EP3394558A1

EP3394558A1 - Reversible safety and arming system for an explosive device

Info

Publication number: EP3394558A1
Application number: EP16825801.0A
Authority: EP
Inventors: Ghislain CORDEIRO GOMES; Guillaume LE CONTE
Original assignee: Nexter Munitions SA
Current assignee: Nexter Munitions SA
Priority date: 2015-12-22
Filing date: 2016-11-25
Publication date: 2018-10-31
Anticipated expiration: 2036-11-25
Also published as: EP3394558B1; FR3045812B1; FR3045812A1; WO2017109313A1

Abstract

The invention relates to a reversible safety and arming system (8) for an explosive device (1), said system comprising a flap (7) for interrupting a pyrotechnic chain which is mounted rotatably relative to an axis and which can be rotated by a motor means (11) between a safety position and at least one armed position. Said system is characterised in that the flap (7) is coupled by at least one pinion (13) to a mechanical chronometric module (14), the transition of the flap (7) from the safety position thereof to the armed position thereof thus causing the winding of the chronometric module (14) by the loading of a spring of said chronometric module, a means for releasing (17) the motor means (11) being provided and allowing the flap (7), once it has entered the armed position, to return to the safety position in a timed manner by the action of the chronometric module (14).

Description

The technical field of the invention is that of the safety and arming devices for an explosive device, and in particular for anti-tank explosive devices posed manually. BACKGROUND OF THE INVENTION

Hand-held explosive devices must meet many very stringent standards to ensure the security of operational implementation.

Indeed, to be able to pass from a security state to an armed state, hand-held ammunition can not use the environmental conditions (speed and acceleration) of a munition fired by a weapon.

To avoid pollution of land areas by unexploded ordnance, it is also necessary to be able to guarantee a return to a state of security of the munition in the event of failure of the electronic control means.

Patent FR2679325 discloses a safety and arming device comprising a bistable arming flap driven by a stepping motor. Thus, in the event of a failure of the cocking motor, the flap returns to its safety position or switches to the armed position, the two positions of the flap being stable equilibrium positions.

This device however has an insufficient level of security since a failure occurring beyond the unstable position of the flap will cause a passage in armed position despite the failure. It is no longer possible to neutralize the explosive device without manual intervention on the arming button.

It is the object of the invention to provide a device for safety and arming for explosive devices that is reversible, so that it can be brought back into a position of security for later reuse, and the implementation of which is completely safe.

Thus the device according to the invention automatically returns to the safety position at the end of a time interval provided for the design, and this regardless of the failures of the control electronics or energy sources.

Thus, the subject of the invention is a safety and reversible arming device for an explosive device intended to be placed manually, a device comprising a pyrotechnic chain interruption flap which is rotatably mounted with respect to an axis and which can be driven. in rotation by a motor means between a safety position and at least one armed position, characterized in that the flap is coupled by at least one pinion to a mechanical chronometric module, the passage of the flap from its safety position to its position thus causing, by the action of the pinion on a winding pinion of the chronometric module, the winding of the latter by the tire of a spring of this chronometric module, a disengaging means of the motor means being provided and allowing, after the passage in the armed position of the shutter, the return of the shutter in the safety position and in a delayed manner by the action of only the time module acting on the pinion and leading to a rotation of the flap in the opposite direction to that leading to the armament.

Advantageously, the flap will be integral with a coaxial shaft which can be connected to a motor pinion by the disengaging means.

According to one embodiment, the disengaging means may comprise an indexing rotor which will be integral with the shaft carrying the flap and which will comprise at least two cylindrical housings, with axes parallel to the axis of the shaft, and receiving each a sliding rod against the action of a spring, each rod having a first end which is held by the rod spring bearing against a fixed cam profile, and a second end which can exit the rotor pushed by the cam profile to cooperate with an indexing pin mounted thereto. even sliding in a cap which is integral with the drive pinion, indexing pin which will be pushed by a spring towards the rotor and which can engage in one of the cylindrical housing of the rotor to ensure a rotational connection of the drive pinion and the indexer rotor .

