US2613605A - Projectile - Google Patents

Description

E. W. BRANDT Oct. 14, 1952 PROJECTILE s Sheets-Sheet 1 Filed July 11, 1947 Z'mventor 5 M (Ittornegs E. W. BRANDT Oct. 14, 1952 PROJECTILE I5 Sheets-Sheet 2 Filed July 11, 1947 Oct. 14, 1952 w BRANDT 2,613,605

PROJECTILE Filed July 11, 1947 '3 Sheets-Sheet 3 7/ 5 I I I as 9 finentor (Ittomegs Patentecl Oct. 1 4, 1952 UNITED STAT-E I PATENTO 2,613,605 FFICUE PRGJECTILE Edgar William Brandt, Geneva, Switzerland, as-

signor to Anstalt fiir die Entwicklung von Erfindungen 11nd gewerblichen Anwendungen Energa, Vaduz, Liechtenstein, a corporation of Liechtenstein Application July 11, 1947, Serial No. 760,423 In Switzerland November 9, 1946 2 Claims.

This invention relates to projectiles and more particularly to hollow charge perforating projecrangements, as well as experimentation, could give them.

The functioning of hitherto designed hollow charge-perforating devices has been previously expounded and described, and may be summed up as follows:

An explosive charge, acting on a preferably metallic cone or hood having a large surface and persecond, and if this core in formation has to.

cover a certain distance before reaching the armour, the gases partially liberated at that moment from the mask and from the hood flow forwards towards the target with a very much greater velocity and may, on the one hand, pre-. vent the correct closing of the hood and, on the other, constitute between the core and the armour a protective cushion which greatly reduces the perforating power. 7

In the design of the hollow charge projectile forming the subject of the present invention, the increase in perforating power relatively to that obtained in prior designs results from structural dispositions and proportions by which the explosive power determines and develops an essential supplementary effect not hitherto analysed or described, but nevertheles capable of supply-- ing the main result.

These novel dispositions and proportions, as will hereinafter be fully described, actually ensure the formation and projection of a jet issuing from the interior ofthe core and thrown forward of the latter with such velocity that it reaches the armour at a useful distance, without the gases 7 of the explosive charge being able to diminish the effect thereof. This result constitutes an effective reply to the protective means that have been designed to equip tanks, by providing on the'exterior of their jackets a light coverin or prearmour intended to effect the bursting of hollow charge devices sufficiently ahead of the principal 5 2 armour so as substantially to reduce the useful effect thereof. 7

Now, it is particularly important to be able to provide combatant units, particularly front line formations, with anti-tank weapons which are at one and the same time, light, simple, powerful,

"and dependable, capable of effective action against armoured fighting vehicles of all classes, even those equipped with the protective devices hereinbefore referred to.

In order to achieve this object, it i therefore convenient to have available very high performance equipments possessing the essential technical characteristics.

The hollow-charge anti-tank projectile of the present invention is of the type comprising an explosive charge of a thickness decreasing from the apex of the hood to become almost zero at the base, and is characterized in that said charge is of conical shape externally for about twothirdsof its height and then substantially cylindrical, the height of the conical portion of said charge being comprised between 80% and 120% of the height of the perforating hood.

Experience ha shown that the perforating efficiency of a projectile complying with the fore-J going feature is far greater than that of any other known hollow charge projectile. The explosive charge, burning from the rear towards the front outside the hood applies to the whole surface of said hood a thrust which at the same time causes its projection forwards and its progressive closing from the rear to the front along its longitudinal axis. Under the powerful action of the explosive, the wall of the hood is projected with considerable velocity from the periphery to-' wards the axial centre; the material of said hood,

which is of great density (for examplemild steel) and has a high coefficient of elongation and therefore great malleability, is thrown in symmetrical fashion and from the rear (apex of the hood) towards the front (base of the hood) with such velocity that, under the influence of the considerable pressure developed, part of the internal and central thickness .of the material forming the hood is projected from the interior 1 and from the rear ahead of the mass, in the form positions forming the subject of the presentinvention, the thickness of steel armour thus perforated reaches, and may exceed even twice the diameter of the hood and of the explosive charge.

