Method And Apparatus For Changing The Trajectory Of A Projectile

Abstract

An armor system comprising an armor base, an armor face on the armor base positioned as to be the first impact point of an incoming projectile, and a plurality of protrusions that extend outwardly away from the armor face. The protrusions act to affect the trajectory of an incoming projectile and divert it away from the optimum angle of attack.

Description

BACKGROUND OF THE INVENTION

[0001] 1. Technical Field

[0002] The invention relates to defensive shielding. More particularly, the invention relates to a defeat mechanism for projectile rounds. Specifically, the invention provides a deflection mechanism to affect the trajectory of a projectile such that it is diverted away from an optimum angle of attack.

[0003] 2. Background Information

[0004] Known defeat mechanisms (armor) for projectile rounds (bullets) have traditionally relied on hardness, tackiness, elongation, weave or other material characteristics for energy absorption. Military vehicles are armored to withstand the impact of shrapnel, bullets, missiles, or shells, protecting the personnel inside from enemy fire. Such vehicles include tanks, aircraft, and ships.

[0005] Through the end of World War II, the type of armor used on almost all tanks and other armored vehicles was a sheet of steel. Increasing the protection on a vehicle meant adding thicker steel sheets. This increased the vehicle's weight, which in turn reduced its mobility. This weight/mobility problem has led to changes in armor design. One form of armor that has been developed uses materials such as ceramics or depleted uranium in addition to steel. These materials are lighter than steel while still being relatively strong and increasing protection while maintaining mobility of the vehicle.

[0006] Another type of armor is composite armor, which is created from layers of two or more materials with significantly different chemical properties. Steel and ceramics are the most common types of materials used in composite armor. Composite armor's effectiveness depends on its composition and this type of armor tends to be effective against kinetic energy penetrators such as bullets.

[0007] Yet another type of armor is spaced armor, which is created from two or more plates spaced a distance apart. Spaced armor reduces the penetrating power of bullets and solid shot. After penetrating each plate, projectiles tend to tumble, deflect, deform, or disintegrate. This minimizes the damage and contains the projectile before it reaches the core of the armored vehicle.

[0008] Given a fixed thickness of armor plate, a projectile striking at an angle must penetrate more armor than a projectile that impacts perpendicularly. For example, if armor is 5'' thick and a projectile hits at a 45.degree. angle, the bullet has to travel through 8'' of armor to reach the core of the vehicle, as opposed to 5'' if the projectile were to strike at a perpendicular angle. Thus, types of armor have been developed which incorporate planar, angled surfaces. The vehicle receives "thicker" armor, but with no weight penalty. These planar, angled surfaces also increase the chance of deflecting a projectile, which happens when the bullet is traveling at a trajectory close to the slope of the planar surface.

[0009] The major drawback with this type of angle-armor technology is that at certain angles, the impact of some projectile hits will not be affected by sloping, such as a "direct hit" at a substantially perpendicular angle. A cost/benefit analysis must therefore be done to determine whether the armor thickness should be increased to account for this type of impact. If the thickness is increased, the weight of the vehicle increases, therefore the costs involved increase. However, the safety of the personnel also increases. If the thickness is not increased to a degree sufficient for impacts at these angles, personnel are left at a greater risk of injury.

[0010] The various types of armor have been moderately effective in stopping traditional projectiles in the past. However, the impact tip of the bullet is so important that many are now tipped with ultra hardened materials such as ceramic silicon carbide and depleted uranium. This helps the bullet retain its shape and kinetic energy when penetrating armor. This increases the probability that the previously known armor technologies will be less capable of stopping modern projectiles.

[0011] Thus, the need exists for a new armor technology that can defeat modern projectiles.

BRIEF SUMMARY OF THE INVENTION

[0012] The present invention is a protrusion armor system which combines the best features of composite, spaced armor and sloping armor technologies, but also adds a new and novel approach to reducing the effectiveness of impacts. This new invention relies on deflection to affect the trajectory of a projectile such that it is diverted away from the optimum angle of attack. The deflection changes the impact point of the projectile from the projectile's tip, where all the mass-energy is concentrated into the smallest possible area, to a region on the projectile having a greater surface area such as the shoulder or side wall of the projectile.

