IMPROVED DEVICE FOR LAUNCHING A DRONE BY SPRING PUSH, METHOD FOR LAUNCHING DRONES USING THIS DEVICE

Abstract

The invention relates to a device for launching a drone by spring thrust, in which the means (4) for ejecting the drone comprise means (7) for controlling the unlocking of an ejection assembly (5) from its armed position which comprise an electromagnet (71), at least one trigger element (70) which is movable, under the action of a magnetic field created by the activation of the electromagnet (71), from a rest position, to a trigger position, in which the at least one trigger element (70) unlocks the ejection assembly (5), and means (74) for returning the at least one trigger element (70) to the rest position, the ejection means (4) further comprising an automatic repositioning mechanism (8) arranged and configured to move the at least one trigger element (70) between the rest and trigger positions, in the absence of activation of the electromagnet (71). the electromagnet,under the effect of a movement of the ejection assembly (5) towards its armed position. The invention also relates to a method for launching drones using the device. Figure to be published with the abstract: Figure 2.,

Description

Title of the invention: IMPROVED DEVICE FOR LAUNCHING A DRONE BY SPRING PUSH, METHOD FOR LAUNCHING DRONES USING THIS DEVICE DEVICE

[0001] The technical field of the invention is that of launching devices for drones, and more specifically, that of launching devices for drones of the spring-push type.

[0002] Drones or remotely controlled aircraft can carry a payload intended for civil or military missions, surveillance, intelligence, combat or transport. Drones are small, cheaper and simpler to operate than an aircraft carrying a pilot, and are experiencing significant growth.

[0003] Several means of launching a drone are known, including launch tube launch devices.

[0004] The purpose of these launch tube devices is to propel the drone a few meters above the vehicle carrying the launch tube for deployment of this drone. This avoids any contact of the drone with the antennas mounted on the vehicle and allows for rapid implementation.

[0005] There are many types of launch tube launch devices, including spring-push type devices in which a compression spring bears against the rear end of a launch tube and presses on an ejection member slidably mounted in the launch tube and against which the drone will be placed. The device is armed by compressing the compression spring and then locking the ejection member into position, the device then being in the armed position. Unlocking is controlled by a trigger mechanism which causes the spring to release and the drone to be launched, pushed by the ejection member.

[0006] Such a type of launching device is disclosed in Chinese patent application CN111572801 A, in which the trigger mechanism is a rotary mechanism driven in rotation by a motor. Similarly, the compression of the spring, after the launch of the drone, is implemented by a motorization integrated into the device and located in the launch tube.

[0007] However, the use of such motorized means increases the cost and weight of the launch device, and does not allow optimal compactness to be obtained, in particular because they limit the volume capable of accommodating a drone in the launch tube.

[0008] It is therefore the aim of the invention to propose a launching device which does not have these drawbacks.

[0009] The solution according to the present invention is based on the use of a trigger mechanism comprising an electromagnet capable of moving at least one trigger element, which movement is obtained by the action of a magnetic field created by the activation of the electromagnet and leads to the unlocking of the ejection element. This solution is compact and in particular makes it possible to reduce the costs and weight of the device. The solution according to the present invention is also based on the use of an automatic repositioning mechanism coupled to the at least one trigger element and making it possible to increase safety when repositioning the device in the armed and locked position.

[0010] The present invention therefore relates to a device for launching a drone by spring thrust, a device comprising a longitudinal launch tube having a first, rear end, which is closed and a second, front end, which is open, and the interior of which defines a launch chamber intended to receive a drone, and means for ejecting the drone from the launch tube which comprise: - an ejection assembly comprising an ejection element, mounted to slide longitudinally in the launch chamber and intended to push the drone to eject it from the launch tube, and a compression spring, called an ejection spring, having a longitudinal axis coaxial with the longitudinal axis of the launch tube and a first end of which bears on the rear end of the launch tube and a second end of which bears against the ejection element, the ejection assembly being capable of being placed in an armed position,in which the ejection spring is compressed by the ejection element, , - locking means for releasably locking the ejection assembly in the armed position, the locking means comprising at least one retaining element connected to the launch tube and movable between a locking position, in which the at least one retaining element is engaged with the ejection element so as to maintain the ejection assembly in the armed position, against the action of the ejection spring, and an unlocking position, in which the at least one retaining element is disengaged from the ejection element, and - control means for controlling the unlocking of the ejection assembly, by moving the at least one retaining element from the locking position to the unlocking position, characterized by the fact that the control means comprise: - an expansion housing, located at the rear of the launch tube and containing an electromagnet capable of being connected to a source of electricity, - at least one relaxation element which is movable in the relaxation housing, under the action of a magnetic field created by the activation of the electromagnet, from a rest position, in which the at least one detent element retains the at least one retaining element in the locking position, to a detent position, in which the at least one detent element has moved the at least one retaining element from the locking position to the unlocking position, and - means for returning the at least one trigger element to the rest position after deactivation of the electromagnet, and by the fact that the ejection means further comprise an automatic repositioning mechanism coupled to the at least one trigger element and arranged to move the at least one trigger element between the rest and trigger positions, in the absence of activation of the electromagnet, under the effect of a movement of the ejection element to its armed position, the automatic repositioning mechanism authorizing a movement of the at least one trigger element from the rest position to the trigger position, against the return means, before the placement of the ejection element in the armed position and authorizing a movement of the at least one trigger element from the trigger position to the rest position, under the effect of the return means, once the ejection element is placed in the armed position.

[0011] In other words, the ejection spring is held in the compressed state by the use of at least one retaining element which hinders the longitudinal sliding of the ejection element in the locking position. The disengagement of the at least one retaining element from the ejection element, under the effect of the activation of an electromagnet, allows the ejection of the ejection element.

[0012] Such unlocking control means are responsive and reliable.

[0013] Such control means are also safe. Indeed, when the at least one trigger element is in the rest position, the at least one retaining element is prevented by the at least one trigger element from moving into the unlocked position, the at least one retaining element being allowed to move to its unlocked position only when the at least one trigger element is in the triggered position.

[0014] The automatic repositioning mechanism allows, during reloading, that is to say when compressing the ejection spring from its initial relaxed state to its compressed state, to move the at least one retaining element, via the at least one trigger element, into the unlocking position in order to allow the ejection element to be moved to the armed position, and to automatically replace the at least one retaining element, via the at least one trigger element, in the locking position once the ejection element is placed in the armed position in order to automatically lock the ejection element in the armed position. Such a mechanism therefore allows simple and safe reloading.

