Classifications

• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F42—AMMUNITION; BLASTING
  • F42C—AMMUNITION FUZES; ARMING OR SAFETY MEANS THEREFOR
  • F42C17/00—Fuze-setting apparatus
  • F42C17/04—Fuze-setting apparatus for electric fuzes

Definitions

• the present invention relates to a device for cocking and tempering a rocket for an ammunition to be fired by a launcher, in particular for tempering during a burst fire by an automatic launcher, and in particular by an automatic grenade launcher, comprising : a rocket comprising an electric ignition primer, ignition means provided with at least one supply capacitor, and an electronic timing unit for controlling ignition of the primer in a selected time interval or at the end of this interval, a tempering device associated with the launcher or a munition supply device and connected to a source of electrical energy, said tempering device having means for selecting said time interval, and transmission means for transmit to the rocket before firing, by an electrical or magnetic transmission circuit between the tempering device and the rocket, a composite signal supplied issant to the energy rocket to charge the supply capacitor and at least one pulsed signal representing said time interval,
• • 2 7 5 also describes a rocket receiving by a single electrical line a signal containing both electrical energy for ignition and timing information, but this information is transmitted in the form of 'an analog signal, after the transmission of energy, and it is then digitized by an appropriate electronic unit in the rocket itself.
• rockets of this kind can be armed or timed incorrectly by disturbing electrical or electromagnetic influences.
• the present invention aims to avoid these drawbacks, by providing a relatively simple and robust device, guaranteeing a safe and precise tempering, in a sufficiently rapid manner to allow, if the device is used with an automatic weapon, to modify the tempering so continues during the shot.
• the invention relates to a device of the type indicated above, characterized in that said composite signal comprises an encoding signal, and in that said electronic rocket unit comprises at least one electronic lock arranged to prevent the ignition of the primer when it is closed, and decoding means containing a code and arranged to open the electronic lock after reception of the coding signal if the latter corresponds to said code.
• the transmission circuit comprises two pairs of electrical contacts, disposed respectively on the munition and in the tempering device.
• the transmission circuit comprises a magnetic circuit passing through a coil in the tempering apparatus and a coil in the ammunition.
• the coding signal is a digital signal.
• Ways decoding may include a memory for a digital code and electronic programming means for storing in this memory a reference digital code transmitted by said transmission circuit.
• said composite signal successively comprises a charge signal, supplying the electrical energy to the rocket, the coding signal and at least one pulsed signal representative of said time interval.
• the composite signal can comprise two successive pulsed signals representative of the start and the end of said interval.
• the electronic unit of the rocket includes an electronic switch controlling the ignition of the primer and controlled by the electronic lock controlled by the decoding means.
• the electronic unit comprises two counters arranged in series and arranged to receive said pulsed signals, and the electronic lock can be interposed between the counters and the electronic switch.
• the rocket usually includes an impact switch, and the electronic lock can be interposed between the impact switch and the electronic switch.
• the tempering device may include two manual control members determining the respective values of the two pulsed signals.
• fig. 1 is a side view of an ammunition for an automatic grenade launcher provided with a rocket arming and tempering device according to the present invention
• fig. 2 schematically represents a trajectory of this munition
• fig. 3 schematically represents the part of the device according to the invention which is associated with the launcher
• fig. is a block diagram of the electrical circuits of the rocket
• fig. 5 is a diagram representing electrical signals as a function of time, during the operation of the circuit of FIG. .
• fig. 6 is a diagram representing a decoding member, incorporated into a circuit shown in FIG. ,
• fig. 7 is a diagram of an electronic lock incorporated in a circuit shown in FIG. .
• fig. 8 schematically represents a magnetic means of transmission in a device according to the invention.
