US2504648A - Projectile - Google Patents

Description

E. F. CHANDLER PROJECTILE April 18, 1950 3 Sheets-Sheet 1 Filed Oct. 25, 1941 INVENTOR. fD/VAQO E (HANDLE/a April 18, 1950 E. F. CHANDLER PROJECTILE 3 Sheets-Sheet 2 Filed Oct. 25, 1941 IN VEN TOR. fan 4R0 E CHANDZBQ April 18, 1950 E. F. CHANDLER 2,504,643

' PROJECTILE Filed Oct. 25, 1941 s Sheets-Sheet :s

I N V EN TOR. 01414 RD E W/VOZSE BY -%M Patented Apr. 18, 1950 UNITED STATES PATENT OFFICE Claims. 1

This invention pertains to projectiles, and more generally to methods of, and means for, improving their ballistic coefiicient andconsequently the range and precision of same. The invention relates more particularly to'projectiles of the reaction type, to which a gyratory motion about their longitudinal axes is imparted. The present invention further relates to projectiles provided withan internal cavity or recess which may contain a, reaction explosive or other charge.

The ballistic properties of a .shell may be improved by elongating the vforward or tapered end to facilitate its passage through the air. A limit, however, is imposed upon this method by the practical impossibility oistabilizing projectiles of considerable length in relation to their caliber. Heretofore, this limitation has proven especially serious as an obstacle to the design of efficient shells of the reaction type.

It is an object of the present invention to overcome this dii'ficulty so as to ensure perfect stability of the projectile even in cases wherein the ratio between the length and caliberis relatively great. This is accomplished by a judicious distribution of the masses in the body of the procoefiicient of stability at the muzzle velocities contemplated.

The improvement inshape is particularly important and as anaturalresult of the increased range resulting from thisimproved shape, it enables the weight of the projectile to be reduced, thereby imparting, for a given propulsive charge,

higher initial velocities without subjecting the materials employed to stresses exceeding permissible limits. The resultant gain in velocity through the improved aerodynamic vform of the projectile more than outweighs the reduction of range, which in the case of an ordinary pro- .iectile wouldnecessarilyresult from the reduction-of its weight; w The rocket or reaction charge may, if desired, discharge into no'zzlesset obliquely in relationto the'longitudinal axis of the ,projectile, for thepurpose of impartingto the'latter a. torque which accelera es; its angular velocity to maintain a suitableratio between such angular velocity and the velocity of translation. Experience shows that the instantaneous character of the deflagration of modern explosives is such that excellent fragmentation of the heavy rear Wall of the charge cavity is obtained, despite the weakening of the ogive by thinning its walls to accommodate an increased charge.

The center of gravity being near to the point of application of the resultant of the thrust .of

the air, and said thrust being applied with a small .lever arm, there is a smaller tendency to upset the projectile. This advantage is obtained in a shell of streamlined profile because the heavy mass is located aft of the ogive instead of in a zone of smaller diameter where the moment of inertia about the horizontal axis of the projectile would normally be reduced. The lightness of the extremities of the shell reduces to a minimum the moment ofinertia about the transverse axis passing through the center of gravity, and hence prevents pitching. By reducing the diameter of the shell butt, or, more preferably, streamlining the same, the detrimental negative pressure prevailing at the rear of the shell during its trajectory is considerably minimized and its range is increased as well. This further aids in obtaining the desired reduction of weight in this zone.

Where both a propelling charge and a reaction charge is carried by the projectile, a suitable choke may be provided, the same being so designed as to facilitate the passage from the propulsion charge of the amount of gas needed for the proper ignition of the reaction charge, and, at the same time, toprevent the full pressure being transmitted to the reaction charge chamber. Moreover, the mass of the projectile is concentrated on its periphery in the zone of the center of gravity, thereby increasing the .coeflicient of stability. The improved profile of the projectile .of the present invention facilitates its travel through the air and affords a greater residual velocity for a given range, thus flattening the trajectory. The invention also has .for an object methods of, and means for, improving the flight ofreaction projectiles whereby their velocity is increased and their trajectory is reduced while their effective range is increased.

