Description:
FIELD OF THE INVENTION
This invention relates to warheads, particularly for fighting ships, and, more particularly, to an improved warhead of this type in which combustion, deflagration, or even detonation setting in at undesired points of the explosive charge are avoided in a simple manner.
BACKGROUND OF THE PRIOR ART
Usually the casing of a warhead is made as light as possible in order to accommodate a maximum explosive charge in the warhead within a given overall weight. As a rule, the explosives comprise substances which are either not desensitized or are only slightly desensitized. Compared to highly desensitized explosives, the usually used substances are characterized by a substantially higher energy content per unit of weight. This assures, at the target, compression and/or fragmentation effects, provided the explosion, or the simultaneous explosion, of the explosive charge takes place at a certain time from certain points. In the case of axially symmetrical charges, for example, the explosion takes place at a certain time from the central section of the axis of rotation.
This prerequisite is not met, however, in many cases, particularly in warheads which are used against ships. In such case, the destructive effect of a warhead is greatest, as known, if it penetrates the ship wall and continues along its path some distance into the interior of the ship before it detonates its explosive charge. The time-delay detonation is effected by a so-called delayed action fuse, where a certain time interval, determined by an interposed delay element, elapses from the response of its release element, such as an impact contact or an inertial contact or both, to the response of the associated priming element or elements at the explosion charge points ensuring optimum compression and/or fragmentation effects. If there are relatively solid structures or fittings directly behind the wall to be pierced by the warhead, as is the case particularly in warships, the desired time-delayed detonation of the explosive charge does not take place at the desired points. The relatively lightweight warhead casing undergoes such deformation at the solid structures or fittings, that the explosive charge, which is sensitive to frictional heat and impact stresses, begins immediately to burn, deflagrate, or even detonate without delay and at undesired points, due to the friction or due to piercing of friction-heated parts. Explosive effects of a low degree, or no explosive effects at all, are the negative results.
SUMMARY OF THE INVENTION
The present invention is directed to the problem of providing a warhead of the above-mentioned type wherein the above-described disadvantages of a combustion, deflagration, or even detonation setting in at undesired points of the explosive charge are avoided in a simple manner.
In accordance with the invention, this problem is solved in that two or more electrodes, of electrically conductive wires, nets, foils, etc., are so installed in the warhead, or associated with the priming elements, that they are short-circuited in a combustion, deflagration or detonation of the explosive charge at another point than that ensuring the optimum compression and/or fragmentation effects, and that the priming elements react, without any time delay, to short-circuiting of the electrodes.
In a warhead embodying the invention, it is thus ensured that, with simple means, the entire, or substantially the entire, explosive charge is detonated from the point or points which assure optimum compression and/or fragmentation effects. In a premature combustion, deflagration, or detonation at any other less effective point of the explosive charge, the reaction products formed, whose electrical conductivity far exceeds that of the starting materials, short-circuit the electrodes. This short-circuiting of the electrodes, which are distributed, in the embodiment according to the invention, over the explosive charge at least at points which are particularly susceptible to undesired combustion, deflagration, or detonations, leads to an immediate response of the priming elements, due to the association of the electrodes with the latter, and thus to an immediate detonation of the entire explosive charge from detonation points which ensure the optimum compression and/or fragmentation effects.
This positive situation has another advantage. As mentioned above, deformation of the warhead casing and the resulting combustions, deflagrations, or detonations, at an undesired point of the explosive charge have no effect, or no marked effect, on the effectiveness of the explosive charge in the warhead casing according to the invention, in contrast to known warheads. For this reason, the mass of the explosive charge can be substantially increased in a warhead embodying the invention at the expense of the wall thickness of the warhead casing and with the same overall weight, in contrast to known warheads, and this increases the efficiency of a warhead embodying the invention.
An object of the invention is to provide an improved warhead particularly for fighting ships.
Another object of the invention is to provide such as warhead which is free of the disadvantages of prior art warheads for fighting ships.
A further object of the invention is to provide such a warhead in which the mass of the explosive charge can be substantially increased at the expense of the wall thickness of the warhead casing without increasing the overall weight.
Another object of the invention is to provide such a warhead which has an increased efficiency as compared to prior art warheads of the same type.
