US3126789A

US3126789A - Hypervelocity propulsion arrangement

Info

Publication number: US3126789A
Authority: US
Publication date: 1964-03-31
Anticipated expiration: 1981-03-31

Description

March 31, 1964 x, MEYER 3,126,789

HYPERVELOCITY PROPULSION ARRANGEMENT Filed May 17, 1962 FIG.4.

L- fl Ef- RUDOLF x. MEYER 2 VACUUM PUMP INVEN TOR.

ATTORNEY.

United States Patent Ofilicc 3,126,789 Patented Mar. 31, 1964 HYPERVELOCITY PROPULSION ARRANGEMENT Rudolf X. Meyer, Pacific Palisades, Calih, assignor to The Aerospace Corporation, Los Angeles, Calif., a corporation of California Filed May 17, 1962, Ser. No. 195,513 14 Claims. (Cl. 898) The present invention relates to the high-strength magnetic field art and more particularly relates to means for propelling projectiles at hypervelocities by means of magnetic fields.

Hypervelocity projection arrangements or guns are useful in several kinds of re-entry laboratory activities wherein a projectile is driven into a low pressure tank for simulating orbital velocity re-entry problems. Although certain hypervelocity guns are known in the prior art, the maximum velocity attainable is of the order of 30,000 ft. per second. However, velocities substantially above this will provide information concerning deep-space probe reentry problems as well as orbital re-entry problems. Moreover, the attaining of velocities substantially above 30,000 ft. per second will provide means for testing meteorite damage in a manner similar to tests already accomplished concerning micro-meteorite phenomena. Furthermore, projectile velocities substantially in excess of expected space vehicle velocity may provide a feasible space weapon.

One example of a prior art hypervelocity gun is a lightgas gun utilizing the compression of a light gas to drive the projectile by the driving of a relatively large cylindrical piston through an enclosed breech chamber containing the light gas toward the projectile at the far end thereof. The projectile is substantially smaller in diameter than the piston and the chamber. When the piston is driven by a high-explosive to compress the light-gas, pressures of 40,000 p.s.i. are typical. However, the performance is fundamentally limited by the finite velocity of sound in the gas within the enclosed chamber. At any given time, the gas pressure near the projectile is only a fraction of the pressure near the piston, resulting in lower acceleration to limit terminal velocity of the projectile. Equilibration of pressure in the chamber proceeds essentially at sound velocity. Thus, energy transmission from the piston to the projectile is a function of the velocity of sound of the light gas.

Usually, with this arrangement the time during which the projectile is accelerated is not long enough to let the pressure equilibrate. As a consequence of incomplete equilibration a differential acceleration of a projectile occurs, with a maximum force being applied to the projectile during its initial acceleration phase and with the applied force decreasing to a lesser amount as the projectile accelerates. Since many projectiles will include simple electronic detecting arrangements, they may be constructed to withstand maximum accelerations creating no greater than 20,000 to 50,000 G loadings. However, even when no electronic circuit is provided in the projectiles, there is always a finite limit of the maximum feasible acceleration loading of a projectile because of the problem of the plastic deformation of the projectile itself. One approach has been to provide arrangements which develop a more uniform accelerating force throughout the acceleration period of the projectile.

In order to accomplish this, it has even been proposed to preheat the light gas as by the use of an arch discharge, to increase its temperature and thus increase the velocity of sound therein. 20,000 to 60,000 p.s.i. are typical and projectile velocities as high as 20,000 to 30,000 feet per second may be at tained. However, the limitations due to the finite sound In such arrangements, pressures of velocity cannot be completely overcome whereby velocities greater than about 30,000 feet per second appear to be unattainable by use of a light-gas gun arrangement.

It is, therefore, an object of my invention to provide a new and improved hypervelocity gun arrangement which is not subject to the limitations of sonic velocities by using a magnetic force as the driving force between a driving piston and a projectile.

A further object of my invention is to provide a new and improved hypervelocity projection arrangement.