[0015] Said return means may be elastic means, such as for example a spring.

[0016] Preferably, the trigger housing is in the form of an outer hollow cylinder which is integral with the launch tube and an inner hollow cylinder integral with the outer hollow cylinder and of smaller diameter than that of the outer hollow cylinder such that a tubular space is formed therebetween, the outer and inner hollow cylinders having coaxial longitudinal axes, the electromagnet being of hollow cylindrical shape and being arranged between a first axial, rear side of the outer hollow cylinder and a first axial, rear side of the inner hollow cylinder with its longitudinal axis coaxial with that of the outer and inner hollow cylinders, and the trigger element is a trigger pin made of a ferromagnetic material mounted in the inner hollow cylinder and in the electromagnet in a sliding manner along the longitudinal axis of the trigger housing.Such a device, comprising hollow cylindrical elements, has very good compactness.

[0017] To further improve the compactness of the ejection means, advantageously, the trigger housing is surrounded by the ejection spring, the or each retaining element is made of a ferromagnetic material and is received in a through opening provided in the inner hollow cylinder and with an axis perpendicular to the longitudinal axis of the trigger housing, and the ejection element comprises a thrust head which is perpendicular to the longitudinal axis of the launch tube and against which the second end of the ejection spring presses, and at least one holding member which is integral with the thrust head and extends into the tubular space, in the locking position, the at least one retaining element projecting into the tubular space and being configured to hold the ejection assembly in the armed position by gripping the at least one holding member, and in the unlocking position,the at least one retaining element projecting into the inner hollow cylinder and being configured to come into contact with the trigger pin on the path of the trigger pin. In other words, the at least one through opening receiving the at least one retaining element opens on the one hand into the path of the trigger pin and on the other hand into the path of the at least one holding member, and the at least one retaining element is configured to project either on the path of the at least one holding member or on the path of the trigger pin.

[0018] Advantageously, the trigger pin comprises at least one external groove arranged so as to be located opposite the at least one through opening of the inner hollow cylinder only in the trigger position and configured to receive the part of the at least one retaining element projecting into the inner hollow cylinder in the unlocked position, and by the fact that the at least one holding member comprises at least one internal groove arranged so as to be located opposite the at least one through opening of the inner hollow cylinder only in the trigger position and configured to receive the part of the at least one retaining element projecting into the inner hollow cylinder in the unlocked position, and by the fact that the at least one holding member comprises at least one internal groove arranged so as to be located opposite the at least one through opening of the inner hollow cylinder only in the unlocked ... at least one through opening of the inner hollow cylinder only in the armed position and configured to receive the portion of the at least one retaining element projecting into the tubular space in the locking position.

[0019] Advantageously, the trigger pin comprises a single external groove formed over the entire external circumference of the pin, and the holding member is in the form of a hollow cylinder comprising a single internal groove formed over the entire internal circumference of said hollow cylinder.

[0020] According to a particular embodiment, the at least one retaining element is in the form of a ball, for example made of steel, and movable between the locking position and the unlocking position by translation along the associated through opening. Such a retaining element is simple, strong and inexpensive.

[0021] Preferably, the internal and external grooves are of a shape complementary to that of the ball(s).

[0022] Advantageously, the device comprises several retaining elements, preferably three retaining elements each mounted movable in translation in a respective through opening of the inner hollow cylinder.

[0023] Preferably, the travel of the trigger pin between the rest and the detent positions is limited on the one hand by an axial stop secured to a first axial side of the trigger pin and capable of coming to bear against a first, rear, axial side of the electromagnet in the rest position, and on the other hand by a shoulder formed on the trigger pin and capable of coming to bear against a second, front, axial side of the electromagnet in the detent position, the means for returning the trigger pin to the rest position being elastic return means, such as a compression spring, bearing on the second, front, axial side of the inner hollow cylinder and pressing against a second axial side of the trigger pin.

[0024] According to a particular embodiment of the invention, the automatic repositioning mechanism is received in an internal housing of the trigger pin and comprises a guide mounted axially movable in the internal housing, along the longitudinal axis of the trigger housing, and configured to cooperate with the ejection element, a so-called soft spring mounted between and bearing against the guide and a guide ring which is traversed by the guide and slidably mounted in the internal housing, a so-called hard spring mounted between the trigger pin and a hammer itself slidably mounted in the internal housing, the soft and hard springs being compression springs concentric and coaxial with the longitudinal axis of the trigger housing, and a spring stop interposed between the hammer and the guide ring and coming into contact with them, the spring stop being movable between an eccentric position relative to the longitudinal axis of the internal housing,in which the guide is not allowed to, axially move against the flexible spring, and a centered position, in which the guide is able to move against the flexible spring, the return means being configured such that the force to be applied to oppose the action of the return means is less than the compression force to be applied to elastically deform the hard spring and greater than the compression force to be applied to elastically deform the flexible spring. Such a mechanism therefore allows simple and safe repositioning of the ejection element in the armed and locked position, without deteriorating the compactness properties of the device.

[0025] Advantageously, the internal housing comprises two cylindrical walls connected to each other by a ramp having an inclined wall converging in the direction of the hard spring and arranged to cooperate with the spring stop when the hard spring is compressed so as to place the spring stop in its centered position, the spring stop being in the form of a hollow cylinder whose outside diameter is less than the inside diameter of the cylindrical wall on the diverging side of the ramp and whose inside diameter allows the guide to pass through the spring stop in the centered position, the spring stop comprising a magnet urging the spring stop into contact with the cylindrical wall of the internal housing when the spring stop is received at the level of the cylindrical wall, so as to place the spring stop in the eccentric position.

[0026] Advantageously, the device comprises two annular elements for limiting the axial movement of the guide in the internal housing, the two annular elements being integral with the wall of the internal housing and arranged in such a way that when the hard and soft springs are relaxed the guide comes into abutment against the so-called front annular element capable of being crossed by a part of the ejection element coming to bear against the guide in the armed position, and that when the soft spring is compressed the guide comes into abutment against the so-called rear annular element, on the side facing the front annular element, the guide ring coming to bear against the face of the rear annular element opposite the face facing the front annular element when the hard spring is relaxed. Thus, the front annular element makes it possible to prevent the guide from being ejected from the internal housing of the spindle in the event of failure of the soft spring.Likewise, the rear annular element prevents any inappropriate movement of the guide ring-spring-hammer stop assembly in the event of failure of the hard spring.

