The present invention relates generally to non-lethal projectiles, and more specifically to aerodynamic forms of such projectiles that enhance their accuracy, speed and distance.
There are essentially three designs in the marketplace for non-lethal payload containing projectiles. The first, as shown in U.S. Pat. No. 6,543,365 to Vasel et al., is a 68 caliber sphere containing a payload, such as an irritant powder, which is released when the sphere ruptures upon impacting a target. The sphere is unable to develop spin when launched through a smooth bore launcher, which is the standard method of firing. The second design is known as a “shaped projectile” and has a front hemisphere, containing a ballast, separated by a central disc sealing the front portion from the back portion, which contains the payload. The third design is another shaped projectile, as shown in U.S. Pat. Nos. 8,875,634 and 9,766,049 to Gibson et al., comprised of a front hemisphere, containing the payload, which has a flat base sealing it from the back portion, which is shaped like a cylindrical cup, forming a skirt, which may be hollow. Both of the shaped projectiles have ridges running longitudinally at a slight slant on the cylindrical portion of the skirt. These ridges are intended to impart spin but, in actuality, reduce the velocity of the projectile when passing down the smooth barrel of a launcher, because the plastic of which the projectiles are composed does not have the capability of obturating the barrel and, thus allows blow-by of air, decreasing velocity. The ridges are too subtle to impart spin and their placement on the cylindrical shaft portion creates a turbulent boundary layer of air that inhibits the projectile's flight. The first two designs are not easily adapted to “nesting” in a loading tube or magazine, since nesting requires the back portion of one projectile to have concave shape complimentary to the front portion of another projectile lined up behind it. The third design could be adapted to nest, but it is vulnerable to stress breakage in a nesting application.
Projectiles launched through a smooth bore are inherently inaccurate due to their lack of spin. Spin creates an axial gyroscopic stabilizing effect which produces a more consistent trajectory and increased accuracy. Non-lethal projectiles by their very nature are not intended to cause lethal consequences, but if the projectile's flight path is inaccurate or unpredictable due to lack of adequate spin, the projectile can impact the intended live target in a lethal manner by penetrating an eye or other similar vulnerable area.
What is needed is a non-lethal projectile with an aerodynamic design to impart spin to enhance accuracy, speed and distance. Also needed is such a design that also may be nested for rapid loading.
The disclosed invention is a non-lethal projectile formed by a front shell, which has a hemispherical nose and a cylindrical shaft, as well as by a base. The hemispherical nose has three or more hi-planar grooves, originating along the junction of the hemispherical nose and cylindrical shaft, extending toward the nose in an inward whorled manner, and terminating around the apex of the hemisphere. The angle of the grooves, when measured relative to the equator, is in the range between 30 degrees and 60 degrees, and the angle of the two sides of the grooves, when measured transverse to their longitudinal path, is in the range from between 60 and 95 degrees. The hemispherical shell has an interior cavity to contain the projectile's non-lethal payload. The grooves in the hemispherical shell cause the projectile to spin, thereby creating a stabilizing gyroscopic effect when expelled through a smooth bore barrel. The second part of the projectile is its base, which has a domed shape and an annular ring to seal the shell's interior cavity and act as an obturating ring within the barrel of a launcher. The convex inner surface of the dome has a profile complimentary to the hemispherical nose of the shell so that multiple projectiles may nest nose to tail when loaded into a multiple round magazine. The convex tail design also creates a more nose forward center of gravity, thereby increasing the aerodynamic stability of the projectile.
This invention is a projectile intended to be fired through a smooth bore launcher (not shown) propelled by a compressed gas, typically compressed air. The size is 68 caliber, the same as recreational “paintballs” and “Pepperballs” of non-lethal marketed projectiles, although the design disclosed here may be applied to other sizes of non-lethal projectiles, such as 12 gauge, 37 mm, and 40 mm. Launchers for 68 caliber projectiles are typically smooth bore and use compressed gas to launch the projectile.
As shown in
The projectile's 10 front shell 11 can be described as having a hemispherical shape, merged at its equator 12 with a cylindrical portion 14 of the same or substantially similar diameter. The hemispherical area 13 has, preferably, three or more bi-planar grooves 15, originating and equidistantly placed along the equator 12 and extending toward the nose or pole 23 at a radial angle in an inward whorled manner, terminating around the apex of the hemisphere 13. As shown in
The grooves 15 on the hemispherical portion 13 of the shell 11 create a spin stabilizing gyroscopic effect when forcefully expelled through a smooth bore barrel to deploy the projectile 10. The projectile 10 is comprised of a frangible material that is intended to disintegrate on impact with the intended target and release the payload (not shown), thereby creating the desired effect.
The assembled projectiles 10 are designed to nest in a nose 23 to tail 33′ manner, thereby protecting the nose 23 of the following projectile 10 from damage when loaded into a multiple round magazine. The hemispherical shape of the nose portion 23 and tail 33′ will allow for both linear and arched or circular positioning of the projectiles. The convex tail design 33′ also creates a more nose forward center of gravity whereby increasing the aerodynamic stability of the projectile.
The present invention has been tested and the results are shown in the table of
In addition to wind tunnel testing, the aerodynamic stability of the non-spinning projectiles were tested using a “drop tank” consisting of a 6 inch diameter by 6 foot transparent acrylic tube. The drop tank was placed in an upright position and filled with water. Each projectile was carefully placed slightly below the surface of the water to allow any entrained air bubbles to be released, then the projectile was allowed to fall. The test was duplicated 5 times for each projectile and the projectile's path through the water was observed and described. The purpose of the drop tank test was to determine the propensity of the projectile to tumble in flight. A projectile with a rear or centrally located center of gravity tends to tumble in flight, which creates an unpredictable flight path. While a very nose heavy design does not tend to tumble in flight, it does however have an arching flight path, like that of a badminton shuttlecock and must overcome the gravitational effects by increased velocity. A flat trajectory is the preferred flight path for a projectile of this type for it exhibits increased accuracy. This testing showed that the present design has significantly improved anti-tumble characteristics compared to commercially-available projectiles.
The drawings and description set forth here represent only some embodiments of the invention. After considering these, skilled persons will understand that there are many ways to make a non-lethal projectile according to the principles disclosed. The inventor contemplates that the use of alternative structures, materials, or manufacturing techniques, which result in a non-lethal projectile according to the principles disclosed, will be within the scope of the invention.
This application claims priority under 35 U.S.C. § 119(e) from provisional patent Application No. 62/720,077 filed on Aug. 20, 2018. The 62/720,077 application is incorporated herein by reference.
Number | Date | Country | |
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62720077 | Aug 2018 | US |