For an understanding of the principles of the invention, reference is made to the following description of typical embodiments thereof as illustrated in the accompanying drawing.
BRIEF DESCRIPTION OF THE DRAWING
In the Drawing:
FIG. 1 is a longitudinal or axial sectional view of one embodiment of a warhead in accordance with the invention; and
FIGS. 2a, 2b, 3 and 4 are schematic wiring diagrams illustrating different embodiments of the ignition system associated with the warhead shown in FIG. 1.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring to FIG. 1, a warhead 1 comprises substantially an axially symmetrical casing 4, forming a point 5 at its forward end, a bottom wall 6 closing the open rear end of casing 4, and an explosive charge 7 of a highly energetic explosive which fills the space enclosed by warhead casing 4 and bottom wall 6. In the marginal region of the explosive charge 7 there are embedded, at a certain spacing from each other, two electrodes 9 and 10 which extend parallel to the surface 8 of the explosive charge. Electrodes 9 and 10, which are consist of electrically conductive wires, nets, foils, coatings, etc., are, like the electric priming elements arranged along the axis of rotation 11 of explosion charge 7, for example, priming pellets 12a - 12d, and the contact hood 13 arranged on the casing point 5, parts of an electic priming system 14. The construction and the method of operation will be described on the basis of the schematic wiring diagram shown in FIGS. 2a, 2b, 3 and 4.
Referring to the schematic wiring diagram of FIG. 2a, two condensers 24, 25, each connected in series with a respective charging resistance 22, 23, are charged from terminals 20 through a diode 21 and the two parallel-connected charging resistances 22, 23. Closing of an impact contact 26a, arranged in the contact hood 13 of FIG. 1, or closing of an inertial contact 26b, connected in parallel with contact 26a, effects discharge of condenser 24 through an electrically energized primary pellet or igniter 27. In turn, this ignites a pyrotechnical delay composition 28 which, after a predetermined delay time, initiates detonation of a first detonator 29.
As previously mentioned, electrodes 9 and 10, located in the marginal region of explosive charge 7 are short-circuited in case of an undesired combustion, deflagration, or detonation in their vicinity and by the electrically conductive reaction products produced. This short-circuit has the result that the other condenser 25 is also discharged through a priming pellet 30 connected in series therewith. Priming pellet or igniter 30 assures the immediate explosion of a second detonator 31, due to the omission of any delay composition.
Detonator 31, which is primed without delay responsive to short-circuiting of electrodes 9 and 10, is in operative association with piezo-electric ignition generators 32a - 32d, as is also detonator 29 exploded, with delay, responsive to closing of impact contact 26a or intertial contact 26b. The ignition generators 32a - 32d are charged responsive to detonation of detonators 29, 31 by the resulting pressure shocks. The ignition pulses produced in this manner are then supplied to the ignition elements arranged along the axis of rotation 11 of explosive charge 7, as shown in FIG. 1, and which may be, for example, priming pellets 12a - 12d. These priming pellets are electrically connected to the piezoelectric priming generators 32a - 32d in a manner such that they detonate simultaneously explosive charge 7 of warhead 1 at the respective points, and which has the advantage of providing optimum compression effects, fragmentation effects, or combined compression and fragmentation effects.
If the short-circuit resistance of electrodes 9 and 10 is too high, it represents a hindrance for a rapid discharge of the series-connected condenser 25. In such a case, it is advisable, as shown in FIG. 2b, to connect an electronic amplifier element in parallel with the electrodes 9 and 10. For example, this electronic amplifier element can be a bi-directional thyristor 33. Thyristor 33 assures a rapid discharge of condenser 25 through the associated priming pellet or igniter 30 as soon as the thyristor is triggered conductive by applying the correct gating voltage to its grid, this gating voltage being derived from a voltage divider comprising two resistances 34 and 35.
