IL106815A - Projectile acceleration system - Google Patents

Abstract

A projectile launching system with increased projectile barrel exit velocity comprising: (a) a barrel (16); and (b) a shell (14) including: (i) a casing (18); (ii) a projectile (10) connected to said casing; (iii) a deflagrating explosive housed in said casing; and (iv) a detonating explosive (26) further designed to detonate during the travel of said projectile in the barrel. 789 ט' באייר התשס" ב - April 21, 2002

Description

PROJECTILE ACCELERATOR PROJECTILE ACCELERATOR FIELD AND BACKGROUND OF THE INVENTION The present invention relates to projectiles and, more particularly, to systems for accelerating projectiles during their travel in the barrel of the launching gun so as to give the projectile additional speed and piercing ability.

Various projectiles are in current use in a variety of military and civilian applications. These range from bullets fired by handguns to large diameter artillery pieces to projectiles fired by tanks, such as, for example, those of the armor-piercing variety.

Typically, projectiles come in casings which include a suitable charge, or propellant, typically a deflagrating explosive, or propelling charge, such as gunpowder, characterized by progressive reaction rates and buildup of pressure which creates a heaving action. The buildup of pressure as gases are released serves to propel the projectile forward in the barrel and accelerates it to its barrel exit velocity.

In most applications it is desirable to attain the highest possible barrel exit velocity since, everything else being equal, the higher the projectile velocity, the higher the penetrating power of the projectile. In addition, at higher velocities the projectile is less influenced by its environment and is therefore more accurate. Furthermore, a higher velocity implies a shorter travel time to the target, giving the target less time to avoid the projectile through a change in position or other evasive maneuvers.

The barrel exit velocity is determined by a number of factors including, among others, the weight and shape of the projectile and associated equipment, the amount, type, nature and geometry of the propellant used, the length, diameter and nature of the barrel, and the like. Considerable effort has been devoted over the years to adjust and optimize the various parameters so as to achieve the highest possible barrel exit velocity at the lowest capital and operational cost.

It is commonly appreciated, for example, that a significant fraction of the heaving forces of the reacting propellant is wasted since the propellant stays in the firing chamber while the projectile travels down the barrel, getting progressively farther from the pressure waves produced by the reacting propellant. To remedy this situation, it has been proposed to mount the propellant on a movable piston which is made to move rapidly forward behind the projectile as the projectile travels down the barrel. In this way it is theoretically possible to increase the heaving efficiency of the propellant and increase the barrel exit velocity. However, because of the relatively slow and unpredictable reaction rates of deflagrating explosives, such a system, to be effective, must be implemented in guns having barrels which are considerably longer than those in common use in today's tanks and artillery.

There is thus a widely recognized need for, and it would be highly advantageous to have, a system for significantly increasing the barrel exit velocity of a projectile beyond the velocities achievable using conventional technology without significantly adding to the cost of the guns or of the projectile and associated components.

SUMMARY OF THE INVENTION According to the present invention there is provided a shell with increased projectile barrel exit velocity, comprising: (a) a casing; (b) a projectile connected to the casing; (c) a deflagrating explosive housed in the casing; and (d) a detonating explosive designed to travel along with the projectile and further designed to detonate during the travel of the projectile in the barrel.

According to further features in various preferred embodiments of the present invention, a sabot is used to connect the projectile to the casing. Most preferably, a sliding block designed to travel with the projectile in the barrel until the time of the detonation is also employed.

According to additional features in preferred embodiments of the present invention, the detonation of the detonating explosive is designed to occur at a certain location in the barrel and may be initiated, for example, by electrical or electromagnetic signals or by physical impact.

According to another embodiment of the present invention, there is provided a projectile launching system with increased projectile barrel exit velocity, comprising: (a) a shell, including: (1) a casing; (2) a projectile connected to the casing; (3) a deflagrating explosive housed in the casing; and (4) a detonating explosive designed to travel along with the projectile and further designed to detonate during the travel of the projectile in the barrel; and (b) a barrel section having an enlarged internal barrel diameter in the vicinity of the location where the detonation occurs.