The considerable instantaneous work andthe enormous pressure produced on the armour bythis perforatingljt result in a likewise considerable heating, which isas high as the melting temperature of the material perforated.

The transmission of fire between the the apexof the hood is ensured 'by waves. The presence of any transmission system of solid and inert matter, placed axially inside the projectile between the fuze head and the apex of the hood,

, would through its presence in weight and volume greatly hinder the aforedescribed phenomenon, and would cause a great diminution of the desired effect and perforating power. 1

.Notgonly' do the given structural dispositions and proportions ensure a greater perforating ef-: fect," butthe latter is conserved over a substantially greater distance than; in the case of previousxdesigns. I ,The'. projectile of "the present invention is further characterizedin that the distance be.-

tween the front of the ,fuze-head and the detona fuze head I and the detonator placed in the chargein rear of tor ,placed inside the charge is at least equal to twice the height of the hood from its apex to its base,;and in that said distancecorresponds to thatnecessary for obtaining the optimum effect of the 'perforatingcore on the tar-get, plus a supplementary distance which, taking into account they speed of the projectile, corresponds to the pathwhich, from the moment of impact,-the perforatingcore still travels towards the target during the time of operation.

The projectile of the present invention 'complieswith the required conditions by reason ,of itsconsiderable perforating power relatively to its weight and'calibre, its ease of firing, and its great accuracy. Furthermore, it has the advantage of possessing-a ballistic form ;of least resistance,

Dfirfect stability; during the trajectory, and, relatively to the speed of projection, maximum range. said projectile, having thin walls preferably of .lightmetal, doesnot throw offsplinters which arev dangerous; to thefirer when it acts on the target, even at short range. Thus, in the case of the type designed for rifle propulsion, the perforating hood constitutesinweight, apart from thecxplosive charge, the principal part of the device, I j

,, In, accorda cewith another feature of the invent-ion, the frontof said head-fuzeand the in-,

ternal safety device of the grenadeare disposed, in relation to the base of the hood, symmetrically and at substantially equahdistances from said base. 1

@The arrangement and proportions of the 'devices permit operation, even at very high incidence, while giving the firer' the maximum safety. A delayed arming device interposed between the fuzeand the detonator prevents any premature transmission of fire to the explosive charge and device'designedto prevent anypremature transmission of fire when the projectile is equipped with its head 'fuze. l

body of the projectile.

In a'projectile of the typeforming the subject .;of the invention and comprising a hollow charge ....provided at the front with a metallic hood, it is difficult to envisagethe'fitting of the detonator through the front. Provision is therefore made for the detachable detonatorY'to be housed in a small, preferably cylindrical, cake of explosive, which is adapted to "be inserted into a corresponding cavity provided in the rear portion of the explosive charge of the projectile. v To this end, the

base portion of the projectile comprises an aper-' ture which is hermetically sealed by means of a safety stopper, which can be locked and immobilised by screwing thetail on the projectile.

' The projectile of the present invention maybe designed:

1. As a rifle grenade; it is'then provided with a tubular vaned tail which caps the launching -attachment fitting the end of the rifle barrel.

2. As a projectile intended to be launched from" a smooth. bore barrel; the outer wall being rein forced, particularly in the conical portion, to

withstand the pressure of the propulsion gases, it then comprises at the rear a cartridge containing the propulsive charge; vanes are mountedeither on the charge carrier tail or on the rear of the 3. As a projectile fitting into provided with a self-propelledyaned device for firing without recoil from an appropriate launching tub'e.

