplete deployments.
Document EP0318359 teaches a projectile with which is associated a device for deploying a fin made secured to the projectile by a hinge located at the rear of the body of the projectile, said hinge being such that the deployment movement is performed in two phases: a first phase in which the fin switches from a carrying position to a semi-deployed position, by rotation in the direction of flow and along a first axis perpendicular to the plane of the fin when the latter is in a carrying position and a second phase in which the fin switches from the semi-deployed position to the deployed position, by a rotation along a second axis which is parallel to the plane of the fin. The hinge comprises an engine acting as an actuator of the first deployment phase and as a lock of the fin assembly, hinge when the fin is in the carriage position.
The documents mentioned above have, however, drawbacks that may affect the good stabilization ensured by the fins. Indeed, the second fin deployment phase depends on the inclination of the projectile, with respect to the direction of the aerodynamic flow, in the flight phase. The aerodynamic constraints that are exerted on a fin depend on the surface presented by said fin facing the aerodynamic flow. Thus, if the projectile is inclined during the second deployment phase, the fins being each subjected to different aerodynamic forces, it is not certain that the fins are deployed correctly, thereby making unreliable the deployment mechanisms or devices taught in the documents above.
Document U.S. Pat. No. 6,761,331 teaches, moreover, fins which have, during the deployment phase, a larger surface facing the aerodynamic flow, which can induce additional constraints to a good stabilization of the projectile.
The aim of the present invention is to overcome one or more drawback(s) of the prior art by proposing a projectile architecture including an effective and reliable wing or fin deployment device regardless of the trajectory of said projectile.
This objective is achieved by a projectile including a body having a longitudinal axis and an intermediate portion comprising a wing or fin deployment device including a number N, equal to at least three, of wings or fins able to be deployed, the deployment method comprising at least two phases, a first deployment phase in which each wing or fin switches from a position tangential to the body of the projectile and parallel to the longitudinal axis to a semi-deployed position, by rotation of the wing or fin around a axis perpendicular to the longitudinal axis of the projectile and a second deployment phase with the switching of each wing or fin from the semi-deployed position, in which it is still tangent to the body of the projectile, to a deployed position, in which it is perpendicular to the body of the projectile, by rotation around a axis parallel to the longitudinal axis of the projectile, said projectile being characterized in that the wing or fin deployment device is configured so that the rotation of a wing or fin around the axis parallel to the longitudinal axis of the projectile drives a toothing which meshes with a synchronizing toothed wheel which drives, by meshing, the rotation of each other wing or fin around each axis parallel to the longitudinal axis of the projectile to synchronize the deployment of the wings or fins in the second phase.
According to another feature, the wings or fins are arranged in the median position on the body of the projectile in order to improve the flight characteristics of the projectile.
According to another feature, in the first deployment phase, the wings or fins of the projectile are deployed from the rear towards the front, in the opposite direction to the aerodynamic flow, the pivot axis being mounted upstream of the wing or fin, in the direction of the aerodynamic flow when the wing or fin is in a position tangential to the body of the projectile.
According to another feature, the first phase of deployment of all the wings or fins is ensured by a single control and lock engine indirectly connected to an expansion system comprising a pressure piston and at least one compression spring, thereby lightening the mechanism in the projectile while ensuring good stabilization.
According to another feature, the pressure piston allows initiating the rotational movement of the wings in the first deployment phase and comprises guide means for guiding said piston during its translational displacement, indirectly generated by the control and lock engine, along the longitudinal axis of the projectile.
According to another feature, the device includes a body comprising on its outer part at least one housing intended to receive at least one synchronizing means and part of the wing or fin, a central chamber in which the pressure piston and at least one orientation means and at least one wing or fin synchronizing means are arranged, the central chamber being located between an upstream chamber with respect to the direction of the aerodynamic flow and called upper chamber in which the engine controlling the deployment and the lock of the wings is arranged, and a downstream chamber with respect to the direction of the aerodynamic flow and called lower chamber, the central chamber and the upper chamber being separated by an upper wall, and the central chamber and the lower chamber being separated by a lower wall.
