FR2475211A1 - THERMAL GENERATOR PROJECTILE - Google Patents

Abstract

PROJECTILE INCLUDING A THERMO-ELECTRIC GENERATOR INTENDED TO OPERATE A CIRCUIT LOCATED IN THE PROJECTILE; GENERATOR 9 IS CONDUCTED IN ZONES IN WHICH THERMAL GRADIENTS OCCUR, ESSENTIALLY DUE TO BRAKING CAUSED BY FRICTION IN FREE FLIGHT. PAIRS OF GENERATOR ELEMENTS 16, ELECTRICALLY CONNECTED TOGETHER, ARE ARRANGED IN A STAR AT LEAST IN A PLANE WHICH EXTENDS SENSITIVELY TRANSVERSALLY AT THE LONGITUDINAL AXIS 22 OF THE PROJECTILE.

Description

The invention relates to a projectile comprising a general

thermoelectric sensor intended to operate a circuit located in the projectile. Such a projectile is known from German patent application DE-OS 24 34 700 and is used as an anti-aircraft projectile; after it was fired from a gun barrel, a pyrotechnic charge located in the

  rear part of the projectile is fired to serve as a ray source

ment emitting a continuation radiance. Between this pyrotechnic charge

serving as a heat source and the explosive payload of the projectile

  derived as a heat sink is arranged a thermoelectric generator

titrated by thermocouples connected in series, which, due to the thermal gradient

that between the ignited pyrotechnic charge and the explosive charge not yet

  on, provides thermoelectric voltage to operate a circuit

  cooked to evaluate the information of the tracking beam in order to trigger

  expensive firing. The disadvantage of this projectile equipment for furnace-

  Define the electrical energy used to operate the circuit is in particular that it is necessary to provide in the projectile a clean thermal source to be

  on especially after firing, which, given the pre-

of the projectile, considerably reduces the volume available for the payload; an additional expense is required here to ensure the ignition of this thermal source only when the projectile has left

the tube, in order to give the projectile intrinsic security. This solu-

tion is only justified in special cases, where, in any case, a heat source is needed to operate the projectile, which must be

  put into service after firing, but before detonation, and which can be used

then to provide the energy necessary for the circuit to operate

as long as this circuit does not have to be already ready to operate before.

In cases where these particular conditions do not exist, it is known to provide in the projectile a battery as an energy source for the circuit. The disadvantage is that the batteries have a very high weight compared to their electrical power, which reduces the payload for given boundary conditions; moreover, the peak current available to trigger the detonation is relatively low in

  a battery due to its high internal resistance. In addition, the bat-

  Ries supporting a long storage time (corresponding to the period during which the stored projectiles must be in working order) without

  unacceptable self-discharge, are very expensive; finally, the new equipment

  stop to ensure the intrinsic safety of the projectile, so to release the energy of the battery intended for the circuit only after the exit of the

  projectile out of the barrel of the weapon, is expensive.

  It is also known to equip projectiles with

  piezo generators which are activated by dynamic pressure in front of the projection

  tile on its free path, that is to say when it left the barrel of the weapon. But the energy thus made available is not enough, generally,

  even with intermediate storage in energy supply capacitors

  negated by piezoelectric elements, to supply a continuous circuit

electronic, only to trigger a high resistance electrical primer

tance used to trigger the detonation.

  The object of the invention is to produce a projectile of the aforementioned type so that it provides the energy necessary to operate a complex electronic circuit during its movement on its free path, between the moment when the projectile leaves the tube and the triggering of the detonation, and possibly already in the barrel of the weapon, and this with

  relatively low manufacturing cost, but with functional safety

high.

This object is achieved in accordance with the invention by the fact that a projectile of the aforementioned type is equipped with a generator produced on

  zones in which there are thermal gradients resulting from access

leration in operation.

The projectile therefore no longer has to be equipped with a particular heat source to be ignited at defined times; on the contrary, one uses the thermal gradients between the environment of the projectile and this one which are produced by the braking of the free flight in the atmosphere and possibly also during the launching of the projectile, i.e. the data

accelerations, positive and negative, which are related to the movement-

projectile.

