US2938460A - Finned projectile - Google Patents

Description

May 3l, 1960 E. w. BRANDT 2,938,460

FINNED PROJECTILE Filed Sept. 5, 1957 2 Sheets-Sheet 1 IN VEN TOR.

ff um uw# May 3l, 1960 E. w. BRANDT FINNED PROJECTILE 2 Sheets-Sheet 2 INVENTOR.

Filed Sept. 5, 1957 United States Patent FINNED PROJECTILE Edgar William Brandt, Geneva, Switzerland, assignor to Anstalt fr die Entwicklung von Erfindungen und Gewerblichen Anwendungen Energa, Vaduz, Liechtenstein, a corporation of Liechtenstein Filed Sept. 5, 1957, Ser. No. 682,183 Claims priority, application Switzerland Sept. 12, 1956 1 claim. (ci. 1oz-s6) This invention relates to a finned projectile.

The improvement of finned projectiles intended for anti-tank warfare is of considerable interest because these projectiles retain the full effect of the hollow explosive charge on impact on the target, unlike the conveutional artillery shells in which the high-speed gyration considerably reduces the penetrating power.

Perfect stabilization of a finned hollow-charge projectile firedV at high speeds requires appropriate solutions to the problems whose difficulties will be clearer from they following considerations:

Since the discovery of the remarkable penetrating effects obtained with a hollow charge projectile, the development and use of which have become widespread during recent years for the purpose of increasing anti-tank combat means, it has been found that the various structural obstacles placed in front of the penetrating jet considerably reduce its effects. Thev hollow-charge projectiles already adopted therefore contain a ballistic cap practically empty and free of any obstacle likely to reduce the penetrating power of the jet, the cap being itself as thin as possible. These arrangements, combined with the fact that the cavity of the hollow charge extends rearwardly over a great part of the depth of the charge holder, contribute in shifting the centre of gravity of the projectile to the rear and show the difficulties of producing a finned hollowcharge projectile whose centre of gravity must, in order to ensure optimum precision and stability, on the contrary lie at a sufiicient distance from the empennage.

It is for this reason that a great deal of research and numerous tests have been and are being carried out for the purpose of producing high-speed projectiles capable of extending the anti-tank action and the remarkable effects of the hollow-charge to a greater distance, which projectiles consequently combine all of the following essential advantages and characteristics:

A. A general aerodynamic shape as perfect as possible, offering a minimum resistance in the air: hence, -the best maintenance of speed over the trajectory and consequently the greatest practical range of use;

B. The maximum initial speed permitted by the dis- .charging weapon and the minimum time of flight until 4meeting the target; C. For a given calibre, optimum penetrating power and effect, with dependable operation irrespective of the angle of impact on the target;

D. High precision, resulting from judicious combination of the forms, resistances and densities of the struc tural materials used, enabling the centre of gravity to be placed at the master section, level with the sealing and `driving band, and thus enabling the optimum stabilizing effect of the empennage to be obtained.

y The magnitude of the preparatory, technical and design research, and the considerable interest of arrangements capable of ensuring the practical realisation of projectiles .combining such advantages even at speeds of 600 to 1000 metres per second and more, will bereadily appreciated.

2,938,460 Patented May 31, 1960 "ice The present invention relates to a finned projecti1e,.of ogival shape at each end, comprising a charge carrying body, an explosive hollow charge housed in said body, a metallic lining for the cavity of the said charge, a balllstic ogive at the front of said body, a percussion fuze 1n the head of the ogive, a means for transmitting combustion from said fuze to a detonator disposed in the charge, and an empennage-carrying tail, said projectile being characterised in that the said ogive comprises a hollowed and resistant rear part serving as support for a dense solid front part deformable on impact and having an axial aperture over its entire height.

Hitherto, care was taken not to ballast the front of hollow-charge projectiles in order to prevent the fluid metallic jet emanating from the lining of the cavity from being deflected and its penetrating effect from being reduced by the additional thickness that a considerable ballast mass might have constituted. Now experience shows that if this mass is sufficiently ductile and its kinetic energy high, it breaks up and spreads on the target before the penetrating jet reaches it.

In one particular embodiment of the invention, the said axial aperture is occupied by an explosive column of which the radial explosive effect on impact disperses the solid part of the ogive and thus frees the passage of the penetrating jet issuing from the hollow charge.

The explosive column thus provides in the ogive an axial channel the aperture of which continues to exist during the breaking up of the ballast mass on the target. Moreover, since the impact of the projectile takes place at a residual speed of the order of 400 to 700 metres per second, and the transmission of combustion to the explo sive charge takes place at a much greater speed, 4000 to 7000 metres per second-hence approximately ten times greaterit follows from the invention that the operation of the hollow charge and the effect of the penetrating ,iet on the armour take place before the projectile has covered all the distance provided in front of the hollow charge.