It is an object to provide a projectile of the reaction type which, upon launching and while still within the directing influence of the launching means, is subject to a gyratory thrust at, or prior to, the time gyratory impulsion is established by the propelling means. This may be accomplished by providing for an initial tangentially directed, high velocity gas discharge at the instant of firing the projectile. A separate, isolated reaction charge may be employed for the purpose, or a portion of a faster acting gasgenerating compound may be associated with the main propelling charge. In any event, the primer should preferably be adapted to ignite both charges simultaneously so as to reduce the time lag between the two effects. That is, while an initial gyratory thrust is desired to establish the rotary action of the projectile, while the same is within the influence of the gun barrel or other launching means, it is also important that the prime driving force be applied early enough to insure maintenance of the course impressed upon the projectile after it leaves said directing influence.

An initial power or launching charge may be detonated by the shell primer, which will also place the propelling charge under sufiicient pressure initially to considerably step up its normal combustion rate during the passage of the shell through the gun barrel. By dividing the pro pelling charge into a plurality of separate charges of relatively small combustion surface area, and then merging these separate charges into one charge exposing a combustion surface area greater in extent than the total area of the several smaller areas, a convenient method is afforded for controlling the rate of gas generation, and hence the gas pressure, during the initial or launching phase, particularly while the shell is within the gun barrel, and for materially increasing the gas generating rate and the shells subsequent velocity. Suitable ratio may be established between the primary and secondary gas evolving areas to meet required conditions. This ratio may be established, as aforesaid, or the composition of the compounds employed may be modified so as to give to each the desired burning and gas forming characteristics.

While the rate of combustion of a given reaction charge does not change, it will be understood that the time of burning is governed by the area of the combustion surface. Accordingly, by providing a relatively uniform area of combustion during the time the charge is being consumed, a relatively uniform evolution of gas is afforded with a substantially even pressure at the reaction jet. If, on the other hand, the charge is perforated or the burning surface is otherwise extended, it will be understood that the rate at which gas is generated will increase in proportion to the rate at which the burning surface area increases, thereby accelerating the pressure of the gas at the jet. The method to be employed depends upon the purpose for which the ammunition is designed and the performance characteristics desired. Among other things, for example, a uniform velocity during the flight of the projectile, or an accelerated rate of travel, may be desired.

Still another object of the present invention is the provision of an improved shell of the reaction type, having a self-contained propulsion charge. On detonating the combustible element contained within the shell, the hot gases within the combustion chamber are so disposed as to preheat the unburned portion of the charge, and the nozzle orifices are of such proportions as to always retain an accumulation of the gases within the chamber until the charge has fully burned.

A still further object of the present invention is the provision of an improved self-propelled or reaction-type projectile which is particularly adapted to be discharged from a smooth-bore gun barrel, the missile being capable of being dispatched accurately over a relatively long range. Another object of the invention is to provide a projectile of this type which may be launched or fired safely and accurately from a gun of light weight and simple construction, the projectile having novel means for imparting rotation thereto relative to its longitudinal axis. A still further object of the invention is the provision of a. novel method of propelling a shell of the reaction type having a self-contained explosive charge.

The present application constitutes a continuation in part of my co-pending applications Serial Nos. 406,944 and 408,284, now issued as Patent No. 2,380,024 of July 10, 1945, and No. 2,391,864 of January 1, 1946.

In the drawings:

Fig. 1 is a central longitudinal section taken through one of the embodiments of the present invention.

Fig. 2 is a longitudinal section taken through a projectile constituting a second embodiment of the present invention.

Fig. 3 is a side elevation, partially in section, of another embodiment of the present invention.

Fig. 4 is a side elevation, partially in section, of another embodiment of the present invention.

Fig. 5 is an end elevation of the projectile shown in Fig. 4.

Fig. 6 is a side elevation, partially in section, of yet another embodiment of the present inven-- tion.

Fig. 7 is a perspective .view of a self-contained explosive unit which may be employed in connection with any of the several embodiments of the present invention.

Fig. 8 is an end elevation of the projectile illustrated in Fig. 2.

Fig. 9 is a broken side elevation of the central or midsection of the projectile.

Fig. 10 is a broken transverse section taken on line iii-4U of Fig. 2.

Fig. 11 is a transverse section taken on line llll of Fig. 2, the view showing one form of reaction or propelling charge.