  According to a development of the invention, the generator

is carried out in areas where thermal gradients occur

  ques mainly due to braking resulting from friction in free flight.

It has been found that, for projectiles flying relatively long, the most suitable for supplying energy to the circuit would be a thermoelectric generator, mounted in the projectile so as to be able to use the thermal gradients which occur on the generator in flight 1 bre , therefore between the start of the barrel of the weapon and the triggering of the detonation, and which are due to friction and therefore to braking, without any additional heat source being encountered. Among the additional provisions to ensure intrinsic safety, it can be overlooked that heat

247 521 1

  produced by the friction of the air becomes effective for the projectile,

  and therefore, to excite the generator, only outside the barrel of the weapon.

According to other developments of the invention, it is possible, alternatively or cumulatively, to consider different typical zones of friction heating on the projectile to produce the generator. Relatively simple and non-critical additional arrangements for operation taken on the projectile in the form of heat sinks or heat accumulators for the duration of free flight may be appropriate in this case. Such preferential areas for carrying out the

  thermoelectric generator for power supply (with safety

  trinsèqueJ of electronic circuits, are in particular the transition between the point of the projectile and the adjacent cylindrical part of the projectile, or for

  projectiles with a "punch" point, the area of the point located immediately-

ment before the shoulder of the projectile; and on the other hand, the area behind

  re the guide ring of a shell, therefore in the vicinity of the crimp groove

  ge used for fixing the socket.

In the first case cited, it occurs from the start of the

barrel of the weapon, due to the friction of the air having a braking effect.

  during the entire free flight, a rise in temperature ranging,

15n the geometry of the projectile, up to 6000C or more. To ensure the thermal gradient, a material can be provided as a thermal sink inside the projectile, the thermal capacity of which is adjusted over the duration of flight, while unacceptable heating of the hot sides of the pairs of thermocouples or of elements Peltier of the generator can be prevented by surrounding them with a protective heat shield. In the case where one uses the heating of the shoulder when the projectile has a point in punch, one can use the thermal gradient on the length of the punch to excite the generator without it being necessary to carry out a thermal well additional. In the case of the second variant, the inversion of the thermal gradient is used at the generator of the projectile when it leaves the barrel of the weapon, since the part of the projectile located behind the guide ring is still subject

  in the hot gas tube of the propellant charge powder of the car-

button, but after leaving the tube it is cooled by the

  ridges behind the guide bar. In this variant of the invention, it is therefore sufficient to store the energy of the powder gases in the posterior zone.

from inside the projectile, before it leaves the barrel, in quant

  tee such that, in the area behind the guide ring, a gradient

thermal occurs in free flight from the inside to the outside.

It results from cesva zancee due to the ex-

citation of the generator, before and after the departure of the tube and without means

  additional xiliaries. a projectile having intrinsic safety, the generator of which is not subject to aging and which is armed after having traversed a certain dead zone in front of the mouth of the tube, thereby

that the generator then supplies the ignition circuit.

  For particular projectiles which must already be armed after the internal combat zone between 50 and 100 m and which must be able to have the firing energy, the dead zone of free flight located in front of the mouth of the tube weapon is, if necessary, too

  large, even at very high output speeds. According to other develop-

  pements of the invention, for projectiles belonging to these fields of use

you have to use the overheating of the rear of the projectile

  duisant in the tube during acceleration during the firing, due to the powder gases, during the separation of the projectile from its casing, and afterwards, for the supply of the circuit. In this case the generator already begins to operate in the barrel of the weapon in order to be able to trigger the firing of the projectile even at a short distance in front of the mouth of the tube. Thermoelectric energy production can no longer be used for

  that the projectile works with its intrinsic safety. We must then dream

nde the usual mechanical security provisions based for example on the function of guiding the barrel of the weapon. These security provisions can

  be supplemented by the function of the circuit supplied by the thermal generator

orLand -

  that, by using a discriminator which becomes active due to the voltage gradient which appears when the projectile leaves the mouth of the tube, therefore in an operating phase of the projectile in which the rear of the projectile is no longer heated by powder gases, but is instead cooled for example by air vortices. The jump in voltage, or polarity, which therefore occurs at the terminals of the thermal generator can be used as an indication signal of the firing carried out, inside the circuit mounted in the projectile in order to prepare already during the time of the path of the projectile in the tube via the powered circuit

  by the thermal generator, firing immediately in front of the mouthpiece

tube chure and therefore already in the near area.