The shutter can be integral in rotation with the pinion which is coaxial with it (pinion gear) and which meshes with a winding pinion of the chronometric module.

The device may comprise an electro-pyrotechnic module comprising an electronic firing control means and a pyrotechnic component intended to initiate an explosive charge of a military head of the explosive device, the chain interruption flap comprising a partially circular light which is opposite the pyrotechnic component when the flap is in an armed position, the pyrotechnic component being opposite a solid part of the flap, therefore outside the light, when the flap is in a safety position .

The light of the shutter can be carried by the pinion indicator which will form the solid part of the shutter.

The shutter can be positioned at any time in a safety position by a control of the motor means rotating the shutter in the same direction as that which led to the armed position.

The indicator gear may include a portion free of teeth, so that the passage of the flap from the armed position to the safety position will be done without acting on the chronometry module. According to one embodiment, the flap can be positioned at any time at a sterilization position by a control of the motor means rotating the flap in the same direction as that which led to the armed position, the motor means being stopped at the level of an intermediate zone in which the pyrotechnic component is no longer facing the light, the electronic firing control means then causing the ignition of the component facing a massive zone of the flap.

According to a particular embodiment, the motor means may comprise a geared motor driving the motor pinion by a worm.

The invention will be better understood on reading the following description given with reference to the appended drawings and in which:

FIG. 1 is a simplified diagram of an explosive device equipped with a security and arming device according to the invention;

FIGS. 2a and 2b are perspective views of the safety and arming device according to

The invention;

- Figures 3 and 4 are two sectional views showing the motor pinion and the disengaging means, Figure 3 showing this assembly in the disengaged position and Figure 4 showing it in the engaged position;

- Figure 5 is a perspective view of the indexing rotor fixed on the shaft carrying the shutter;

- Figure 6 is a perspective view of the bell cam alone;

FIGS. 7a, 7b and 7c show, in a simplified way, the safety and arming device so as to display the relative positions of the chain interruption flap, the motor means, the driving pinion and its disengaging means, sprocket reassembly of the chronometric module and the pyrotechnic initiation component, FIG. 7b being a side view and FIGS. 7a and 7c of frontal views of each side of the device, the device being represented in the safety position;

- Figures 8a, 8b and 8c are similar views showing the device being armed;

- Figures 9a, 9b and 9c are similar views showing the device in the armed position;

FIG. 10 is a view similar to FIG. 9c and showing the beginning of a voluntary disarming phase;

FIGS. 11a, 11b and 11c are views similar to the preceding ones showing the device in the intermediate phase of voluntary disarmament;

FIGS. 12a, 12b and 12c are views similar to the preceding ones showing the device during the continuation of the voluntary disarming phase;

- Figures 13a, 13b and 13c are views similar to the previous showing the device at the end of voluntary disarmament, the device has returned to a security position identical to that of Figures 7a, 7b and 7c;

FIGS. 14a, 14b and 14c are views similar to the previous ones showing the device during an intermediate phase of the automatic disarming process (or "fail safe");

FIGS. 15a, 15b and 15c are views similar to the preceding ones showing the device at the end of the automatic disarming process, the device has returned to a security position identical to that of FIGS. 7a, 7b and 7c; - Figures 16a, 16b and 16c are views similar to the previous showing the device in the sterilization position. Referring to FIG. 1, an explosive device 1 comprises an explosive military head 2, here of shaped charge type having a conical coating 3. Such a military head 2 has an anti-tank effect. The coating could be concave so that it can form a core. Such type of anti-tank warhead is well known to those skilled in the art and described for example by the patent FR2793314. The explosive military head 2 comprises an explosive charge which can be initiated by a detonation relay 4 which is itself initiated by a pyrotechnic component 5 integral with an electro-pyrotechnic module 6 which, in addition to the pyrotechnic component 5, also comprises a electronic means for controlling the firing.