[0027] The present invention also relates to a method for launching drones using a spring-loaded launch device as defined above, characterized in that it comprises the following successive steps: - a positioning step, comprising positioning a drone in the launch chamber, the ejection assembly being locked in the armed position; - a launching step of the drone, comprising activating the electromagnet to move the trigger element from the rest position to the trigger position, whereby the ejection assembly is unlocked and ejects the drone from the launch tube; and - before repeating the positioning step, a repositioning step, comprising returning the ejection assembly to the armed position, in which it is locked by the at least one retaining element.

[0028] To better illustrate the object of the present invention, a particular embodiment thereof will be described below, with reference to the attached drawings. In these drawings:

[0029] [Fig.l] is a side view, in longitudinal section, of the launching device according to the particular embodiment of the present invention, in the armed position;

[0030] [Fig.2] is a side view, in longitudinal section, showing more specifically the ejection means of the device of [Fig.l] in the armed position;

[0031] [Fig.3] is a side view, in longitudinal section, showing the ejection means of the device of [Fig.l] in the launching position;

[0032] [Fig.4] is an exploded perspective view of the locking means, the control means and the automatic repositioning mechanism;

[0033] [Fig.5] is a side view, in longitudinal section, showing the locking means and the control means in the rest position after the ejection of a drone;

[0034] [Fig.6] is a side view, in longitudinal section, showing the ejection means during a first stage of repositioning the ejection assembly in the armed position;

[0035] [Fig.7] is a side view, in longitudinal section, showing the ejection means during a second stage of repositioning the ejection assembly in the armed position; and

[0036] [Fig.8] is a side view, in longitudinal section, showing the ejection means during a third stage of repositioning the ejection assembly in the armed position.

[0037] If we first refer to [Fig.l], we can see that the launching device 1 according to the present invention is intended for launching a drone-type object 2.

[0038] Such a drone 2 comprises, in a conventional manner, a base body 20 containing a powertrain, a battery pack and navigation electronics. The drone 2 is equipped with a payload 21 removably mounted on the base body 20. This payload 21 may be a lethal or non-lethal load. For example, the drone 2 could be equipped with a lethal load of the explosive type, a non-lethal load allowing paint or a smoke bomb to be released, or an optronic load allowing observation and detection.

[0039] As can be seen in [Fig. 1], the device 1 comprises a launch tube 3 with a longitudinal axis A1, intended to receive the object to be launched, namely the drone 2, before its launch, and ejection means 4 for ejecting the drone 2.

[0040] The launch tube 3 has a generally cylindrical shape around its longitudinal axis A1, and it has a front end 3a forming the mouth for the exit of the drone 2 and a rear end 3b in the region of which the ejection means 4 are arranged.

[0041] It is emphasized here that the terms “front” and “rear” are understood by reference to the predetermined direction of movement of the drone 2 relative to the launch tube 3 during launch.

[0042] The front end 3a is closed, before launch, by a circular-shaped sealed plug 30 whose diameter corresponds to the external diameter of the launch tube 3.

[0043] The rear end 3b is closed by a base 31 which is in the form of a block of circular section, the diameter of which corresponds to the external diameter of the launch tube 3. The base 31 is fixed to an internal shoulder 32 of the launch tube 3, of annular shape, by fixing members 33, such as screws, passing through orifices provided in the base 31 and orifices provided in the internal shoulder 32 and located opposite each other.

[0044] The launch tube 3 defines inside thereof a cylindrical launch chamber 34 having, in the region of the rear end 3b, a seat 35, here formed by the internal shoulder 32, against which the drone 2 will be placed before ejection from the launch tube 3 by the ejection means 4.

[0045] The ejection means 4 comprise an ejection assembly 5 adapted to be placed in an armed position, locking means 6 for releasably locking the ejection assembly 5 in the armed position, control means 7 for controlling the unlocking of the ejection assembly 5, and an automatic repositioning mechanism 8 for allowing the ejection assembly 5 to be placed again in the armed and locked position.

[0046] As can be seen in Figures 1 to 3 and 6 to 8, the ejection assembly 5 comprises an ejection element 50 and an ejection spring 51 which consists of a compression spring.

[0047] In the present particular embodiment, the ejection element 50 is in the form of an ejection piston 52 having a piston body 53, a thrust head 54 and a holding body 55.

[0048] The piston body 53 is a hollow cylindrical body having a first axial side 53a, directed towards the rear end 3b of the launch tube 3, which is open, and a second axial side 53b, directed towards the front end 3a of the launch tube 3, which is closed. by a transverse wall 56. This transverse wall 56 also closes one side of the holding body 55. The piston body 53, the holding body 55 and the transverse wall 56 are formed in one piece.

[0049] The holding body 55 is a hollow cylindrical body extending from the transverse wall 56 and whose longitudinal axis is coaxial with the longitudinal axis AL. The holding body 55 has a first axial side 55a, directed towards the rear end 3b of the launch tube 3, which is open, and a second axial side 55b, directed towards the front end 3a of the launch tube 3, which is closed by the transverse wall 56. The external diameter of the holding body 55 is smaller than the internal diameter of the piston body 53. Thus, a tubular space is defined between the external wall of the holding body 55 and the internal wall of the piston body 53. The tubular space is arranged and dimensioned in such a way that the ejection spring 51 is received inside this tubular space.

[0050] The holding body 55 extends slidably in a tubular space 36 formed in an expansion housing 37. This expansion housing 37 extends inside the piston body 53. This housing 37 comprises an outer hollow cylinder 37e extending from the base 31 and having a front side, namely directed towards the front end 3a of the launch tube 3, open and an inner hollow cylinder 37i carried by the outer hollow cylinder 37e and having an open front side and an open rear side. The outer hollow cylinder 37e and the inner hollow cylinder 37i are connected to each other by an annular transverse wall 37t.