Fig. 12 is a side elevation, partially in section, showing another form of propelling charge.

Fig. 13 shows still another form of propelling charge.

Fig. 14 is an end elevation of the structure shown in either Figs. 12 or 13.

Fig. 15 is a diagram indicating the method of propulsion acceleration of a projectile in a gun barrel.

Fig. 16 is a side elevation, partially in section, of another embodiment of a projectile.

Fig. 1.7 is an end elevation thereof.

Fig. 18 is a section taken on line l8--l8 of Fig. 16.

Fig. 19 is an enlarged broken section of the rear portion of the afterbody of the shell shown in Fig. 16.

Fig. 20 is an enlarged, fragmentary end elevation of the projectile shown in Fig. 16.

In Fig. 1, the projectile comprises an afterbody 4, a mid-section 2, and a suitable ogive 3. The butt 4 of the shell is provided with a suitable primer 5, which, upon firing, may ignite a fuse train which is desirably positioned within a central tube 6, such tube passing through the center of a propelling charge 8. This propelling casing 9 and carries the flame into combustion chamber 1. Gases evolved by the burning propellant issue under pressure from a plurality of spaced nozzle openings l0 positioned just to the rear of mid-Section 2, and also from a plurality of nozzle openings l i in butt portion 4. Tubular casing 9 is desirably of smaller diameter than that of the bore within the afterbody, and it will accordingly be noted that pressure on said nozzle openings is balanced by the passage l2 between the tubular casing and the bore.

The rear nozzles Il may be appropriately set for a substantially direct forward thrust, while the nozzles are preferably set tangentially with respect to the longitudinal centerline of the proj ectile. Thus, upon firing, the projectile is simultaneously driven forward and is rotated by reaction of the gases issuing through the nozzle openings l0 and II. The projectile is preferably so designed that when loaded and ready to be fired, its center of gravity is at, or slightly forward of, its true center and within the full caliber midsection, the proportions of which are preferably such that, as the propelling charge is consumed, the ultimate position of the center of gravity does not pass out of this full caliber zone. Rotational balance of this projectile in the gun barrel is aided to some extent by the centralizing effect of the gases under pressure, which form a minute film between the outer surface of the projectile and the inner surface of the smooth bore gun barrel. Some of the nozzles, particularly those for producing a gyratory effect, are situated at or near the greatest diameter of the projectile and expand rearwardly over a section of the shell afterbody, so that upon leaving the gun barrel this rotary propulsive action takes place in the slipstream, thereby reducing the resistance to travel.

The projectile shown in Figs. 2 and 8 to 13 comprises an afterbody 20 which contains a suitable reaction or propelling charge 2|. The forward end of afterbody 29 is slightly enlarged in diameter, as shown at 22, and represents the external diameter for the particular caliber of the shell. Connected to afterbody 20 in any suitable manner is the forward section 23. This section may be hollow, as shown, and is adapted to carry an explosive charge, or any type of charge desired, which may be detonated by a fuse which is designated generally by the reference numeral 24, or may be detonated in any well known manner. Between members 2|] and 23 is a suitable wall or partition 25. This may be solid, as shown, or may be provided with suitable fuse means so that at a predetermined point in flight of the projectile, hot gases from the burning reaction charge 2i may be caused to ignite the explosive or other charge carried within head section 23.

At its rear end afterbody 20 is closed by wall '26 which carries a suitable primer 2'! and a plurality of spaced, propelling-gas-outlet nozzle openings 28. These openings are adapted to direct the hot expanding gases formed Within section 2!! by the burning reaction charge 2|, such gases being directed rearwardly for the purpose of driving the projectile forward, while some of the gases so generated issue from a plurality of spaced, nozzle openings 29, the outer terminals of which lie just to the rear of enlarged portion 22 of afterbody 20.

It will be noted from an examination of Figs. 9 and 10 that openings 29 project rearwardly at an angle to the shell, and in Fig. 10 it will be iii) seen that these openings are set tangent to the diameter. It is also important that the nozzles for setting up a gyratory effect be placed so that reaction takes place at or near the greatest diameter of the shell. The reaction or propelling charge 2i is provided with a plurality of spaced, tapered holes 30, the purpose of which is to increase the area of combustion surface, and at the same time control the rate of combustion. Another purpose of these tapered holes is to afford access of the gases to rear chamber 3| and forward chamber 32, thereby balancing the pressure of the gases within afterbody 20 and making it possible by suitably adjusting the relative crosssectional areas of nozzles 28 and 29 to establish the desired relationship between the propulsion and the shell-rotating reactions.