  The generator may suitably have a shape

  ring, disc, or cylinder, hollow or not, in order to be able to manufacture it

  quer separately and insert it into the projectile or between parts of the

  projectile during the manufacture of the latter or its equipment.

  The invention will be clearly understood on reading the description

detailed information given below by way of example only, of reaction forms

reading represented schematically on the drawing in which:

Figure 1 shows, in side view and in section through

  tielle a projectile intended for relatively long trajectories with the casing in place, before firing, the thermoelectric generator being placed in the point of the projectile, Figure 2 is a diagram of the principle of the feeding

  of a part of the projectile circuit consisting of a thermoelectric generator

  stick made of thermocouples, according to Figure 1;

FIG. 3 shows, as a variant of FIG. 1, the realization

sation of the generator in the transition zone between the tip of the projecti-

  the and the cylindrical part of the projectile; Figure 4 shows in section along arrows IV-IV of Figure 3 the arrangement of the generator according to Figure 3; FIG. 5 shows the production of a generator in the rear part of the projectile behind its stabilizing ring;

  Figure 6 shows a variant of the realization of the ge-

niner in a projectile with a pointed tip;

  Figure 7 shows, based on structural data

  Figure 5 shows a generator in a projectile which must be ready for firing already inside the internal combat zone;

Figure 8 shows the arrangement of the pairs of thermo

  cross-sections according to arrows VIIl-VIII in Figure 7; and

FIG. 9 shows, as a variant of FIG. 2, a circuit

  cooked for a heat generator according to Figures 7 and 8 also ensuring

the safety functions, which feeds the circuit already during the firing of the pro-

jectile in the barrel of the weapon.

Figure 1 shows in partially rear side view

  chée, a projectile 1 with a casing 2 to receive a propellant charge

  cartridge 3. In the rear area of its cylindrical casing 4, the pro-

jectile 1 is surrounded by a guide ring 5, which, in cooperation with the scratches in the inner casing of a weapon tube (not shown in the drawing) gives projectile 1 the gyration necessary for stability

directional.

  Behind the guide ring 5 is formed in the cylindrical casing 4 of the projectile 1 at least one peripheral crimping groove 6 which is used for mechanical fixing and by cooperation of shapes of the zone

  front of the sleeve 2 on the projectile 1, if it is, as in the example-

  ple shown, of a projectile to be introduced in one piece into the tube in the other case, the projectile is produced in two parts, the projectile 1

  and socket 2, Without the mutual fastening shown.

  The interior of projectile 1 houses a charge volume

useful 7 used in particular to receive firing substances and explosives

  sifs. In the conical anterior zone of the projectile 1 is housed a circuit 8 which is used to prepare or transform electrical energy to process signals from detectors to determine the instant of firing and the triggering thereof. To supply this energy, a thermal generator 9 is arranged in the region of the point of the projectile 10. Before the generator 9, a reinforcing material 11, thermally stable and good conductor of heat, can be placed, in which can also be placed detectors for triggering firing. Behind the generator 9, with respect to the longitudinal axis 22 and to the direction of flight of the

  projectile 1, is arranged a heat sink 12 of high thermal capacity.

It may be, for example, a reservoir of bad conductive material

  heat, filled with a liquid, such as distilled water.

After firing of projectile 1, so when it is

separated from the sleeve 2 and left the tube, it occurs due to the resistance

of air during the free flight of projectile 1, an accumulation of

  heat in front of the point of the projectile 10, which accumulation is transmitted

se by the reinforcement material 11 on the hot side 13 (see figure 2) of the

aerator 9, the cold side 14 of which is applied against the heat sink 12.

