EP1010964B1 - Device for igniting a detonator - Google Patents

Abstract

An explosive charge fuse detonator used e.g in an anti-tank mine comprises a detector or switch in the form of a row of membrane contact elements with two plates and a conductor strip. The detonator, especially for a charge set off by an electrical circuit, has a detector or pressure switch formed by a row of membrane contact elements (12). Each contact element consists of first and second plates (15, 17) with apertures containing a membrane (21) with a conductor strip (22) attached to its underside. The row of contact elements is contained inside a sleeve of a deformable material and is connected e.g. to a signal processor in the form of a microcontroller.

Description

The present invention relates to the field of firing mechanisms electric for projectiles, missiles, mines and miniature bombs and more particularly for object a device for firing a primer of the type of that described in patent DE3206285 that is to say comprising in particular a electrical supply of a circuit comprising in particular means of switching and means, such as an electrical resistance or comprising a striker and means capable of moving it, capable of igniting the primer.

There are a number of devices for igniting a primer

Thus, patent application No. FR2742859 in the names of the applicants describes a programmable time priming device comprising a primer, electrical supply means of a circuit mainly comprising a ignition resistance, switching means of the supply circuit of the ignition resistance, means for programming a delay time and control means of the switching means constituted by a microcontroller and a coding wheel, as well as a trapping module connected to the microcontroller.

For example, the trapping means can be of the opening type contact and constituted by a closed circuit supplied by the supply means and comprising a certain number of contactors with remote controlled opening at distance, or inertial or a tripping thread.

These types of contactors can present disadvantages for their setting implemented as part of an anti-tank land mine. Indeed, in some cases it it is not possible to envisage a remote-controlled triggering, or of the type inertial and, moreover, the trip wire does not allow discrimination for the firing of the bait between an infantryman and a vehicle.

To remedy this problem and to fire only presence of a vehicle, patent FR2654824 mentions that for the recognition of a vehicle, one can for example use a detector sensitive to vehicle or pressure contact, or a field sensitive detector magnetic or to the variation of that of the earth under the action of the vehicle, or a vibration detector.

It further describes the use of dual detection, one by influence and the other by contact or pressure.

Among the detectors sensitive to the contact or to the pressure of a vehicle, may cite those described in patents FR2504254, FR2507307 and EP942257.

The first describes an anti-tank mine with a detector in its part upper constituted in particular by a pressure plate intended to cause the ignition by ignition of a pyrotechnic chain composed of a striker, a primer, an ignition relay and an ignition block enabling the fire of the useful pyrotechnic charge enclosed by the mine.

The second and third patents describe an anti-tank mine comprising a payload, as well as double tank detection, one by influence, and the other by contact that causes the payload to ignite directly.

All the devices described in the aforementioned patents have disadvantages. Thus, the plateau mine described in patent FR2504254 requires a passage of the vehicle to be destroyed directly above the mine, which significantly reduces the probability of mine activation by the vehicle.

The patents FR2654824 and FR2507307 teach the possibility of increasing significantly the range of a mine by use, in addition to contact detection or pressure, that of an influence detection.

However, this double detection requires the presence of two sets separate electronics which increases the number of components and therefore the cost of means for igniting the primer and decreases the overall reliability of the device.

Furthermore, the devices described in these latter patents do not allow not to optimize the effects on the tank of the mine explosion.

The object of the invention is to propose means for igniting a primer very reliable, requiring a minimum of electronic components and, although using only one type of detection means, has an increased range by compared to a device such as that described in patent FR2504254 and allowing optimize the effects of the explosion of the explosive device associated with the means of fire.

The solution provided is a device for igniting a primer of the type comprising in particular at least one electrical supply of a circuit comprising in particular detection and / or switching means and means, such an electrical resistance or comprising a striker and means capable of move, capable of igniting the primer, and characterized in that the means of detection and / or switching consist of a network of suitable contactors to open, respectively to close, a circuit comprising at least said supply electric, under the action of a contact or a force and to close, respectively to open said circuit when said contact or said force disappears.

According to a particular characteristic, the network consists of a ribbon of contactors.

According to another characteristic, said contactors are constituted by membrane switches.