The pyrotechnic component 5 will for example be a "slapper" type component, that is to say plasma projecting a thin plastic plate on an explosive material. These components make it possible to generate a detonation wave without using a primary explosive. They therefore authorize an installation of the pyrotechnic initiation component 5 directly opposite the pyrotechnic relay 4 to be initiated (no misalignment of the pyrotechnic chain). A simple interruption of the pyrotechnic chain C by a flap 7 is then sufficient to ensure safety.

The safety and arming device 8 according to the invention thus comprises the electro-pyrotechnic module 6 and it also comprises the pyrotechnic chain interruption flap 7 which is rotatably mounted with respect to an axis 9 which is parallel to the Axis 10 of the Explosive Military Head 2. The flap 7 may be rotated by a motor means 11 between a safety position in which the flap 7 interrupts the pyrotechnic chain and at least one armed position in which the flap no longer interrupts the pyrotechnic chain. Specifically, the flap 7 will include a light 12 (see for example Figure 7a) which is partially circular and which is opposite the pyrotechnic component 5 when the flap 7 is in an armed position. The pyrotechnic component 5 can then initiate the relay 4 through the light 12.

When the rotary shutter 7 is in a safety position, the pyrotechnic component 5 is opposite a solid part of the shutter 7, thus outside the light 12. The effect of its initiation is stopped by the shutter 7 and Relay 4 can not be initiated.

Specifically here the flap 7 comprises a portion forming a cocking state indicator and which is made of light sheet or plastic and a more massive part, for example steel, forming a pinion 13 (called thereafter pinion gear ).

As seen in FIG. 7c, the flap 7 thus has an opening 24 on its face disposed on the side of the motor means 11. This opening 24 is in the form of a half-crown defined by two arcs and extending over an angular sector of 180 °. The opening 24 is in correspondence with the light 12 which is carried more precisely by the pinion indicator 13 which is fixed on the other face of the flap 7, arranged on the side of a chronometric module 14. Thus the pyrotechnic effect from the pyrotechnic component 5 will pass through the flap 7 through the opening 24 and the light 12.

The flap 7 is coupled by at least one pinion, here the indicator pinion 13, to the mechanical chronometric module 14.

Such a mechanical chronometric module is well known to those skilled in the art and therefore it is not necessary to describe in detail. It comprises a clockwork mechanism combining sprockets, a spring, a balance and an escapement. FIGS. 7a to 16c show a pinion 15 of this chronometric module 14, a pinion subsequently called a winding pinion 15 of the timekeeping module 14. The pinion gear 13 which is integral in rotation with the shutter 7 meshes with the winding pinion 15. It thus makes it possible to band a spring of the chronometric module 14 during the passage of the flap 7 from its safety position to its armed position.

The chronometry module 14, which is without energy during the storage phases of the explosive device 1, can thus be energized by the simple arming movement of the flap 7. It can then operate to gradually bring the flap 7 into position security as will be described later.

The flap 7 can be rotated by the motor means 11 to arm the machine 1.

The motor means 11 (which is better visible in Figures 2a and 2b) comprises a geared motor 11a which drives a worm 11b. The worm 11b is engaged in a driving pinion 16. A disengaging means 17 makes it possible to connect or not the driving pinion 16 with the flap 7.

If we consider Figures 2a and 2b, we see that structurally the device comprises two plates 18a and 18b parallel to each other and forming a stirrup. The plate 18a (or upper plate) carries the motor means 11 and the electro-pyrotechnic module 6.

The plate 18b (or lower platen) carries the chronometric module 14 which is fixed on its outer face. The two plates 18a and 18b are connected to one another by spacers 19. One of the spacers 19 'through the winding pinion 15 of the chronometry which comprises a light 49. This spacer acts as a stop for the module The extreme positions ("up" and "not reassembled") of the chronometric module 14 are thus well defined.

The winding pinion 15 is disposed between the two plates 18a and 18b and is integral with an axis (not shown) of the chronometric module 14.