In the ignition circuit schematically illustrated in FIG. 3, four priming condensers 43a - 43d are connected in parallel and are charged from terminals 40 through a diode 41 and a charging resistance 42. Each condenser 43a - 43d is connected in series with a respective electric priming pellet or electric igniter 12a -12d arranged along the axis of rotation of 11 of warhead 1, as shown in FIG. 1. In the event of closure of an impact contact 44a, provided in hood 13 of the warhead shown in FIG. 1, or of an inertial contact 44b connected in parallel with contact 44a, an electric delay member 45 is activated. The delay member 45 is charged from one of the aforementioned terminals 40 and a terminal 40a. After an adjustable time, delay member 45 transmits a pulse to a thyristor 47 connected in parallel with priming condensers 43a - 43d, the pulse being transmitted through a diode 46 and gating thyristor 47 conductive. As a result, all four priming condensers 43a - 43d are discharged simultaneously through the associated electric ignitors 12a - 12d in the explosive charge 7 of FIG. 1.
In the event of a short-circuiting of electrodes 9 and 10, arranged in the marginal regions of explosive charge 7 of FIG. 1, by the products of combustion, deflagration, or detonation, a transistor 48 has its base biased to make the transistor conductive by virtue of the base being connected to a voltage divider comprising resistances 49 and 50 connected in series with electrodes 9 and 10. The transistor 48, thus rendered conductive, triggers thyristor 47 conductive, and thus effects discharge of the parallel-connected priming condensers 43a - 43d without any delay, through the collector current of transistor 48 which is shunted, in the non-conductive condition of transistor 48, through a resistance 51. Priming condensers 43a - 43d discharge simultaneously through the respective electric igniters 12a - 12d, in the same manner as previously mentioned.
One example of an electronic delay member of the type included in FIG. 3 is illustrated schematically in FIG. 4. Referring to FIG. 4, four priming condensers 63a - 63d are connected in parallel with each other, and each priming condenser is connected in series with a respective electric priming pellet or igniter 12a - 12d embedded in explosive charge 7 of warhead 1, shown in FIG. 1. Condensers 63a - 63d are charged from terminals 60 through a diode 61 and a charging resistance 62.
In the event of closing of an impact contact 64a, provided in hood 13 of warhead 1 of FIG. 1, or of an inertial contact 64b connected in parallel with contact 64a, a first thyristor 65 is gated conductive. The necessary igniting voltage or gating voltage for thyristor 65 is supplied by an associated voltage divider comprising two series connected resistances 66 and 67 whose junction point is connected to thyristor 65. When thyristor 65 is gated conductive, condenser 68 is charged through a resistance 69. A resistance 70, connected in parallel with condenser 68, limits the holding current of thyristor 65.
The delay member shown in FIG. 4 and being charged from one of the aforementioned terminals 60, and a terminal 60a also includes a p-channel field effect transistor 71. The so-called "source electrode" of transistor 71 is connected to a voltage divider comprising series connected resistances 72 and 73. If the value of the charge in condenser 68 drops below the adjusted potential less the gate cut-off voltage, this results in triggering field effect transistor 71 conductive through diode 74. As a result of conductivity of transistor 71, a so-called drain current which, in the non-conductive condition, is shunted through resistance 75, flows to the gate of a second thyristor 76 connected in parallel with priming condensers 63a - 63d and triggers thyristor 76 conductive. The delay time elapsing from the closing of either of the contacts 64a or 64b to the gating conductive of thyristor 76 with the resulting simultaneous detonation of the explosive charge by the igniters 12a - 12d is determined primarily by the time constant of the R-C member comprising condenser 68 and resistance 69 connected in series with each other.
If, instead of contacts 64a or 64b closing, electrodes 9 and 10, embedded in the marginal region of the explosive charge 7 of FIG. 1, are short-circuited, which occurs in the case of combustions, deflagrations, or detonations in the range of the explosive charge, the adjusted threshold voltage of field effect transistor 71 is exceeded immediately through resistances 77 and 78. This leads to a delay-free gating conductive of thyristor 76 connected in parallel with priming condensers 63a - 63d, with the above-mentioned consequences. It should be pointed out, in this connection, that the transfer resistance of electrodes 9 and 10 which should lead to the immediate release of the ignition system can be adjusted by selection of resistances 77 and 78. Also, it should be noted that the casing 4 of the warhead, if made of electrically conductive metal, may constitute one of the electrodes short-circuited in the event of combustion, deflagration or detonation.
While specific embodiments of the invention have been shown and described in detail to illustrate the application of the principles of the invention, it will be understood that the invention may be embodied otherwise without departing from such principles.