  The generator 9 itself essentially consists of a compressive mass

  made of refractory material 15, for example hardened cast ceramic

  sand, now as best as possible, thanks to its poor thermal conductivity

  that, the gradient on generator 9; in this mass are coated pairs of elements 16 to transform the thermal gradient (between the hot side and the cold side 13/14) according to the Peltier effect or the Seebeck effect into an electrical voltage. The pairs of elements 16 of the generator are connected in series - at least partially, as shown in FIG. 2 - in order to be able to take the thermoelectric voltage at two output terminals 17. This thermoelectric voltage can operate the components of the circuit

  electric 8 by inserting a voltage multiplier 47 starting to oscillate

  ler already at low excitation voltages, or it can be brought directly to circuit parts 18. In order to be able, with these circuit parts, for example operational amplifiers, to get away with

2 47521 1

  small operating voltages, it is advisable to equip the series mounting of the pairs of elements 16, with a central socket 19 connected to the terminal 20 of

  reference potential of the circuit parts 18, which condition a supply

mentation in bipolar tension.

  The heat leaving the tip 10, or the reinforcing material 11 by the generator 9 is absorbed by the heat sink

  12, so that during the period of operation of this thermal generator

  that 9, its cold side 14 does not heat significantly, so that the gradient

  thermal remains substantially maintained to produce the thermoelectric tension

  stick. It is particularly suitable to make the pairs of elements

  16, in the compressed material 15 of the generator 9, in the form of Pel-

  tier, since these have a particularly high resistance to heat transmission and thus delay the heating of the heat sink 12 serving as thermal counterweight, which allows the mounting of a small heat sink 12 compact. In addition, the Peltier elements constitute

  themselves small pairs of space-saving elements which allow

Even with a moderate temperature difference of around 1500C, a no-load operating voltage of around 0.5 V. It is easy to avoid critical overheating of the Peltier elements as

pairs of elements 16, on the one hand by appropriately choosing the ma-

  reinforcement plate 11 in the point of the projectile 10, on the other hand by

  not making the pairs of elements 16 go into the generator 9 until

sagging of the area of the wall of the projectile 1 or by surrounding the generator 9 with a thermal protection ring 21. The pairs of elements

  16 can be arranged in a spiral or in a circle. If to increase the power

  generator output available, individual circuits must be connected in parallel, groups must also be grouped

  corresponding pairs of elements 16, to ensure the reliability of function-

  electrical connections between them. If the circuit parts 18 according to FIG. 2 are not supplied directly from the generator 9 but via a voltage multiplier 47, relatively few pairs of elements 16 are sufficient if the voltage multiplier 47 is made with semiconductor components based on silicon, because this starts to oscillate suddenly when an output voltage of the

low generator defined (typically 0.6V), therefore provides the supply voltage

tation for circuit parts 18.

Unlike the example in Figure 1, in the example in Figure 3, the heat generator 9 'is no longer oriented parallel, 247521i

but transverse to the direction of flight, therefore from the longitudinal axis 22 of the pro-

  jectile 1, with regard to its temperature gradient. The pairs of ele-

  elements 16 are then mounted radially, that is to say in a star in the material

  compressed compressed 15 which concentrically surrounds as a generator ring 23 the heat sink 12 which may again be constituted by a reservoir,

preferably in electrically insulating material, filled with a protective substance

high thermal city, for example of a liquid. The cold connection points 14 of the pairs of elements 16 are thermally connected. to the heat sink 12; their hot connection points 13, electrically isolated from one another, are located directly under the wall of the projectile 24, or else

  to ensure a better thermal bond with the layer of air surrounding them

  veloppe, they protrude into recesses 25 in the wall of the projectile 24,

  as shown by way of example in FIG. 4.