According to another feature, the central chamber of the deployment device body also comprises at least one main column, centered on the axis of the projectile and secured to at least one of the lower or upper walls, around which a large central compression spring is wound, at least the same number N of secondary columns peripherally located around the main column and around which small compression springs are also wound, a lock disc including at least the same number N of tenons and at least one activation toothed wheel actuated by the control engine, the activation toothed wheel being connected to the lock disc so as to transmit the rotational movement thereto in order to allow the unlocking of the wings or fins.
According to another feature, the guide means comprise at least one guide disc fixed to the rear of the piston body and at least the same number N of guide rings.
According to another feature, the pressure piston also comprises at least the same number N of grooves facing the tenons of the lock disc when the latter pivots, the grooves being able to receive said tenons, at least the same number N of abutments on which rods are fixed, each rod having at its end a guide ring configured to receive a secondary column so that the small spring is located between an inner portion of the body in the vicinity of the lower wall and the ring, and at least one axial cavity centered on the axis of the projectile and configured to receive the main column and part of the large central compression spring.
According to another feature, the orientation means comprise at least the same number N of split latches, each latch including a groove able to receive a rod secured to a wing or fin comprising a tenon at its end, and at least the same number N of cams, each cam being secured to a latch.
According to another feature, the means for synchronizing the deployment of the wings comprise at least the synchronizing toothed wheel arranged in a circular groove coaxial with the central chamber, and at least the same number N of pivots equal to the number of wings, each pivot being included in the housing of the outer part of the device body and including a cavity able to receive the rod of a wing, and a pinion mounted at one of its ends, said pinion meshing with the synchronizing toothed wheel.
According to another feature, the device includes at least one fixing means for preventing the continuous rotation of at least one wing or fin around the axis of rotation of the first deployment phase once the second deployment phase is engaged.
According to another feature, the pivot is held in the housing of the outer surface of the deployment device body by a front flange located at the front end of the pivot in the direction of the upper wall and by a rear flange located at the rear end of the pivot comprising at least one pinion and in the direction of the lower wall, the flanges being provided with cylindrically-profiled grooves capping the pivot and guiding the rotational movement of said pivot.
According to another feature, the housing comprised in the outer surface of the deployment device body comprises a profile forming a V-shaped secondary housing, configured to receive part of the wing or fin at the end of the deployed phase, said deployed phase consisting of the positioning of part of the wing in said secondary housing.
Other features and advantages of the present invention will appear more clearly upon reading the following description, with reference to the appended drawings, in which:
The present invention relates to a projectile (P) and to the wing or fin deployment device (1) [
In some embodiments, the projectile (P) includes a body (P0) having a longitudinal axis (L) and an intermediate portion comprising a device (1) for deploying wings (2) or fins including a number N, preferably equal to at least three, of wings (2) or fins able to be deployed, said wings being evenly distributed angularly around the axis (L) of the projectile. The deployment method comprises at least two phases, a first deployment phase in which a wing (2) or fin switches from a position tangential to the body (P0) of the projectile and parallel to the longitudinal axis (L) (
In the following description, a number of parts or members will be in a number N which is equal to the number of wings (2) or fins.
The projectile (P) is, for example and without limitation, a missile, a shell or a rocket, the body (P0) of which may comprise at least three stabilizing fins (P1) fixed at the tail of the body (P0) of said projectile (P) and/or at least three piloting fins (P2) (or canard fins) fixed on the front tip of the body (P0) of the projectile (P), as seen for example in
The deployment device (1) can be fixed on the body (P0) of the projectile (P) between the tail and the front tip of said projectile (P). Preferably, the device is fixed on the body (P0) of the projectile so that the wings (2) or fins of the device are arranged in the median position on the body of the projectile (P) in order to improve the lift characteristics ensured by the wings (2), such as for example the wings of an airplane.
The wings (2) are deployed in the vicinity of the peak of the ballistic trajectory of the projectile and their lift allows increasing the range of said projectile.
In some embodiments, in the first deployment phase, the wings (2) or fins of the projectile (P) are deployed preferably from the rear towards the front, in the opposite direction to the aerodynamic flow, the pivot axis being mounted upstream of the wing (2) or fin, in the direction of the aerodynamic flow, when the wing (2) or fin is in a position tangential to the body (P0) of the projectile (
In some embodiments, the first phase of deployment of all the wings (2) or fins is ensured by a single control and lock engine (M) indirectly connected to an expansion system comprising a pressure piston (12) and at least one compression spring (16A, 16B), as seen for example in
In the case where the wings or fins of the device (1) are deployed in the opposite direction to the aerodynamic flow, it is necessary to provide a force to counter the aerodynamic constraints. The pressure piston (12) and the compression springs (16A, 16B) provide this force necessary to perform the first deployment phase. In this arrangement of the wings or fins, the aerodynamic constraints act as a brake and thus reduce the risks that the first deployment phase is sudden and damages the deployment device, which can thereby lead to a destabilization of the projectile along its trajectory.