According to one embodiment of the present invention a magnetic field is created between two parallel conductors lying on opposite sides of a breech chamber by the discharging of a high voltage capacitor through these conductors with a connection therebetween being the projectile of the arrangement. At the instant the current flow reaches its maximum value, a conductive piston is driven at high velocity toward the projectile while engaging both of the conductors and thereby shunting them and maintaining the maximum current flow in the loop circuit thus created. The establishing of this short circuited current loop traps the magnetic flux therein. The velocity of the driven piston tends to reduce the area of the short circuited loop circuit at a rate creating an extremely rapid magnetic field buildup. This magnetic field buildup is re lieved by acceleration of the projectile and the velocity limit of light-gas guns is essentially removed by substituting the propagation velocity of electromagnetic waves in a wave guide (approximately the speed of light) for the velocity of sound. This arrangement also facilitates charges of gas for shock tube purposes.

The subject matter which is regarded as this invention is particularly pointed out and distinctly claimed in the concluding portion of the specification. The invention, however, as to its organization and operation, together with further objects and advantages thereof, will best be understood by reference to the following description taken in connection with the accompanying drawing in which:

FIG. 1 is a cross sectional plan view of one embodiment of the present invention;

FIG. 2 is a cross sectional view taken along line 2-2 of FIG. 1;

FIG. 3 is a cross sectional view taken along the line 3-3 of FIG. 1;

FIG. 4 is a view similar to FIG. 1 showing another embodiment of my invention; and

FIG. 5 is a partial side elevational view showing still another embodiment of my invention.

Referring now to the drawing, wherein like numerals refer to similar parts, in FIG. 1, a projectile 10 is positioned within a bore 12 of a gun barrel 13 near the end thereof adjacent to an enlarged breech 14. At the opposite end of the breech 14 is a piston 15 which will substantially fill a breech chamber 16. The piston 15 is arranged to be long enough to prevent tumbling or skewing. The upper portion of the barrel 13 includes a condoctor 17 fabricated from a low resistance metal such as copper or silver alloys. The conductor 17 extends through the enlarged breech region of the gun as indicated by the numeral 17'. Similarly, the lower portion of the barrel 13 is fabricated to include a low resistance conductor 18 which extends throughout the length of the breech 14 as indicated by the numeral 18'. These conductors define respectively diametrically opposed arcuate surfaces of the bore 12. In certain arrangements requiring bore rifling, the

conductors

17 and 18 are spiraled. spiraling also is used to assure good electrical contact between the couductors and the projectile 10.

As illustrated more clearly in FIGS. 2 and 3, the

conductors

17 and 18 occupy a relatively small portion of thebarrel circumference in the present invention and are not coupled electrically except through the projectile 10.

To prevent undesired electrical coupling, a substantial portion of the barrel 13 is constructed of an insulating material 20 such as epoxy resin or Mylar. The gun itself is completed by a casing 22 which contains the magnetic force, protects the dielectric insulating material 20 and provides a construction which is readily secured to carrying vehicles or other portions of the equipment. It should also be noted that for the magnitude of flux contemplated, all adjacent metal parts are saturated whereby the path of the flux 23 is not limited to the structural elements.

FIG. 2 also indicates an electrical connection between conductors l7 and it; only through the projectile 10. Because of the requirement of a low resistance system, the projectile 10 should be slightly larger than the bore 12 to provide a good connection between the conductors 1'7 and 18 and to provide a means for initially preventing undesired movement of the projectile 10. With the current flows of the present invention, at least the rear surface of the projectile 10 should be made of a highly conductive material which has sufiicient physical and thermal strength to withstand the operations contemplated. Certain metals such as nickel, copper, silver, and gold alloys will provide these basic characteristics. Usually it is preferably to provide a conductive sliding lubrication arrangement between the conductive portions of the present invention such as those used in commutating brushes or trolley collectors. This includes certain carbon and metallic graphite surface materials and various other lubricants. On the other hand, ablating or other materials for testing purposes may be used in the fabrication of the forward conical end of the projectile 10.

Similarly, at least the leading surface of the piston 15 should be of a low resistance material to obtain maximum utilization of the shunted magnetic field of the present invention. Since the entire operation of the present invention is accomplished in a millisecond or so, a major portion of the current flow is on the surface of the conductive portions of the loop circuit whereby relative efficient and expensive conducting surface coatings may be utilized without requiring a great mass of precious metals.