According to other embodiments of the present invention, a plurality of detonating explosives are included which are designed to detonate sequentially during the travel of the shell through the gun barrel.

Also according to the present invention, there is provided a projectile launching system with increased projectile barrel exit velocity, comprising: (a) a shell, including: (1) a casing; (2) a projectile connected to the casing; (3) a deflagrating explosive housed in the casing; and (4) a detonating explosive designed to detonate during the travel of the projectile in the barrel; and (b) a barrel section having an enlarged internal barrel diameter in the vicinity of the location where the detonation occurs; wherein the detonating explosive is further designed to separate from the shell prior to the initiation of the deflagrating explosive and travel to, and emplace in, the barrel section having an enlarged internal barrel diameter, the detonating explosive being further designed to detonate in such a way as to accelerate the projectile toward the barrel exit.

In operation, the deflagrating explosive of a shell according to the present invention is initiated, propelling the projectile through the gun barrel. At a suitable point during the travel of the projectile through the barrel a detonating explosive is set off to impart to the projectile additional velocity.

The present invention successfully addresses the shortcomings of the presently known configurations by providing shells and projectile launching systems capable of achieving significantly increased projectile barrel exit velocities using gun barrels of substantially the same length as conventional barrels.

BRIEF DESCRIPTION OF THE DRAWINGS The invention is herein described, by way of example only, with reference to the accompanying drawings, wherein: FIG. 1 depicts a conventional armor-piercing shell prior to launch; FIG. 2 schematically depicts a projectile according to the present invention as it might appear during its travel in the barrel of the launching gun; FIG. 3 shows another embodiment of a projectile according to the present invention as it would appear during travel in the barrel of the launching; FIG. 4 shows a projectile similar to that of Figure 3 but launched using a modified gun barrel having an enlarged diameter section; FIG. 5 shows a projectile as in Figure 4 but with different placement of the explosives; FIG. 6 shows a projectile as in Figure 4 but with different placement of the sliding block; FIG. 7 illustrates an embodiment designed for multiple explosions; 5 FIG. 8 illustrates an embodiment wherein the explosives set up in the barrel prior to launching.

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention is of a shell and system for enhancing the barrel exit velocity of a projectile. The principles and operation of shells 10 and systems according to the present invention may be better understood with reference to the drawings and the accompanying description.

Referring now to the drawings, Figure 1 illustrates a typical conventional armor-piercing shell, of the type which might be fired by a tank gun. While the present invention may be applied to a large variety of 15 projectiles and projectile systems, for illustrative purposes only, and without in any way limiting the scope of the present invention, the description will be limited to applications of the present invention to armor-piercing projectiles of the type illustrated in Figure 1.

The armor-piercing shell of Figure 1 includes a suitable projectile 20 10, typically made of a hard metal, such as high-strength steel, tungsten or depleted uranium. Projectile 10 typically includes stabilizers 12 to enhance its aerodynamic stability during free flight to the target.

Typically, surrounding a portion of projectile 10 is a sabot 14 which is a device designed to center projectile 10 in a gun barrel 16 (e.g., Figure 2) and to prevent the escape of gases ahead of projectile 10, thereby serving to efficiently transmit the full thrust generated by the propellant to projectile 10. Sabot 14 may be of any suitable type, for example as shown in Figures 1, 2 and 5-8 or as depicted in Figures 3 and 4, among other designs. Sabot 14 may, for example, be made of three or more identical but independent portions which are designed to adjoin projectile 10 during its travel through barrel 16 and to separate and fall away from projectile 10 shortly after the emergence from barrel 16.

Projectile 10 is mounted in, or connected to, typically through sabot 14, a casing 18 which houses a suitable deflagrating explosive 20, which may be made up of a mixture of various materials. A deflagrating explosive 20 is a material which, when triggered, releases heat in a self-sustaining progressive reaction which effects a pressure buildup producing a heaving action. Examples of deflagrating explosives which are commonly used as propellants include, but are not limited to, various types of gunpowder.