4.. As an anti-tank aircraft projectile; in this case, on being releasedfrom the aircraft, suitable v'aning, for example deploying over a greater diameter than that of the projectile, ensures its stability; the vaning may also cause the gyration of the projectile and, in consequence, the arming of the internal safetydevice at a desired distance,

Other advantages and features of the invention will be apparent from'the followingdescription taken in conjunctionwith the accompanying drawings which illustrate diagrammatically and by way of example various. embodiments there;

of, and in which:

Fig. 1 illustrates in elevation and partial lon- 1 gitudinal section one embodiment;

Fig. 2 illustrates diagrammatically the formation of the core under the ,action of the 'deflagration of the explosive charge;

Fig. 3 is a'plan view of'the phenomenon illustrated in Fig. 2;

Fig. 4 illustrates, in elevation and partial 1ongitudinal section a perforating, hollow charge projectileprovided-with a detachable detonator; I Figs. Sand 6 show respectively,v in elevation, embodiments of projectiles intended to befired from smooth bore barrels;

Fig. 7 shows, in exterior view, va projectile fitted into a rear tubular case carrying the explosive charge;

Fig. ,8 illustrates in elevation a projectile provided with a-self-propelling device;

. Fig. 9 is an exterior view, partly in section, of ananti-tank aircraft projectile provided with vanes adapted to deploy over agreater diameter than that of the projectile; v

The projectile illustrated in Fig. 1 consists of.

a body I provided at the front with a conical head 2, and at the, rear with a tail .3 provided with vanes 4 I H p Thebody I is formed of ajacket 5 housing the explosive, charge formed by two superimposed mas s a d The p er ma s 5 t m in.

, a tubular a e;

carrying the propulsive charge, or as a projectile charge and. consists of high explosive, which may be either compressedor cast, and the lower mass 1 or relay charge preferably consists of compressed pulverulent explosive.

. On its front face,. the mass 6 has a deep conical cavity 8 which opens outfrom the rearitowards the front. Against the walls of this cavity is applied a metallic hood or cone 9 immobilized in position by a collar or mask l;fixed on the.

shell below the conical head 2;. The explosive charge 6-1, which is thus of decreasing thickness fromthe apex of the hood and becomes almost zero at the base of the latter, is conical externally overabout two-thirds of its height and then substantially cylindrical; the height of the conical portion of said charge beingequal to that of the perforating hood or approximating thereto. i i

The collar or mask 10 has at its base an outer diameter substantially equal to that of the base of the perforating hood 9;. the internal oblique face H of said mask being of a height-at least equal to its width in section I2, it forms with the inner wall of the perforating hood 9 an angle a of at least 90. 1

A member l3 caps the mask l,0,forming a support for the crimping of the'jacket 5 on the conical head 2 provided with the fuze Land is extended inside said fuze-carrying head.

This general arrangement and theproportions allowed, enable a minimum external calibre, relatively to the diameter of the perforating hood, to be obtained, and thus minimum weight in relation topower, as well as easy mounting of the component parts.

.A detonator I5 is housed preferably in the mass 1 of pulverulentexplosive, whichacts as a relay between said 'detonator I5 and the high ex plosive 6. Fire is transmitted by waves from the fuze I4 tothe detonator l5.

A wedging washer 31,.preferably of cork, is provided to immobilise the detonator l5.

Fig. 2 illustrates the operation and effect obtained with the novel arrangement of Fig. l.

The explosive charge, deflagrating "from the rear towards the front outside the hood 9,.which is made. of, a material of suflicient density (such as mildsteel) and having a high coefficient of elongation and therefore. great malleability, appliesto the whole of the surface of said hood a thrustv which effects the concentration and projection of the material constituting said hood:

1. Projection to the front of the whole of the material of the hood in accordance with the arrows a, b, andso on. i n I 2. Concentration of said material towards the longitudinal axis of the hood, following the arrows a, b, and soon.

It is noted that the resistance that the material constituting the hood, which is beaten out and driven by the explosive charge, can offer is negligible in relation to the power of action of said charge. i it I Now, ifthe speed of projection a, b or, respectively, any other'speed 0:, along the longitudinal axis is already relatively great (about 2000 metres per, second), the speed :c, or respectively any other speed Va, acquired transversely bythe material of said hood is already decidedly greater, and at least double. l u

It will be seen, moreover, that the transverse nents of the speeds Va and vnwhich are 333 1? oppose one another; "so thatthe conver gence towards the axisof; the mater al of the hood will take place according to a resultant V at extremely high speed.

