US2879955A - Airborne bodies and in particular self propelled missiles - Google Patents

Description

March 31, 1959 H. P, G. A. R. VON ZBOROWSKI AIRBORNE BODIES, AND IN PARTICULAR SELF PROPELLED MISSILES Filed J l 22, 1952 4 '2 Sheets-Sheet 1 Q N g March 31, 1959 H. G. A. RI VON ZBOROWSKI 2,879,955

AIRBORNE BODIES, AND IN PARTICULAR SELF PROPELLED MISSILES Filed July 22, 1952 2 Sheets-Sheet 2 ATTORNEY United States Patent p 2,879,955 PatentedMar. 31, 1959 AIRBORNE BODIES AND IN PARTICULAR SELF PROPELLED MISSILES The present invention relates generally to airborne bodies (this expression including all bodies travelling through air and having an aerodynamic lift) which carry a charge of matter (for instance a propellent, a fuel, etc.) which is being consumed as'said body is travelling. My invention is more particularly concerned with rocket-propelled devices, and especiallywith missiles carrying a destructive explosive charge.

TThe object of my invention is to provide a body of this kind which is better adapted to meet the requirements of practice than those known at the present time.

.According to my invention, such a body includes, in combination with aerodynamic control means for giving said body a positive incidence or upwardly inclined attitude with respect to its path of travel, so that an aerodynamic lift is constantly maintained which opposes the action of gravity on said body, means (which may be constituted by the above mentioned charge of matter itself, suitably arranged for this purpose) for automatically varying this lift in accordance with the consumption of said matter so as to compensate, either fully or partly and in accordance with a predetermined law, for the variation-of weight of this body resulting from the consumption of its charge of matter.

Other features of my invention will become apparent intthe courseof the following description thereof with reference to the accompanying drawings, given merely by way of example, and in which:

Fig. 1 shows an anti-tank missile according to my invention, the top part being in axial section and the lower part-in elevation, with portions cut away;

Fig. 2 is a cross section on the line 11-11 of Fig. 1;

Fig. 3 is an enlarged section on the line III-III of Fig. 1;'

Fig. 4 is a sectional view on an enlarged scale of a detail of Fig. 1;

Fig. 5. is a diagrammatical view illustrating a modification of the same detail;

Figs. 6m 8 are diagrammatical views showing different arrangementsof a' spoiler included in the device shown by'the above mentioned figures;

Fig. 9 shows a modification of the armored head of the missile.

,"The following description relates toan anti-tank projectile. This projectile includes the following elements:

(a) A war head including a hollow charge 1, a hollow. armoredpoint 2 located ahead of said hollow charge and capable of opening a passage for said hollow charge in any Eprotective structure located in front of the tank armor wall proper, andcharge igniting means 3 such for instance as a delayed action detonator capable of starting, the explosion of the hollow charge 1 after the armor point 2 has already opened a passage through the proteetive structureof the tank;

(b) A main propelling system 4, advantageously of thei'powder'rocket type;

(c) A starting or launching propelling system 5 fixed on the projectile and which is also preferably of the powder rocket type; and

(d) Means for enabling the projectile to have, and keep, along its path of travel, a lift such that at least a portion of its trajectory is nearly rectilinear.

Preferably," the main propelling system i disposed line with and ahead of the starting propelling system and I provide, for the jet of combustion gases issuing from the main propelling system, an annular nozzle or outlet 6 (or a plurality of outlet orifices disposed annularly).

Furthermore, according to my invention, account being taken of the fact that the weight of the engine and the position of its center of gravity vary as a consequence of the consumption of powder, means are provided for causing the ratio of the total weight of the projectile to the aerodynamic lift thereof (controlled through means which will be hereinafter described) to comply with a predetermined law fixed in accordance with the desired path of travel of the projectile.

If the path of travel is to be substantially rectilinear (which is desirable in order to increase the probability of striking a given target), this weight to lift ratio should remain substantially equal to 1.

For this purpose, the propelling system 4 may be arranged so that the variation of its thrust and/or the displacement of the center of gravity of the projectile resulting from the consumption of the powder used for this propelling system comply with the above mentioned law. Concerning the thrust factor, the propelling system should be arranged in such manner that this thrust dej creases as more and more powder has been consumed so that, for a constant incidence or attitude of flight, the

lift decreases simultaneously with the total weight and at the same rate, whereby'the ratio of weight to lift reand which assists in producing the angle of inclination, decreases as the total weight decreases.

I Thus, the incidence, and therefore the lift of the projectile will decrease as the total weight decreases as a consequence of the consumption of powder. It will be possible, by a suitable choice of the law determining the relative dis-[ 7 placement (due to the consumption of powder) of the center of gravity with respect to the center of lift, to

obtain such conditions that the weight to lift ratio' remains substantially constant as the projectile is travelling.