The flap 7 is pivotally mounted between the two plates 18a and 18b. For this it is secured to a shaft 20 which is coaxial with the axis 9 of rotation of the flap and which is pivotally mounted in plain bearings arranged in each plate 18a and 18b.

FIG. 2b shows that the bottom plate 18b has a circular opening 21 which is positioned coaxially with the axis 10 of the explosive military head 2. This opening is intended to allow the pyrotechnic effect coming from the pyrotechnic component 5 to pass when the device 8 is in the armed position. The opening 21 has a diameter which is chosen to be large enough to allow the device 8 to be positioned relative to the warhead 2 by means of centering means (not shown). This positioning makes it possible to ensure coaxiality between the axis 10 of the warhead 2 and the pyrotechnic component 5.

The electro-pyrotechnic module 6 is connected by electrical connections to a control block 22 (FIG. 1) which encloses a source of electrical energy, a communication module with a remote control station, software means associated with a computer ( means not shown).

A detection means 23 may be associated with the explosive device 1. This detection means will be connected to the control block 22. It is the control block 22 which contains all the operating logic of the explosive device 1 and which allows to control the arming of the explosive device 1 so remotely controlled by an operator located at a distance. The arming will be done by the command, by the block 22, of the motor means 11.

Once the security and arming device 8 in the armed position, the explosive device will be initiated for example as a result of the detection, with the detection means 23, a target of a given type (armored vehicle for example ). The moment of ignition of the pyrotechnic component 5 will be determined by the control block 22.

The remote operator may at any time control, via the control block 22, the disarming or sterilization of the device 8.

The components of the control block are essentially batteries, a computer and communication means, for example wireless (means not shown).

These means are not the subject of the present invention and it is therefore not necessary to describe them in detail.

As has been mentioned above, it can be seen in FIG. 7c that the flap 7 has an opening 24 on its face disposed on the side of the motor means 11. This opening 24 is in the form of a half crown delimited by two arcs and extending on an angular sector of 180 °. The opening 24 is in correspondence with the light 12 which is carried more precisely by the pinion indicator 13 which is fixed on the face of the flap 7 disposed on the side of the chronometric module 14. Thus the pyrotechnic effect from the pyrotechnic component 5 will pass through the flap 7 through the opening 24 and the light 12.

Figures 3 and 4 show more precisely the structure of the disengaging means 17.

The disengaging means 17 comprises a rotor 25 (hereinafter referred to as an indexing rotor) which is integral with the shaft 20 carrying the flap 7. The fastening of the rotor 25 and the shaft 20, both in rotation and in translation, is provided by a pin 26 (see FIGS. 3, 4 and 5):

As can be seen in FIGS. 3 to 5, the rotor 25 comprises two cylindrical housings 30a and 30b, with axes parallel to the axis of the shaft 20. Each housing 30a, 30b receives a rod or ejector (respectively 31a and 31b) which is sliding in its housing against the action of a spring 32a, 32b.

Each spring 32a, 32b is supported on one side against a countersink of the rotor 25 and the other against a shoulder of the rod.

Each rod has a first end 33a, 33b which is rounded (half-spherical). Each rod is held by the rod spring 32a, 32b bearing against a bell cam 34 which is fixed to the upper plate 18a.

Annular closure plugs 27a, 27b are screwed and seal the housings 30a and 30b at the lower face of the rotor 25 adjacent to the cam 34. These plugs 27a, 27b also allow the guide rods 31a, 31b.

Each rod has a second end 35a, 35b which can exit the rotor 25 when the rod considered is pushed by the profile of the bell cam 34.

Thus, in FIG. 3 the rod 31b has its second end 35b which is slightly above an upper face 36 of the rotor 25.

The disengaging means 17 also comprises a cap 37 which is integral with the motor pinion 16. The fastening of the cap 37 and the motor pinion 16 is provided by a pin 38 and a bonding. The axial positioning of the cap assembly 37 / motor pinion 16 relative to the shaft 20 is provided by the motor means 11 whose worm 11b positions the motor pinion 16. An elastic ring 48 it also axially positions the cap 37 with respect to the rotor 25.