• an automatic grenade launcher 1 is designed to fire, piecemeal or in bursts, ammunition 2 which is delivered to it in series in the form of bands. It is a known infantry weapon, which can come in different forms, either portable or mounted on vehicles. Such a weapon does not benefit from a fire control system, so that the present invention aims to provide a rocket cocking device simple enough to be able to be controlled manually during firing, by the shooter himself or by another person observing the effect of fire.
• the ammunition 2 comprises a metal socket 3 at the front of which a warhead 4 appears which contains an ignition rocket 5. At its front end, the warhead is provided with a central metal contact 6 isolated by an insulating ring 7
• the rocket 5 is electrically connected on the one hand to the central contact 6, which can also be part of the rocket itself, and on the other hand to the socket 3 serving as ground contact.
• the contacts 3 and 6 could be replaced by two parallel annular bands, isolated from one another and surrounding the central part of the ammunition.
• the trajectory illustrated in FIG. 2 is traversed by the projectile in three consecutive phases having durations T Q , T. and T_ up to the desired ignition point 9.
• T ⁇ is a mouth safety time which is constant; ignition cannot be given during this phase. T.
• T fl being defined constantly by the construction of the rocket, the timing consists in recording in the rocket the values T. and T_. The device described below is designed to perform this operation just before the ammunition enters the launcher, in particular during a burst fire.
• the launcher 1 is supplied with ammunition 2 in the form of a support strip or chain 12 similar to a machine gun strip.
• This strip passes through a tempering device 13 supplied by an electric power source 14, for example an autonomous generator, dry cells or an accumulator battery which may be that of a vehicle carrying the device.
• the device 13 is arranged to electrically record the values T. and T ⁇ in the rockets 5 of the ammunition 2, these values being able to vary from one ammunition 2 to the next in the same burst.
• These values are represented by a coded composite signal which the device 13 transmits to each rocket 5 by an electrical circuit passing through two contact members such as elastic strips (not shown) which touch the contact surfaces 3 and 6 of the munitions to their passage through the device 13.
• the operator has two manual members 15 and 16 actuating two corresponding electrical selectors which define the times T. and T- in a digital electronic unit.
• the members 15, 16 are rotary buttons to which are associated graduations 17, 18 in time or distance, or simply symbols indicating simply which direction of rotation corresponds to an increase in values.
• the device 13 can also include a digital display of the total value T Q + T. + T- or the corresponding approximate distance.
• the input of the electrical circuit network of the rocket 5 has only two terminals 21 and 22, respectively connected to the external contacts 6 and 3 of the ammunition (fig. 1), so that the terminal 22 is grounded.
• the network mainly comprises an electronic unit 23 provided with an electronic switch 24 such as a thyristor, controlling the electrical ignition of an explosive primer 25 when it connects it to a ground conductor 26.
• the energy electric used to ignite the primer 25 is the charge of a capacitor C- » delivered on a conductor 27 through a mouth safety switch 28 controlled in known manner by an inertia mechanism which keeps the switch 28 open until the start of the move, then closed permanently after it.
• the ignition capacitor C_ is connected between ground and a terminal 29 connected to the input terminal 21 through two consecutive diodes 30 and 31.
• a second capacitor C. intended to supply the electronic unit 23, is connected between earth and a terminal 32 located between the diodes 30 and 31 and connected to a power supply terminal 33 of the unit 23.
• Another input terminal 34 of this unit is connected directly to the terminal 21 by a conductor 35 , to receive signals of any polarities.
• a resistor 36 is connected between the conductor 35 and the ground to ensure a progressive discharge of the residual voltages.
• the terminal 29 is connected, through a diode 37, to another input terminal 38 of the unit 23, to allow the latter to discharge on command the capacitors C1 and C2.
• the electronic unit 23 comprises an input logic block 40 associated with a timing block 41 which ensures mouth safety during the fixed duration T Q.
• the logic block 40 is connected to an internal oscillator 42 delivering clock pulses to it, at the ground conductor 26, at input terminals 34 and 38, as well as to conductor 27 by an input terminal 43.
• Exits from block 40, 41 are formed by three conductors 44 to 46 which are connected, like the indicates the diagram, at a first counter 47 for the time T., a second counter 48 for the time T-, and an output logic block 49 arranged to actuate the electronic switch 24 by delivering an appropriate voltage to an output 50.