In view of the fact that some mixtures or compounds employed for the propulsion of rockets and self-propelled projectiles are hygroscopic and/or contain volatile agents and hence may be impaired by exposure to the atmosphere, it has been found advantageous to protect the charge by hermetically sealing same, as by the use of a suitable material which is readily ruptured and burned upon the primer being detonated. For example, the charge 34 may have a casing of Celluloid or other plastic material enclosing the combustible material 35, as shown in Fig. 12, the charge having the spaced, tapered holes 36. As a further modification, the charge 39 may have its entire surface coated, as at 40 and 4| in Fig. 13, or the nozzle openings 28 and 29 may be sealed with a suitable substance which is readily burned out and eliminated, or, in some in stances, both methods may be employed or some combination thereof.

It will be seen that combustion of the propelling charge takes place at both ends, the pressure balancing channels passing through the charge. Uniform combustion at both surfaces and, accordingly, a uniform evolution of gas pressure, may be obtained by molding into the charge, metallic tubes so as to limit the burning areas to the diameter of the two ends. If the tubes are not so employed, it will be understood that the extra surface exposed by the channels will result in a constantly increasing generation of gas and pressure with a proportional increase in the heat released per unit of time. The method selected will depend upon the characteristics desired, and the purpose for which the projectile is designed.

Fig. 3 is a projectile which may be generally of the type shown in Figs. 1 and 2, except that housed within the ogive is a tubular barrel 5! which contains a sub-caliber-projectile 52. Behind this sub-caliber-projectile is preferably a powerful explosive charge 53, which is adapted to be detonated to expel the sub-caliber-projectile when the main projectile strikes. Upon the projectile striking, detonation may be caused by the setback, a suitable primer 54 serving for ignition. Between the butt of the sub-caliber-projectile and the primer is a suitable firing pin 55, and forward of the charge 53 may be placed a suitable wad or buffer 56. Because of the characteristic, head-on flight of the reaction projectile, a shell of the order just described is especially effective against tanks and other equipment where a piercing action is desired. If desired, a charge of any suitable nature may be carried by the projectile in the space 53 to function with, or independently of, the sub-caliber-projectile. Preferably, the nose of the sub-caliber-projectile is embedded in a, soft metallic plug 51 forming the forwardpartpf the-cgive, This may serve as a lubricant .to the action of the-sub-caliber-projectile.

The-projectileshown inFigs. 4 and 5 is formed with a streamlined buttportion 69, and prefer- ,ablyihoused within this butt B0 are a plurality of tubes 51 disposed about the longitudinal center line. :Preferablythese tubes are formed at $2 to provide reaction nozzles, and are so positioned .as to develop a rotational-as well as a forward longitudinal thrust when in action. These tubes contain a suitablecombustible charge, and at their forward end are in communication with the charge in the main chamber A suitable primer (not shown) in the butt til is adapted, -upon firing, to simultaneously ignite the several charges in the tubes 6!, If these tubes are charged withthe same-combustible material that chamber .63 is charged with, the operation will be substantially as follows.

During launching of the projectile, and while tubes iii are in action, the. gas evolved, and hence the pressure at the nozzles, willbe relatively con- .stanhand proportional to-the combustion surface area of the several tubes. Then, upon the combustion reaching the. surface 65, which is greater than the combined areas 64, the evolution of gas, and hence the pressure at the nozzles, will be stepped up, resulting in an accelerated velocity of the projectiles flight. itself well to anotherimportant method of oper ating a reaction projectile wherein it is desired to utilize an initial launching impulse for overcoming the inertiaof the shell in the gun barrel and starting ,it rotating while the propelling charge is becoming fully active, such rotational movement commencing before the shell leaves the directing influence of the said barrel. Accordingly, tubes 61 may be specially loaded, as, for example, with a faster acting compound than the propelling charge 6,3. These tubes may, if desired, be partly loaded with a fast acting, expelling'andtorque producing charge, and partly with a propellant such as may be used in the main charge 63.