[0051] The outer hollow cylinder 37e extends perpendicularly from the transverse wall of the base 31, in other words parallel to said longitudinal axis A1, towards the front end 3a of the launch tube 3. The inner hollow cylinder 37i also extends parallel to said longitudinal axis A1 inside the outer hollow cylinder 37e. The diameters of the outer 37e and inner 37i hollow cylinders are defined such that the tubular space 36 formed therebetween is adapted to receive the holding body 55 with the outer wall of the holding body 55 coming into contact with the inner wall of the outer hollow cylinder 37e and the inner wall of the holding body 55 coming into contact with the outer wall of the inner hollow cylinder 37i. Preferably, the expansion housing 37 is formed integrally with the base 31.

[0052] The trigger housing 37 is dimensioned such that it is contained within the piston body 53 in the armed position of the ejection assembly 5, and that the free end of the holding body 55, at the first axial side 55a, comes into contact with the annular transverse wall 37t in the armed position of the ejection assembly 5.

[0053] The holding body 55 comprises, at its free end region, opposite its end region connected to the transverse wall 56, an internal groove 550 intended to receive the locking means 6 in the locking position. The internal groove 550 is formed over the entire inner circumference of the holding body 55.

[0054] The ejection spring 51 is located in the space formed between the outer wall of the trigger housing 37 and the inner wall of the piston body 53, between the rear end 3b of the launch tube 3 and the transverse wall 56. More precisely, the ejection spring 51 has a first end bearing on the transverse wall of the base 31 and a second end bearing against the transverse wall 56, made integral with them by any appropriate means.

[0055] The thrust head 54 is a hemispherical body secured to the transverse wall 56, on the outer side of the piston body 53. The diameter of the base of this hemispherical body is equal to the outer diameter of the piston body 53.

[0056] The transverse wall 56 comprises, in its center, on the side opposite the thrust head 54, a cylindrical central projection 56a which extends inside the holding body 55, from the transverse wall 56. The central projection 56a extends along the longitudinal axis AL

[0057] The locking means 6 make it possible to maintain the ejection spring 51 in the compressed state, and therefore to prevent the ejection piston 52 from sliding towards the front end 3a of the launch tube 3, whereby they maintain the ejection assembly 5 in the armed position.

[0058] In the particular embodiment shown in Figures 1 to 8, the locking means 6 comprise three retaining elements 60.

[0059] Each retaining element 60 is mounted to move in translation in a tubular through opening 38 made in the inner hollow cylinder 37i. Each through opening 38 extends along a radial translation axis, perpendicular to the longitudinal axis A1, the three through openings 38 being located in the same transverse plane. Each through opening 38 opens on the one hand into the tubular space 36 of the expansion housing 37 and on the other hand into the interior of the inner hollow cylinder 37i. The through openings 38 are arranged such that they are located opposite the internal groove 550 of the holding body 5 in the armed position.

[0060] Each retaining element 60 is here in the form of a ball 60 of diameter substantially equal to the diameter of the tubular through opening 38. The wall thickness of the inner hollow cylinder 37i, and therefore the length of each tubular through opening 38 is less than the diameter of the ball 60 received in the opening 38. Thus, when the ball 60, at one of its caps, is flush with the inner wall of the inner hollow cylinder 37i, its opposite cap region projects into the tubular space 36. Conversely, when the ball 60, at one of its caps, is flush with the inner wall of the inner hollow cylinder 37i, its opposite cap region projects into the tubular space 36. cap, is flush with the outer wall of the inner hollow cylinder 37i, its opposite cap region protrudes into the inner hollow cylinder 37i. Each ball 60 is made of a ferromagnetic material, preferably hardened steel. The region of each ball 60 capable of protruding into the tubular space 36 is sized so as to be capable of being received in the internal groove 550, of complementary shape, of the holding body 55.

[0061] The control means 7 are intended to control the movement of the retaining elements 60 towards their unlocking position, by the action of a magnetic field.

[0062] The control means 7 comprise a relaxation element 70 and an electromagnet 71 capable of being connected to an electricity source 72.

[0063] The electromagnet 71 is arranged at the rear of the launch tube 3 and extends from the base 31 to the annular transverse wall 37t. The electromagnet 71 is a cylindrical body with an outside diameter substantially equal to the inside diameter of the outer hollow cylinder 37e. The electromagnet 71 has a cylindrical passage 710 passing through it along the longitudinal axis AL. The diameter of the passage 710 is less than the inside diameter of the inner hollow cylinder 37i, so that the face of the electromagnet cooperating with the annular transverse wall 37t and projecting laterally inside the inner hollow cylinder 37i forms a circular stop surface 711.

[0064] The electricity source 72 can be any electricity source. For reasons of space requirement, the electricity source 72 is advantageously an external electricity source, that is to say it is arranged outside the launch tube 3 and is capable of being connected to the electromagnet 71 at the rear end of the base 31.

[0065] The trigger element 70 is in the form of a trigger pin made of a ferromagnetic material. The trigger pin 70 is slidably mounted in the passage 710 and in the inner hollow cylinder 37i. Thus, the translational movement path of the pin 70 is located inside the inner hollow cylinder 37i, while the translational movement path of the holding body 55 is located outside the inner hollow cylinder 37i, the path of the pin 70 and the path of the holding body 55 both communicating with the through openings 38 receiving the balls 60. The trigger pin 70 is a cylindrical body having a first axial side 70a, directed towards the rear end 3b of the launch tube 3, which is closed, and a second axial side 70b, directed towards the front end 3a of the launch tube 3, which is open and formed by an annular end 70c. The first axial side 70a is integral with an axial stop 73.The axial stop 73 comprises a rod portion 73a, one end of which is secured to the pin 70 and the other end of which carries a disc portion 73b. The rod portion 73a extends into the passage 710. along the longitudinal axis A1, and the disc part 73b extends perpendicular to the rod part 73a outside the passage 710. The axial stop 73 is dimensioned such that, in the rest position, the disc part 73b comes to bear against the face of the electromagnet 71 on the base 31 side. This axial stop 73 makes it possible to limit the travel of the trigger pin 70, namely its sliding, in the direction of the front end of the trigger housing 37.

