Rojectile

Application filed June 17,

To all whom it may concern:

Be it known that Robert Lundell, a citizen of the United States, and resident of New York city, in the county of New York 5 and State of New York, has invented certain new and useful Improvements in Projectiles, of which the following is a specification.

This invention relates to projectiles or shells particularly adapted for naval war10 fare, the chief object being to provide a projectile of this type which will strike an object below the water level as well as at or above it. In this manner, the effectiveness of the projectile is considerably increased as 15 it is capable of striking a part of the target, such as a ship, which is below the water level and, therefore, not protected by armor and, consequently, extremely vulnerable. The projectile is, moreover, especially adapted for 20 use against submarines or other craft which present little freeboard. To attain the above mentioned object, the projectile has to be prevented from ricocheting upon a surface of water when fired at a low angle of eleva25 tion and the resistance offered by the air and the water to the flight of the proj ectile must be kept within practicable limits.

A further obj ect of the invention, is to provide a high velocity projectile which will 30 permit the twist of the rifling of the gunbarrel from which it is discharged to be reduced or kept within practical limits and this is effected by constructing the same in such manner that its speed of rotation will 35 be increased or affected in a desirable manner during flight. Still another object is to provide a projectile with means for effecting a proper spin thereof during flight in combination with means effecting stabilizing of 40 the projectile when fired from a smooth bore gun.

It is well known that the ordinary shell will ricochet when striking a surface of water at a comparatively small angle unless 45 the shell is provided with a. specially cupshaped or square nose, in which case the resistance offered by the air or the water is materially increased which, of course, seriously interferes with the effective range 50 of the shell. It is also well known that in order to prevent a projectile from tumbling or keyholing, it is necessary to impart thereto a considerable speed of rotation, to insure sufficient stability by reason, of gyroscopic 55 action. It is also known that the speed of rotation has to be increased with an increase

1,384,841 chisel-shaped forward edge of the steel tube will immediately bite or cut into the water and the cylindrical portion of the tube will serve as a tubular rudder causing the 5 projectile to keep to its true trajectory until the speed of the same is very much reduced by the resistance of the water. It will be readily appreciated that, if there were no outlets provided in the steel tube, the air or 10 the water contained within the tube would be under great pressure on account of the high speed of the projectile and considerable resistance would be. offered to its travel. Even with adequate outlets there will still 15 be considerable pressure from the air or the water within the tube but in the preferred form .of my invention this pressure of the fluid is utilized to affect the rotary motion of the projectile. .The pitch of the slots 20 shown in the drawing corresponds approximately to about one turn in twenty calibers. Assuming that the shell is fired from a gun having a moderate twist of rifling of one turn in thirty calibers the air or water pressing 25 through the tube 9 and being forced outwardly by the pointed portion of the projectile, will exert a greater pressure upon the edges 11 than upon the opposite edges of the ribs 13,. thereby tending to cause the 30 projectile to gradually increase its speed of rotation until it approximates one turn in twenty calibers. The above description applies in a general way to the construction shown in Figs. 3 and 4. Instead of the 35 steel tube 9 and Fig. 1 a machined steel casting or a die casting is used, which consists of a conical central portion 13 and numerous leaf-like ribs or blades 14 connecting said central portion to an outer tubular 40 or cylindrical portion 15 as clearly shown in the drawings. It will be seen that the . steel casting is- attached to the shell substantially like the steel tube in Fig. 1. It may, however, be attached in many different 45 ways, in fact, the central conical portion 13 may be attached to the shell like the well known soft steel cap used for armor-piercing projectiles and it may even serve the same purpose. As the steel casting in Fig. 50 3 is more elaborate than the simple steel tube in Fig. 1 it has to be carefully machined and balanced for rotation. However, it has the advantage that the blades 14 will· exert a far more powerful rotary force than the ribs 55 12 in Fig. 1 and will quickly increase the speed of rotation of the projectile after it has left the gun. It will be noticed that the greater portions of these blades are spread out at the periphery of the casting, 60 so that maximum leverage or torque for the rotary motion is obtained. The blades are also placed in a position (relative to the body of the projectile) where the air or water is under the greatest compression. 65 Attention may here be directed to the'fact that various types of bombs and slow speed bullets or projectiles fired from smooth bore guns,.are usually furnished with fan-shaped tails or propeller-blades in order to prevent tumbling or wabbling motion. Such de- 70 vices are effective mainly because they serve to place the center of gravity of the bullet or the projectile well forward. The rotary effort from a propeller-shaped tail-piece applied to a high speed projectile would, how- 75 ever, be insignificant because the device would travel in a rarefied atmosphere which would produce relatively little turning movement. Hence the importance of my invention, is in placing the turning ar- 80 rangement at the forward end of the projectile. As shown in Figs. 1 and 3 the tubular. ribs 9: and 15 are relatively light in weight as compared with the body portion of the projectile. This is important in order 85 that they offer little resistance and do not materially alter the ballistic characteristic of the projectile. Also the spiral blades or members are much longer in the axial· direction of the projectile than in their radial 90 direction in order to obtain maximum torque.. With certain, ballistic proportions such as indicated in. Fig. 5 it is possible to further reduce the twist of the rifling in a gun-bar- 95 rel. The projectile shown in Fig. 5 has an exceptionally: heavy head as shown at 16 and the base of the projectile is; made exceptionally light by means of the tubular extension 17. This type, of projectile, hav- 100 ing its center of gravity far forward, has less tendency to wabble after being .fired than the ordinary type and will quickly increase its stability in the air when furnished with the style of diving-cap shown in Fig. 105 3. Other means attached to the fuse-block 18 may in certain cases be preferable to the tubular extension. 17. By using, a projectile of this type having a reduced length relative to its diameter, the rifling of the gun 110 barrel may be entirely dispensed with and the projectile may advantageously be fired from a smooth bore gun, the main point being to shift the center of gravity of the shell far enough forward to insure sufficient 115 initial stability, until the requisite speed of rotation is attained by means of the blades 15 or the like. A diving-shell or a torpedoshell of the type described, will naturally be very effective in a naval engagement in that 120 it will readily reach the vulnerable portions of an armored ship below the water line. When fired at a submarine which is just awash or with only the conning-tower or periscope showing the chances of scoring an 125 effective hit will be considerable· increased.

