Aerodynamic shape for projectile

Abstract

A projectile has a rounded or conical front, a cylindrical body and a base, the base meeting a wall of the cylindrical body at an angle of between 10 and 80 degrees, the base being rounded or conical.

Description

[0001] AERODYNAMIC SHAPE FOR PROJECTILE

[0002] RELATED APPLICATION / S

[0003] This application claims the benefit of priority of Israel Patent Application No. 310845, filed on February 13, 2024, the contents of which are incorporated herein by reference in their entirety.

[0004] FIELD AND BACKGROUND OF THE INVENTION

[0005] The present invention, in some embodiments thereof, relates to an aerodynamic shape for a projectile and, more particularly, but not exclusively, to such a shape for a projectile launched from a gun.

[0006] In general, bullets and shells are rounded or pointed at the front and flat at the rear. In the past, bullets and cannonballs were spherical, but became elongated to take advantage of rifling. The rear became flat to attain momentum more evenly from the gunpowder charge.

[0007] At the speeds bullets are fired even a round tip will easily penetrate human skin. Bullets are shaped to maximise the accuracy of the weapon, minimize drag when they're in the air, and inflict a lot of damage when they do penetrate the target.

[0008] However, the flat rear end of the bullet causes eddy currents in the air as the bullet leaves the barrel and thus causes drag, which reduces the speed and accuracy of the bullet. Nevertheless a flat base is retained so as to evenly absorb momentum from the charge that launches the bullet from the barrel, so that accurate fire may be obtained.

[0009] SUMMARY OF THE INVENTION

[0010] The present embodiments provide a standard elongated bullet shape as before but with rounding at the base, or with a conical base. As the bullet fits relatively tightly in the barrel the blast from the charge does not escape but rather applies momentum to the bullet or shell in the normal way. Indeed, as the rounding is symmetrical about the central axis of the bullet, the momentum is in fact applied evenly to the bullet allowing for accurate fire. However, the rounding reduces eddy currents in the air and thus reduces drag. Furthermore eddy currents are capable of destabilizing the flight and reducing accuracy.

[0011] According to an aspect of some embodiments of the present invention there is provided a projectile having a rounded or conical front, a cylindrical body and a base, the base being rounded or conical. At the meeting point between the body and the base, the base may be inclined with respect to a wall of the cylindrical body at an angle of between 10 and 80 degrees. The base may be rounded, such that the angle relates to a tangent to the part of the base that meets with the body.

[0012] In an embodiment, the base is conical, with linear slopes to a point. The point at the end may itself be rounded.

[0013] In an embodiment, the angle is about 45 degrees.

[0014] In an embodiment, the angle is 45 degrees.

[0015] According to a further aspect of the present invention there is provided a projectile having a rounded or conical front, a cylindrical body and a base, the base being rounded or conical.

[0016] Unless otherwise defined, all technical and / or scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which the invention pertains. Although methods and materials similar or equivalent to those described herein can be used in the practice or testing of embodiments of the invention, exemplary methods and / or materials are described below. In case of conflict, the patent specification, including definitions, will control. In addition, the materials, methods, and examples are illustrative only and are not intended to be necessarily limiting.

[0017] BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS

[0018] Some embodiments of the invention are herein described, by way of example only, with reference to the accompanying drawings. With specific reference now to the drawings in detail, it is stressed that the particulars shown are by way of example and for purposes of illustrative discussion of embodiments of the invention. In this regard, the description taken with the drawings makes apparent to those skilled in the art how embodiments of the invention may be practiced.

[0019] In the drawings:

[0020] Fig. 1 is a simplified schematic diagram of a musket ball according to the prior art;

[0021] Fig. 2 is a simplified diagram of a conventional bullet with a rounded front and a flat base;

[0022] Fig. 3 is a simplified diagram of a conventional bullet with a pointed front and a flat base;

[0023] Fig. 4 is a simplified diagram of a conventional bullet with a pointed front and a so-called boat tail base;

[0024] Fig. 5 is a simplified diagram of a bullet according to the present embodiments with a rounded base having a radius larger than that of the bullet itself;

[0025] Fig. 6 is a simplified diagram of a further bullet according to the present embodiments with a sloped base; and Figs. 7A and 7B illustrate two further bullets according to the present embodiments with two different slopes for the base.