• an electronic lock blocks the output 50 until it receives an unlocking signal by the conductor 46.
• the logic block 49 also has an input 51 connected to the conductor 27 through a contactor 52 which is an impact switch in this case, but which could also be a proximity sensor.
• the upper line represents the coded composite signal E delivered by the tempering device 13 on the contact 6 of the ammunition, therefore on the terminal 21 of the rocket.
• the signal E successively comprises a load signal 60 with DC voltage, which transmits the energy necessary for the rocket 5 by charging the capacitors C1 and C2, a coding signal 61 which is a pulsed signal representing a code, preferably digital, and two pulsed signals 62 and 63 which respectively represent the values T. and T_ and which can each consist of a number of pulses defined by the positions of the control members 15 and 16 of the device 13.
• the rocket receives both its energy and the timing information in the same signal, which requires only two input contacts on the ammunition, and the rocket has the advantage of being devoid of an electric generator.
• the digital code of the coding signal 61 received on the terminal 34 is compared with a corresponding code recorded in the logic block, in a manner which will be described later. If the two codes do not match, the logic block 40 immediately discharges the capacitors Cl and C2 by grounding the terminal 38. In this case, the rocket no longer contains the electrical energy necessary to ignite of the initiator 25. If the codes match, the logic block 40 changes the state of a locking signal S on the conductor 46 connecting it to the output logic block 49, to open the electronic lock authorizing the operation of the latter . The number of pulses of signal 62 (T.) is recorded in counter 47, and that of signal 63 (T-) in counter 48.
• the signal K present on the conductor 27 takes its high value which is equal to the voltage in the ignition capacitor C ⁇ .
• this initiates on the one hand the time delay T ⁇ for mouth safety, and on the other hand a conventional so-called safety time delay, which will discharge the capacitors by terminal 38 after a relatively long time * , for example one minute, if the primer 25 could not be ignited normally.
• a counting control signal U / D changes state on the conductor 44 to activate the counters 47, 48 and the logic block 49, while the conductor 45 transmits a signal of counting f based on the clock pulses of oscillator 42.
• the second counter 48 is blocked until the first counter 47 has counted the number of pulses corresponding to time T .. It then receives a signal S, which activates it and which is also transmitted to the output logic block 49. From this moment, the latter can close the electronic switch 24 if the ammunition undergoes an impact closing the switch 52 and delivering a signal K. on the terminal 51.
• the logic block 49 is arranged to control ignition by the signal K. during the interval T_, that is to say when the signal S.
• the output signal S- of the counter 48 goes to the high state at the end of the time interval T--.
• the logic block 49 then delivers on the conductor 50 a voltage which makes the electronic switch 24 conductive and which causes the desired ignition 9 of the primer 25, therefore the explosion of the projectile at the precise instant defined by the tempering.
• Fig. 6 schematically represents an electronic decoding member 70, constituting a part of the input logic block 40 appearing in FIG. 4.
• This member comprises a decoding logic block 71 which receives on the one hand the signal E arriving on the terminal 34 and containing in particular the coding signal 61, and on the other hand the clock signal f Q delivered by l 'oscillator 42. On the basis of these signals, the block 71 then delivers a composite digital signal 72 representing a code, to a memory 73 connected to an input 74 of an AND gate 75. The other input 76 of this gate is connected to a read only memory (ROM) 77 in which a reference code is recorded to which the code entered in memory 73 must correspond.
• ROM read only memory
• the AND gate 75 presents an output signal 78 in the high state, which is transmitted to an input of a second AND gate 79, the other input of which receives a signal 80 from a counter 81 which receives the clock signal f 0 .
• This. counter plays the role of timer to validate the comparison only after the introduction of the code into memory 73.
• the gate 79 delivers at its output a locking signal S which is high, in order to 'open the electronic lock as described above.
• the memory 77 can be of an electrically programmable type (EPROM), in a variant shown in broken lines in FIG. 6.
• EPROM electrically programmable type