[0013] The armor in accordance with the present invention is a plate having a surface area that includes a plurality of smooth, raised, pointed, or rounded protrusions extending outwardly therefrom. The protrusions are generally conical in shape having a wider base and a narrower tip with an arcuate sidewall extending therebetween. The sidewall preferably is concave. The sidewalls of these protrusions are shaped so that, on impact, the projectile's tip is diverted from its original trajectory to a path where the projectile is induced to travel in a direction less lethal. Thus, if the projectile strikes the armor, a region other than the tip is the most likely impact point. This invention increases the available impact surface area on the projectile. At thousands of feet per second there is little time to control the trajectory, but little force or resistance is needed to change the path of the projectile if the armor catches the projectile at an appropriate angle of inducement.

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS

[0014] The preferred embodiments of the invention, illustrative of the best modes in which Applicant has contemplated applying the principals of the invention, are set forth in the following description and are shown in the drawings.

[0015] FIG. 1 is a side view of a tank incorporating the armor of the present invention;

[0016] FIG. 2 is a perspective view of an armored plate in accordance with the present invention;

[0017] FIG. 3 is a cross-sectional view of the armored plate of FIG. 2 showing the plurality of protrusions useful for deflecting the trajectory of projectiles and showing composite layers and empty caverns within the plate;

[0018] FIG. 4 is a partial cross-sectional view of the armored plate showing a projectile approaching the armor;

[0019] FIG. 4A is a partial cross-sectional view of the armored plate showing the projectile striking a first protrusion;

[0020] FIG. 4B is a partial cross-sectional view of the armored plate showing the trajectory of the projectile after impact:

[0021] FIG. 5 is a partial cross-sectional view of the armored plate showing a projectile approaching the armor at a slightly different trajectory to that shown in FIG. 4;

[0022] FIG. 5A is a partial cross-sectional view of the armored plate and a projectile impacting a first protrusion and being deflected by the slope of the sidewall of the protrusion;

[0023] FIG. 5B is a partial cross-sectional view of the armored plate showing the projectile penetrating the armor at a less than optimum angle because of the change in trajectory;

[0024] FIG. 6 is a partial cross-sectional view of the armored plate and a projectile approaching the armor on a trajectory that will cause it to strike intermediate two protrusions;

[0025] FIG. 6A is a partial cross-sectional view of the armored plate showing the projectile penetrating the armor.

[0026] FIG. 6B is a partial cross-sectional view of the armored plate showing the projectile penetrating the second layer of material;

[0027] FIG. 7 is a partial cross-sectional view of the armored plate and a projectile approaching the armor along a first trajectory;

[0028] FIG. 7A is a partial cross-sectional view of the armored plate where the projectile has penetrated the armor through to a cavern and has impacted the sidewall which defines the cavern;

[0029] FIG. 7B is a partial cross-sectional view of the armored plate showing the projectile traveling along its altered trajectory;

[0030] FIG. 7C is a partial cross-sectional view of the armored plate showing the projectile diverted by the second sidewall and beginning to exit the armor; and

[0031] FIG. 8 is a partial cross-sectional view of a second embodiment of the armor of the present invention, showing armor that includes composite layers, with a second material being disposed in discrete pockets within the interior of the armor.

DETAILED DESCRIPTION OF THE INVENTION

[0032] Referring to FIGS. 1 and 2, there is shown an armored vehicle that includes the protrusion armor system in accordance with the present invention and generally indicated at 1. Protrusion armor system 1 is applied to the outside of armored vehicle 3 to create a protective layer for personnel or sensitive equipment inside vehicle 3. Protrusion armor system 1 can be applied to various types of armored vehicles such as tanks, armored personnel carriers, ships, missile batteries, and unmanned aerial vehicles. Protrusion armor system 1 comprises an armored plate comprising an armor base 2 and an armor face 4 having a plurality of protrusions 6 in accordance with the present invention extending outwardly away therefrom.

[0033] Armor face 4 is the external edge of armor base 2, which faces outward from the armored vehicle. Armor base 2, armor face 4, and protrusions 6 are preferably composed of steel, but can be fabricated from any appropriate shielding material. Armor base 2 provides a desired thickness to the armor system. Protrusions 6 are provided on armor face 4, either through fabrication from a single block of shielding material or through welding or other means of attachment. Protrusions 6 may be lubricated with a dry or wetted lubricant 21, such as a polymer lubricant manufactured by E.I. du Pont de Nemours and Company.