I. wish it to be understood that I do not limit my invention to the specific constructions shown as various modifications in the design could be made and the invention em- 130

1,384,841 a

4. A proj ectile having a heavy and pointed forward portion and a comparatively light rear portion, a tubular member extending about the said forward portion and being 55 spaced therefrom, said tubular member being relatively light in weight as. compared with the body portion of the projectile, and a plurality of spiral blades of substantially uniform twist throughout their entire length 60 for rigidly securing the tubular member to the body portion of the projectile.

5. A projectile having an annular nm extending forward of the head end of the projectile and being spaced therefrom, said 65 -rim being of substantially the same diameter as the body portion of the projectile and being connected therewith by a plurality ox spiral blades of substantially uniform twist throughout their entire length, lateral ports 70 being formed between said blades for the escape of air or water which has entered the mouth of said rim during the flight of the projectile.

6. A projectile having a pointed head por- 75 tion and a diving head comprising a tubular metal rim spaced from and surrounding the pointed portion of the projectile and of substantially the same diameter as the projectile, and a plurality of blades connecting 80 said rim with the projectile, and forming open ports between said blades for the escape of the air or water which has entered the mouth of said rim during the flight of the projectile. . , ⁸⁵

7. A projectile having a pointed head’.and a tubular member relatively light in weight as compared with the body portion of the projectile, said tubular member extending over the pointed head and being connected 90 with the body portion of the projectile by a plurality of spiral blades between which exit areas are formed for the air or. water confined by the tubular member, said exit areas being at least substantially equal to 95 the cross-section of the body portion of the, projectile.

Signed at New York city, in the county of New York and State of New York this 15th day of June, A. D. 1918.

ROBERT LUNDELL.

bodied in small arms projectiles and other widely differing forms without departing from the main features of the invention. Although Figs. 1 and 3 both show detach5 able diving-caps, such construction is not essential unless different qualities of metal are to be employed.