The cap 37 carries a hole 39 in which slides an indexing pin 40 which is pushed by a spring 41 in the direction of the rotor 25. A plug 42 screwed into the cap 37 gives an axial stop to the spring 41. The hole 39 further comprises a internal counterbore which constitutes an axial abutment for the pin 40 which comprises a shoulder.

The end of the pin 40 is rounded. The pin 40 can engage in one of the cylindrical housings 30a, 30b of the rotor 25 to ensure a rotational connection of the motor pinion 16 and the indexing rotor 25, thus the driving pinion 16 and the shaft 20 carrying the flap 7.

Thus, when the pin 40 is facing the upper face 36 of the rotor 25, the motor means 11 drives the motor pinion 16 without driving the flap 7. When, after a certain angular pivoting, the pin 40 is engaged in one of the cylindrical housings 30a, 30b of the rotor 25. The rotor 25 is then rotatably connected to the motor pinion 16, and the motor means 11 drives the indexing rotor 25 and the flap 7.

When, as in FIG. 3, the rounded end of the pin 40 is close to the upper face 36 of the rotor, this rounded shape of the pin 40 facilitates the exit of the pin 40 from the housing 30b and the disengagement of the rotor 25.

Note that the rods 31a and 31b follow at their first ends 33a, 33b the profile of the upper face of the bell cam 34.

FIG. 6 shows the shape of this bell cam 34 which is a massive annular piece surrounding the shaft 20 and whose upper face has a profile having: a projecting portion 43 which is followed by a fast slope 44 which opens onto a flat area 45 thin. A profile gently sloping 46 finally leads from the flat area 45 to the projecting portion 43.

The protruding part 43 corresponds to the declutching zone of the clutching means 17. When, as a result of the rotation of the flap 7, the rotor 25 positions one of its rods 31a or 31b opposite the protruding part 43, said rod is pushed towards the cap 37 and it ejects off the rotor 25 the pin 40 which was possibly engaged in the housing 30a or 30b. This results in a disengagement of the motor means 11 which, if it always drives the cap 37 in rotation, no longer causes the flap 7.

Conversely, when the disengaged motor rotates the cap 37 alone, the pin 40 ends at the end of a certain angular sector by being positioned in a housing 30a or 30b corresponding to the rod 31a or 31b whose first end 33a or 33b is located next to the flat zone 45 (neutral zone or bottom dead center). This causes a re ^¬ coupling of the cap 37 and the rotor 25, therefore the drive by the motor means 11 of shutter 7.

The gently sloping profile 46 allows a gradual transition from the flat zone 45 to the projecting portion 43, thus a progressive ejection of the pin 40 during the rotation of the flap 7.

Of course the relative angular positions of the housings 30a, 30b on the rotor 25 as well as the angular amplitudes of the parts 44, 45 and 46 of the cam 34 are chosen so as to disengage the motor means 11 and the re-clutch for the desired angular positions for the flap 7.

Concretely as seen in Figure 5 (front view), the angular sector from the axis of the housing 30a to the axis of the housing 30b is less than 180 ° (here it is 167 °). The operation of the device will now be described with reference to FIGS. 7a to 16c.

Figures 7a, 7b and 7c show the device in the safety position.

It is noted that the flap 7 comprises sectors having color marks for viewing from the outside of the explosive device 1 the state of the device 8. The visualization of the state is through windows 47 which are advantageously arranged in the housing of the machine 1 in at least three directions so as to facilitate a remote location of the armed state or not the machine.

The sector with double hatching in the figures (green in reality) means that the device is in a safety position.

The sector with hexagonal patterns in the figures (yellow in reality) means that the device is in the sterilization position (this will be specified with reference to Figures 16a, 16b and 16c).

The sector with simple hatching on the figures (red in reality) means that the device is in the armed position.

The various figures also show the location of the pyrotechnic component 5 as well as that of the indexing pin 40 with respect to the rotor 25.