[0026] DESCRIPTION OF SPECIFIC EMBODIMENTS OF THE INVENTION

[0027] The present invention, in some embodiments thereof, relates to an aerodynamic shape for a projectile and, more particularly, but not exclusively, to such a shape for a projectile launched from a gun.

[0028] The bullet or shell according to embodiments of the present invention is rounded or spiked at the front as with a conventional bullet, and is elongated. However the base is also rounded or conical. If rounded, the curve of the base may be continuous with the end of the cylinder of the bullet, or there may be an angular discontinuity. For example the base may extend at forty five degrees from the cylinder wall and then curve in towards the center. It is stressed that the base may be rounded and the front conical or vice versa or both ends may be rounded or both ends may be conical.

[0029] Before explaining the invention, reference is made to various shapes of bullets according to the existing art. FIG. 1 is a simplified schematic diagram of a musket ball 10 according to the prior art. The ball is sized to fit the barrel but the high pressure gas used to fire the ball is able to leak out alongside the ball and end up in front of the bullet. Musket balls were generally abandoned after the invention of rifling, which allowed a bullet to spin and thus become more stable in the air. A conventional rifle bullet is shown in FIG. 2. The bullet 12 has a rounded front 14 and a flat base 16. The rounded front is sufficient to penetrate targets at the kind of speed that a bullet flies at. The flat base 16 ensures that the high pressure gas that launches the bullet firstly transfers as much energy as possible to the bullet and does not leak around the sides and secondly the energy is transferred evenly, thus ensuring that the bullet is launched accurately. An elongated length 18 provides for engagement with the rifling of the barrel to spin the bullet.

[0030] FIG. 3 is a simplified diagram of a conventional bullet 20 with a pointed front 22 and a flat base 24.

[0031] FIG. 4 is a simplified diagram of a conventional bullet 26 with a pointed front 28 and a so- called boat tail base 30. A taper on the base of the bullet gives the bullet a higher Ballistic Coefficient. More particularly, the taper on the back of the boat tail bullet means there is less air muzzle. Nevertheless the boat tail is believed to be less good than a flat base bullet in terms of raw

[0032] Before explaining at least one embodiment of the invention in detail, it is to be understood that the invention is not necessarily limited in its application to the details of construction and the arrangement of the components and / or methods set forth in the following description and / or illustrated in the drawings and / or the Examples. The invention is capable of other embodiments or of being practiced or carried out in various ways.

[0033] The present embodiments attempt to find a bullet shape that provides at least some of the advantages of the boat tail and of the flat base together, that is to say to retain as much as possible the high power of expulsion from the barrel of the flat base along with the high ballistic coefficient of the boat tail. Also the base may be a shape that is easy to machine accurately.

[0034] Reference is now made to FIG. 5, which is a simplified diagram of a bullet 40 according to the present embodiments with a rounded base 42 having a radius larger than that of the cylindrical part of the bullet itself. The corners 44 and 46 are rounded so as not to present a discontinuity but ignoring the rounding of the comers, the angle between the tangent to the radially outer part of the base and the side of the cylinder may be between about 30 and 60 degrees and typically about 45 degrees. The radially outer part of the base may be any of an outer half of the radius of the base and is typically indicated by arrow 48. The angle ensures that very little of the high pressure gas is channeled along the barrel, as opposed to the conventional boat tail shape where the high angle creates a pocket that acts as a trap for the gas. Additionally the rounded shape reduces drag when leaving the muzzle. A rounded shape is easier to machine in a way that is correctly centered than the conventional boat tail.

[0035] Reference is now made to Fig. 6, which illustrates a variation 50 of the bullet of Fig. 5 in which base 52 is not rounded. The angles are about the same but the edges are straight in cross section instead of rounded. In an embodiment, the angle at the center of base 52 has a slant angle of at least 5 degrees up to 89 degrees. The flatter the angle the more drag there is. As the angle gets sharper there is a reduction in drag and furthermore the flight is more stable as the reduction in pressure is spread over a greater length, the length of the sloping face. The reduction in pressure is much more focused on a single point and therefore less turbulence is created, again making the flight more stable. Again, unlike the conventional boat tail, there is no pocket that acts as a trap for the gas, forcing it alongside the bullet into the barrel, and thus greater muzzle velocity is achieved. The sloping surface facing the gas is much larger than in the conventional case and thus the gas is able to impart a larger velocity to the bullet. A sloped edge ending at a point is easier to machine accurately than a conventional boat tail.