Fig. ,6 is a projectile .of the reaction type in which 10 is the afterbody carrying a charge 1!, having a uniform diameter and, hence presenting a substantially constant combustion surface area 12, bacl; of the orifice plate 13. the-butt of the shell may serve to ignite the propelling charge H at its face 12, gases from which pass through the orifice into the combustion space 74 from'which they issue as a high velocity jet through the nozzles '15, which are preferably positioned to afford both thrust and rotation to the projectile. Shown in connection with this projectile is a special feature of construction which may be appliedin one form or another to rocket ammunition to prevent bursting of the shell by excessive .gas pressure resulting from whatever cause, such as accidental increase in the combustion surface areav due to cracks in the compound, shrinkage of the charge, etc. This improvement comprises equipping the shell with ,gas vents which are normally closed and which, as long-asthepressures developed'do not materially exceed those for which the nozzles are clesigned, do not-come into play. If, however, the jressure, combustion temperature, or both,- exceed apredetermined amount, the means closing the .vents are blown out, or burned away, and theexcess gas is-permittedito escape in a manner calculated best to aid intheflight-of the projectile. For example, rearwardly directed, tangen- .tial jets .18 mayprovided at suitable. points in .This construction lends A primer H5 in the shell of the ,afterbody 10, and positioned to .be exposed as the charge is consumed. Normally these openings .may be closed by a. thin metallic shell 19 enclosing the charge H, this shell being adapted to rupture-under pressure or heat, or both, when either or both become excessive. Gases thus suddenlyreleased while the shell is in flight accordingly will not interfere with the course of the shell though it may accelerate its velocity and gyroscopic' effect.

In the design of a projectile of this character, it is desirable to construct the afterbody with a relatively thin wall and of as light and strong material as is consistent with the pressures to be encountered, inv order that the heavier forward section will bring the vcenteroi gravity forward of the mid-section of the projectile. As the propulsive charge isconsumed, the center of gravity will gradually moveprogressively forward. This increases the stability .of the projectile during its flight and tends to overcome the action of wind resistance to cause"pitching or the deflecting of theprojectile fromits course by movement about a transverse axis passing through the center of gravity. The stability of the projectileis further increased by the gyroscopic effect maintained by the axial torque established by the obliquely set nozzles, at or near the maximum periphery ofthe projectile, and which are so set as to aid in.reducing the skinfriction of substantially half the length of the total-surface area of the projectile.

Because a projectile of the rocket type is propelled by the reaction of gases emitted under pressure, such gases being generated by a relatively slowburning combustible mixture within the same, there is no explosive violence at the instant of firing as in the case of a, shell fired by the explosion of a powder charge within the gun, or within the shell butt. Even though the action is rapid in the case of the self-propelled shell, only ,sufiicient v pressure is generated initially to eject the shell from the gun barrel at a velocity which is being rapidly accelerated as the rate of combustion increases, due to the increasing gas pressure within the reaction chamber. The discharge of a gunof this type is comparatively noiseless, and pressures developed within the gun barrel may be-relatively low. The recoil, which is the result of what may be termed a push rather than the hammer-like-blow of an explosive discharge, is readily absorbed and compensated for in a gun of light weight construction.

When the primer-cap is detonated by the firing pin of the gun, thus igniting the reaction charge, an evolution of gas is initiated. This pressure must first overcome the inertia of the shell mass, i..e., getit in motion, and then begin to accelerate its velocity'ithrough the gun barrel, while, at the same time, imparting to the shell a sharp, rotary action. The fact that shells of 2-inch caliber, constructed in accordance with this invention, maybe fired at the rate of one per second indicates that the total time re- .quired for the above steps is very brief. However, it has been found that the operation may be improved by adjusting the primer charge in such a manner thatgases are generated initially to overcome the inertia of the shell and coordinate themovement thus imparted to the shell with the accelerating movement of same immediately following as a result of the reaction pressure-simultaneously being'generated by the combustion of th propelling charge; This effect -;may be accomplished, by a separate charge of a crosses composition, designed to rapidly evolve the. re

quired gas volume and pressure, and associated directly with the primer, or the :required quantity; ofsuchanadmixture-may lee-assembled, for example, upon the face of the mainreaction charge,

or in any, other suitable manneradapted for the purpose.