It is useful to note that the bell cam 34 (not visible) is fixed relative to the upper plate 18a. The cam 34 does not rotate with the flap 7 and the rotor 25. Practically in all the figures showing the indexing pin 40, it will be noted that the projecting portion 43 of the bell cam 34 is positioned upwards, below the screw endless 11b, while the junction between the flat area 45 and the beginning of the slope 46 is opposite the worm. This means that, in the figures, when the pawn 40 is next to the worm 11b, it is out of the housing of the rotor 25 (disengaged rotor).

In the safety position of FIGS. 7a, 7b and 7c, the indexing pin 40 is thus outside the housing of the rotor 25. The motor / rotor link is disengaged.

Figures 8a, 8b and 8c show the device being armed. Initially the motor 11 was controlled by the control block 22. With the rotor 25 disengaged, the motor 11 rotates the cap 37 until the pin 40 is introduced into the housing 30a or 30b which is free. The motor pinion 16 is then coupled to the flap 7 and the flap, driven by the motor 11, rotates in the direction of the arrow A. It is noted in FIG. 8a that this pivoting causes the winding pinion 15 to rotate (direction of rotation). the arrow C1) which is driven by the pinion gear 13 secured to the flap 7.

The pyrotechnic component 5 begins to appear opposite the opening 24 and the light 12.

As soon as the component 5 appears, the single-hatched sector of the flap 7 begins to appear in the state display windows 47.

Figures 9a, 9b and 9c show the device in the armed position.

When the device is in this position, the electronic safety devices have also been raised at the control block 22 and the explosive device is operational. The computer of the control block has information relating to the angular position of the flap 7, a position given to it by a rotation sensor mounted at the end of the shaft 20 (not shown).

Note that in the armed position the single-hatched sector of the flap 7 occupies all the state viewing windows 47. Furthermore the pin 40 is ejected from the housing of the rotor 25 (rotor 25 disengaged). Note also that the complete pivoting of the flap 7 has led to position the pyrotechnic component 5 at the other end of the opening 24 and the light 12. The explosive device 1 is operational and it will remain so as the pyrotechnic component 5 will be next to the opening 24 and the light 12.

At any time the machine can be disarmed at the request of a user by a specific command addressed to the command block 22.

Figure 10 shows the beginning of a voluntary disarming phase (DV) controlled by an operator, for example using a remote control.

Figure 10 differs from Figure 9c only by the angular positioning of the cap 37. Indeed, the motor means 11 is actuated with a rotation in the same direction that led to the arming. The motor means rotates the cap 37. The pin 40 which was released from the rotor 25 moves angularly until it engages in another free housing of the rotor (FIG. 11c).

Figures 11a, 11b and 11c show the beginning of the pivoting movement of the flap 7 (arrow DV which has the same direction as the arrow A). It can be seen that the pyrotechnic component 5 leaves the opening 24 and the light 12 in order to gradually position itself facing a solid part of the flap 7 (that constituted by the indicator pinion 13).

Figures 12a, 12b and 12c show the continuation of the pivoting movement of the flap 7. Note that the indicator gear 13 has a portion 13a which is toothless and therefore no longer interferes with the winding pinion 15. Thus this movement of the flap 7 beyond the armed position is done without acting on the chronometry module 14, so without damaging it. As an alternative it would be possible to predict in the chronometry module a wheel for disengaging the winding pinion 15 during such a phase.

The winding pinion 15 being released, the chronometry module rotates (arrow C2) so as to relax its internal spring.

The pyrotechnic component 5 (located in FIG. 12c) is now in front of a solid part of the flap 7 and the double-hatched sector of the flap 7 is in the state display windows 47. The machine no longer presents any danger.

Figures 13a, 13b and 13c show the device at the end of voluntary disarmament. The device has returned to the safety position and these figures are identical to FIGS. 7a, 7b and 7c respectively.