[0034] Referring to FIG. 3, there is shown a first embodiment of armor 1 wherein the armor base 2 is a composite armor being made from at least two materials, such as steel and ceramic. The steel and ceramic are disposed in layers, such as in an exterior layer 8a, a middle layer 10 and an interior layer 8b. So, for example, in FIG. 3, exterior and interior layers 8a, 8b may be steel layers and middle layer 10 may be a ceramic layer. Layers 8a, 8b, and 10 are secured together in any manner known in the art. It will be understood that a plurality of layers of each of the two materials may be integrated into armor base 2. It will further be understood that additional layers of other materials, such as rubber or polymers, may also be incorporated therein.

[0035] Armor base 2 preferably further defines one or more caverns 14 spaced a distance inwardly from armor face 4. Caverns 14 are shown defined in interior layer 8b, but may alternatively or additionally be formed in any of the other layers. Each cavern 14 consists of an empty space defined by the surrounding material. Each cavern has an arcuate cavern sidewall 24 that has a generally parabolic slope, beginning in a generally vertical slope 24a and ending in a generally horizontal slope 24b at cavern base 26. A radius of curvature in the range of 0.05'' to 1.05'' and of preferably 0.08'' has been used in experiments in involving the present invention and has been found to produce the desired change in trajectory of a projectile.

[0036] In accordance with a specific feature of the present invention, the plurality of protrusions 6 extend upwardly and outwardly away from outermost surface 5 of armor face 4. Each protrusion 6 preferably is generally conical in shape with a wider base 22 and a narrower tip 23 with an arcuate sidewall 18 extending therebetween. The word conical in the context of this description is used to describe a shape that resembles a chocolate candy kiss, such as those manufactured by The Hershey Company of Hershey, Pa. Protrusions 6 have a generally circular base 22, a pointed tip 23 and a concavely shaped sidewall 18 extending between base 22 and tip 23.

[0037] The base 22 of each protrusion preferably is integrally formed with exterior layer 8a and is flush with outermost surface 5. Base 22 is of a larger diameter than is tip 23. Protrusion 6 tapers radially from base 22 to tip 23 and tip 23 is spaced a distance 16 from outermost surface 5. Tip 23 may be a rounded `U` shape, an inverted "V" shape, or may be truncated so that it presents a planar surface. The planar surface may be oriented substantially parallel to the surface 5 of armor face 4. In the latter instance the diameter 19 of tip 23 preferably is approximately 0.064'' to 0.128''. Tips 23 of protrusions 6 preferably are spaced equidistant from each other. Preferably, the distance 17 between adjacent tips is 0.8625''. Every tip 23 preferably is also disposed at substantially the same distance 16 away from outermost surface 5. Distance 16 is between 0.7'' to 1.2'' and preferably is 0.812''.

[0038] The tapered sidewall 18 between base 22 and tip 23 is arcuate in cross-sectional profile, and preferably is concave. Sidewall 18 has a radius of curvature from base 22 to tip 23 of between 0.5'' to 2.0'' and preferably between 0.812'' to 1.835'' in experiments involving the present invention. The radius of curvature preferably varies from a large radius of curvature proximate base 22 and a small radius of curvature proximate tip 23. Furthermore, the bases 22 and side walls 18 of adjacent protrusions 6 are substantially continuous with each other so that a substantially U-shaped channel 27 is formed around each protrusion 6. Lubrication 21 preferably coats tip 23, sidewall 18, base 22 and channels 27 of protrusions 6. It will be understood that while adjacent protrusions 6 are shown to be substantially continuous and separated by channels 27, protrusions 6 may, alternatively, be spaced sufficiently far apart that a flatter section of outermost surface 5 extends for a distance between sidewalls 18 of adjacent protrusions 6.

[0039] FIGS. 4-7C show armor 1 in use changing the trajectory of a projectile 30 upon impact. Protrusions 6 alter the trajectory of an incoming projectile, thereby forcing the projectile to strike the vehicle at a less than optimum angle. Projectile 30 has a tip 30a, a shoulder 30b and a sidewall 30c. When projectile 30 comes into contact with curved sidewall 18, the side 30c and shoulder 30b of the projectile 30 impact sidewall 18. Sidewall 18 dissipates some of the kinetic energy of projectile 30, and the curvature of sidewall 18 pushes projectile 30 off its original trajectory and onto a less lethal path. The new trajectory will cause the projectile 30 to travel away from armor system 1 completely, or increase the distance projectile 30 will have to travel through the armor base 2 to reach the core of the vehicle. A projectile approach vector that results in minimal contact with arcuate protrusion sidewall 18 will undergo minimal redirection.

[0040] In FIG. 4, projectile 30 is shown approaching protrusion armor system 1 along a trajectory indicated by arrow A. Projectile 30 contacts arcuate sidewall 18 on first protrusion 6a in FIG. 4A. From the contact with sidewall 18 projectile 30 is deformed and its trajectory A is changed by the arcuate sidewall 18 to a trajectory indicated by arrow B. During the deflection, kinetic energy of projectile 30 is dissipated. Projectile 30 slides along base 22 and encounters arcuate sidewall 18 of 2.sup.nd protrusion 6b. Once again, the trajectory of projectile 30 is altered from B to C. Arrow C in FIG. 4B shows projectile 30 fully redirected by sidewall 18 and base 22 and now traveling outwardly away from protrusion 6b and away from protrusion armor system 1. The friction between armor 1 and projectile 30 is lowered by lubrication 21 and this helps in the redirection of projectile 30. This scenario represents a full redirection where the entire protrusion armor system 1 is still intact after an encounter with projectile 30.

[0041] As seen in FIG. 5, 5A, 5B, projectile 30 may strike protrusion 6a at a second angle. Arrow D shows the trajectory of projectile 30 approaching protrusion armor system 1. When projectile 30 contacts arcuate sidewall 18, projectile 30 deforms and changes trajectory to that indicated by arrow E. While projectile 30 has deformed and changed direction, lessening the kinetic energy, there is still sufficient kinetic energy for projectile 30 to enter material 8a along a trajectory indicated by arrow F. The direction projectile 30 is traveling has been affected by contact with arcuate protrusion sidewall 18 leaving projectile 30 traveling in a less critical trajectory. The redirection results in projectile 30 proceeding at an angle that requires projectile 30 to travel through a greater distance within material 8 to reach the core of vehicle 3, thus lessening the severity of the impact.

[0042] As seen in FIG. 6, 6A, 6B, protrusion armor system 1 is still able to defend against projectiles that do not encounter arcuate sidewalls 18 and therefore do not undergo redirection. In FIG. 6, projectile 30 approaches protrusion armor system 1 at a perpendicular to protrusion base 22, as indicated by arrow G. In FIG. 6A, when projectile 30 contacts protrusion base 22, it undergoes some deformation and enters first layer of material 8a with little to no redirection. Material 8 is sufficiently strong and thick to dissipate some of the kinetic energy from projectile 30 as it continues material 8, shown at arrow H. Composite armor is made of materials with different properties to act on a projectile 30 in different ways and increases the ability to dissipate much to all of the kinetic energy of projectile 30. In FIG. 6B, projectile 30 has traveled through first layer 8a and entered into second layer material 10 finally coming to rest within material 10 and outside of the core of vehicle 3.

[0043] As seen in FIG. 7, 7A, 7B, 7C, armor 1 is designed so that the trajectory of projectile 30 can undergo redirection even after projectile 30 enters protrusion armor system 1. In FIG. 7, projectile 30 approaches protrusion armor system 1 along a trajectory indicated by arrow I. In FIG. 7A, projectile 30 penetrates through first and second material layers 8a and 10, losing some of its kinetic energy. When finally breaching cavern 14, projectile 30 has undergone significant kinetic energy dissipation. As previously indicated, cavern 14 is an empty space defined by the surrounding material layers 8a and 10. This empty space within system 1 facilitates deforming and tumbling of the projectile. Arcuate cavern sidewall 24 affects a projectile's trajectory using the same technique as the protrusions 6 on armor face 4. Once inside cavern 14, the projectile may contact arcuate cavern sidewall 24. The arcuate sidewall changes the projectile's trajectory from "I" to "J" and causes the projectile to slide onto cavern base 26. The encounter with sidewall 24 causes projectile 30 to undergo further trajectory changes, deformation, and energy dissipation. Projectile 30 follows the arcuate of sidewall 24a and is directed along cavern base 26 within cavern 14, shown in FIG. 7B following a trajectory indicated by arrow K. Shown in FIG. 7C, the trajectory is changed from "K" to "L", when projectile 30 encounters arcuate cavern sidewall 24b. This change causes projectile 30 to enter layer 8a in an outward trajectory away from the core of vehicle 3.

[0044] A second embodiment of protrusion armor system is shown in FIG. 8 and generally indicated at 100. Armor 100 comprises a first layer 108a and a second layer 108b made from the same material. A second material 110 is provided in discrete pockets 110a and 110b within material 108. Armor 100 includes protrusions 106 that provide a similar type of protection as armor 1, but in addition to this pockets 110a and 110b include arcuate interior sidewalls 124. These arcuate sidewalls 124 aid in deflecting projectiles 30 in much the same way as the sidewalls 118 of protrusions 106, except that a projectile would be forced to travel through the material within pocket 110a and 110b whereby the kinetic energy of the projectile will therefore be greatly dissipated.

[0045] Operationally, the second embodiment of the present invention deflects projectiles in the same method as the first embodiment. The second embodiment of protrusion armor system 110 deflects projectiles using a plurality of a protrusion 106 on an armor face 104. However, in armor system 100, a projectile 30 encounters more material 110 before it can reach the inner core of the vehicle.

[0046] In the foregoing description, certain terms have been used for brevity, clearness, and understanding. No unnecessary limitations are to be implied therefrom beyond the requirement of the prior art because such terms are used for descriptive purposes and are intended to be broadly construed.

[0047] Moreover, the description and illustration of the invention is an example and the invention is not limited to the exact details shown or described.

Claims

1. An armor system for a vehicle comprising: an armor base, adapted to be applied to an exterior surface of the vehicle; an armor face on the base, positioned as to be the first impact point for an incoming projectile; and at least one arcuate surface extending outwardly away from said armor face, said arcuate surface being adapted to change the trajectory of the incoming projectile upon impact.

2. The armor system as defined in claim 1, further comprising a protrusion extending outwardly away from the armor face, and wherein the arcuate surface comprises a curved sidewall of the protrusion.

3. The armor system as defined in claim 2 wherein the protrusion further includes a base proximate to the armor face and a tip remote from the armor face, and wherein the curved sidewall extends between the base and tip.

4. The armor system as defined in claim 3 wherein the sidewall has a radius of curvature that is between 0.5'' and 2.0''.

5. The armor system as defined in claim 3 wherein the base of the protrusion is one of integrally formed and secured to the armor face.

6. The armor system as defined in claim 3 wherein the tip of the protrusion is one of rounded, pointed, and planar in shape.

7. The armor system as defined in claim 3 wherein the protrusion is conical in shape; and wherein the protrusion includes a wider base proximate the armor face and a narrower tip remote from the armor face and said sidewall radiates outwardly from said tip to said base and is concave in cross-sectional shape.

8. The armor system as defined in claim 7 further comprising a plurality of substantially identical conical protrusions extending outwardly away from the armor face.

9. The armor system as defined in claim 8 wherein the protrusions are spaced equidistant from each other.

10. The armor system as defined in claim 8 wherein the tips of the protrusions are disposed equidistant from the armor face.

11. The armor system as defined in claim 8 wherein the sidewall of a first protrusion is substantially continuous with the sidewall of an adjacent second protrusion.

12. The armor system as defined in claim 8 wherein adjacent protrusions are separated from each other by "U" shaped channels.

13. The armor system as defined in claim 1 wherein the armor base comprises a first outer layer of a first material and a second inner layer of a second material.

14. The armor system as defined in claim 13 wherein the base further comprises a third innermost layer of one of the first and a third material.

15. The armor system as defined in claim 14 wherein the second layer comprises a plurality of discrete pockets of the second material interspersed in the first layer.

16. The armor system as defined in claim 13 wherein the armor system further comprises at least one hollow cavern defined in one of the first and second layers.

17. The armor system as defined in claim 16 wherein the cavern includes at least one interior sidewall that is arcuate, and wherein said arcuate cavern sidewall is disposed so as to change the trajectory of the incoming projectile upon impact therewith.

18. The armor system as defined in claim 1 further comprising a lubricating material applied over an exterior surface of the arcuate surface and the armor face.

19. The armor system as defined in claim 18 wherein the lubricating material comprises one of a wet and dry lubricant.

20. A defensive armor plate for a vehicle, said plate comprising: a base affixed to an exterior surface of the vehicle; and a plurality of protrusions extending outwardly from an exterior surface of the base.

21. The defensive armor plate for a vehicle, wherein each protrusion is conical in shape and is wider proximate the base and tapers to a narrower tip, and wherein an arcuate sidewall extends from the tip to the base; and wherein said protrusions are adapted to alter the trajectory of an incoming projectile upon impact.