US3760731A

US3760731A - Infantry projectile

Info

Publication number: US3760731A
Application number: US00194058A
Authority: US
Inventors: G Gaughan; E Buchanan; E Thompson
Original assignee: US Department of Army
Current assignee: US Department of Army
Priority date: 1971-10-28
Filing date: 1971-10-28
Publication date: 1973-09-25
Anticipated expiration: 1990-09-25

Abstract

A supersonic high explosive anti-tank projectile capable of being launched from a tube by individual personnel including, at its forward end, stand-off means joined to a generally conical high explosive portion having its apex directed rearwardly. A boom of reduced cross-sectional area, extending rearwardly, affixed to the apex of the high explosive portion and carrying at the opposite end thereof a converging/diverging nozzle of circular cross section and provided with a plurality of radially extending fins, intermediate its ends, of a diameter equal to that of said conical portion. A plurality of stick shaped propellant charges supported by a step shaped means disposed about said conical portion. The sticks being supported only about said conical section intermediate the nozzle and the conical portion and filling this volume. A combustible casing surrounding the propellant sticks and extending approximately between the conical portion and a blowout disc closing the open end space between the outer periphery of the nozzle and the casing.

Description

Waited States Patent 191 Gaughan et al.

[ INFANTRY PROJECTILE [75] Inventors: Gerald E. Gang hail Dd'veE'E'aii I H. Buchanan, Bemardsville; Emil W. Thompson, Succasunna, all of NJ.

[73] Assignee: The United States ot Anieri caas represented by the Secretary of the Army [22] Filed: Oct. 28, 1971 [21] Appl. No.: 194,058

[ Sept. 25, 11973 Primary ExaminerBenjamin A. Borchelt Assistant Examiner]. V. Doramus Att0rneyl-larry M. Saragovitz [5 7] ABSTtCT A supersonic high explosive anti-tank projectile capable of being launched from a tube by individual personnel including, at its forward end, stand-off means joined to a generally conical high explosive portion having its apex directed rearwardly. A boom of reduced cross-sectional area, extending rearwardly, affixed to the apex of the high explosive portion and carrying at the opposite end thereof a converging/diverging nozzle of circular cross section and provided with a plurality of radially extending fins, intermediate its ends, of a diameter equal to that of said conical portion. A plurality of stick shaped propellant charges supported by a step shaped means disposed about said conical portion. The sticks being supported only about said conical section intermediate the nozzle and the conical portion and filling this volume. A combustible casing surrounding the propellant sticks and extending approximately between the conical portion and a blowout disc closing the open end space between the outer periphery of the nozzle and the casing.

10 Cllaims, 2 Drawing Figures Pmmmmsms v Y 3.760.731

SHETIBFZ FIG.

BACKGROUND OF THE INVENTION The present invention relates to projectile propulsion systems and more particularly pertains to structural propulsion arrangement for a shoulder fired personnel weapon of increased velocity and range.

ln the field of shoulder fired anti-tank systems it has been the general practice to employ either rocket motors or recoilless rifle arrangements. Both of these systems provide relatively low launch velocity in that, for the recoilless rifle, the interior ballistics are such that the limitations imposed by the pressure and nonuniform burning reduce the terminal speed. Additionally, the high pressures used in the breach require a very heavy and bulky launch tube as well as providing a non-uniform chamber volume. In the case of the rocket the limitation is imposed by the motor weight as compared to the propellant. For these reasons such devices have not proved to be entirely satisfactory and the present invention overcomes these difficulties.

SUMMARY OF THE INVENTION The general purpose of this invention is to provide a projectile propellant launch system that has all the advantages of similarly employed prior art devices and has none of the above described disadvantages. To attain this, the present invention provides a unique projectile and propellant configuration wherein a restricted diameter boom connects the forward high explosive portion and the inverted bob type nozzle. The stick propellants are supported by the forward portion and extend lengthwise of the boom while substantially filling the volume between the boom and the outer combustible casing of the projectile. Thus the propellant is maximized while retaining a constant chamber volume. Support means in step-like structure are affixed to the rear of the high explosive member so as to permit the use of propellant in varying lengths and eliminate voids. A blowout disc releasably closes across the nozzle to permit a temporary pressure buildup prior to launch.

An object of the present invention is to provide a low cost, accurate, highly efficient, reliable, high velocity projectile capable of being launched by ground personnel.

Another object is to provide a projectile in which the motor casing is not required and having improved interior ballistics of relatively constant chamber volume and maximum round weight relation.

A further object is the provision of a personnel launched projectile of high velocity and increased first round hit probability with a flat trajectory.

A still further object is to provide a projectile wherein the maximum propellant is employed but without the inherent size to weight to payload limitation.

Other objects and many of the attendant advantages of this invention will be readily appreciated as the same becomes better understood by reference to the following detailed description when considered in connection with the accompanying drawings.

BRIEF DESCRIIPTION OF THE DRAWIINGS lFIG. l is a cross-sectional view of an embodiment made in accordance with the principle of the instant invention; and,

H6. 2 is a perspective view of the embodiment of FIG. 11 with a portion thereof broken away and with a different standofi structure.