It should be noted from FIGS. 1 and 3 that although the piston 15 is placed behind the upper and lower conductor extensions 17 and 18' it is of a diameter sufficient to engage electrically both of these conductors during its travel through the breech chamber 16. Moreover, it is preferred that the piston 15 have substantially more mass than the projectile 10 so that the magnetic force of the present invention is more effective in accelerating the projectile 10 than it is in decelerating the piston 15.

The electrical circuit of the present invention is illustrated schematically in PEG. 1 as a large capacitor 24 which is charged from a power supply 25, a sequentiallyoperable switch 26, leads coupling the switch 26 and the opposite side of the capacitor 24 to the

conductor extensions

17 and 18 at a point adjacent to the piston 15 and a trigger mechanism 28. The remaining portions of the gun include a primary propellant means such as a charge of high explosive 30 placed directly behind the piston 15 and, in the particular construction illustrated in FIG. 1, Within a cartridge 32 which is secured to the casing 22 by any conventional means such as a threaded engagement. etonation of the charge 30 may be accomplished by any convenient means such as a more volatile cap charge 34 which is ignited by a spark plug arrangement 36. Both the switch 26 and the spark plug arrangement 36 are sequentially controlled by the trig ger 28.

Depending on the particular dimensions and materials utilized and the voltage which may be applied to the capacitor 24, the curernt in the loop circuit including the conductor 17'17, the projectile 10, and the conductor lit-18 will build up a maximum value of many thousands of amperes in a millisecond or less, after the closing of the switch 26. Moreover, the detonation of the charge 30 in response to a spark from the spark plug arrangement 36 will result in the piston 15 engaging the conductor extensions 17'18' within a similar short period. The exact reaction time of the piston 15 to the spark depends on the particular propellant material used in the charge 30 and the configuration of the cartridge 52. Thus, once the capacitor 24 has been charged to its maximum voltage, such as 50 kilovolts, the switch 26 and a spark plug arrangement 36 may be operated simultaneously or with a time sequence of a few hundred microseconds to obtain initial short-circuiting of the loop circuit including the piston 15, the projectile l0, and the conductor It18' at the precise instant maximum current flow is attained.

With respect to the projectile 10 itself the basic driving force is essentially the same as that used in an induction motor. The loop circuit current generates a high magnetic flux within the loop, and the current flow in the projectile 10 is repulsed. The flux density is a function of the area of the loop as well as the current flow around the loop circuit. As the piston 15 is forced toward the projectile 10, the flux density is increased rapidly by the rapid reduction of the area through which the flux must pass. In the time durations involved the total flux is not reduced substantially. As a result, the magnetic force increases inversely proportional to the square of the loop circuit area reduction. As the projectile 10 moves forward, after overcoming the initial movement restriction, the magnetic pressure is relieved.

Because of the disparity in the diameters of the piston 15 (and the chamber 16) and the projectile 10 (and the bore 12), the projectile 10 must move a far greater distance to compensate for movement of the piston 15 (in an attempt) to maintain constant magnetic forces. For instance, with a disparity in diameters of 5 to 1, magnetic equilibrium could be maintained if the projectile 10 moved 5 times as far per unit time as the piston 15. At least during the initial travel of the piston 15, such relative movement is not attainable. This phenomenon is assured by the providing of means such as a press fit for restricting the initial movement of the projectile 10. Thus, the projectile does not move until after the magnetic force starts to increase because of movement of the piston 15. The Maxwellian magnetic force created to accelerate the projectile 10 may be arranged to develop forces which facilitate hypervelocity projection at velocities substantially above the 30,000 feet per second attainable with light-gas guns. In most applications of the present invention the overall length of my gun will be of the order of fifty feet to attain velocities in excess of 50,000 feet per second.

It is relatively obvious that if the breech 14 and the bore 12 are made very long, the magnetic force may be effectively used to attain maximum velocity of the projectile. This maximum velocity is a function, among other things, of the maximum velocity attainable by the piston 15. Thus, driving the piston 15 at a low velocity will create neither as great a magnetic force, nor as great a velocity of the projectile 10, as a high-velocity piston.