[0066] The detent pin 70 has a first cylindrical section 700 and a second cylindrical section 701 of greater diameter than that of the first cylindrical section 700, such that a shoulder 70d is formed between the two sections 700, 701. The first cylindrical section 700 extends from the first axial side 70a to the shoulder 70d and the second cylindrical section 701 extends from the shoulder 70d to the annular end 70c. The shoulder 70d is arranged and dimensioned such that it comes into contact with the stop surface 711 when the pin 70 is in the detent position. The first cylindrical section 700 has a diameter substantially equal to the diameter of the passage 710. The second cylindrical section 701 has a diameter substantially equal to the inner diameter of the inner hollow cylinder 37i.

[0067] The pin 70 comprises an external groove 702 intended to receive the locking means 6 in the unlocked position. For this purpose, the external groove 702 is arranged on the second cylindrical section 701, at a distance from the shoulder 70d which is equal to the axial distance between the stop surface 711 and the rear edge of the through openings 38. The external groove 702 is of a shape complementary to that of the balls 60 and is formed over the entire outer circumference of the pin 70.

[0068] A compression spring 74 extends around the pin 70, in particular around the second cylindrical section 701. This spring 74 has its front end connected to the annular end 70c and its rear end connected to the free end of the inner hollow cylinder 37i, by any suitable means. This spring 74 is a return spring intended to urge the trigger pin 70 towards the front end 3a of the launch tube 3, in other words opposite the stop surface 711. Thus, once the trigger pin 70 is no longer subjected to the magnetic field of the electromagnet 71, the trigger pin 70 is automatically returned to its rest position, namely to a position in which the trigger pin 70 places the retaining elements 60 in the locking position.

[0069] Thus, the activation of the electromagnet 71 by passing a current towards the terminals of the electromagnet 71 causes, under the action of the magnetic field created, a displacement of the trigger pin 70 in the direction of the electromagnet 71 until the shoulder 70d comes into abutment against the stop surface 711. In other words, the electromagnet 71 forces the pin 70 to move from the rest position to the trigger position against the action of the return spring 74. In the position of rest of the pin 70, the second cylindrical section 701 comes into contact with the balls 60 which are pushed into the locking position in the path of the holding body 55. In the relaxed position of the pin 70, the external groove 702 is opposite the through openings 38 and the steel balls 60 are attracted into the external groove 702 under the effect of the magnetic field, so that the balls 60 are no longer in the path of the holding body 55 which is therefore free to slide towards the front end 3a of the launch tube 3.

[0070] The trigger pin 70 delimits an internal housing 75 having a closed rear end 75a and an open front end 75b opening at the annular end 70c. This internal housing 75 extends axially along the longitudinal axis A1. The internal housing 75 is delimited by a first cylindrical wall 750, a second cylindrical wall 751 and a conical ramp having an inclined wall 752. The first cylindrical wall 750 extends between the rear end 75a and the converging end of the ramp. The second cylindrical wall 751 extends between the diverging end of the ramp and the front end 75b. Thus, the diameter of the second cylindrical wall 751 is greater than the diameter of the first cylindrical wall 750.

[0071] The automatic repositioning mechanism 8 is received in an internal housing 75. This mechanism 8 comprises a guide 80, a flexible spring 81, a guide ring 82, a hard spring 83, a hammer 84 and a spring stop 85.

[0072] The guide 80 is intended to cooperate with the ejection element 50, in particular with the central projection 56a of the ejection element 50, before ejection. Thus, the ejection element 50, before its ejection and during its repositioning in the armed position, cooperates with the mechanism 8 housed in the pin 70 via the guide 80, but does not cooperate directly with the pin 70. The guide 80 comprises a cylindrical head 80a, a cylindrical projection 80b and a cylindrical rod 80c, in one piece. The head 80a is a hollow cylindrical head mounted to slide axially in the second cylindrical wall 751 and has an outside diameter substantially equal to the diameter of the second cylindrical wall 751.The projection 80b extends from the face of the head 80a directed towards the front end 75b, centrally, along the longitudinal axis AL. In the armed position, the free end of the projection 80b is at the open end 75b, and after ejection, the projection 80b projects out of the internal housing 75. The rod 80c extends axially inside the second cylindrical wall 751, along the longitudinal axis Al, from the face of the head 80a opposite the projection 80b. The rod 80c is received, in a sliding manner, through a through orifice 820 made in the guide ring 82. The guide ring 82 is a cylindrical ring having an outside diameter substantially equal to the diameter of the second cylindrical wall 751. The guide ring 82 is slidably mounted along this second wall 751.

[0073] The flexible spring 81 is mounted around the rod 80c and is connected on the one hand to the ring guide 82 and on the other hand to the guide 80, the end of the flexible spring 81 integral with the guide 80 being received in the head 80a of the guide 80. This flexible spring 81 is a compression spring of stiffness less than the stiffness of the return spring 74 urging the pin 70 into the rest position. This flexible spring 81 is intended to urge the guide 80 opposite the guide ring 82.

[0074] The spring stop 85 is also a cylindrical body crossed by a central cylindrical passage 850 and provided with a magnet 851. This passage 850 is dimensioned to be able to receive the rod 80c of the guide 80 in a sliding manner. The external diameter of the spring stop 85 is less than the diameter of the second cylindrical wall 751 and greater than the diameter of the converging end of the inclined wall 752. Thus, the spring stop 85 is able to move both at the level of the second wall 751 and at the level of the inclined wall 752. When the spring stop 85 is in contact with the inclined wall 752, the inclined wall 752 brings the spring stop 85 into the centered position, the magnet 851 no longer being in contact with the wall of the internal housing 75.The magnet 851 is arranged such that when the spring stop 85 is at the level of the second cylindrical wall 751 it comes into contact, by its section comprising the magnet 851, with the second wall 751, its through passage 850 then being offset relative to the longitudinal axis A1 and therefore relative to the axis of the rod 80c. The spring stop 85 is interposed between the guide ring 82 and the hammer 84.

[0075] The hammer 84 is a cylindrical body with an external diameter equal to the diameter of the first cylindrical wall 750. Thus, the hammer 84 is mounted to slide along the first wall 750 and is capable of extending beyond the first wall 750.

[0076] The hard spring 83 is mounted between the closed end 75a of the internal housing 75 and the hammer 84. The diameter of the hard spring 83 is substantially equal to the diameter of the first cylindrical wall 750 and therefore to the diameter of the hammer 84. This hard spring 83 is a compression spring of stiffness greater than the stiffness of the return spring 74 urging the pin 70 into the rest position. This hard spring 83 is intended to urge the assembly comprising the hammer 84, the spring stop 85 and the guide ring 82 opposite the closed end 75a, in other words to urge the spring stop 85 towards its eccentric position.