BRIEF DESCRllPTlON OF A PREFERRED EMBODIMENT In the illustrated embodiment of FIG. l the projectile lltl is shown within a gun tube or launcher ill and includes at its forward end a projecting standoff 12 which carries at its tip a piezoid l3 and a power supply. The supply is electrically connected to a fuze assembly l4 Within the high explosive portion 15. This explosive portion also includes the main charge 116 and a shaping liner 117. Since the ammunition is intended to penetrate steel plate, the rear positioned charge 116 is formed by liner 117 to provide a jetlike burst directed forwardly upon impact. For this purpose there is provided a standoff distance between the shaped charge and the projectile tip. In order to insure proper jet blast configuration, the charge must be activated instantaneously on impact to preserve the standoff.

The outermost peripheral surface of the explosive portion 115 slidingly fits within the launch tube so as to properly guide the projectile. Extending rearwardly from the explosive portion 115 and coaxially with the launch tube is a reduced diameter boom Eh which terminates in a first diverging and then converging hollow bob-like inverted nozzle member 19. Forward of the nozzle member, affixed to and extending radially from the boom 11%, are a plurality of stabilizing fins 20 whose outer edge surfaces extend proximate of the inner launch tube surface. In order to conserve weight the boom and any other suitable components may be constructed of a lightweight metal such as aluminum. The explosive charge housing is rearwardly frustroconical and is formed with a series of encircling support regions or bands 21 which carry a multiplicity of propellant hooks 22 thereabout and form a step-like outer structure, as illustrated in FIG. 2. Propellant sticks (m7) 23 terminate at one end in a stud 2 1 which has an aperture at its leading end that engages with the book 22 to longitudinally support the propellant stick. The sticks extend to the rear of the projectile proximate the nozzle member, are only supported at one end and substantially till the plenum between the boom and the launch tube ll thus maximizing the propellant within the projectile. The annular nozzle opening intermediate the nozzle member 19 and the tube ii. is releasably closed by a blowout disc 25 which permits the buildup of gas pressure within the projectile chamber just prior to movement of the weapon projectile. immediately forward of the disc 25 is an igniter assembly 26 which is suitably connected to a firing mechanism (not shown) external to the tube and that activates or ignites the propellant sticks.

Since the entire projectile must be self-contained, exclusive of the launch tube, it is provided with an outer combustible casing 27, as illustrated in H6. 2, which may be of nitrocellulose and will completely burn upon ignition of the propellant. The standoff structure illustrated in FIG. 2 includes three forwardly extending legs 12 which converge at and support the piezoelectric element assembly 13'. It should be noted that the combustible casing extends from the forward ring 28 to the blowout disc 25 so as to fully encompass the propellant sticks 23.

It should be understood, of course, that the foregoing disclosure relates to only a preferred embodiment of the invention and that numerous modifications or alterations may be made therein without departing from the spirit and the scope of the invention as set forth in the appended claims.

We claim:

1. A high explosive projectile, adapted to be launched from an open-ended launch tube, comprising:

a large diameter forward high explosive portion adapted to slidingly fit within said launch tube,

a rear bob-like inverted nozzle member having a maximum diameter substantially smaller than said forward portion,

an elongated boom having a diameter substantially smaller than said nozzle member rigidly affixed to and intermediate said forward portion and said nozzle member,

a plurality of elongated propellant sticks extending lengthwise of and surrounding said boom,

means carried by said forward portion for individually supporting said sticks,

a combustible casing attached to said forward portion and surrounding said boom, propellant sticks and said nozzle member, said casing having a diameter substantially equal to forward portion,

a releasable blowout disc closing the opening between said nozzle member and said casing, and

an igniter assembly located between said disc and said propellant sticks, for igniting the latter to launch said projectile,

whereby said projectile may be launched with a maximum velocity.

2. The projectile according to claim 1 wherein said sticks substantially fill the chamber between said boom and said casing.

3. The projectile according to claim 2 wherein said nozzle member peripheral surface is axially symmetrical and in a rearward direction first diverges and then converges.

4. The projectile according to claim 3 further including a multiplicity of radially extending stabilizing fins carried by said boom.

5. The projectile according to claim 4 wherein said projectile is circular in cross section and said forward portion converges rearwardly.

6. The projectile according to claim 5 wherein said means for supporting includes hooks carried and disposed circularly about the converging section of said forward portion, and, studs affixed to the ends of said sticks having apertures engaging said hooks.

7. The projectile according to claim 6 wherein the said hooks are carried by bands encircling said converging section.

8. The projectile according to claim 7 wherein said forward portion includes a shaped high explosive charge having a fuze assembly for detonating said charge.

9. The projectile according to claim 8 further including initiator means comprising standoff means for selectively activating said fuze assembly upon impact of said standoff means with a target.

10. The combination of the projectile according to claim 1 with a launch tube, open at both ends, in which said projectile slidingly fits.

Claims

1. A high explosive projectile, adapted to be launched from an open-ended launch tube, comprising: a large diameter forward high explosive portion adapted to slidingly fit within said launch tube, a rear bob-like inverted nozzle member having a maximum diameter substantially smaller than said forward portion, an elongated boom having a diameter substantially smaller than said nozzle member rigidly affixed to and intermediate said forward portion and said nozzle member, a plurality of elongated propellant sticks extending lengthwise of and surrounding said boom, means carried by said forward portion for individually supporting said sticks, a combustible casing attached to said forward portion and surrounding said boom, propellant sticks and said nozzle member, said casing having a diameter substantially equal to forward portion, a releasable blowout disc closing the opening between said nozzle member and said casing, and an igniter assembly located between said disc and said propellant sticks, for igniting the latter to launch said projectile, whereby said projectile may be launched with a maximum velocity.