The diagram shown in Fig. 15; isintended to illustrate the application of this method. The. distance A to B indicates-the time period during which the projectile is .passing through the gun barrel. C indicates the'degree of acceleration attained, by the projectile upon leaving the muzzle. The initial impulseimp'ressed upon the projectile upon detonation of the primer may take place within the period -A--a-, and the accelerationjthereofjmay' bejrepresented by Bb. By this time the reactionv charge is fully active so that at the substantiallymid-point D, acceleration may be represented byd, from. which point the rapidly'ihcreasin'g acceleration is representedby that part of the curve marked-E. By thus initially 'causing'theprojectile to be lifted from its position of rest during the period in which the reaction charge gas generation is rapidly building up pressure, a. cushioning effect is aiforded'behind the projectile which not only accelerateslthe'velocity attheihstant that actual flight commences, but also greatly reduces the normal resistance "of the "gunfba'rrel to theinitiation of 'rotatidn'b'y the reduction of friction because or 'tl'l'elubrialtionefict'of the minute film of gas which surrounds tlieprojectile within the gun barrel at this stage. v

Thaiexplosive unit I illustrated in Fig. Y-may, as I aforesaid, be inserted in an'y one of the several embodiments of thejpresezit invention, and includes an outer 'tubulareasirig I DI formed of metal 'o'ran'y other suitable iniaterial. .A charge of 'explosive I I U2is positioned within the casing, its endwalls m3"beingsubstantiauy flush with the terminal portions of the tubular casing. An inner tubular member I04 extends from end to end and thus provides a passageway therethrough. By forming tubular members IIlI and IM of metal, the effective burning surface of the charge is reduced. If desired, each end of the unit may be initially sealed with any suitable material, such as moisture-impervious paper, flexible plastic material, or otherwise. It will also be appreciated that materials other than metal may be used for tubular members IOI and I04.

.;-,-;with a reduced, threaded forward extension I2I upon which the forward section I22 is mounted. In the shell shown, the forward section and the afterbody are of substantially the same diameter, the latter having an annular recess I I1 adjacent to the butt portion to facilitate positioning the projectile in firing position in the barrel of a gun. The forward section is formed with a chamber I23, which chamber is adapted to carry any type of offensive charge in solid, liquid or gaseous form. The forward end of the chamber is closed by means of a closure member I24 which may contain a fuse of any suitable character, or any other appropriate means of detonation may beemployed in connection with this forward section At its rear end, forward section I22 is formed with a; threaded aperture which receives threaded portiofi lfl of the afterbody.

a'shfglloftliischaracter, the outer periphery thereo, preferably slightly smaller than the bore of the gun barrel, and in order to eifect a;

relatively close gas seal between the shell and the bore of the gunbarrel, a gasket I2Iof slightly greater diameter than that of the shell is positinned between the sections adjacent to their outer peripheries. Afterbody I20 is also provided with a hollow chamber or bore I26 extending forwardly from therear'endthereof. Adjacent to'its rear end, the bore is provided with a section of reduced diameter, as shown at I28, and is provided with internal threads :29. The rear facev 53-! of the aiterbody has formed therein aplurality of nozzle openings I32 which are dis-. posed. at an angle to a line running longitudinally of the shell, all as shown in Figs. 19 and 20.

Within the threaded opening I29 an internal cartridge 435 is positioned, such cartridge havinga forward tubular portion I36 containing the combustible charge I39 having a central bore I40 therethrough formed with a longitudinally splined surface to increase the combustible area. The-charge is detonated by means of a primercap I 12, and when-the charge is set off the combustiblegases within chamber I26 pass outwardly through the diagonal nozzle openings I32, propelling the shell forward and also setting up a gyratory effect.

The combustile gases which are generated within thecartridge are first caused to passfor wardly through the internal cartridge I 35, and thence rearwardly through-the area between the cartridge and the interior of the shell. By thi means, the hot gases within this space tend to preheat the combustible chargewhich, together with themessure. generated in the chamber, accelerates the rateofgas evolution. Thenozzle orifices are-proportioned toprovide a desired accumulation. of pressure within chamber I2 5-.