• the memory 77 is then controlled by a programming block 88 receiving the clock signals f n and the signals arriving at the terminal 34.
• the memory 77 can be reprogrammed by a specially coded signal, simply delivered to the contacts rocket entrance. This offers the manufacturer or the user of the rocket wide possibilities to reserve certain rockets for certain uses. We can also keep rockets without a valid code, therefore unusable directly, and there save the code you want shortly before using it.
• Fig. 7 shows how an electronic lock 82 can be produced in a very simple manner in the output logic block 49.
• An AND gate 83 receives on its inputs the locking signal S and the signal S. coming from the first counter 47. Consequently , its output 84 is in the high state only after the time T., and only if the coding signal 61 is correct.
• an OR gate 85 receives on its inputs the signal K. coming from the impact contactor 52, and the signal S ⁇ coming from the second counter 48.
• an output 86 of the OR gate 85 passes to the high state as soon as there is an impact or at the end of the time interval T-.
• the output 50 of the electronic lock is formed by the output of an AND gate 87 whose inputs are respectively connected to the outputs 84 and 86 of the doors 83 and 85.
• the output 50 is not in the high state, so to order the ignition of the rocket, only when the signals S, S. and S-, or S, S. and K. are in the high state.
• Fig. 8 illustrates an embodiment in which the composite signal E is transmitted from the tempering device 13 to the ammunition 2 by magnetic means, instead of the electrical contacts mentioned above.
• This mode of transmission has the advantage of being insensitive to the presence of moisture or dirt on the ammunition, thanks to contactless transmission.
• a magnetic circuit 90 is formed by a magnetic core 90a in the device 13 and a complementary magnetic core 90b preferably located at the top of the warhead of the ammunition, having a rounded surface 91 opposite which the device 13 has a corresponding concave rounded surface 92.
• the ammunition can be placed opposite this surface 92 by providing a small air gap 93 between the two magnetic cores 90a and 90b.
• Each core has a central pole 94a, 94b surrounded by a coil 95a, 95b, and an annular outer pole 96a, 96b, so that the ammunition 2 does not need to be rotated around its longitudinal axis.
• the coil 95b is connected directly to the two input terminals 21 and 22 of the electrical circuit of the rocket 5, as it appears in FIG. 4.
• the composite signal transmitted by magnetic means can be similar to the signal E shown in fig. 5, except that the continuous charge signal 60 is replaced by a alternative signal.
• the primary advantage of the present invention is the possibility of achieving, on an automatic weapon firing relatively simple and inexpensive ammunition, a continuously adjustable timing during firing, thanks to the fact that it is recorded immediately before loading the ammunition into the launcher.
• the timing information is transmitted by extremely simple means and it is protected by a code, which avoids inadvertent ignition due to ammunition errors or external electromagnetic influences. Coding also has the great advantage of making it possible to reserve the use of ammunition for certain weapons, and therefore for certain users, so that there is no longer any possibility of diverting the ammunition to unauthorized users.
• a device as described above can be delivered separately and easily installed on an existing weapon, without any modification of the weapon itself.
• tempering inexpensive infantry weapons such as an automatic grenade launcher
• the application of the invention is not limited to weapons of this kind, but it extends to all weapons capable of using "tempered" ammunition, whether automatic or not.
• the device described above can be subject to numerous modifications or variations depending on the particular applications.
• the time T. could be constant and predefined by a fixed electrical value in the circuits of the rocket 5, or simply be zero, that is to say that the tempering device 13 would have only one only selection lever that can, if necessary, be easily actuated by the shooter even during a burst.

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• Engineering & Computer Science (AREA)
• General Engineering & Computer Science (AREA)
• Aiming, Guidance, Guns With A Light Source, Armor, Camouflage, And Targets (AREA)
• Air Bags (AREA)

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• 1989
  • 1989-09-14 WO PCT/CH1989/000170 patent/WO1990003549A1/fr not_active Application Discontinuation
  • 1989-09-14 JP JP50917389A patent/JPH03501517A/ja active Pending
  • 1989-09-14 EP EP19890909699 patent/EP0388449A1/de not_active Withdrawn

Non-Patent Citations (1)

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