  The annular generator 9 ′ according to FIGS. 3 and 4 may include star arrangements of pairs of elements 16 in several

planes parallel to each other, transversely to the longitudinal axis 22 of the pro-

  jectile. This annular generator 9 'is mounted in the projectile 1 in the

  transition zone 26 between the point 10 of the projectile and the cylindrical envelope

drique 4 of it, so in an area in which the air flow

during free flight produces an accumulation of heat, after the projection

  tile was taken from the barrel of the weapon, and where the largest heater occurs

  relative to the roughly constant temperature of the heat sink

  12. In the transition zone 26, this temperature reaches approximately 6000C.

  The thermal properties of the compressed material 15 of the generator 9 ', as well as of the thermal well 12, must be adjusted on the fact that the flight time of such a projectile 1 is 6 to 8 seconds, during which the gradient

  temperature on the hot side 13 to the cold side 14 of the generator 9 must not

  seriously drop in order to be able to have, also at the end of the flight time and as much as possible without being obliged to make an intermediate storage of energy, the operating voltage necessary for the circuit-8, directly

as a voltage across the terminals of the thermal generator 9 ′, or else by the

intermediate of the intercalated voltage multiplier 47.

  In the case shown in Figures 3 and 4, the general-

detonator 9 ′ is crossed by a detonator 27 which, on one side is connected to the firing sections of circuit 8, and on the other hand enters the volume

  useful 7, in order to ignite the charge therein at a given time.

  In the example of FIG. 3, there is provided in the tip 10, before the circuit 8, an impact trigger device 28 which is in functional connection

2 47 521 1

  with the detonator via parts of circuit 8; in replacement

cement or in addition, it is also possible to place in this anterior zone detectors for the operation of the projectile, which are not housed

in the circuit area 8.

  The generator structure according to Figure 4 with the arrangement of Figure 3 (or according to Figure 5 which will be explained later)

  particularly suitable for couples of material of thermoelectric elements

  triques, which certainly have a lower thermoelectric sensitivity than Peltier elements, but on the other hand can operate at a temperature

  higher; protective measures against thermal deduction of the

  nerator 9 are therefore useless; much more, the heat of friction reaching its maximum in the environment of the projectile 1 can be used directly

  to produce thermoelectric energy, using cheap materials.

The example of FIG. 5 relates to an embodiment of the generator 9 ′ as a ring similar to that described with reference to the

figure 4. Here, the generator 9 'is arranged in the area of the pos-

  of the projectile 1, for example in the region of the crimp groove

  ge 6, in any case behind the guide ring 5 of the shell. The general-

  annular tor 23 ′ does not, however, surround a heat sink 12, but a heat accumulator 29, for example a block of material similar to chamotte. In this variant, the frictional heat of the surrounding air on the wall of the projectile 24 is not used to produce the thermal gradient, but the thermal energy of the propellant gases transmitted by the propellant charge 3 of the cartridge (see figure 1) to the accumulator of

  heat 29 when the projectile 1 is fired from the barrel of the weapon; these gases released

  return their thermal energy to the gun barrel behind the guide ring

  ge 5 of the projectile 1 emerging from the sleeve 2 (see Figure 1).

  Contrary to the conditions in Figure 4, for the general

  rator 23 'of Figure 5, the cold sides 14 of the pairs of elements 16 are outside, so on the periphery of the cylindrical casing 4 behind the guide ring 5; while their warm sides (not shown on

FIG. 5) are in thermal connection with the heat accumulator 29.

  As long as projectile 1 is still advancing in the weapon barrel, the propellant gases

  hot impulse mttEatûent directly the outer periphery of the ring generator

23 'but on the other hand they act on the internal connection points of the

  res of elements only via the interposed heat accumulator 29. During this period of the shot, the external connection points 14 of the pairs of elements are therefore exposed to a similar heating, itself higher than that of the points located inside; this means that there is not yet a thermoelectric voltage at the output terminals 17 of the thermal generator 9 "during the firing, or that there is a thermoelectric voltage of reverse polarity with respect to the data of subsequent operation. In any case, when it is a question, for the circuit parts 18, or possibly for the interposed voltage multiplier 47, of elements having a behavior