The provision of the weighty ogive thus defined in the head of the projectile considerably increases the stability of the projectile and its ballistic qualities, because of the position given to its centre of gravity, without there being any consequences having an adverse effect on penetration.

In one embodiment of the invention, the solid front part of the ogive is of a depth approximately equal to or greater than that of the hollowed part following it.

According to another feature, the aforesaid parts of the ogive are made in a single piece (for example of brass or mild steel).

By way of modification, the solid and hollowed parts of the ogive may be constituted by two separate superimposed parts (for example, lead or lead alloy for the solid part, and brass for the hollowed part). In this case, the rear part of the ogive has at tbe front a shoulder which acts `as a support for the front solid part; said shoulder may be provided with an extension of smaller diameter penetrating into the solid part of the ogive.

A strong retaining sleeve is preferably disposed along the axis of the solid part, for the purpose of securing and centring the latter and forming an ogival head and fuze carrier.

According to a particular embodiment, the rear part of the said column,` solely ensuring the very high speed of the transmission of combustion to the detonator, is of a smaller diameter than its front part housed in the solid part of the ogive.

According to afurther feature of the invention, one or more elements adapted to produce a secondary effect on impact (smoke-producing, toxic, incendiary and like effects) added 'to the penetrating effect of the hollow charge, may be incorporated in the solid part of the ogive.

Moreover, depending upon the nature of the metal or alloy constituting the said solid part, it is advisable to provide the latter externally with a resistant and insulating covering.l

A finned hollow-charge projectile complying with the aforementioned features has, according to the invention, a general profile ogival at each end in the absence of a cylindrical part, the charge-carrying body being connected without break, from the front of the band, to the profile of the ogive, while the empennage-carrying tail is the extension, also without break, of the conical rear of the said body, the angle of departure of which does not exceed 6. Moreover, the constituent parts of the projectile in front of the master section are connected along a continuous profile of an angle less than 10 and are of a total height equal to at least 21/2 calibres. The centre of gravity, the master section and the driving band of a projectile of this kind are preferably situated at the level of the connection of the front and the rear ogival parts.

According to another feature of the invention, the front of the hollow charge and of the metallic penetrating cone, at the maximum diameter of the cavity of the charge-carrying body, are situated beyond the master section, in the externally ogival part of the projectile. This particularly judicious arrangement contributes to the desired advancing of the centre of gravity of the assembly, without reducing the calibre or the penetrating power of the hollow charge.

In order to enable the invention to be more readily understood, reference is made to the accompanying drawings, which illustrate diagrammatically and by way of example, various embodiments thereof and in which:

Fig. l is a partial axial section of a first embodiment of a projectile according to the invention;

Fig. 2 is an axial section of the front part of a projec tile constructed according to a second embodiment;

Fig. 3 is likewise an axial section of a modification of the front part of the projectile shown in Fig. 1;

Fig. 4 is a modification of Fig. 3;

Fig. 5 is a detail of Fig. 1 lon a larger scale and in section; and

Figs. 6 and 7 diagrammatically illustrate the operation of the projectile at rest and on impact on the target.

The projectile shown in Fig. 1 comprises a percussion fuze 1 in the head of an ogive 2a, 2b, an axial explosive column 3a, 3b housed in a casing 4 and following the fuze 1; a charge-carrying body 5 provided with a sealing and driving band 6, a hollow explosive charge 7 housed in the said body 5, -a metallic cone 8 lining the cavity of the charge 7, and an empennage-carrying tail 9 which is an extension of the rear of the said body. A detonator (not shown) is disposed in manner known per se in the explosive charge behind the open top ofthe cone 8.

The ogive 2a, 2b, made in a single piece (for example of mild steel or of brass) comprises a front part 2a of truncated conical shape, solid, and of high density, provided with an axial aperture occupied by the part 3a of the explosive column the casing 4 of which screw-threaded at 10, is screwed to the front of the ogive 2a.

The rear part 2b is entirely hollowed, its wall section being of sufficient strength to withstand the inertia of the solid part 2a on firing. The extension 3b of the explosive column, solely ensuring a very high speed of transmission of combustion to the detonator, is of smaller thickness than the part 3a, and extends as far as the region of the base of the cone 8. A centring piece 11 solid with the part 2b of the ogive ensures that the explosive column is held in the axis of the projectile.

The front part 2a of the ogive may be of a depth approximately equal to or even greater than that of the hollowed wall 2b and its mass may, in consequence, constitute a considerable part of that of the projectile.

The ogive 2a, 2b is connected along a continuous profile, of an ogival angle a equal to approximately to lthe ogival end 12 of the body Sin which it is screwed-at Y the front threaded at 21, constitutes the fuze carrier.

13. The body 5, of ogival shape at each end, has no cylindrical part in the region of the master section and has at the rear of the band an angle of departure which is preferably equal to or less than 6 and the empennagef carrying tail 9 is an extension,-without any interruption, of the conical rear of the body 5.