[0077] This mechanism 8 further comprises two annular elements 86a, 86b of the circlip type arranged in the internal housing 75 and intended to serve as a stop limiting the movement of the different elements of the mechanism 8. The circlips 86a, 86b extend orthogonally to the longitudinal axis A1 and have a central opening with an axis coaxial with the longitudinal axis A1. The front circlip 86b is integral with the pin 70 at the level of the open annular end 70c and its opening is sized to be able to be crossed by the projection 80b of the guide 80. The rear circlip 86a is integral with the pin 70 at the level of the second wall 751 of the internal housing 75 and its opening is sized to be crossed by the rod 80c of the guide 80. The rear circlip 86a is arranged such that when the hard spring 83 is relaxed, the guide ring 82 comes to bear against the rear circlip 86a.

[0078] Referring again to [Fig. 1], it can be seen that the device 1 further comprises a launching shoe 9 intended to receive the drone 2.

[0079] The launch shoe 9 is sized and configured to be received in the launch chamber 34 in order to allow the drone 2 to be guided in the launch tube 3 during the launch phase, and to surround the drone 2 in order to allow the drone 2 to be protected during launch. It should be emphasized that a different shoe 9 is defined according to the profile of the drone 2 and its payload 21.

[0080] This shoe 9 defines a space for receiving the drone 2 having an opening intended to be located opposite the front end 3a of the launch tube 3, as well as a space for receiving the ejection means 4, having an opening intended to allow the passage of the ejection means 4 when the shoe 9 is introduced into the launch chamber 34.

[0081] The launching device 1 according to the present invention allows the launching of drones 2 in an easy, rapid, reliable, and secure manner, the launching method comprising a pre-launch phase, a launch phase and a post-launch phase.

[0082] During the pre-launch phase (Figures 1 and 2), the launch shoe 9, in the receiving space of which the drone 2 is received, is first introduced through the open front end 3a of the launch tube 3, until it comes into contact with the seat 35, then the front end 3a of the launch tube 3 is closed by the sealed cap 30.

[0083] During this phase, the ejection means 4 are placed in the receiving space of the ejection means of the sabot 9. In particular, the ejection assembly 5 is in the armed position, the ejection spring 51 being compressed and the trigger pin 70 placing and retaining the retaining elements 60 in the locking position.

[0084] When one wishes to launch the drone 2, during the launch phase, it is sufficient to pass an electric current towards the electromagnet 71. The magnetic field created by the electromagnet 71 will then force the trigger pin 70 to move towards the electromagnet 71, until the shoulder 70d of the trigger pin 70 comes to bear against the stop surface 711 of the electromagnet 71. For this, the magnetic force generated in the pin 70 must be greater than the force of the return spring 74. At the end of this sliding movement, the external groove 702 of the trigger pin 70 comes opposite the retaining elements 60 and causes them to move in translation towards the inside of the inner hollow cylinder 37i. until they are engaged in the external groove 702 and therefore disengaged from the internal groove 550 of the holding body 55. Once the retaining elements 60 are disengaged from the holding body 55, therefore retracted into the unlocked position, the holding body 55 is released and the ejection piston 52 is free to slide and no longer holds the ejection spring 51 in the compressed state. The ejection spring 51 is therefore released instantly and its relaxation causes the ejection piston 52 to suddenly slide towards the front end 3a of the launch tube 3 ([Fig. 3]). In this position, the thrust head 54 applies a thrust force against the sabot 9, thus ejecting the sabot 9 and the drone 2 it contains out of the launch tube 3. Once at its apogee, the drone 2 starts, stabilizes and its mission can begin.

[0085] After the ejection of the sabot 9 and the drone 2, the electromagnet 71 is deactivated and therefore the balls 60 and the trigger pin 70 are no longer subjected to a magnetic field. The detent pin 70 is then returned to the rest position by the spring 74, which pushes the balls 60 towards their locking position in the path of the holding body 55. With the pin 70 in its rest position, the balls 60 are stopped against the wall 701 of the pin 70 of the same diameter as the internal diameter of the inner hollow cylinder 37i and are therefore prevented from retracting into the path of the pin 70. In other words, when the balls 60 are in the locking position and the pin 70 is in the rest position, the balls 60 are securely retained in the locking position by the pin 70. As can be seen in [Fig. 5], in this rest position, the spring 74, the soft spring 81 and the hard spring 83 are in the relaxed state.The guide 80 comes into abutment against the front circlip 86b under the action of the flexible spring 81. Similarly, under the action of the hard spring 83, the hammer 84, the spring stop 85 and the guide ring 82 are pushed forward and come into abutment against the rear circlip 86a. The spring stop 85 is therefore in the eccentric position in contact with the wall of the internal housing 75 of the pin 70, under the action of the magnet 851. The trigger pin 70 is retained by its axial stop 73. In this position, the ejection means 4 are ready to be reloaded, in other words to be replaced in their armed and locked position.

[0086] During the post-launch phase, it is appropriate to prepare the launch device 1 for the launch of another drone 2, in other words, to reposition the ejection assembly 5 in its armed position, during which the ejection spring 51 is compressed again.

[0087] This phase is implemented by any suitable tool (not shown), distinct from the device 1, capable of being introduced into the launch chamber 34, after the launch step, which tool is capable of coming to bear against the ejection element 50 in order to move it towards the rear end 3b of the launch tube 3 so as to compress the ejector spring 51 and return the ejector assembly 5 to the armed position.

[0088] In practice, during the post-launch phase, the tool is positioned in the launch tube 3. The ejection element 50 is then gradually displaced in translation, in the direction of the rear end 3b of the launch tube 3, thus gradually compressing the ejection spring 51. During this translational displacement, the ejection element 50 exerts a pushing force F on the guide 80, which pushing force F is applied along the longitudinal axis Al, thus along the translation axis of the ejection element 50, the guide 80 and the mandrel 70.