Casing 18 typically also houses a primer 22 which serves to initiate the reaction of deflagrating explosive 20. Primer 22 may be part of a suitable safe and arm system designed to arm deflagrating explosive 20 8 106815/4 only after certain actions have been taken.

To launch a conventional projectile 10 (Figure 1) the shell, after proper arming, is placed in the firing chamber 24 (Figure 2) of the gun. Deflagrating explosive 20 (Figure 1) is then set off, typically through impact of a hammer of appropriate design, producing large amounts of gases and a large buildup of pressure on the back side of projectile 10 and sabot 14 which serve to produce forward thrust, thereby accelerating projectile 10 to its barrel exit velocity.

According to the present invention, the barrel exit velocity of projectile 10 is increased by setting off one or more suitable detonating explosives, either simultaneously or sequentially, at a suitable point or points during the travel of projectile 10 through gun barrel 16 (Figure 2). Detonating explosives differ from deflagrating explosives in that they are characterized by extremely rapid chemical reactions, a high pressure buildup and high brisance, i.e., shattering action. Without in any way limiting the scope of the present invention, it is to be noted that while the typical travel time of a projectile through a gun barrel is on the order of a few milliseconds, a detonating explosion can be initiated in the time frame of a few microseconds.

The general concept of the present invention is depicted schematically in Figure 2 which shows projectile 10 during its travel through barrel 16. In contrast to a conventional shell depicted in Figure 1 , 9 106815/2 a shell according to the present invention further includes a detonating explosive 26 which, as is shown in Figure 2, may be attached to the rear portion of projectile 10, and which stays in the vicinity of projectile 10 during its travel through gun barrel 16 up until the point of detonation of detonating explosive 26.

The detonation of detonating explosive 26 creates pressure waves, some of which are directed so as to accelerate projectile 10 toward the barrel exit. To increase the forward-thrust efficiency of the detonating explosive, a system according to the present invention preferably further includes a sliding block 28 (e.g., Figure 3) of proper dimensions and weight. Sliding block 28 travels through barrel 16 with projectile 10 prior to the detonation of detonating explosives 261 and 262. Upon detonation of detonating explosives 261 and 262, sliding block 28 serves to effectively decrease the volume of barrel 16 posterior to projectile 10 and thereby diverts some of the forces which would otherwise be lost so as to redirect them anteriorly where the forces aid in increasing the thrust on, and the forward velocity of, projectile 10.

Preferably, sliding block 28 is designed so that following detonation its forward velocity is greatly decreased yet remains positive, allowing sliding block 28 to leave barrel 16 at a low velocity through the barrel exit and dropping on the ground relatively near the gun. Sliding block 28 may initially be located posteriorly of projectile 10 as shown in Figures 3-5 or 10 106815/2 it may be placed so as to surround a portion of projectile 10, as shown in Figure 6.

Sliding block 28 may also be utilized as an anchoring device for detonating explosives 261 and 263, as can be seen in Figures 3 and 4. Alternatively or additionally, as shown in Figure 3, detonating explosives 262 may be in the form of an annular structure surrounding projectile 10 or, as in Figures 5 and 6, detonating explosives may be surrounding sabot 14, among several possibilities.

Preferably, a shell according to the present invention also includes an outer envelope 30 (Figures 3-6), made of a suitable material, and preferably annular in shape, which is designed to travel with projectile 10, aiding in delivering thrust from sliding block 28, with which envelope 30 is in contact, to sabot 14, up until the time of the detonation of detonating explosives 261 - 265.

The detonation of detonating explosives 261 - 265 is preferably timed to occur at a certain location in barrel 16. The initiation of detonating explosives 261 - 265 can be effected by any suitable means including, but not limited to, through the use of electrical or electromagnetic signals or through physical impact.