[0036] Although Figs 5 and 6 show pointed noses, rounded noses may be substituted.

[0037] Reference is now made to Figs. 7A and 7B which illustrate cross sections showing shaping for the rear end of the bullet according to further embodiments of the present invention. As shown in Fig. 7A two rear walls 70 and 72 reach to a relatively sharp point 74, which helps to reduce drag. In Fig. 7B two rear walls 76 and 78 reach to a less sharp point 80. The two angles each give an element of streamlining to the rear of the bullet, reducing turbulence and thus increasing the stability of the flight. The angle used to define each shape is the angle between the wall of the bullet in the cross section and the central axis of the bullet, so that the bullet of Fig. 7a would have a smaller angle than that of Fig. 7b.

[0038] In this disclosure the term “about” refers to ± 10% so that discussion of an angle that lies between 30 and 60 degrees and may advantageously be at 45 degrees is to be construed accordingly.

[0039] The terms "comprises", "comprising", "includes", "including", “having” and their conjugates mean "including but not limited to".

[0040] The term “consisting of’ means “including and limited to”.

[0041] As used herein, the singular form "a", "an" and "the" include plural references unless the context clearly dictates otherwise.

[0042] It is appreciated that certain features of the invention, which are, for clarity, described in the context of separate embodiments, may also be provided in combination in a single embodiment and the present description is to be construed as if such embodiments are explicitly set forth herein. Conversely, various features of the invention, which are, for brevity, described in the context of a single embodiment, may also be provided separately or in any suitable subcombination or may be suitable as a modification for any other described embodiment of the invention and the present description is to be construed as if such separate embodiments, subcombinations and modified embodiments are explicitly set forth herein. Certain features described in the context of various embodiments are not to be considered essential features of those embodiments, unless the embodiment is inoperative without those elements.

[0043] Although the invention has been described in conjunction with specific embodiments thereof, it is evident that many alternatives, modifications and variations will be apparent to those skilled in the art. Accordingly, it is intended to embrace all such alternatives, modifications and variations that fall within the spirit and broad scope of the appended claims. All publications, patents and patent applications mentioned in this specification are herein incorporated in their entirety by reference into the specification, to the same extent as if each individual publication, patent or patent application was specifically and individually indicated to be incorporated herein by reference. In addition, citation or identification of any reference in this application shall not be construed as an admission that such reference is available as prior art to the present invention. To the extent that section headings are used, they should not be construed as necessarily limiting. In addition, any priority document(s) of this application is / are hereby incorporated herein by reference in its / their entirety.

Claims

WHAT IS CLAIMED IS:

1. A projectile having a rounded or conical front, a cylindrical body and a base, the base meeting a wall of the cylindrical body at an angle of between 10 and 80 degrees, the base being rounded or conical.

2. The projectile of claim 1, wherein the base is rounded, and said angle relates to a tangent to a part of said base touching said wall of said cylindrical body.

3. The projectile of claim 2, wherein said rounded base is part of a sphere having a radius larger than a radius of said cylinder.

4. The projectile of claim 1, wherein the base is conical.

5. The projectile of any one of the preceding claims wherein said angle is between 30 and 60 degrees.

6. The projectile of any one of the preceding claims, wherein said angle is 45 degrees.

7. A projectile having a rounded or conical front, a cylindrical body and a base, the base being rounded.

8. The projectile of claim 7, wherein said base has a radius which is greater than a radius of said cylindrical body.

9. The projectile of claim 8, wherein the junction between said base and said cylindrical body is rounded.

10. The projectile of claim 9, wherein a tangent to an outer part of said base not including said rounding with said cylindrical body is at an angle of between 30 and 60 degrees to a wall of said cylindrical body.

11. The projectile of claim 10, wherein said angle is about 45 degrees.

12. The projectile of claim 11, wherein said angle is 45 degrees.

13. A projectile having a rounded or conical front, a cylindrical body and a base, the base being conical.

14. The projectile of claim 13, wherein an angle subtended between a wall of said conical base and a central axis of said projectile is 10 and 80 degrees.

15. The projectile of claim 13, wherein an angle subtended between a wall of said conical base and a central axis of said projectile is between 30 and 60 degrees.

16. The projectile of claim 13 wherein an angle subtended between a wall of said conical base and a central axis of said projectile is 45 degrees.

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