of said cap Moreover, the plan view (Fig. 3). shows that the material .is projectedin converging. manner to?- i wards the centre .(longitudinal'axis of the hood); Now the meeting of said matter takes place from the rear towards the front on this centre, and V the high speed at which it takes'place, as well as the irresistible. pressure developed, cause the projection of ajetahead of the central portionhof the closedihood, thespeedof said jet accelerating to reach the value W which is considerably higherstill. The arrangements and proportions of the projectile of the present invention ensure. this jet of optimum formation and remarkable.

effectiveness. The speed of' said jet is in fact liable to exceed to a marked degree that ofthe explosive deflagration proper, which itself attains a speed of 7000 to 8000 metres per second;

It is clear from Fig. 1 that the distance be of the fuze head M are equal and inferior ree; spectively to twice the length and diameterof the transmitter cap IS. The total weight givon' by the assembly of. parts constituting said fuze-ls thus reduced to less than four [6. The front fuze head [4 and to the base of the perforating hood, disposed symmetrically and at substantially equal distances from said-base; this enables the projectile to be given the aerodynamic shape compatiblewith stability,iminimum resistance, and maximum range.

The fuze carrier member quence of the ready deformation of the fuze carrier 2, the fuze l4 acts instantaneouslyonimpact through being driven in and by inertia; without any reduction of speed or the weight of? the projectile having to intervene inthis operaa tion.

This result is all the betterfor: the fact that, on the one hand, the fuze body is. shorter, more rigid, and less deformable by shock, and that,"on

the other hand, the fuze carrier has less resist-J ance to the shock of impact. The apex of the hood 9 is situated towards the centre of the total length of the projectile .(Fig. 1) The outer jacket 5 of the explosivev chargedomed in the first place and, when straightened by pressure, giving the desired expansion ensuring the maintenance of the fit.

This method of mounting is extremely simple and at the same time very strong; it enables the weight of the affected members to be reduced to the minimum, and thus contributes towards obtaining a particularly light projectile. The base portion, I8, placed inrear ofthe explosive charge, covers peripherally, over its enand , tire height, the small cake of explosive 1 (Fig.

1), and the diameter of the latter is. about half that of the principal cake 6. g V I The weight of the explosive charge 6 as a whole is substantially equal to half the total weight of the projectile. The vaning 4 is composed of a series of thin times the weight theinternal safety; .device I! of the grenade (Fig. 1) are, in relation 2 andthle when, are combined in such manner that, incomet m the examm aeraeosr I vanes S21 bedded in the thickness of theiwall' 22 b zgt ;mubularilguiding tail,-..these vanes pro-t jecti'ng to the rearl of. said. .tail and; forming a vaningwfanheight .substantially less than its diameter. i I

;= This disposition of multiple vanes renders .it

si'stance; to obtain: an optimum stabilisation 'ef-. fectwith a minimum surfacenand weight of materi'a'l,."the'minimumweight of the vaningat'a greatf distance from. the: centre .of gravity effectively.:iriterveningto increase the stabilityof.

thri -projectile;

e. 'jectileIequipped linsaccordance with: the features of the invention; the base of the perforating hood supports, xon firing; the'inertiaeffect of the whole of' thezfront-portion (mask, ogival head, fuze).

Use? is thus made .of the very? great strength at thebase of thelhoodqa'nd of thecake of explosive, which 'thus as'sure the "whole assemblya remarkable solidity.' I a ;-Finally, the proportions allowed enable a projectile.:.'to ;'be designed the centre of gravity of which .is -substantially midway in its total length.

, Theip'roiectile illustrated in Fig. 4is similar: to that'zillustrated in Fig. .1,but comprises a detachable-netonatorhoused in a small .cake of llustrated'in Fig; '1 of a propossible with; the .minimum aerodynamic ree.

constituting; an aanti-tanl: aerialjbomb (Fig. 9):.

it comprises suitable vaning 26 which, on release from the aircraft, is adapted to unfold in-accordance with 26', for example, over a greater diameter than that of 'theprojectile itself, and. thus ensures great stability of the latter; it may also cause the. gyrationof: the projectile and, in cone sequence, the arming of the :internal safety de- WhatI claim is: v 1.. A hollow charge perforating projectile, said vice of the latter at'a desired distance.