Therefore, referring now to FIG. 4, I have shown an arrangement providing an extremely high velocity piston 15'. The piston 15' is substantially the same as the piston 15 with respect to the conductor 1717, a projectile 10 and the conductor 1818. However, the means of propelling the piston 15' has been substantially changed compared to that shown in FIG. 1, by the replacing of the cartridge 32 and the high explosive charge 30 with a light-gas gun 40 which includes an enlarged breech chamber 41 fillable with a light gas from a source 42 by sequential operation of the valves 43 and 43'. At the rear of the enlarged breech chamber 41 is an enlarged piston 44 which, because I am now utilizing a light-gas gun, may include a resilient seal ring 45. A high explosive charge 30' is secured behind the enlarged piston 44 by a breech plug 46.

In order that the light gas from the source 42 maybe contained in the enlarged breech chamber 41, the piston 15' is provided with a sealing means 48 on a rear portion which is flanged outward and arranged to engage tightly the tapered end surface 49 of the enlarged breech chamber 41. The sealing arrangement shown operates in the same manner as ordinary valve seats in conventional internal combustion engines. In this manner the lightgas pressure in the enlarged breech chamber 41 can be raised substantially above atmospheric pressure prior to the triggering of the gun. The tight fit of the projectile 10 also allows the obtaining of a substantial magnetic force prior to the initial motion of the projectile.

I have considered additional innovations to accomplish increased velocity of the projectile 10 that include substantial evacuation of the breech chamber 16' and the bore 12' to prevent the mass of any gases therein from substantially reducing the velocities attainable, by the phenomenon of effectively increasing the mass of both the piston 15 and the projectile 10'. In order to accomplish substantial vacuum in these portions, a rupturable diaphragm seal 50 is provided at the end of the barrel 13 as illustrated in FIG. 4. The seal 50 is mounted in a manner allowing substantial reduction of the pressure within these portions of the gun. Even with the vacuum contemplated suflicient pressure will be built up by the motion of the projectile 10' to rupture the seal d. Moreover, the seal 50 is arranged to be ruptured in a way removing it from the flight path of the projectile prior to any physical contact therebetween whereby the projectile 10' will not be deflected in any way because of the use of the seal 50.

The operation of my invention, as illustrated in FIG. 4, combines the features of a light-gas gun and the embodiment of my invention shown in FIG. 1. A triggering arrangement 28' is similar to that shown in FIG. 1 as 28, but because of its having more functions to perform, is slightly more complex. A first series of operations controlled by the trigger 28', includes evacuating the bore 12', and the breech chamber 16' by energizing a vacuum pump arrangement 52. The pressure diiferential developed across the piston assures a tight seal in the region of the sealing means 48. As soon as this tight seal has been accomplished with the valve 43' open, a light gas is admitted to the enlarged breech chamber 41 by opening the valve 43. The

ports

54 and 56 in the enlarged breech chamber 41 are arranged to provide relatively complete scavenging of the air, much in the same manner as scavenging is accomplished in a 2-cycle combustion engine. As soon as the enlarged breech chamber 41 is substantially filled with light gas, the valve 43 is closed, and the pressure within the enlarged breech cham ber 41 is raised above atmospheric pressure.

Because of the increased number of operations necessary to initiate motion of the piston 15', it may be expected that the time delay between initiation of a spark arrangement 36 and the engagement of the conductor extensions 17 and 18' will be longer than that necessary to attain maximum current flow in the loop circuit components 17'-17, 10' and 1818. Therefore, in most operations contemplated, the trigger 28' energizes the spark arrangement 36' an instant before closing the switch 26.

The explosion of the charge 30' moves the piston 44 toward the piston 15' and substantially increases the pressure until the sealing means 48 is ruptured, whereupon the piston 15' is driven rapidly to shunt the loop circuit. The remaining operation of the arrangement is substantially identical to that described above in connection with FIG. 1.

As will be apparent to those familiar with the art of the'present invention,there are many uses for the present invention. For instance, either of the

projectiles

10 or 10 is usable as a cylindrical piston 10" to drive a pre selected charge of air from a high pressure cartridge 58 into a shock tunnel arrangement at velocities greater than orbital velocities. In such arrangements the charge of air maybe provided by the mass or charge of air normally residing in the bore 12', or, when a more precisely controlable system is necessary, by air or other gas contained within the cartridge 58 between two spaced apart rupturable diaphragms as that illustrated at 50' and 50 in FIG. 5. Moreover, although the bore 13" of the cartridge 58 is substantially the same diameter as the bore 12 or the bore 12, I have provided a smaller exhaust port 59 so that the cylindrical projectile 10" is prevented from escaping into the shock tunnel test area. A similar small exhaust port 39 may be secured to the barrel 13 of FIG. 1 when it is desired simply to project the air within the bore 12 into a test area. Rupturable diaphragm 50 may also be used to define the mass of air projected.