The drawings are schematic and not intended as'working drawings, but are'inten'de'd to illustrate principles and features which have been developed as a result of research and actual experience in the construction and testing of reaction ammunition. It will be understood that in constructing shells in accordance with these disclosures they may be fabricated in any approved manner, the several parts or sections being constructed from materials calculated best to meet the service in which the are to be used, the said parts being assembled and secured together by means well known in the art.

What I claim is:

1. In a projectile of the reaction type-the combination of a forward section and a tubular afterbody forming a combustion chamber and provid-, ing a gas-storage space atj'each end of the combustion chamber, a gas-forming element positioned in said chamber, means supplyin gases from the combustion charge to both of said spaces, and a plurality of rearwardly directed nozzles positioned forward and aft in said afterbody communicating with said spaces and adapted to emit gas under pressure from said combustion chamber for driving the projectile, said forward noz- Zles being obliquely positioned so that a portion of their driving force acts to rotate the projectile about its longitudinal axis.

2. In a projectile of the reaction type, a forward section adapted to contain an offensive charge, an afterbody, a combustion chamber having a rear wall formed within the afterbody, nozzles carried by the afterbody and positioned in the rear wall of the combustion chamber, a propellant rocket charge in the combustion chamber and having a, bore therethrough, a percussion cap 11 in the rear wall and adapted to ignite said charge within said bore, and means whereby gases evolved by the ignition of said charge pass forwardly through said bore and then pass rearwardly within the combustion chamber to issue through said nozzles.

3. A rocket projectile provided with a plurality of jet-forming nozzles for accelerating its linear and angular velocity of translation, a powder charge carried Within the projectile and in discharge communication with said nozzles, a propellant rocket charge carried by the projectile and in discharge communication with said nozzles, and means for detonating the powder charge for energizin the nozzles to initially drive and rotate the projectile, said means causing the ignition of the propellant rocket charge for subsequently continuing and accelerating the driving and rotating of the projectile by said nozzles.

4. In a rocket projectile, the combination of a forward part and an afterbody having a chamber therein, a combustible gas-generating charge in said chamber, said charge bein of cylindrical form and provided with a plurality of longitudinal passages open at both ends of the charge, a plurality of rearwardly-directed and obliquely-positioned reaction jets at the forward end of the charge, the afterbody having a plurality of jets in its, rear end at the rear end of the charge, the latter jets being in axial alignment with the passages extending through the charge.

5. A projectile for a smooth-bore weapon comprising a body including an ogival front part, a full-calibre cylindrical guiding part engaging the bore of the weapon and into which the ogival front part merges, said full-calibre cylindrical part terminating at substantially the center of gravity of the projectile, a sub-calibre cylindrical afterbody connected thereto, a group of rearwardly-directed reaction nozzles obliquely positioned to rotate the projectile, arranged in annular formation adjacent to the rear terminus of said cylindrical guiding part, a second group of nozzles also arranged in annular formation at the rear portion of the afterbody, the annulus defined by the outer ends of the nozzles in the first group being of greater diameter than that defined by the nozzles in the second group, and a propulsion rocket charge in the afterbody and in discharge communication with the nozzles in both groups.

EDWARD F. CHANDLER.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 40,041 Hyde Sept. 22, 1863 579,035 Bell Mar. 16, 1897 1,293,653 Mackiewicz Feb. 4, 1919 1,376,316 Chilowsky Apr. 26, 1921 1,380,172 Abbott May 31, 1921 1,504,144 Romberg Aug. 5, 1924 1,901,852 Stolfa et al Mar. 14, 1933 1,994,490 Skinner Mar. 19, 1935 2,070,946 Joyce Feb. 16, 1937 2,113,313 Brandt Apr. 5, 1938 2,206,809 Denoix July 2, 1940 2,232,928 Sekalla Feb. 25, 1941 2,271,280 Weinert Jan. 27, 1942 FOREIGN PATENTS Number Country Date 11,705 France Oct. 5, 1844 2,497 Great Britain of 1858 5,099 Great Britain of 1878 503,166 France Mar. 10, 1920 831,496 France June 7, 1938 516,865 Great Britain Jan. 12, 1940

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