In some embodiments, the pressure piston (12) allows initiating the rotational movement of the wings (2) in the first deployment phase and comprises guide means (121, 1221) for guiding said piston (12) during its translational displacement, indirectly generated by the control and lock engine (M), along the longitudinal axis (L) of the projectile (P).
In some embodiments, the device (1) includes a body (10) (
In some embodiments, the central chamber (CC) of the deployment device (1) body (10) also comprises at least one main column (15A), which is centered on the axis (L) of the projectile and here secured to the lower wall (PI) and positioned in a bore of the upper wall (PS), around which a large central compression spring (16A) is wound. Conversely, the central column could be secured to the upper wall and positioned in a bore of the lower wall. A number N of secondary columns (15B), N being equal to the number of wings (for example five, as shown in
It should be noted that, for the clarity of the partial sectional figures, some of the elements are not always represented. Particularly, it is seen in
In some embodiments, the guide means (121, 1221) comprise preferably at least one guide disc (121) fixed to the rear of the piston body (120) (
In some embodiments, the pressure piston (12) (
Each rod (1220) carries at its end a guide ring (1221) which is configured to receive a secondary column (15B). Each secondary column (15B) receives a small spring (16B) which is located between an inner portion of the body (10) in the vicinity of the lower wall (PI) and the ring (1221), as represented for example in
In the locked state, the large spring (16A) pushes the piston (12) in abutment against the tenons (130). When the control engine (M) is activated during the flight, the lock disc (13) is rotated. The tenons (130) are then positioned opposite the grooves (1201). This positioning of the tenons (130) allows unlocking the pressure piston (12), the body (120) of which slides along the main column and the guide rings (1221) along the secondary columns (15B), from the lower wall (PI) to the upper wall (PS) of the device (1), under the action of the compression springs. The translational displacement of the piston (12) is stopped when the end of the body of said piston (12) abuts on the upper wall (PS) of the device (1). The tenons (130) of the lock disc (13) are then abutting on surfaces comprised in the grooves of the piston (12).
The guide means (121, 1221) allow preventing the longitudinal axis of the piston (12) from oscillating around the longitudinal axis (L) of the projectile during the translational movement of said piston (12), in which case an angular offset could occur and the cams (17) would no longer face the abutments (122) of the piston. This would lead to a non-deployment or partial deployment of the wing 2, thus causing a destabilization of the projectile (P).
In some embodiments, the orientation means (17, 18) (
The tenon (21) of the rod (20) of the wing or fin is configured to be inserted into the groove (180) of the latch (18) so that the movement of the latch (18) drives that of the rod (20) and therefore of the wing (2) or fin during the first deployment phase.
In some embodiments, the wing (2) deployment synchronizing means (14B, 11) comprise preferably at least one synchronizing toothed wheel (14B) (
According to the invention, the first deployment phase results from the translational displacement of the pressure piston (12) along the longitudinal axis (L) of the projectile (P) in the direction of the upper wall (PS) separating the central (CC) and upper (CS) chambers of the device (1) body (10), this displacement causing the rotation of the cams (17) around the axes (ZZ′) perpendicular to the longitudinal axis (L) of the projectile (P).
The translational movement of the piston (12) is triggered by the start of the control and lock engine (M) which rotates the lock (13) and positions the tenons (130) facing the grooves (1201) of the piston, thereby releasing the piston (12) which can move pushed by the springs (16A) and (16B). The central compression spring (16A) and small springs (16B) switch from a compressed state to an expanded state thereby causing the displacement of the pressure piston (12) towards the upper wall (PS).
As shown in
In the lock position, the compression springs (16B) are compressed, as shown in
The start of the engine (M) causes the unlocking of the piston (12) and compression springs (16A, 16B) which extend along the main and secondary columns (15A, 15B), allowing the piston (12) to move along the main column.