While I have shown and described particular embodiments of the present invention, further modifications may occur to those skilled in this art. For instance, when the entire gun is in an evacuated environment, the breech 14 and the barrel 13 may be provided with apertures or otherwise have lateral openings therein, so long as sufficient support is provided to prevent tumbling or other loss of contact between the piston, the conductors and the projectile which form the high current loop circuit. I desire it understood, therefore, that my invention is not limited to the particular form shown and I intend by the appended claims to cover all such modifications which do not depart from the true spirit and scope of my invention.

I claim:

1. A hypervelocity gun arrangement comprising:

a gun barrel defining a bore;

a first conductor within said barrel defining a first arcuate surface of the bore throughout the length thereof;

a second conductor defining a second arcuate surface of the bore diametrically opposed to said first arcuate surface;

an enlarged breech secured to said barrel at one end thereof and defining an enlarged breech chamber;

said first and second conductors each having extensions extending along diametrically opposed arcuate surfaces of the breech chamber;

a projectile positionable in the bore adjacent to said breech and of a diameter sufficient to electrically engage both of said conductors throughout the length of the bore;

a piston positionable adjacent to the end of said extensions in the breech chamber and of a diameter sufficient to engage both of said extensions throughout the length of the breech chamber;

means for inducing electric current flow of the order of thousands of amperes through said extensions and said projectile to create a magnetic force for accelerating said projectile through the bore;

and means for driving said piston through the breech chamber toward said projectile so that it will engage said extensions at an instant when the current flow is maximum, whereby said piston initially shortcircuits the current flow in the loop circuit established thereby and sequentially increases the magnetic flux thereof to increase rapidly the magnetic force on said projectile, the relative diameter of the breech chamber and the bore being such that said :proj'ectile must move a greater distance than said piston to maintain 'the area of said loop circuit constant.

2. A'hypervelocity gun arrangement comprising:

a gun barrel defining a bore;

a first'conductor Within said barrel defining a first arcuate surface of the bore throughout the length thereof;

a second conductor defining a second arcuate surface of the bore opposite to said first arcuate surface;

an enlarged breech secured to said barrel at one end thereof and defining an enlarged breech chamber, said first and second conductors having extensions extending along diametrically opposed arcuate surfaces of the breech chamber;

a piston positionable adjacent to the end of said extensions in the breech chamber and of a diameter suflicient to couple electrically both of said extensions throughout the length of the breech chamber;

means for inducing electric current flow of the order of thousands of amperes through said extensions and said projectile to create a magnetic force for accelcrating said projectile through the bore;

means for preventing the initial movement of said projectile until said magnetic force exceeds a predetermined magnitude; and

means for driving said piston through the breech chamber toward said projectile so that it will engage said extensions at an instant when the current flow is maximum, whereby said piston initially shortcircuits the current flow in the loop circuit established thereby and sequentially increases the magnetic flux thereof to increase rapidly the magnetic force on said projectile, above said predetermined minimum.

3. A hypervelocity gun arrangement comprising:

a gun barrel defining a bore;

a pair of conductors within said barrel defining opposed arcuate surfaces of the bore throughout the length thereof;

an enlarged breech secured to one end of said barrel and defining an enlarged breech chamber;

a pair of extensions of said pair of conductors respec tively and positioned along opposed arcuate surfaces of breech chamber;

a projectile positionable in the bore adjacent to said breech and arranged to couple electrically said pair of conductors throughout the length of the bore;

a piston positionable adjacent to the end of said pair of extensions and arranged to couple said pair of extensions throughout the length of the breech chamber only after initial movement thereof;

first restricting means for preventing the initial movement of said piston;

means for inducing electric current flow of the order of thousands of amperes through said pair of extensions and said projectile to create a magnetic force for accelerating said projectile through the bore;

second restricting means for preventing the initial movement of said projectile until said magnetic force exceeds a predetermined magnitude; and

means for developing suflicient force to overcome said first restricting means for driving said piston through the breech chamber toward said projectile so that it will couple said pair of extensions at an instant when the current flow is maximum, whereby said piston initially shortcircuits the current flow in the loop circuit established thereby and sequentially increases the magnetic flux thereof to increase rapidly the magnetic force on said projectile to overcome said second restricting means.