[0089] As can be seen in Figures 6 and 7, during the translational movement of the ejection element 50, the central projection 56a of the ejection element 50 comes to bear against the projection 80b of the guide 80. The spring stop 85 being in the eccentric position, the rod 80c of the guide 80 cannot pass through the spring stop 85. As a result, the flexible spring 81 is not compressed under the effect of this thrust force F on the guide 80 in the direction of the rear end 3b. It is therefore the return spring 74, of stiffness lower than that of the hard spring 83, which will be compressed. The compression of this spring 74 causes the trigger pin 70 to move in translation towards the electromagnet 71, until the shoulder 70d of the pin 70 comes to bear against the stop surface 711 of the electromagnet 71, the pin 70 then being placed in the trigger position.In this relaxed position, the balls 60 are located opposite the external groove 702 and are caused, by the translation of the holding body 55, to enter the external groove 702 of the pin 70. Indeed, when the pin 70 is in the relaxed position and the electromagnet 71 is deactivated, the balls are allowed to move towards their unlocked position by a pushing action exerted by the holding body 55 on the balls 60. The balls 60 are then in the unlocked position, in which they do not come out into the path of the holding body 55 and no longer hinder its translational movement towards the rear. Thus, during this phase, the automatic repositioning mechanism 8 allows the ejection element 50 to move in translation towards the armed position of the ejection assembly 5, despite the presence of the spring 74 for returning the pin 70 towards the rest position.

[0090] Then, as can be seen in [Fig.8], once the internal groove 550 of the holding body 55 is opposite the balls 60, the continuation of the thrust force F applied by the ejection element 50 on the guide 80 causes the hard spring 83 to compress. Due to the thrust force F on the guide 80 towards the rear end 3b, the guide 80 pushes the guide ring 82, the spring stop 85 and the hammer 84 towards the rear end 3b. During this translational movement, the spring stop 85 comes to bear against the inclined wall 752, which leads to the centering of the spring stop 85 in the axis of the rod 80c. Once the spring stop 85 is in position centered, the rod 80c of the guide 80 can pass through the passage 850 of the spring stop 85 under the effect of the relaxation of the hard spring 83. In turn, the return spring 74 of the pin 70, which was compressed, relaxes until the pin 70 occupies the rest position. In this rest position, the pin 70 is retained axially by the axial stop 73 which abuts against the electromagnet 71. The flexible spring 81 is compressed. The guide ring 82, the spring stop 85 and the hammer 84 come to bear against the rear circlip 86a. During this passage of the pin 70 into the rest position, the balls 60 are pushed by the pin 70 towards their locking position, until the balls 60 engage in the internal groove 550 of the holding body 55, then preventing the ejection element 50 from being ejected.Thus, the automatic repositioning mechanism 8 allows automatic locking of the ejection element 50 as soon as the armed position is reached. Safety is therefore maximum during reloading.

[0091] As can be seen in [Fig.2], at the end of this step, the ejection assembly 5 is in its armed and locked position, with the ejection spring 51 placed in its compressed state, ready for a new launch phase. The tool used for recharging is then removed from the launch tube 3 and a new sabot 9 can then be positioned in the launch chamber 34, and the previous phases repeated for the launch of this drone 2 and other drones.

[0092] It is understood that the particular embodiment which has just been described has been given for informational purposes and is not limiting, and that modifications may be made without departing from the scope of the present invention.

Claims

Claims

1. Device (1) for launching a drone (2) by spring thrust, device (1) comprising a longitudinal launching tube (3) having a first end (3b), rear, which is closed and a second end (3a), front, which is open, and the interior of which defines a launching chamber (34) intended to receive a drone (2), and means (4) for ejecting the drone (2) from the launching tube (3) which comprise: - an ejection assembly (5) comprising an ejection element (50), mounted to slide longitudinally in the launch chamber (34) and intended to push the drone (2) to eject it from the launch tube (3), and a compression spring, called an ejection spring (51), having a longitudinal axis coaxial with the longitudinal axis (Al) of the launch tube (3) and a first end of which bears on the rear end (3b) of the launch tube (3) and a second end of which bears against the ejection element (50), the ejection assembly (5) being able to be placed in an armed position, in which the ejection spring (51) is compressed by the ejection element (50), - locking means (6) for releasably locking the ejection assembly (5) in the armed position, the locking means (6) comprising at least one retaining element (60) connected to the launch tube (3) and movable between a locking position, in which the at least one retaining element (60) is engaged with the ejection element (50) so as to maintain the ejection assembly (5) in the armed position, against the action of the ejection spring (51), and an unlocking position, in which the at least one retaining element (60) is disengaged from the ejection element (50), and - control means (7) for controlling the unlocking of the ejection assembly (5), by moving the at least one retaining element (60) from the locking position to the unlocking position, characterized in that the control means (7) comprise: - an expansion housing (37) located at the rear of the launch tube (3) and containing an electromagnet (71) capable of being connected to a source of electricity (72), - at least one relaxation element (70) which is movable in the relaxation housing (37), under the action of a magnetic field

2. magnetic created by the activation of the electromagnet (71), from a rest position, in which the at least one trigger element (70) retains the at least one retaining element (60) in the locking position, to a trigger position, in which the at least one trigger element (70) has moved the at least one retaining element (60) from the locking position to the unlocking position, and - means (74) for returning the at least one trigger element (70) to the rest position after deactivation of the electromagnet (71), and by the fact that the ejection means (4) further comprise an automatic repositioning mechanism (8) coupled to the at least one trigger element (70) and arranged to move the at least one trigger element (70) between the rest and the trigger positions, in the absence of activation of the electromagnet (71), under the effect of a movement of the ejection element (50) to its armed position, the automatic repositioning mechanism (8) authorizing a movement of the at least one trigger element (70) from the rest position to the trigger position, against the return means (74), before the placement of the ejection element (50) in the armed position and authorizing a movement of the at least one trigger element (70) from the trigger position to the rest position, under the effect of the return means (74), once the ejection element (50) placed in armed position. Device (1) according to claim 1, characterized in that the expansion housing (37) is in the form of an outer hollow cylinder (37e) which is integral with the launch tube (3) and an inner hollow cylinder (37i) integral with the outer hollow cylinder (37e) and of smaller diameter than that of the outer hollow cylinder (37e) so that a tubular space (36) is formed between them, the outer (37e) and inner (37i) hollow cylinders having coaxial longitudinal axes, the electromagnet (71) being of hollow cylindrical shape and being arranged between a first axial, rear side of the outer hollow cylinder (37e) and a first axial, rear side of the inner hollow cylinder (37i) with its longitudinal axis coaxial with that of the outer (37e) and inner (37i) hollow cylinders, and the expansion element (70) is a expansion pin (70) made of a ferromagnetic material mounted in the inner hollow cylinder (37i) and in the electromagnet (71) slidably along the longitudinal axis of the expansion housing (37).