The embodiment illustrated in Fig. 2fshows a projectile of which the ogive 2a, 2b made in a single piece comprises a front part 2a which is solid and ofy high density and through which passes an axial aperture 2c-in the head of which is mounted the fuze 1, provided with a primer capable of transmitting the combustion to the rear detonator.

According to the rembodiment shown-inFig. 3, `the parts 2a and 2b of the ogive constitute two separate superimposed parts; the solid part 2a may be made of lead or lead alloy and the part 2b of a stronger material. At the front, the latter comprises a shoulder 14 which acts as a supportfor the part 2b; the shoulder 14 may be provided with an extension 15 of smaller diameter which penetrates into the part 2a. A retaining sleeve 16, interposed between an explosive column 3'and the front part 2a. of the ogive is held in place by a screw thread 17 in the extension 15 of the part 2b,for the purpose of centring and securing the said part Y2a. The said explosive column, threaded at 18, is vscrewedinto the sleeve r16, the latter thus constituting the'ogivalhead and fuze carrier.

In the modification illustrated in Fig. 4, the solid part 2a contains a covering part 19 the Vrear of which is connected and secured at 20 by crimping, screwing or in some other manner, to the part 2b of the ogive; A sleeve 22 is interposed between the casing 4 of the explosive column and the part 2a.

Naturally, each of the two modifications described hereinabove could be applied to a projectile not having an explosive column, such as shown in Fig. 2.

Fig. 5 shows that the front of the hollow charge 7 and of the metallic cone 8 are situated beyond the master section, in the externally ogival part at 12 of the chargecarrying body 5. Now atV this point the cavity of the body 5 is at its maximum diameter, owing to the fact that its wall is of' a slightly decreasing thickness in front of the band 6.

It will finally be seen that the band 6 has an outer diameter exceeding that of the master section only by a fraction of a millimetre. The section of the said band is also very small owing to the fact that since there is no need 'of gyration to stabilise the finnedV projectile, a very small twist of the riing of the weapon (for example 1 degree) is sul'Hcient to give the said projectile a reduced speed of rotation which is definitely insufiicient to affect the penetrating action, and intended more particularly to obviate any systematic deviation which it might undergo in relation to the direction of discharge, dueto a structural fault, eccentricityY of dissymmetrical action of the empennage.

Figs. 6 and 7 illustrate diagrammatically the effect, at rest, of an explosive column on the solid ypart 2a of the ogive and the effect obtained on impact on the said solid part of the projectile fired on a resistant target.

In Fig. 6, operation of the fuze 1 has been produced and, consequently, that of the explosive column 3a, 3b: the cap of the projectile deforms and opens tulipfashion, from front to rear, solely under the action of the said column the explosive of which (Pentrite, Hexogen or the like) is actuated with a detonation speed of the order of 6000 to 7000 metres per second. v

In Fig. 7, the cap of the projectile, when fired on steel sheet, opens and deforms under the combined action of the explosive column and the speed of impact on the target; the elements of the solid part 2a spread and disperse radially on the plate, giving a central `free zone through which the penetrating jet of the hollow charge will pass after having axially cleared the rear hollowed part of the ogive.

In fact, the residual speed of the projectile is at least ten times less than that of the transmission of the cornbustion of the explosive column to the detonator of the hollow charge and the penetrating jet in consequence reaches the `armour before the projectile has covered all the hollow length of the ogive.

Nevertheless, the kinetic energy of the projectile on impact is such that the deformation and spreading of the solid part of the ogive take place Without there being any transmission of force liable to deforrn the rear part of the projectile or, consequently, adversely affect the normal operation of the hollow charge.

What is claimed is:

A finned projectile of biogival shape, comprising an explosive-carrying body, an explosive `charge housed in said body, a front cavity in said charge, a metallic lining for said cavity, `an empennage-carrying tail, -a ballistic.

high density supported therein along the front portion only of said ogive, said mass presenting an axial aperture over its entire length, a retaining sleeve in said axial aperture, an explosive column integral with said fuze and in said sleeve, said sleeve being screwed in said rear part to retain said ballast mass 'on said rear part.

References Cited in the le of this patent UNITED STATES PATENTS 1,153,425 Dunwoody Sept. 14, 1915 2,345,619 Moore Apr. 4, 1944 2,359,777 Moore Oct. 10, 1944 2,429,599 Beavers Oct. 28, 1947 2,672,094 Roberts Mar. 16, 1954 2,728,296 Meister Dec. 27, 1955 2,737,888 Brandt Mar. 13, 1956 2,764,092 Massey Sept. 25, 1956 2,821,924 Hansen et al. Feb. 4, 1958 FOREIGN PATENTS 1,058,268 France Nov. 4, 1953

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