4. A hypervelocity gun arrangement comprising:

a gun barrel defining a bore;

a pair of parallel extensions of said pair of conductors respectively which are spaced apart several times the diameter of the bore;

a projectile positionable in the bore adjacent to said extensions and arranged to couple electrically said pair of conductors throughout the length of the bore;

a piston positionable adjacent to the end of said pair of extensions and arranged to couple said pair of xtensions throughout the length thereof only after initial movement of said piston;

restricting means for preventing the initial movement of said piston;

a high explosive driving means for developing sufficient force to overcome said restricting means to drive said piston toward said projectile so that it will couple said pair of extensions at an instant when the current how is maximum, whereby said piston initially shortcircuits the current fioW in the loop circuit established thereby and sequentially increases the magnetis flux thereof to increase rapidly the magnetic force on said projectile whereby said projectile accelerates through the bore to relieve the magnetic force.

5. A hypervelocity gun arrangement comprising:

a gun barrel defining a bore;

a breech secured to said barrel at one end thereof, said pair of conductors each having an extension defining diametrically opposed arcuate inner surfaces of said breech;

a projectile positionable in the bore adjacent to said breech and of a diameter sufficient to electrically couple said pair of conductors throughout the length of the bore;

a piston positionable adjacent to the end of said extensions in the breech chamber and of a diameter sufficient to couple electrically said pair of extensions throughout the length of said breech;

means for inducing electric current flow of the order of thousands of amperes through said extensions and said projectile to create a magnetic force for accelerating said projectile through the bore; and

light-gas gun means for driving said piston rapidly through said breech toward said projectile so that said piston engages said extensions during an instant when the current flow is maximum, whereby said piston initially shortcircuits the current flow in the loop circuit established thereby and sequentially increases the magnetic flux thereof to increase rapidly the magnetic force on said projectile.

6. A hypervelocity gun arrangement comprising:

a pair of parallel conductors defining opposed arcuate surfaces;

means for maintaining said pair in a predetermined spaced relationship;

said pair of conductors each having an extension defining diametrically opposed arcuate surfaces having substantially greater spacing, therebetween than said pair of conductors;

a projectile positionable between said pair of conductors adjacent to said conductor extensions and of a diameter sufiicient to electrically couple said pair of conductors throughout the length thereof;

a piston positionable adjacent to the end of said conductor extensions remote from said projectile and of a diameter sufiicient to couple electrically said conductor extensions throughout the length thereof;

means for inducing electric current flow of the order of thousands of amperes through said conductor extensions and said projectile to create a magnetic force for accelerating said projectile along said conductors; and

light-gas gun means for driving said piston rapidly along said conductor extensions toward said projectile so that said piston engages said-extensions during an instant when the current flow is maximum, whereby said piston initially short-circuits the current flow in the loop circuit established thereby and sequentially increases the magnetic flux thereof toincrease rapidly the magnetic force on said iprojectile.

7. A hypervelocity gun arrangement comprising:

a pair of parallel conductors defining opposed arcuate surfaces;

said pair of conductors each having an extension defining diametrically opposed arcuate surfaces having substantially, greater spacing therebetween than said pair of conductors;

a projectile positionable between said pair of conductors adjacent to said conductor-extensions and of a diameter sufficient to electrically couple said pair of conductors throughout the length thereof;

a piston positionable adjacent to the end of said conductor extensions remote from said projectile and of a diameter suflicient to couple electrically said conductor extensions throughout the length thereof;

means for inducing electric current flow of the order of thousands of amperes through said conductor extensions and said'projectile to create a magnetic force for accelerating said projectile along said conductors; and

means for driving said piston-rapidly along said conductor extensions toward said projectile so that said piston engages said extensions and sequentially increases the magnetic flux of the loop circuit created thereby to increase rapidly the magnetic force on said projectile.

8. A hypervelocity projection arrangement comprising:

a pair of parallel conductors defining opposed arcuate surfaces;

said' pair of conductorseach having an extension defining diametrically opposed arcuate surfaces having substantially greater spacing therebetween than said pair of conductors;

means for evacuating the region between said pair of conductors and between said conductor extensions;

a projectile positionable between said pair of conductors adjacent to saidconductor extensions and of a diameter sutficient to electrically couple said pair of conductors throughout the length thereof;

a piston positionable adjacent to the end of said conductor extensions remote from said projectile and of a diametersuficient to couple electrically said conductor extensions throughout the length thereof; means for inducing rapidly electric current flow of the order of thousands of amperes through said conductor extensions and said projectile to create a magnetic force for accelerating said projectile along said conductors;

said pair of conductors, said conductor extensions, the rear of said projectile, and the leading portion of said pistoneach being provided with low resistance surfaces to facilitate rapid changes of current flow thereover;

and light-gas gun means for driving said piston rapidly along said conductor extensions toward said projectile so that-said piston engagessaid extensions during an instant when the current flow is maximum, whereby said piston initially short-circuits the current flow in the loop circuit established thereby and sequentially increases the magnetic flux thereof to increase rapidly the magnetic force on said projectile.

9. A hypervelocity projection arrangement comprising:

a pair of parallel conductors defining opposed arcuate surfaces;

said pair of conductors each having an extension defining diametrically opposed arcuate surfaces having substantially greater spacing therebetween than said pair of conductors;

means for evacuating the region between said pair of conductors;

'a projectile positionable between said pair of conductors adjacent to said conductor extensions and of a diameter sufficient to electrically couple said pair of conductors throughout the length thereof;

a piston positionable adjacent to the end of said conductor extensions remote from said projectile and of a diameter sufiicient to couple electrically said conductorextensions throughout the length thereof;

means for inducing rapidly electric current flow of the order of thousands of amperes throughsaid conductor extensions and said projectile to create a magnetic force foraccelerating said projectile along said conductors;

said pair of conductors, said conductor extensions, the rear of said projectile, and the leading portion of said piston each being provided with low resistance surfaces to facilitate rapid changes of current flow thereover;

and means for driving said piston rapidly along said conductor extensions toward said projectile so that said piston engages said extensions during an instant when the current flow is maximum, whereby said piston initially short-circuits the current flow in the loop circuit established-thereby and sequentially increases the magnetic fiux thereof to increase rapidly the magnetic force on said projectile.

10. A hypervelocity projection arrangement comprisa pair of parallel conductors defining opposed arcuate surfaces;

' said pair of conductors each having an extension defining diametrically opposed arcuate surfaces having substantially greater spacing therebetween than said pair of conductors;

means for evacuating the region between said pair of conductors; a projectile positionable between said pair of conductors adjacentto said conductor extensions and of a diameter sufficient to electrically couple said pair of conductors throughout the length thereof;

a piston positionable adjacent to the end of said conductor extensions remote from said projectile and of a diameter sufiicient to couple electrically said' conductor extensionsthroughout the length thereof;

means for inducing rapidly electric current flow of the order of thousands of amperes through said conductor extensions and said projectile to create a magnetic force for accelerating said projectile along said conductors;

and means for driving said piston rapidly along said conductor extensions toward said projectile so that said piston engages said extensions during an instant when the current flow is maximum, whereby said piston initially short-circuits the current flow in the loop circuit established thereby and sequentially increases the magnetic flux thereof to increase rapidly the magnetic force on said projectile.

11. A hypervelocity projection arrangement comprisa pair of parallel conductors defining opposed arcuate surfaces;

said pair of conductors each having at one end thereof an extensiomsaid conductor extensions defining di- 65 -ametrically opposed arcuate surfaces having substantially greater spacing therebetween than said pair of conductors;

a high pressure cartridge securable to the other end of said pair of conductors and having a bore there- 70 through;

means for sealing said bore to contain therein a predetermined charge of gas;

a cylindrical projectile positionable between said pair of conductors adjacent to said conductor extensions and of a diameter sufiicient to electrically couple said pair of conductors throughout the length thereof and to substantially fill said bore of said cartridge;

means for driving said piston rapidly along said conductor extensions toward said projectile so that said piston engages said extensions and sequentially increases the magnetic flux of the loop circuit created thereby to increase rapidly the magnetic force on said projectile.