Note that, in case of voluntary disarmament (DV), from the beginning of the rotation of the flap 7, the control block 22 will replace electronic security prohibiting the control of the pyrotechnic component 5. The latter will be short-circuited and the energy sources or batteries will be disconnected from the pyrotechnic component 5. The security of the device is thus reinforced upon receipt of a voluntary disarmament command (DV).

According to the invention, the safety and arming device can automatically return to the safety position at the end of a time interval envisaged at the design, and this whatever the failures of the control electronics or sources of energy. This automatic disarming operation is designated hereafter by the English expression "Fail Safe" (FS) or anti-failure security (this designation, well known to those skilled in the art, is used in military standards).

For this purpose, the mechanical chronometric module 14, which does not contain a pre-banded spring, is mechanically raised during the arming process (FIGS. 7a to 9c). At the end of this process, the rotor 25 is disengaged, which means that the flap 7 is not blocked by the motor means 11, despite the presence of the worm 11b (irreversible component). The disengagement thus occurs automatically as soon as the passage in the armed position and by the action of the disengaging means 17 described above. The chronometric module 14 then acts freely on the flap 7 by means of the indicator pinion 13 and rotates the flap 7 in a reverse direction FS of that corresponding to the cocking (cocking A in FIG. 8c, Fail Safe FS in Figure 14c).

Figures 14a, 14b and 14c thus show the device during an intermediate phase of this automatic disarming process (Fail Safe). We see that the flap 7 has begun to turn in the FS direction. The winding gear 15 rotates in the direction C2 and drives the flap 7 via the indicator pinion 13. It is noted in FIG. 14c that the pin 40 has remained in its initial position of FIG. 9c, whereas the rotor 25 has rotated with the flap 7.

During all this automatic disarming movement (or

Fail Safe) of the explosive device, the pyrotechnic component 5 is next to the light 12 and the opening 24. The safety and arming device is always in an armed position and the explosive device is operational. . The single-hatch sector of the pane 7 occupies the state display windows 47.

Figures 15a, 15b and 15c show the device at the end of the automatic disarming process (or Fail Safe).

The device 6 is returned to its safety position which is identical to that of Figures 7a, 7b, 7c and 13a, 13b, 13c.

The chronometric module is then in its rest state, internal spring uncoupled. The pyrotechnic component 5 is opposite a solid part of the flap 7 (opposite pinion gear 13). The pin 40 has disengaged the rotor 25. Furthermore, the control block 22 has short-circuited the pyrotechnic component 5 to prevent any firing of the latter.

The explosive device can be safely removed and reused at another location.

The chronometric module 14 will be chosen so as to ensure the desired operating time for the explosive device, for example a duration of the order of 30 minutes to several hours. It is of course possible to modify the activation characteristics of the explosive device 1 by changing the chronometric module 14.

Figures 16a, 16b and 16c finally show the device when in the sterilization position.

It may indeed be necessary to control, not the return of the device to a state of safety allowing the subsequent reuse of the machine, but rather to cause sterilization of the device prohibiting reuse.

For this, the control block 22 will cause, for example following an order sent to the control unit 22 by radio, an operating cycle in which the motor means 11 is controlled so as to rotate the motor pinion 16 from the armed position shown in Figures 9a to 9c, or from another intermediate armed position as shown in Figures 14a to 14c.

This control of the driving pinion 16 will cause, just as during the voluntary disarming of the device (FIG. 10), the rotation of the cap 37 until engagement of the pin 40 in the rotor 25. The motor means 11 then turns the flap 7 in the DV sense of voluntary disarmament (identical to sense A). The control block 22 stops the rotation of the motor when the flap 7 is in the position shown in Figures 16a to 16c. As previously described, this position is detected by means of an angular sensor (not shown).

Once the flap in this position, the pyrotechnic component 5 is in front of the mass of the indicator gear 13. The control block 22 then causes the pyrotechnic component 5 to be fired. The pyrotechnic effect is stopped by the indicator gear 13 and the device 8 is sterilized because there is no pyrotechnic component operational.

The hexagonal patterned sector of the flap 7 then occupies all the state display windows 47, indicating the sterilized state of the device.

Claims

1-reversible security and arming device (8) for an explosive device (1) to be placed manually, device comprising a flap (7) of pyrotechnic chain interruption which is rotatably mounted relative to an axis and which can be rotated by a motor means (11) between a safety position and at least one armed position, characterized in that the flap (7) is coupled by at least one pinion (13) to a mechanical chronometric module ( 14), the passage of the flap (7) from its safety position to its armed position thus causing, by the action of the pinion (13) on a winding pinion (15) of the chronometric module (14), the reassembly of this last by the bandage of a spring of this chronometric module, a disengaging means (17) of the motor means (11) being provided and allowing, after passage in the armed position of the flap (7), the return of the flap (7) in safety position and in a timed way by the only acti the chronometric module (14) acting on the pinion (13) and leading to a rotation of the flap (7) in the opposite direction to that which led to one arming.

2- security device and reversible arming according to claim 1, characterized in that the flap (7) is integral with a shaft (20) coaxial which can be connected to a drive pinion (16) by the disengaging means (17).

3-security device and reversible arming according to claim 2, characterized in that the disengaging means (17) comprises an indexing rotor (25) which is integral with the shaft (20) carrying the flap (7) and which comprises at least two cylindrical housings (30a, 30b), axes parallel to the axis of the shaft (20), and each receiving a rod (31a, 31b) sliding against the action of a spring (32a) , 32b), each stem having a first end (33a, 33b) which is held by the rod spring (32a, 32b) bearing against a stationary cam profile (34), and a second end (35a, 35b) which can exit the rotor (25) pushed by the cam profile (34). ) to cooperate with an indexer pin (40) mounted itself sliding in a cap (37) which is integral with the drive pinion (16), indexing pin (40) which is pushed by a spring (41) towards the rotor (25) and which can engage in one of the cylindrical housings (30a, 30b) of the rotor (25) to ensure a rotational connection of the drive pinion (16) and the indexing rotor (25).

4- security device and reversible arming according to claim 3, characterized in that the flap (7) is integral in rotation with the pinion (13) which is coaxial with it, or pinion indicator, and which meshes with a winding pinion (15) of the chronometric module (14).

5-security device and reversible armament according to one of claims 1 to 4, characterized in that it comprises an electro-pyrotechnic module (6) comprising an electronic firing control means and a pyrotechnic component (5) intended to initiate an explosive charge of a warhead (2) of the explosive device (1), the chain interruption flap (7) comprising a partially circular light (12, 24) which is opposite the pyrotechnic component (5) when the flap is in an armed position, the pyrotechnic component (5) being opposite a solid part of the flap (7), thus outside the light (12, 24), when the flap ( 7) is in a safe position.

6. Security device and reversible armament according to claims 4 and 5, characterized in that the light

(12) of the flap is carried by the pinion indicator (13) which thus forms the solid part of the flap (7).

7- safety device and reversible armament according to one of claims 5 or 6, characterized in that the shutter (7) can be positioned at any time in a safety position by a control of the motor means (11) rotating the flap (7) in the same direction as that which led to the armed position.

8- security device and reversible armament according to claims 4 and 7, characterized in that the indicator gear (13) comprises a portion (13a) devoid of teeth, so that the passage of the flap (7) of the armed position at the safety position is done without acting on the chronometry module (14).

9- safety device and reversible arming according to one of claims 5 or 6, characterized in that the flap (7) can be positioned at any time to a sterilization position by a control of the motor means (11) rotating the flap (7) in the same direction as that which led to the armed position, the motor means (11) being stopped at an intermediate zone in which the pyrotechnic component (5) is no longer opposite the light (12), the electronic control means (6) for firing then causing the ignition component (5) facing a solid zone of the flap (7).

10- safety device and reversible armament according to one of claims 2 to 9, characterized in that the motor means (11) comprises a geared motor (11a) driving the motor pinion (16) by a worm (11b).