3. Device (1) according to claim 2, characterized in that the trigger housing (37) is surrounded by the ejection spring (51), the or each retaining element (60) is made of a ferromagnetic material and is received in a through opening (38) provided in the inner hollow cylinder (37i) and with an axis perpendicular to the longitudinal axis of the trigger housing (37), and the ejection element (50) comprises a thrust head (54) which is perpendicular to the longitudinal axis (A1) of the launch tube (3) and against which the second end of the ejection spring (51) presses, and at least one holding member (55) which is integral with the thrust head (54) and extends into the tubular space (36), in the locking position, the at least one retaining element (60) protruding into the tubular space (36) and being configured to hold the assembly ejection (5) in the armed position by gripping the at least one holding member (55),and in the unlocked position, the at least one retaining element (60) protruding into the inner hollow cylinder (37i) and being configured to contact the trigger pin (70) in the path of the trigger pin (70).,

4. Device (1) according to claim 3, characterized in that the trigger pin (70) comprises at least one external groove (702) arranged so as to be located opposite the at least one through opening (38) of the inner hollow cylinder (37i) only in the triggered position and configured to receive the part of the at least one retaining element (60) projecting into the inner hollow cylinder (37i) in the unlocked position, and in that the at least one holding member (55) comprises at least one internal groove (550) arranged so as to be located opposite the at least one through opening (38) of the inner hollow cylinder (37i) only in the armed position and configured to receive the part of the at least one retaining element (60) projecting into the tubular space (36) in the locked position.

5. Device (1) according to any one of claims 3 and 4, characterized in that the at least one retaining element (60) is in the form of a ball and movable between the locking position and the unlocking position by translation along the associated through opening.

6. Device (1) according to any one of claims 2 to 5, ca-

7.

8. characterized by the fact that the movement stroke of the trigger pin (70) between the rest and release positions is limited on the one hand, by an axial stop (73) integral with a first axial side (70a) of the trigger pin (70) and capable of coming to bear against a first axial side, rear, of the electromagnet (71) in the rest position, and on the other hand, by a shoulder (70d) formed on the trigger pin (70) and capable of coming to bear against a second axial side, front, of the electromagnet (71) in the release position, the means (74) for returning the trigger pin (70) to the rest position being elastic return means, such as a compression spring (74), bearing on the second axial side, front, of the inner hollow cylinder (37i) and pressing against a second axial side (70b) of the trigger pin (70). Device (1) according to any one of claims 2 to 6, characterized in that the automatic repositioning mechanism (8) is received in an internal housing (75) of the trigger pin (70) and comprises a guide (80) mounted axially movable in the internal housing (75), along the longitudinal axis of the trigger housing (37), and configured to cooperate with the ejection element (50), a so-called soft spring (81) mounted between and bearing against the guide (80) and a guide ring (82) which is crossed by the guide (80) and slidably mounted in the internal housing (75), a so-called hard spring (83) mounted between the trigger pin (70) and a hammer (84) itself slidably mounted in the internal housing (75), the soft springs (81) and hard springs (83) being compression springs concentric and coaxial with the longitudinal axis of the trigger housing (37), and a spring stop (85) interposed between the hammer (84) and the guide ring (82) and coming into contact with them,the spring stop (85) being movable between an eccentric position relative to the longitudinal axis of the internal housing (37), in which the guide (80) is not allowed to move axially against the flexible spring (81), and a centered position, in which the guide (80) is able to move against the flexible spring (81), the return means (74) being configured such that the force to be applied to oppose the action of the return means (74) is less than the compression force to be applied to elastically deform the hard spring (83) and greater than the compression force to be applied to elastically deform the flexible spring (81)., Device (1) according to claim 7, characterized in that the internal housing (75) comprises two cylindrical walls (750, 751)

9.

10. connected to each other by a ramp having an inclined wall (752) converging in the direction of the hard spring (83) and arranged to cooperate with the spring stop (85) when the hard spring (83) is compressed so as to place the spring stop (85) in its centered position, the spring stop (85) being in the form of a hollow cylinder whose external diameter is less than the internal diameter of the cylindrical wall (751) on the diverging side of the ramp and whose internal diameter allows the passage of the guide (80) through the spring stop (85) in the centered position, the spring stop (85) comprising a magnet (851) urging the spring stop (85) into contact with the cylindrical wall (751) of the internal housing (75) when the spring stop (85) is at the level of the cylindrical wall (751), so as to place the spring stop (85) in the eccentric position. Device (1) according to any one of claims 7 and 8, characterized in that it comprises two annular elements (86a, 86b) for limiting the axial displacement of the guide (80) in the internal housing (75), the two annular elements (86a, 86b) being integral with the wall of the internal housing (75) and arranged in such a way that when the hard (83) and soft (81) springs are relaxed the guide (80) comes into abutment against the so-called front annular element (86b) capable of being crossed by a part (56a) of the ejection element (50) coming into abutment against the guide (80) in the armed position, and that when the soft spring (81) is compressed the guide (80) comes into abutment against the so-called rear annular element (86a), face side directed towards the front annular element (86b), the guide ring (82) coming into abutment against the face of the rear annular element (86a) opposite the face directed towards the front annular element (86b) when the hard spring (83) is relaxed. Method for launching drones (2) using a spring-loaded launch device (1) as defined in any one of claims 1 to 9, characterized in that it comprises the following successive steps: - a positioning step, comprising positioning a drone (2) in the launch chamber (34), the ejection assembly (5) being locked in the armed position; - a step of launching the drone (2), comprising activating the electromagnet (71) to move the trigger element (70) from the rest position to the trigger position, whereby the ejection assembly (5) is unlocked and ejects the drone (2) from the tube of launch (3); and - before repeating the positioning step, a repositioning step, comprising returning the ejection assembly (5) to the armed position, in which it is locked by the at least one retaining element (60).

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