  ment polarized in service, (in FIG. 2, quartz diodes 30 for voltage

  service sion mounted in series, shown in dashes), activation does not yet occur during the critical period during which projectile 1 progresses in the weapon barrel. On the other hand, when it has left the weapon tube, therefore during the free flight of the projectile 1, there is behind the guide ring 5 air vortices which cause a cooling of the zone of the cylindrical envelope 4 which is there, and therefore also on the cold side 14 of the generator 9 ". On the other hand, the heat accumulator 29 heated

in the tube, transfers its heat to the hot connection points of the pairs of elements

  elements located inside, and (contrary to the conditions of Figure 3) a thermal gradient is established from the inside to the outside;

  that is to say that at the output terminals of the generator 9 ", there is a voltage

  with a polarity corresponding to the polarization of the passage of the quartz diodes 30 (see Figure 2). Since in free flight there is

  practically the vacuum at the rear 31 of the projectile 1, it practically does not occur

  no heat loss from the heat accumulator 29 during the short operating period of the generator 9 "(at

  know during the free flight time of projectile 1 until detonation).

  To quickly introduce heat from the propellant

in the heat accumulator 29 while ensuring therein a pro-

  thermal wire desirable in relation to the geometry of the pairs of elements, it may be appropriate to introduce, as shown in FIG. 5, heat conducting bodies 32 in the form of bars and / or metal plates, possibly staging in the direction of the depth in the heat accumulator 29, the free ends or even coming out of the rear side 31 of the projectile are directly subjected to the heat of the

propellants, and which allow a more adequate heat conduction

  quate and faster in the area of the annular generator 23 'than through the

  material of the heat accumulator 29 itself.

  In cases where the generator 9, 9 ′, 9 ″ is produced in the form of a ring 23, 23 ′, it should be manufactured as a self-contained part which is introduced into the interior volume of the projectile 1 during the equipment thereof, or, in the case of a projectile 1 in several

247 521 1

parts, which is inserted between the parts of the projectile by screwing or any

  other mechanical connection and / or by form cooperation.

  FIG. 6 represents, schematically simplified, a variant of the structure of the generator, in the case of a projectile, with a shoulder marked 33 behind a pointed tip 34. There is no need here,

  neither special provisions for making a heat sink nor pre-

  adorn a heat accumulator; because, due to the very overheating

important and very localized from the shoulder 33 itself and from the im-

  medially adjacent to the point in punch 34, it occurs in free flight

  of the projectile 1, in the longitudinal direction of the point 34 a thermal gradient

  sufficient to excite the generator 9 "'. Provision is made here for producing the voltage, a generator winding 35, namely a strip formed by commercially available thermoelectric elements in sheet form, the sides of which

  13 are oriented in the direction of the shoulder 33. As shown

  felt in the drawing, this element sheet 36 is suitably placed in a groove 37 in the outer wall of the tip 34, so, in the

  whenever possible, not to influence the aerodynamics of projectile 1.

This embodiment in winding by means of thermoelectric elements in sheet form, makes it possible to accommodate the pairs of elements in very large number in

a very small olume, therefore to obtain an idling voltage of the general-

very high.

  The exemplary embodiments of FIGS. 1 to 4 and of FIG. 6, as well as the example of FIG. 5 are suitable for projectiles

  having a relatively large tactical range, up to a few hundred

taines of meters and consequently having a free flight time after leaving the weapon tube of the order of 1.5 seconds and more. The structure and the assembly of the generator which have been described, particularly according to the

  Figures 1 to 4 and Figure 6 are ideally suited for feeding

  long-term tation therefore, if it does not matter that the dead zone between the moment when the ectile leaves the tube and that when it is ready for firing is limited as possible. In addition, there are flying projectiles

* fast, provided for what is called the interior combat zone, which

wind be able to have the ignition energy for a detonation after only 0.1 seconds of free flight, i.e. within a range

from 50 to 100 m.