The abutment (122) of the pressure piston (12) in contact with the cam then generates the rotation thereof around a axis (ZZ′) perpendicular to the longitudinal axis (L) of the projectile (P). The latch (18), connected to the cam (17) and including the end of the rod (20) of the wing (2) or fin, in turn causes the rotation of said wing or fin, switching it from a position tangential to the body (P0) of the projectile (P) and parallel to the longitudinal axis (L) to a semi-deployed position and tangent to the body (P0) of the projectile (P) (
In some embodiments, the device includes at least one fixing means for preventing the continuous rotation of at least one wing (2) or fin around the axis of rotation (ZZ′) of the first deployment phase once the second deployment phase is engaged.
Thus, when the wings (2) or fins are in the semi-deployed position (
In some embodiments, the second deployment phase is ensured by the rotational movement, around a axis (XX′) parallel to the longitudinal axis (L) of the projectile (P), of at least one pivot (11) comprised in at least one housing (103) of the outer surface of the deployment device (1) body (10). During the rotation of the wing (2) or fin around the axis (XX′) parallel to the longitudinal axis (L) of the projectile (P), the tenon (21) of the rod (20) of said wing (2) or fin comes out of the groove (180) of the catch (18), as seen for example in
Moreover, at least one groove (106) [
In some embodiments, the pivot (11) is preferably held in the housing (103) of the outer surface of the deployment device (1) body (10) by a front flange (102A) located at the front end of the pivot (11) in the direction of the upper wall (PS) and by a rear flange (102B) (
The rotation of the pivot (11) causes the rotation of a drive pinion (110) or toothing of the synchronizing toothed wheel (14B). During the rotation of the pivot (11) causing the rotation of the wing (2) or fin, the pinion (110) fixed to one of the ends of the pivot (11) also rotates at the same speed as the latter. The pinion (110), being connected to the synchronizing toothed wheel (14B), will cause its rotation. The synchronizing toothed wheel (14B), by its rotation, simultaneously induces the rotation of each of the other pinions (110) with which it is connected. The rotation of each other pinion causes the rotation of the pivot (11) with which it is associated and the rotation of each other pivot allows the rotation of the wing to which it is connected, thus allowing a synchronized deployment of all the wings or fins.
In some embodiments, as shown in
During its rotation around the axis (XX′) parallel to the longitudinal axis (L) of the projectile (P) in the second deployment phase, the wing (2) or fin therefore switches from a position tangential to the body (P0) of the projectile (P) to a position perpendicular to the body (P0) of the projectile (P). Part of the wing (2) or fin then abuts against the wall of the V-shaped secondary housing (1030), so as to hold the position of the wing (2) or fin fixed in the deployed phase (
In some embodiments, the movement in the second deployment phase is activated by the resultant of the aerodynamic forces exerted on the wings (2) in the semi-deployed position.
The present application describes various technical features and advantages with reference to the figures and/or various embodiments. Those skilled in the art will understand that the technical features of a given embodiment can in fact be combined with features of another embodiment unless explicitly stated otherwise, or unless the combination does not provide a solution to at least one of the technical problems mentioned in the present application. In addition, the technical features described in a given embodiment can be isolated from the other technical features of this embodiment unless explicitly stated otherwise.
It must be obvious to those skilled in the art that the present invention allows embodiments in many specific forms without departing from the field of application of the invention as claimed. Consequently, the present embodiments must be considered as illustrations, but can be modified in the area defined by the scope of the appended claims, and the invention must not be limited to the details given above.
Number | Date | Country | Kind |
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1601109 | Jul 2016 | FR | national |
Filing Document | Filing Date | Country | Kind |
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PCT/EP2017/068092 | 7/18/2017 | WO | 00 |
Publishing Document | Publishing Date | Country | Kind |
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WO2018/015367 | 1/25/2018 | WO | A |
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20130032659 | Castor et al. | Feb 2013 | A1 |
Number | Date | Country |
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0318359 | May 1989 | EP |
2354755 | Apr 2011 | EP |
2620738 | Jul 2013 | EP |
02079716 | Oct 2002 | WO |
Entry |
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International Search Report and Written Opinion from corresponding International Application No. PCT/EP2017/068092, dated Jul. 18, 2017, pp. 1-12, European Patent Office, Rijswijk, The Netherlands. |
Number | Date | Country | |
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20190219373 A1 | Jul 2019 | US |