In both cases, it-will be advantageous to give the powder bars which constitute the reserve of propulsive energy surface of each bar that is burning, it will be readily un-- derstood that non cylindrical bars of revolution give a lawof variation of the thrust which depends upon the shape of their generatrices.

As for the displacement of the center of gravity, it is determined by alaw which depends upon the shape the device that the center of gravity of the main propelling system is located, after combustion of the powder of the starting or launching propelling system, at the rear of l the center of gravity of the whole projectile, combustion of the powder of the main propelling system then producing a frontward displacement of said total center of gravity and therefore a decrease of the angle of incidence.

It should be noted that it will be advantageous to arrange the main propelling system 4-so that it keeps the speed substantially constant during the duration of the flight (balancing of the drag), a speed of about 500 3 metresI-per se'con'd. beingtconsidered as favorable for this" kind. of projectile, because it, makesgitpossible. to..use.;a1 launching propelling system of relatively small weight, to obtain a sufficient perforating power of the armored pointl2 and to reduce the-duration. oftfiight to values:

compatible with the destruction of moving targets:..(fromr 2 to.- 3 seconds foritargets located iat-IOOO-ISOO-metres).

Concerning; the launching propellingrsystem. 5, it. is? arranged, as alreadyindicated, in. such manner that its".

envelope is incorporated in the'projectilebody, to avoid thedangers which ,would be-runrby troopsdocated: ahead" of the. launching station, if. this launching: system. were" detached after it hasplayed its part.

On: the other hand, it-isadvantageous to distribute: the powder bars. of. the launchingypropelling system: in

atleast.two-groups,,disposed in tandemdike fashion;with:, respect-to each other, the bars 5b of the rear. group gbeings.

fewer in number and at a greater distance from. each other? than the bars Saof the frontgroup This propelling systemrfurther includes a'frangible rear;

diaphragm 7 of .a resistancesuchthatit is destroyed only. when: the internal pressure of the-system, afterignitingz thereof (preferably electrical. igniting), has reached at:

predetermined value; for instance; ahout lol) kgs; per square: centimeter the" combustion gases then. escaping throughnozzle 8..

Advantageously, the envelope of the: auxiliary propellingsystem is givena slightly convergentshape-toward the front, which facilitates thearrangement of the outlet. nozzle 6- of. the main propellingsystem"(without increas ing the maximum diameter of the'projectile). andis further favorable for aerodynamic stability.

Such an auxiliary propellingr system" achieves a:: high stability of combustion; andkan', improved'fsafety concerns; in the critical internal pressuremottobeexceeded;

To givethe projectile apositive or upwardly inclined incidenceon. its trajectory and .to maintain. this. incidence,. the projectileisfitted with aniaerodynamic controlzsystern';

subjected to the action of a weighted or pendular device;-

so. that the incidence remains constantlyx positive-and. of the-same value regardless of1th'epositionwof the-projectile when it turns about its .longitudinalaxis.

Such a control. system is for. instance-constituted, asv shown by Figs. 1 and 3, by aring19 freely rotatable in the" intervalbetween the hollowcharge 1 and the main pro-' pellingzsystem (advantageouslywiththe interposition of. a ball bearing .a. counterweight 11. and a spoilerull projecting slightly from the outline of the projectile cross section, these two elements being? located on. the same side of ring 9, so that saidspoiler always projects from,v

the lower portion of the projectile andcreates in this. region a zone of aerodynamic overpressure capable ofproducing the desired positive incidence.v Although; the

pressure of the air on the spoiler will have some tendency, to. exert a downward torque onthenose: of the-missile, the dimension-of: the spoiler is-such that; this ;torque is much. less than the upward aerodynamic pressure. createdizin front of the spoiler, so. that the resultant thrust on the nose-of the missile is upward;

A. tail unit, preferablyconstituted byarrear annular wing ofa diameter equal to the caliber of the projectile,

is advantageously provided for stabilizing. said projectile on its trajectory.

But if this tail unit is. adapted to. work satisfactorily at. the supersonic speedlfor which-the: projectileis de-- signed, it might happen that, during the launching period (wherethe speed is subsonic and the stabilizing effect of 'the tail unit is relatively small), the axis; of the projectile should assume the wrong direction.- In particular,. wh'en..the projectile is passing fromr csubsonic to supersonic speed, it could.be stabilized only by means-of a tail unit. of a diameter greater. thtmsthat of. ,said 1 projectile;

In order to obviate this diificulty,;- I..make"use' of' an' arrangement illustratedby Figs. 1. andA.

I provide, at the outlet. ofthe-nozzleS ofthe-launching;

propelling system, adjustable deflectors; for instance a: plurality of. spoilers. 14 (four in. thetexamplel illustrated).. distributed at equal angular intervals along the periphery of the nozzle and capable, when they are made to project into the gas jet (as shown for the lower spoiler in Fig. 4), of deflecting said jet and therefore of modifying the direction of the propulsive thrust:

These spoilers are operated by a system, for instance including dynamic; air intakes; sensitive to angular dis'-- placements of the'axisof'the projectile" so as to exert a correcting effect tending to return the" projectile axisinto its initial direction.

Preferably,I couple diametrically'opposed spoilers with each other through adevice having, some. flexibility, so that the operation of one causes the other to be brought into retracted position: For this purpose, for instance, every spoiler 14 is mounted at one end of a lever 15 pivoted in its middle part about an axis 16, the other end of this" lever being-coupled'with the corresponding 'end of the diametrallyopposed lever through aring element 17, which is 'made flexible in order to=avoid" 'play."

It is therefore necessary, intheexample shown by tlie drawing, to'provide'two flexible rings-'17, disposed one behind the'other. However, the points-where the respective'levers 15are in contact withthese rings.must all 'be'- located in the same plane at right angles-to the axis 'o'fltheprojectile; For this purpose, every lever. l's bears'against' asmall projection 17a of'the edgeof'thecorrespondingt. ring 17, this projection extending t'owardthe rearfon that front ring 17 and toward the-front= for the rearrmg l'l, whereby the centers of th'ese four projectionsare locatedn in the same transverse plane. L

The dynamic air intake control means -may'be constrr tuted,'. as shown by the drawing; by four" manometrie': boxes 18 the inner wallsof which are flexible and bears: respectively against the forwardends of levers 15 (which-f forward" ends in turn. bear against elastic-rings 17) and.

theouter wallsof which, constituted'by the i envelope of the projectile, are provided with respective air intakes 19.-

Ifit is desired to collect a portion nof the dynamic:-

pressure when the projectile gets slightly inclined on its;

trajectory, it is advantageous to give a sharp bevelled? shape to the rear edge of 'each orifice 19', as shown by Fig. 4. This rearedge might be made tol project from'ta the wall of the projectile to increas'e the air inflow."

On the contrary, if it is desired merely tozutilize the variations of. static pressure taking! place on Ithe rear part,

of smaller diameter, ofthe projectilebody,v when 'saidi projectile assumes an undue.oblique positionzonvits trajec-t tory, I may, as shownbyFig. 5, provideholeslQ having straight edgesand: locate' the point where the flexible walls of boxes 18 act upon levers 15a between thecfub' crums 16a of these levers andthe correspondingcspoilers.

Preferably, in order to take into account theifactthati the counterweight 1 1. of? thearotary." control member (spoiler 12) tends to bring the center.ofygravitys.of!tha projectileawaytrbmthe: axis of. symmetry-thereof, means will be provided for slightly-deflecting, the? thrust \so-thati. it passes exactly through this center. ofgravitye SUCI'M meansmay be constituted, asshownby the drawings,.by applying a small gravity load on the levers 15 whichcon'; trol spoilers 14, this load being, constituted, for instance, by; the weight of" rings 17 'in the construction t of Fig.4;

and" by a special counterweight'20 in the'constructionof ner as to reduce the importance of this transvers'eb component. I

For this purpose, in the constructionof.Figao -thea spbilers 'are' inclined toward the front with respeet to the jet and iii-this case the residual transverse component facilitates the displacements of the spoiler toward its active position under the action of its manometric box.

In the construction of Fig. 7, the spoilers are inclined toward the rear, in which case it is the displacement toward retracted position which is facilitated.

In the construction of Fig. 8, the spoilers have a curved shape (determined by experiments and calculation) such that the transverse-component is reduced or eliminated.

A'projectile such as above described may have its main elements made of a light metal or alloy so that it can be easily carried by an infantry man. It can be launched by means of a very simple tube. It will comply with the above stated conditions of velocity and straight trajectory.

It may be fitted with a target-seeking head, as shown at 21 in Fig. 9, for correcting its trajectory at the end of its travel, this head being preferably housed in an axial recess provided for this purpose in the armored point 2. This head will operate supplementary control members (for instance spoilers) distributed regularly over the periphery of the projectile body.

In a general manner, while I have, in the above description, disclosed what I deem to be practical and efficient embodiment of my invention, it should be well understood that I do not wish to be limited thereto as there might be changes made in the arrangement, disposition and form of the parts without departing from the principle of the present invention as comprehended within the scope of the accompanying claims.

What I claim is:

1. A rocket propelled device of the class described, comprising: a smooth elongated hollow body of generally circular cross-section, said body defining a combustion chamber; directing means carried by said device and maintaining said body in an upwardly inclined attitude during flight thereof through the atmosphere for producing an aerodynamic lifting force acting on the surface of said body; a combustible propellant charge disposed in said combustion chamber, said charge being formed to produce gaseous products of combustion at a varying rate, the manner of variation of said rate being predetermined by saidformation of said charge; and nozzle means communicating with said chamber for directing said gaseous combustion products rearwardly to produce a thrust for forward propulsion of said device, the magnitude of said thrust being controlled by said formation of said charge to maintain said lifting force continuously at a value which decreases in accordance with the loss of total weight of said device accompanying combustion of said charge.

2. A device according to claim 1, in which lifting force is maintained at a value substantially equal to said total weight.

3. A device according to claim 1, wherein said directing means maintains said upward inclination unchanged and in which the relationship between said lifting force and said total weight of said device is determined solely by said formation of said charge.

4. A device according to claim 1, wherein said combustible charge has its own center of gravity disposed rearwardly of the center of gravity of said entire device including said charge, whereby combustion of said charge will cause the center of gravity of said device to move forwardly during the courseffof said combustion and decrease the angle of said inclination to decrease said lifting force in accordance with the decrease in the total weight of said device.

5. A rocket propelled device of the class described, comprising a body defining a combustion chamber; nozzle means communicating with said chamber for directing gases formed therein rearwardly to produce a thrust for propelling said device forwardly; means for causing said body to assume an upwardly inclined angle for producing an aerodynamic lifting force during flight of said device through the atmosphere;a propellant charge disposed i said combustion chamber, said propellant charge being shaped to expose a continuously decreasing area for combustion, thereby producing gaseous products of combustion at a continuously decreasing rate, said rate of combustion decreasing in a structurally predetermined manner in accordance with the loss of weight of said device caused by combustion of said charge, said charge being so positioned with respect to the center of gravity of said device and the line of action of the force produced by said aerodynamic deflecting surface, that the angle, of said inclination is controlled during the course, of said combustion directly and solely as a concurrent result of said decreasing rate of combustion, together with the decrease in the weight of said device accompanying said combustion of said propellant charge and any displacement of the center of gravity of said device accompanying said combustion.

6. A device according to claim 5, wherein the angle of said inclination is continuously controlled to maintain the lift produced by said aerodynamic support substantially equal to the decreasing total weight of said device.

7. A self-propelled flying device which comprises, in combination, a streamlined body, a jet propulsion system for said body including a main propulsion engine and a launching propulsion engine located behind said main engine, a charge of fuel for each of said propulsion engines, the mass of the full charge of fuel of the main propulsion engine having its center of gravity located rearwardly of the center of gravity of said entire device, both of said engines being arranged to operate from the starting of said flying device but the mass of fuel of said launching engine being determined to last for only a fraction of the time of operation of said main engine, and aerodynamic means carried by said body for giving it a positive incidence position relatively to its trajectory.

8. A self-propelled flying device which comprises, in combination, a streamlined body, a jet propulsion system for said body including a main propulsion engine and a launching propulsion engine located behind said main propulsion engine, said launching propulsion engine including a rearwardly directed nozzle at the rear end of said body, a charge of fuel for each of said propulsion engines, the mass of the full charge of fuel of the main propulsion engine having its center of gravity located rearwardly of the center of gravity of said entire device, both of said engines being arranged to operate from the starting of said flying device but the mass of fuel of said launching engine being determined to last for only a fraction of the time of operation of said main jet engine, aero dynamic means carried by said body for giving it a positive incidence position relatively to its trajectory, deflector means movably supported by said body inside said nozzle for controlling the mean direction of the jet issuing therefrom, and aerodynamic means carried by said body and responsive to angular displacements, away from a predetermined position, of the axis thereof with respect to the direction of its trajectory for controlling said deflector means in response to said displacements to vary the direction of the jet to tend to restore said axis into said predetermined position with respect to said trajectory.

'9. A self-propelled flying device which comprises, in

combination, an aerodynamic streamlined body, vanes at the rear end of said body in planes substantially radial to the longitudinal axis thereof, a jet propulsion system carried by said body, said body having two jet passages opening rearwardly thereof, said jet propulsion means including means to supply propelling fluid to a first of said passages during launching only and to a second of said passages during a longer period at least after launching, deflector means movable with respect to said first passage for varying the mean direction of the fluid issuing therefrom during launching, and aerodynamic means carried by said body and responsive to angular displacements, away from a predetermined position, of the axis thereof with respect to the direction of its trajectory for controliing

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