  For such alternative use cases, the use of a generator similar to that of FIG. 5 should be modified, so that - while retaining the usual mechanical safety measures,

24752 11

  for example, during the progression of the projectile in the weapon tube - we already use the effect of the heat of the propellant gases of the cartridge on the thermoelectric generator in the weapon tube to supply energy to the circuit contained in the projectile, so that we do not first wait for a thermal gradient occurring during free flight on the projectile after it leaves the weapon barrel, to activate the supply of the circuit from

of the generator.

An exemplary embodiment is shown in FIG. 7, based on the representation of FIG. 5 and taking into account the

  figure 1. The 9 "" thermal generator, oriented parallel to the longitu-

  dinal of the projectile 22, is disposed in the rear region of the projectile 1, approximately between its guide ring 5 and its rear side 31 facing the propellant charge 3 of the cartridge (see FIG. 1). To prevent the direct destructive action of the hot powder gases from the propellant charge during the firing of the projectile 1 into the weapon tube (not shown in the drawing), pairs of thermoelectric elements 16 are provided behind the hot side.

  thermal protection layer 38 made of refractory material together with electrical

  triply insulating. The cold sides 14 of the pairs of thermoelectric elements

ques 16 are oriented towards the payload volume 7 of the projectile

  1 and are placed against a heat sink 12; we can use for this last-

deny the metallic mass of a mechanical safety device provided for all

ways in such a projectile (for example a clock movement stage-

rie, or a separation plate between the detonator and the charge of transmission-

  can pivot out of the pyrotechnic chain (not shown on the

drawing).

  To make good use of space in order to

  hold a high thermoelectric efficiency of the generator 9 "", the pairs of ele

  thermoelectric elements 16 are grouped in a spiral to form a cylinder, as shown in FIG. 8 in the rear view; in the intermediate volumes we pour a refractory ceramic to trade

  as a compressed material to maintain shape (e.g. ceramics

alumina mica KAGER), which then hardens by fixing the pairs of thermoelectric elements 16. Instead of the structure of this generator 9 "" shaped

spiral formed by individual pairs of elements 16, we can also

Here use a sheet of elements 36 which is introduced by inserting compressed material 15 (as sketched in FIG. 8) or in the form

  of compact winding in the posterior end of the projectile 1.

  As already explained with reference to Figure 2,

247 521 1

  there occurs on the posterior side 31 of the projectile a sudden decrease in the action of heat when the hot combustion gases of the propellant charge 3 have expelled from the weapon tube the projectile 1 at the same time as the casing 2 of the propellant charge separates. Figure 9 shows how the corresponding shape of the generator output voltage can be used as information to indicate that the shot has actually taken place, and therefore as an additional safety device - in addition to the mechanical device connected to the tube. For operation, or at least for preparation for operation, before projectile 1 leaves the weapon barrel,

  circuit 8 'is supplied with thermoelectric voltage, as a voltage

service sion, directly according to FIG. 9, or via a voltage multiplier 47 connected in series, according to FIG. 2; this voltage is supplied by the generator 9 "" due to its activation by the hot gases of the propellant powder. Immediately after the projectile 1 leaves the weapon barrel, the action of heat on the posterior side 31 of the projectile decreases (see Figure 7) and therefore the output voltage supplied

by the generator 9? h ', which is transmitted, via a discrimi-

  polarity limiter 39 - for example in the form of a series connection consisting of

  citué by a comparator 40 and a diode 41 mounted to let pass the im-

corresponding differentiation voltage pulse - to form a signal

control to a priming input 42 of a circuit 8 'already ready for function-

  ment. Following the priming input 42 is mounted the position input-

nemrient 43 of a flip-flop circuit 44, which was prepared due to the prepa-

ration to the operation of the circuit 8 'and which transmits from the priming input 42, during positioning, unlocking information to a

  firing device (not shown, for example an electro-

or electro-mechanical).

  In the event that, due to the thermal data in the region of the posterior end of the projectile 1, after the exit from the tube, there is an inversion of the cold-hot supply of the pairs of thermoelectric elements 16, and therefore reverse polarity of the voltage

generator output 9 "", power must be supplied to the circuit

  cooked 8 'from the generator 9 "" via a bridge rectifier 45, so that the supply polarity is preserved. A capacitor

memory 46 can be beneficial, to keep available uninterruptedly

broken during the reverse polarity of the generator output voltage,

  therefore during the crossing of the generator dead zone directly from

  before the mouth of the weapon tube, the operating voltage for circuit 8 '.

  If several generators 9 are produced on different

  your zones of projectile 1, circuit 8 'can be supplied in parallel by these, so that it is already in operation during the firing of projectile 1 and after a very short dead zone in front of the mouth, even during relatively long flight times.

Claims (17)

R E V E N D I C A T I 0 N S   1. - Projectile comprising a thermoelectric generator intended to operate a circuit located in the projectile, characterized   in that the generator (9) is produced in areas on which there is reduce thermal gradients due to acceleration.   2. - Projectile according to claim 1, characterized in that the generator (9, 9 ', 9 "') is produced in areas on which   thermal gradients occur mainly due to pro-   invoked by friction in free flight.   3. - Projectile according to claim 2, characterized in that the generator (9) is mounted in the point (10) of the projectile. 4. - Projectile according to claim 2, characterized in that pairs of generator elements (16), electrically connected together, are arranged in a star at least in a plane which extends substantially-   ment transversely to the longitudinal axis (22) of the projectile.   5. - Projectile according to claim 4, characterized in that the pairs of elements (16), in the region of the transition between the point of the projectile (10) and the cylindrical envelope (4) of the projectile,   pour a hollow cylinder wall of thermally insulating material (15), which surrounds a heat sink (12).   6. - Projectile according to claim 4, characterized in   that the pairs of elements (16) are arranged in the area behind   re the guide ring (5) of the projectile and surround an accumulator of   heat (29), which is turned, with its free surfaces, towards the connection zone cord to a propulsion socket (2).   7. - Projectile according to claim 1, characterized in that the generator (9 ") is embedded between a connection part of the pro-   thermally insulating jectile and a heat accumulator (29), the area opposite to the generator (9 ") faces a propulsion socket (2). 8. - Projectile according to any one of claims   6 and 7, characterized in that the heat accumulator (29) is equipped with   heat conducting bodies (32). 9. - Projectile according to claim 1 or the claim   tion 2, characterized in that pairs of generator elements (16) connect electrically arranged, are arranged in stars in at least one cylindrical envelope surface placed concentrically with the longitudinal axis (22) of the   projectile on a punch point (34) in front of a shoulder (33) of the pro- jectile. 10. - Projectile according to claim 9, characterized in that the generator is produced in the form of a coil (35) consisting pairs of sheet-shaped thermoelectric elements (element sheet 36). 11. - Projectile according to claim 1, characterized in that the generator (9 "") with its pairs of hot cold thermoelectric elements (13-14; 16) is oriented parallel to the longitudinal axis (22) of the projectile and is arranged in the projectile (1) with the hot side   (13) oriented towards the posterior side (31) of the projectile. 12. - Projectile according to claim 11, characterized   in that the generator (9 '"') is a winding (35) made up of pairs of elements   elements (16) arranged in a spiral to form a cylinder.   13. - Projectile according to any one of claims 11 and 12, characterized in that a heat sink (12) is associated with the sides pairs (16) of elements (16) in the projectile (1). 14. - Projectile according to claim 13, characterized in that a metal safety device for firing the projectile (1)   is produced in the form of a heat sink (12). 15. - Projectile according to any one of claims   Preceding, characterized in that the generator (9) is arranged as a prefabricated element inside the projectile or between parts of the projectile.   16. - Projectile according to any one of claims   previous, characterized in that following the generator (9 '"') a polarity discriminator (39) is connected which is connected to a priming input (42) of the circuit (8 '). 17. - Projectile according to any one of claims   previous, characterized in that following the generator (9) a voltage multiplier (47).