12. A hypervelocity projection arrangement comprising:

a barrel defining a bore;

a pair of parallel extensions of said pair of conductors respectively, which are spaced apart several times the diameter of the bore;

a projectile positionable in the bore adjacent to said extensions and arranged to couple electrically said pair of conductors throughout the length of the bore during its travel through the bore;

means for entrapping a predetermined mass of fluid in the path of said projectile;

said means having an inner diameter substantially equal to the diameter of said projectile;

a piston positionable adjacent to the end of said pair of extensions and arranged to couple said pair of extensions throughout the length thereof only after initial movement of said piston;

means for inducing electric current flow of the order of thousands of amperes through said pair of extensions and said projectile to create a magnetic force for accelerating said projectile through the bore to drive before it the mass of entrapped fluid;

driving means for developing suflicient force to drive said piston toward said projectile so that it will couple said pair of extensions at an instant when the current flow is maximum, whereby said piston initially short circuits the current flow in the loop circuit established thereby and sequentially increases the magnetic flux thereof to increase rapidly the magnetic force on said projectile whereby said projectile accelerates through the bore to relieve the magnetic force.

13. A hypervelocity projection arrangement comprising:

a pair of parallel conductors defining opposed arcuate surfaces;

said pair of conductors each having at one end thereof an extension, said conductor extensions defining diametrically opposed arcuate surfaces having substantially greater spacing therebetween than said pair of conductors;

a high pressure cartridge having one end securable to the other end of said pair of conductors and having a bore therethrough and having the other end restricted in size;

means for sealing said bore to contain therein a predetermined charge of gas;

a cylindrical projectile positionable between said pair of conductors adjacent to said conductor extensions and of a diameter sufficient to electrically couple said pair of conductors throughout the length thereof, to substantially fill said bore of said cartridge and be confined by the restriction in size of said cartridge;

means for driving said piston rapidly along said conductor extensions toward said projectile to increase rapidly the magnetic force on said projectile.

14. A hypervelocity projection arrangement comprising: 7

a pair of parallel conductors defining opposed arcuate surfaces;

said pair of conductors each having at one end thereof an extension defining diametrically an arcuate surface with said conductor extensions having substantially greater spacing therebetween than said pair of conductors;

a high pressure cartridge securable to the other end of said pair of conductors and having a bore therethrough;

means for sealing said bore to contain therein a predetermined charge of gas;

a cylindrical projectile positionable between said pair of conductors adjacent to said conductor extensions and of a diameter sufiicient to electrically couple said pair of conductors throughout the length thereof; and to substantially fill said bore of said cartridge;

means for stopping said projectile after it has completed its passage through said bore;

a piston positionable adjacent to the end of said conductor extensions remote from said projectile and of a diameter sufficient to couple electrically said conductor extensions throughout the length thereof;

and light-gas gun means for driving said piston rapidly along said conductor extensions toward said projectile so that said piston engages said extensions during an instant when the current flow is maximum, whereby said piston initially short circuits the current flow in the loop circuit established thereby and sequen tially increases the magnetic flux thereof to increase rapidly the magnetic force on said projectile.

No references cited.

Claims

1. A HYPERVELOCITY GUN ARRANGEMENT COMPRISING: A GUN BARREL DEFINING A BORE; A FIRST CONDUCTOR WITHIN SAID BARREL DEFINING A FIRST ARCUATE SURFACE OF THE BORE THROUGHOUT THE LENGTH THEREOF; A SECOND CONDUCTOR DEFINING A SECOND ARCUATE SURFACE OF THE BORE DIAMETRICALLY OPPOSED TO SAID FIRST ARCUATE SURFACE; AN ENLARGED BREECH SECURED TO SAID BARREL AT ONE END THEREOF AND DEFINING AN ENLARGED BREECH CHAMBER; SAID FIRST AND SECOND CONDUCTORS EACH HAVING EXTENSIONS EXTENDING ALONG DIAMETRICALLY OPPOSED ARCUATE SURFACES OF THE BREECH CHAMBER; A PROJECTILE POSITIONABLE IN THE BORE ADJACENT TO SAID BREECH AND OF A DIAMETER SUFFICIENT TO ELECTRICALLY ENGAGE BOTH OF SAID CONDUCTORS THROUGHOUT THE LENGTH OF THE BORE;