Preferably, the detonation takes place at or near a section of barrel 16 which has an enlarged internal barrel diameter (Figures 4-6). The enlarged diameter section creates an additional volume which serves as a 11 106815/2 buffer to absorb some of the initial forces produced by the explosion, thereby greatly reducing or eliminating the damage to barrel 16 which may otherwise result from the detonation. The enlarged diameter barrel section may be integrally formed with barrel 16. Alternatively, it may be added to a conventional barrel 16 on a retrofit basis.

To prevent projectile 10 from diverting laterally during its travel through the enlarged diameter barrel section, use is made of leading guiding members 32 (Figures 3-6) having an outer diameter slightly smaller than the inner diameter of barrel 16. The dimensions of guiding members 32 are designed to allow guiding members 32 to slide easily through barrel 16 yet ensure that projectile 14 continues in a straight path through barrel 16 even during its passage through the enlarged diameter section.

In another embodiment of the present invention, a plurality of detonating explosives 266 are used, each of which is designed to detonate separately and without affecting the others at selected points during the travel of projectile 10 through barrel 16. An example of such a system is depicted in partial view in Figure 7. The detonations are designed to proceed sequentially from the posterior-most explosive to the anterior-most detonating explosive, with each of detonating explosives 266 being designed to travel along with projectile 10 until the time of its detonation.

Preferably, each detonating explosives 266 is separated from its 12 106815/2 immediate neighbors by suitable sliding blocks 281. Each sliding block 281 is designed to travel with projectile 10 in barrel 16 until the time of the detonation of detonating explosive 266 located immediately anteriorly of sliding block 281. The use of a series of sequential explosions roughly approximates the acceleration and velocity imparted to a projectile by the traveling charge technique but achieves these accelerations and velocities without the need for an unusually long barrel.

In yet another embodiment according to the present invention, depicted in Figure 8, detonating explosives 267 are initially located anteriorly of sabot 14. Prior to the initiation of the deflagrating explosive-detonating explosives 267 separate from the shell and travel to, and emplace in, the enlarged diameter barrel section, with the help of a suitable mechanism (not shown). After detonating explosives 267 have been properly located, the deflagrating explosives are be set off, sending projectile 10 through barrel 16. At a suitable point during the travel of projectile 10 through barrel 16, such as immediately after projectile 10 has passed detonating explosives 267, detonating explosives 267 are initiated by some suitable mechanism so as to accelerate projectile 10 toward the barrel exit.

While the invention has been described with respect to a limited number of embodiments, it will be appreciated that many variations, modifications and other applications of the invention may be made.

Claims (30)

1 3 106815 ^ WHAT IS CLAIMED IS:

1. A method for firing a projectile from a barrel, the method comprising: (a) detonating a quantity of deflagrating explosive in such a manner as to cause the projectile to accelerate along the barrel; and (b) detonating, while the projectile is moving along the barrel, a quantity of detonating explosive in such a manner as to further increase acceleration of the projectile along the barrel.

2. The method of claim 1, wherein said quantity of detonating explosive is attached to said projectile so as to be accelerated along the barrel with the projectile by detonation of said deflagrating explosive.

3. The method of claim 1, further comprising providing an outer envelope configured to travel with the projectile along the barrel at least until the detonation of said detonating explosive, said detonating explosive being attached to said outer envelope.

4. The method of claim 1, further comprising providing a sliding block configured to be accelerated along the barrel with the projectile by detonation of said deflagrating explosive, said detonating explosive being detonated at a position interposed between said sliding block and the projectile.

5. The method of claim I, wherein said quantity of detonating explosive is detonated at a portion of the barrel having an enlarged internal barrel diameter.

6. The method of claim 1, wherein said quantity of detonating explosive is detonated at a fixed position within the barrel.

7. The method of claim 1, wherein said quantity of detonating explosive is mounted in a fixed position within the barrel prior to detonation.

8. A shell with increased projectile barrel exit velocity, comprising: (a) a casing; (b) a projectile connected to said casing; (c) a deflagrating explosive housed in said casing; and (d) a detonating explosive associated with said projectile for detonating during the travel of said projectile in the barrel.