According to another characteristic, the membrane switches are constituted by a first plate having an opening, a second plate itself comprising an openwork and drooping edges which are part of the openwork of the first plate, a spherical membrane having the shape of a segment spherical directed upwards is fixed on the end of the falling edges, a strip electrically conductive being fixed on the underside of the membrane.

According to a preferred characteristic making it possible to introduce a threshold of detection, in this case a pressure threshold, said network is arranged inside a deformable sheath made of a material whose hardness is preferably greater at 40 ° shore. The choice of the shape and of the constituent material (s) of the sheath as well that the constitution of the membrane switches allows to introduce a minimum pressure threshold above which the diaphragm switch can be close and below which it cannot.

According to a particular characteristic, this sheath is constituted by a profile made of extruded silicone with a hardness of 60 ° shore.

According to a preferred characteristic, the sheath comprises several segments delimited by a modification of its structure and able to facilitate its folding.

According to an additional characteristic, this structural modification consists in reducing its thickness over all or part of its circumference and may for example be constituted by a groove, the switches being preferably positioned outside of the cross section of the modification of sheath structure.

According to another characteristic allowing for example to introduce a threshold the trigger switches, the membrane switches are connected to means for processing the electrical signals from the detection means, these processing means being able in particular to filter the objectives and to order the initiation of the priming.

According to an additional characteristic, these processing means have a counting module.

According to a particular characteristic, these processing means are constituted by a microcontroller.

According to another characteristic, the processing means are connected to the power supply, the detection means and the ignition resistance of the primer.

According to an additional characteristic, switching means controlled by the processing means are disposed between the latter and the firing resistance of the primer.

According to another additional characteristic, timing means are associated with the processing means and / or the switching means controlled by the processing means.

The invention also relates to an explosive device of the type comprising a explosive charge, a primer and means for igniting that charge explosive and characterized in that the firing means includes a firing device fire according to one of the above characteristics.

• la figure 1 montre une variante de réalisation des moyens de détection selon l'invention,
• la figure 2 présente un schéma d'une vue en coupe des moyens de détection selon cette variante de réalisation de l'invention
• la figure 3, illustre un commutateurs à membrane utilisé dans le cadre de cette variante de réalisation de l'invention,
• la figure 4 présente un schéma d'un dispositif de mise à feu selon un premier mode de réalisation,
• les figures 5 et 6 montrent un schéma d'un dispositif de mise à feu selon un deuxième mode de réalisation,
• les figures 7a et 7b montrent un exemple d'actionnement d'un commutateur à membrane,
• la figure 8 présente un schéma d'un dispositif de mise à feu selon un troisième mode de réalisation.
• la figure 9 présente une disposition particulière d'engins explosifs utilisant des moyens de mise à feu selon l'invention

Other advantages and characteristics will appear in the description of particular embodiments of the invention with regard to the appended figures among which:

• FIG. 1 shows an alternative embodiment of the detection means according to the invention,
• Figure 2 shows a diagram of a sectional view of the detection means according to this alternative embodiment of the invention
• FIG. 3 illustrates a membrane switch used in the context of this variant embodiment of the invention,
• FIG. 4 presents a diagram of a firing device according to a first embodiment,
• FIGS. 5 and 6 show a diagram of a firing device according to a second embodiment,
• FIGS. 7a and 7b show an example of actuation of a membrane switch,
• Figure 8 shows a diagram of a firing device according to a third embodiment.
• FIG. 9 presents a particular arrangement of explosive devices using firing means according to the invention

Figures 1 and 2 show detection means 10 according to the invention intended to be integrated into a device for igniting a primer, with a view to its association with an explosive device, such as a mine.

These detection means 10 consist of a strip 11 of switches with membrane 12 and are inserted into a sheath 13 in the form of a section tube rectangular.

This sheath 13 is made of extruded silicone with shore hardness 60 ° and obtained by extrusion. It also includes structural modifications 25 regularly distributed over its length to allow it to be folded in accordion. These structural modifications consist of a longitudinal reduction in its section a few millimeters, or in other words, in a groove located over the entire outer periphery of the sheath 13.

The external dimensions of this sheath are 54mm wide and 10mm high while the internal free space is 30mm wide and 6mm high. Its total length is 4m and it has four structural modifications allowing it to be folded into 5 segments.

The strip 11 of switches 12 has a width of 24mm and it is arranged centered on the lower internal face 14 of the sheath 13. The switches 12 are of the type those described in patent EP202711. As shown in Figure 3, they include a first plate 15 comprising a circular aperture 16, a second plate 17 itself comprising a circular aperture 18 and falling edges 19 which are inscribed in the opening 16 of the first plate 15. A spherical membrane 21 having the shape of a spherical segment directed upwards is fixed on the end 20 of the falling edges 19. An electrically conductive strip 22 is fixed on the face membrane 21.

The second plate 17 is fixed to the first plate 15 by gluing. A conductive strip 23 arranged longitudinally is centered on the flexible tape 11 and each of the assemblies constituted by the plates 15 and 17 and the membrane 21 is fixed on the ribbon 11 and centered on it. So, for each set, a part of the conductive strip 22 is perpendicular to a part of the conductive strip 23.

As shown in FIG. 4, the detection means 10 are connected to processing means 30 of the electrical signals generated (0 or 5V) by the means detection 10.

These processing means are further connected on the one hand to means power supply 40, as well as a firing resistor 31 of a primer 32.

As shown in Figure 5 and in order to improve the safety of priming, the processing means may consist of a microcontroller and be connected to means 38 for programming a time delay consisting, for example example, by encoder wheels, as well as means 34 for switching the power supply circuit for the starting resistor 31 and a capacitor 36 providing an intensity I2 during its discharge, the intensity I1 of the charging current of this capacitor being insufficient to cause the ignition of the primer.

The microcontroller 30 controls the opening and / or closing of the means switching 34.

As shown diagrammatically in FIG. 6, these switching means 34 comprise first means 41 constituted by an electromechanical device safety device comprising a mechanical clock, associated with a mechanical inverter which is normally in the open position and which closes the circuit at the expiration of a predetermined duration of operation of this clock. This inverter is connected to a capacitor 36 capable of supplying an intensity I2 during its discharge, the intensity I1 of the charging current supplied by the supply means 40 of this capacitor being insufficient to cause the ignition of the primer.

These switching means 34 comprise second means constituted by a transistor 50 whose source is connected to the power supply 40, the gate at microcontroller 30 and the drain at the input of the inverter of the assembly electromechanical 41, and a transistor 55 whose source is connected to the resistor priming 31, the grid to the microcontroller 30 via a resistor 72 and the drain to the capacitor output 36.

In addition, the drain 53 of transistor 50 is connected to a short transistor 60 circuit itself connected to the microcontroller 30 and to ground.

In addition, resistors 70,71,72 for limiting the intensity of the current are arranged on the circuit upstream of the electromechanical means and between the microcontroller 30 and transistor 55 so that, in the event of failure of the transistors and electromechanical means, the starting resistance 12 is crossed by a current of insufficient intensity to cause ignition of the detonator.

In addition, signaling means 81 and 80 are arranged respectively downstream of the power supply 40 and in parallel with the resistor boot 31.

Finally a mechanical lock 21 with two positions, disposed at the outlet of the food, allows in a first position, to put all the means electronic to ground while in the second position all means electronics are supplied but the capacitor 36 is, in all cases, connected to the supply circuit, only after a safety delay generated by the electromechanical safety device 41.

The operation of a device according to the invention is as follows. All Network membrane switches are initially open. As shown on Figures 7a and 7b, the application of a roller 90 of a tank on one of these switches 12 cause contact between the conductive elements 22 and 23 then rupture of this contact as soon as the roller has passed, the switch being reversible and returning to its original position. A voltage pulse is thus generated and accounted for by the processing means 30.

These processing means can either trigger immediately supplying the resistor 60 with sufficient intensity to ignite the primer 32, or only trigger this firing after detection of a certain number of pulses. As an example, the processing means can be programmed to fire the primer only after detection of three pulses separated by a minimum duration, so that after the passage of three rollers, so that the explosion occurs at the most vulnerable place in the tank, especially at the level of the ammunition compartment.

They can also be programmed to not trigger the firing of the initiation only after detection of four or even five pulses separated by a duration minimal and occurring in a limited space of time, in order to destroy only tracked machines. The processing means can thus have a function of filtering of objectives.

In the context of the example of FIGS. 5 and 6, the operation is substantially the same as described above but means are provided to guarantee as much as possible the persons responsible for laying mines.

The operation is as follows:
The mechanical lock 21 is initially in its first position, the electronic means 10, 30, 34, 36 then not being supplied.

The user controls, using the encoder wheels, a duration of timer D1 then puts, using a special key, the lock 21 in the position in which all electronic means are electrically powered and the locked encoder wheels.

The firing means are then positioned on a mine, and this mine buried in the ground while the detection means are placed on the ground be buried.

In this position, the countdown of the delay time D1, started during the operation of the lock 21, continues, while the mechanical clock of electromechanical safety means time delay is triggered. AT the expiration of a preprogrammed time Tp1 of operation of this clock, it produces the tilting of the mechanical reverser 41 and therefore the closing of the part of the circuit located between transistor 50 and capacitor 36.

Also, in all cases where the duration D1 of the timer programmed by the user is less than the preprogrammed time Tp1 or in case of failure of the microcontroller 30 or transistors 50, 55, 60, firing cannot possibly occurring, in all cases, only after the expiration of this time Tp1.

At the end of the countdown of the value D1, the microcontroller 30 deactivates the transistor 60 of short circuit, and activates transistor 50 which then becomes conducting. The capacitor 36 then charges and at the end of a preprogrammed time Tp2 the activation, by the microcontroller 30, of the transistor 55 produces the discharge of the capacitor 36 through this transistor 55 and the starting resistor 31, the intensity I2 flowing in the latter then being sufficient to cause initiation of the detonator and explosion of the mine.

The activation of transistor 55 is controlled as described above, that is to say upon detection of a voltage pulse by the detection means 10 or after detection of a certain number of pulses, for example three for reach a sensitive part of the tank or 4 or 5 to destroy only the machines to tracks, this number of pulses being preferably combined with times separating and encompassing these impulses.

It should also be noted that for security reasons, it is preferable that the charge time Tp2 of the capacitor is long compared to its time of dump. Thus, the malfunctions which would result in commands of all transducers (case of EMP and nuclear effects) would not have no consequence.

According to an alternative embodiment of the invention, the timing means can be simplified as shown in Figure 6. The priming device then comprises the detection means 10, an electrical supply 40, in the occurrence of batteries, a time-delayed relay 33, a closing relay timed 35, a capacitor 36 and a starting resistor 31 of the primer 32.

As soon as the batteries are inserted, the two relays are energized. Relay 33 being everything first closed, the capacitor 36 charges. This relay 33 opens after a time Tp4, then relay 35 closes and, as soon as one of the membrane switches 12 detection means 10 closes the circuit, the capacitor 36 discharges into the resistance 31, causing ignition of the primer 32.

In the case of priming by moving a mechanical part, the discharge of the capacitor feeds a solenoid whose activation causes the release of the electromechanical part which initiates the detonator.

Due to the reversibility of the detection means according to the invention, it is possible to adapt the firing procedures according to the nature of the objective. So, if that is constituted by a column of tanks as presented on figure 9, it is possible to program the microcontroller 30, so that the ignition the primer is only ordered after the passage of a certain number of tanks.

The explosive devices 91 to 95 shown in FIG. 9 are arranged, by example every 30 meters, and this over 150 meters. These five explosive devices each have their own detection means 10 according to the invention connected to means 30 for processing electrical signals comprising a microcontroller.

However, the means of firing explosive devices 91, 92, 94 and 95 are deactivated while the means for igniting the explosive device 93 are activated.

This deactivation consists in preventing the ignition of the primer even in case of detection of a tank; so tanks can roll on the means of detection 10, be detected by these means but without firing occurring primer. It can, for example be carried out by software at the level of microcontroller of the processing means or by hardware with a light switch...

Furthermore, the means 30 associated with the explosive devices 91, 92, 94 and 95 are programmed so that, after activation, they trigger firing at the first detection of a tank by their associated detection means 10.

The processing means 30 associated with the explosive device 93 are programmed on the one hand to trigger the ignition of the explosive device 93 upon detection of the passage of a third tank and on the other hand to activate the means 30 of the others explosive devices after detection of this third passage, this activation can for example be carried out, by wire or by air with a set transmitter receiver.

Thus, the detection of the passage of tanks 100 and 101 on the means of detection 10 associated with explosive device 93, the only one with the means of firing be activated, produces nothing. On the other hand, the passage of a third tank, in the occurrence of tank 102, causes the explosion of the explosive device 93 and the activation means of firing associated with explosive devices 91, 92, 94 and 95. Consequently, the detection of a tank by one of the detection means 10 associated with these vehicles explosives ignites the primer and therefore detonates the explosive device corresponding.

Such operation of the ignition means causes the trap effect. The tanks located between the detection means 10 of the explosive device 91 and those of explosive device 95, upon the explosion of explosive device 93, will be destroyed at their turn as soon as they are detected by means 10 of an explosive device not yet exploded, until all of the explosive devices have exploded.

So, in the example of the tank column in the figure, at least 5 tanks are destroyed by the use of the ignition means according to the invention.

Many changes can be made to the example of embodiment described without departing from the scope of the invention. So the network can have the shape of a star, a square ... and in the case of a strip 11 of contactors, its length can be of the order of a meter or even a decameter and in this case be linked to several explosive devices.

In addition, by adding a receiver associated with the ignition means, it it is possible, using a transmitter, to control, for example, the closing of a switch on the firing circuit of the primer, the firing can then occur produce at the appropriate time after the detection of a tank by the means of detection 10. It is thus possible to select the target.

Claims (14)

1. Device for firing a primer (32) of the type comprising, in particular, at least one electrical supply (40) of a circuit comprising, in particular, detection and/or switching means (10) and means (31), such as an electrical resistor or comprising a striker and means suitable for actuating it, suitable for igniting the primer (32), and characterized in that these detection and/or switching means (10) are constituted by a system of contactors (12) suitable for opening and for closing, as the case may be, the said circuit due to the action of a contact or a force, and for re-closing and for opening, respectively, the said circuit when the said contact or the said force disappears.
2. Device for firing a primer (32) according to Claim 1, characterized in that the system is constituted by a strip (11) of contactors (12).
3. Device for firing a primer (32) according to one of claims 1 and 2, characterized in that the said contactors are constituted by diaphragm switches (12).
4. Device for firing a primer (32) according to claim 3, characterized in that the diaphragm switches are constituted by a first plate (15) comprising an opening (16), a second plate (17) itself comprising an opening (18) and creased edges (19) which fit into the opening (16) of the first plate (15), a diaphragm (21) having the shape of a spherical segment pointing upwards being fixed to the end (20) of the creased edges (19), and an electrically conductive strip (22) being fixed to the lower face of the diaphragm (21).
5. Device for firing a primer (32) according to one of claims 1 and 2, characterized in that the said system is disposed inside a sheath (13) of deformable material.
6. Device for firing a primer (32) according to claim 5, characterized in that the sheath (13) is constituted by an extruded silicone profile.
7. Device for firing a primer (32) according to one of claims 5 and 6, characterized in that the sheath (13) comprises several segments delimited by a modification of its structure (25) suitable for facilitating the folding thereof.
8. Device for firing a primer (32) according to Claim 7, characterized in that the structural modification consists of a reduction of its thickness over all or part of its circumference.
9. Device for firing a primer (32) according to one of claims 1 and 8, characterized in that the switching and/or detection means (10) are connected to means (30) for processing electrical signals coming from the detection means (10), these processing means (30) being suitable, in particular, for controlling the triggering of the priming.
10. Device for firing a primer (32) according to claim 9, characterized in that these processing means (30) comprise a counting module.
11. Device for firing a primer (32) according to claim 10, characterized in that these processing means (30) are constituted by a microcontroller.
12. Device for firing a primer (32) according to one of claims 9 to 11, characterized in that the processing means are connected to the electrical supply (40), to the detection means (10) and to the resistor (31) for firing the primer (32).
13. Device for firing a primer (32) according to claim 12, characterized in that switching means (34) controlled by the processing means (30) are disposed between the latter and the resistor (31) for firing the primer.
14. Device for firing a primer (32) according to one of claims 12 and 13, characterized in that time delay means (38, 41) are associated with the processing means (30) and/or with the switching means (34) controlled by the processing means (30).

Images