projectile'comprising: a shell, a. highexplosive charge in said. shell, said highexplosive charge being formed withla front cavity, a hood applied against the wallsof said cavity. and" adapted to be transformed by the detonation intoa core,

a base portion on said shell, a vaned tubular guiding tail mounted at the rear of said base portion, said base portion being formed with' an compressed explosive 21, in which isprovided a cavity 28' corresponding to the .external shape of the detonator 1.5.7: A cylindrically shaped cavu ity-28 ismoreoven'provided in the lower mass of compressed pulverulent explosive'l, the diameter ofisaidiz cavity corresponding. exactly to that of the"cake:2 1. 1';

- The 1 safety device :may' either, be integral 'withthe detachable detonator, or be independent and "be. permanently mounted in the housing 39' annular inside groove at its rearinside'end, said shell and said base portion engaging mutuallyover the height of the base portion, and a washer:

engaging the :back part ofsaid shell and being adapted to be forced during mounting into saidgroove to set together the shell with the baseportion, in order to-ensure thetightness -between them. Y

2. 'A hollow charge perforating projectile, said projectile comprising: a shell, a high explosive charge in said shell, said high explosive charge being formed with a front cavity, a hood applied against the walls of said cavity and adapted'to be transformed by the detonation. into a' core, a base portion on said shell, a vaned tubular guiding tail mounted at the rear of said basepor-tion;

said base portion being formed withan annular inside groove'at its rear inside end, said shell provided'qforvthatpurpose'in the upper mass gh re'xplosive: 6.

I- JAn :aperture 1:3'l';'of" the same diameter as the cavity 29, is reserved in the base 18 of the projectile'zto permit the introduction of the ideto 'nator =intoi..;said cavity 29. The aperture 3! is provided with a safety stopper 32, which is locked an'dimmobilised by screwing on to the basethe tail.3.

;--:'In this particular'c'ase, provision has-been made for astrongerimounting for the vanesthan in the device illustratedin Fig.1. The tube 22 of the tail3c'omprises nar its rear end, a circular I countersunk portioni33 edgedonthe one hand, 'atzth'e' f-ro'ntfi'by a re-entrant" bevelled rim 34 and, atthe rean'iby a circular-"flange 35. The vanes 2 I are fashioned in sets of twoficut from the'sainesheetof metal, and have between them apor'tion in' th'e shape of av cylindrical segment 36,"whic'h engages inthe circular countersunk portion 33, after which theflange'35' is fitted over thevanes, which"'are thus immobilised on the tube 22." 1 1 v 1 The'projecti'les illustrated in Figs. and-6 are intended-to'rb'e' fired from a smooth bore. barrel; they 'c'omp'r-ise at the rear a cartridge 23 containi'ng the pi opulsiv'e charge. Vaning- 4 is mounted either -j-on the charge carrier tail 3 (Fig; 6) or on'the rear'of-thefprojectile"(Figi 5). g The;projectilefillustratd in Fig. '7 -is fitted into a rear tube 24" c'arryin'g the propulsive charge 23.

The-projectile mayalso be provided with a varied self propulsion; device 25 for firing without recoil 51a the event of the'projectilefof the invention from an appropriate launching tube and said base portion" engaging mutually over theheight of the base portion,:an'd a washer en'-, gaging the back part of said shell andf-being adapted'to be forced during mountingflintosaid groove to set together the shell with the'base portion, in order to ensure the tightness between them, said high-explosive charge comprising a large cake 'and a small cake of explosive, said small cake being placed at the rear of the large cake, said base portion covering peripherally said small cakeof high ex'plosiv'e' for its entire height.

EDGAR ILLIAM BRANDT.

' REFERENCES CITflD:

.The following references, are of file of this patent:

v UNITED STATES PATENTS 1 Australia Aug: 14, 1941 joTHER REFERENCES j The Shaped; Charge,- Explosives: Engineer,

. July-Aug. 1945,-pp. -163.

'I"h'e Explosives Engineer, 848 Delaware Irust Building, Wilmington, Delaware."Copy in Divi-,

' siOn 70.

""Z'itshrift Pfur 'dasj 'gesamte' schiess und record, the

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