9. The shell of claim 8, wherein said detonating explosive is attached to said projectile and travels along with said projectile.

10. A shell as in claim 8, further comprising a sabot through which said projectile is connected to said casing.

11. 1 1. A shell as in claim 8, further comprising a sliding block designed to travel with said projectile in the barrel until the time of said detonation. 15 106815/6

12. A shell as in claim 8, wherein said detonation of said detonating explosive is designed to occur at a certain location in the barrel.

13. A shell system as in claim 8, wherein said detonating explosive is attached to said projectile.

14. A shell as in claim 8, further comprising an outer envelope designed to travel with said projectile until the time of said detonation of said detonating explosive for imparting force to said sabot and wherein said detonating explosive is attached to said outer envelope.

15. A shell as in claim 8, wherein said detonating explosive is further designed to separate from said projectile prior to the initiation of said deflagrating explosive and to detonate in such a way as to accelerate said projectile toward the barrel exit.

16. A projectile launching system with increased projectile barrel exit velocity, comprising: (a) a barrel; and (b) a shell, including: (i) a casing; (ii) a projectile connected to said casing; (iii) a deflagrating explosive housed in said casing; and (iv) a detonating explosive further designed to detonate during the travel of said projectile in the barrel.

17. The system of claim 16, wherein said detonating explosive is connected to said projectile and designed to travel along with said projectile and wherein said barrel features a barrel section having an enlarged internal barrel diameter in the vicinity of the location where said detonation occurs.

18. A system as in claim 17, wherein said barrel section having an enlarged internal diameter is integrally formed with said barrel.

19. A system as in claim 17, wherein said barrel section having an enlarged internal diameter is connected to said barrel.

20. A system as in claim 17, wherein said shell further includes leading guiding members having an outer diameter slightly smaller than the inner diameter of said barrel to prevent said projectile from diverting laterally during its travel through said barrel section having an enlarged internal diameter.

21. A system as in claim 16, wherein said shell further comprises a sabot through which said projectile is connected to said casing.

22. A system as in claim 16, further comprising a sliding block designed to travel with said projectile in the barrel until the time of said detonation.

23. A system as in claim 16, wherein said detonation of said detonating explosive is initiated by electrical signals. 1 7 106815/ί^

24. A system as in claim 16, wherein said detonation of said detonating explosive is initiated by electromagnetic signals.

25. A system as in claim 16, wherein said detonation of said detonating explosive is initiated by impact.

26. A system as in claim 16, wherein said detonating explosive is attached to said projectile.

27. A system as in claim 16, further comprising an outer envelope designed to travel with said projectile until the time of said detonation of said detonating explosive for imparting force to said sabot and wherein said detonating explosive is attached to said outer envelope.

28. The system of claim 16, wherein said barrel features a barrel section having an enlarged internal barrel diameter in the vicinity of the location where said detonation occurs; and wherein said detonating explosive is further designed to separate from said projectile prior to the initiation of said deflagrating explosive and travel to, and emplace in, said barrel section having an enlarged internal barrel diameter, said detonating explosive being further designed to detonate in such a way as to accelerate said projectile toward the barrel exit.

29. A shell with increased projectile barrel exit velocity, comprising: (a) a casing; (b) a projectile connected to said casing; 1 8 106815/6 (c) a deflagrating explosive housed in said casing; and (d) a plurality of detonating explosives connected to said projectile, each designed to detonate at selected points during the travel of said projectile in a barrel, said detonations designed to proceed sequentially from the posterior-most explosive to the anterior- most detonating explosive, each of said detonating explosives further designed to travel along said barrel said barrel with said projectile until the time of its detonation.

30. A shell as in claim 29, further comprising a sliding block located substantially between each pair of said detonating explosives, each of said sliding blocks designed to travel with said projectile in the barrel until the time of the detonation of the detonating explosive located immediately anteriorly of the sliding block. By: