US3468216A - Hypervelocity gun having a hydraulic stage for velocity conversion - Google Patents

Description

Sept. 23, 196% J. F. CHARPENTIER 3,468,216

HYFERVELOCITY GUN HAVING A HYDRAULIC STAGE FOR VELOCITY CONVERSION 4 Sheets-Sheet 1 Filed May 13. 1968 eirl - J WHMHWVL Q n E INVENTOR JEAN F. CHARPENTIER ATTORNEYS p 23, 1969 J. F. CH PENTIER 3,468,216

TY GUN HAV HYFERVELOCI A HYDRAULIC STAGE FOR VELOCITY CONVERSION Filed May 13. 1963 4 Sheets-Sheet Z INVENTOR JEAN F. CHARPENTIER Sept. 23, N69 J. F. CHARPENTIER 3,468,216

HYPERVELOCITY GUN HAVING A HYDRAULIC STAGE FOR VELOCITY CONVERSION Filed May 13, 1968 4 Sheets-Sheet 5 |NVENTOR JEAN F. CHARPENTIER awmwzw ATTORNEYS Sept. 23, 1969 J. F. CHARPENTIER HYFERVELOCITY GUN HAVING A HYDRAULIC STAGE FOR VELOCITY CONVERSION 4 Sheets-Sheet 4 Filed May 13, 1968 2% ivy m INVENTOR JEAN F CHARPENTIER ATTORNEYS 3,468,216 HYPERVELOCITY GUN HAVING A HYDRAULIC STAGE FOR VELOCITY CONVERSION Jean F. Charpentier, Akron, Ohio, assignor to Goodyear Aerospace Corporation, Akron, Ohio, a corporation of Delaware Filed May 13, 1968, Ser. No. 728,665 Int. Cl. F41f 1/00 US. Cl. 89-8 Claims ABSTRACT OF THE DISCLOSURE This invention relates to a high velocity gun utilizing a hydraulic accelerator stage which converts the limited velocity transmitted by a heavy large caliber projectile into a hypervelocity motion transmitted to a light subprojectile.

In todays space-age, in order to simulate speeding micrometeorites, it has become necessary to develop guns that will shoot tiny projectiles at extremely high velocities. Many efforts have been made along these lines using various mechanical and electrical principles. However, none of these prior art devices have been able to obtain the velocities desired, nor have they been as simple and inexpensive as desirable. Further, none of these prior art devices have been suitable for incorporation to larger caliber projectiles.

Therefore, it is the general object of the present invention to provide an improved high velocity gun which has great efficiency, and which is relatively low in cost.

A further object of the invention is to provide a gun for providing an extremely high velocity to a light subprojectile by transmitting the force from the explosive firing of a heavy large caliber projectile to the light sub projectile by a hydraulic accelerator stage.

A further object of the invention is to provide a high velocity gun which utilizes a hydraulic accelerator stage operating through a change of fluid volume configuration to which only the opposing forces of inertia and viscosity cause energy loss to thereby maximize the magnitude of the energy transmitted from the explosive acceleration of a heavy large caliber projectile to a light subprojectile.

The aforesaid objects of the invention and other objects which will become apparent as the description proceeds are achieved by providing in a high velocity gun the combination of an elongated barrel having a uniform diameter bore from one end through most of the length thereof, but a reduced diameter bore coaxially aligned with and extending from the other end to the uniform diameter bore, a piston slidably received in the uniform diameter bore, means to propel the piston down the uniform diameter bore, a non-explosive liquid carried by the piston in the end thereof nearest the reduced diameter bore, and a pellet of substantially the same diameter as the reduced diameter bore carried by the piston in such a manner whereby the kinetic energy of the propelled piston is transferred to the liquid when the piston reaches the reduced diameter bore, and the liquid transfers the kinetic energy to the pellet causing it to be expelled from the end of the reduced diameter bore.

For a better understanding of the invention, reference should be had to the accompanying drawings, wherein:

FIG. 1 is a side elevation showing the shape and configuration of the entire gun;

FIG. 2 is an enlarged cross-sectional view of the muzzle and illustrating the relationship between the large diameter bore and the reduced diameter bore, as well as the piston ejecting mechanism;

3,468,2l6 Patented Sept. 23, 1969 FIG. 3 is an enlarged cross-sectional view similar to FIG. 2 except illustrating how the piston ejecting mechanism functions;

FIG. 4 is a vertical cross-sectional view taken on line 4-4 of FIG. 2;

FIG. 5 is a vertical cross-sectional view taken on line 5-5 of FIG. 2;

FIG. 6 is a vertical cross-sectional view taken on line 6-6 of FIG. 2;

FIG. 7 is an enlarged cross-sectional broken-away illustration of the piston and hydraulic energy transfer characteristics as the piston approaches engagement with the reduced diameter bore;

FIGS. 7A, 7B, and 7C are transverse cross-sectional views taken on respective lines along the length of the piston of FIG. 7 to better show the configuration thereof;

FIG. 8 is an enlarged cross-sectional broken-away view of the piston an instant after it has engaged the reduced diameter bore showing the expansion of the hydraulic fluid1 to cause final acceleration to the pellet or sub-projecti e;

FIG. 8A is a transverse cross-sectional view of the subprojectile taken on line 8A8A of FIG. 8;

FIG. 9 is an enlarged cross-sectional broken away illustration of the pellet or subprojectile as it is finally discharged from the muzzle of the gun, particularly showing the discharge of the hydraulic fluid therefrom;

FIGS. 9A, 9B, and 9C are transverse cross-sectional views taken on respective lines along the length of the compressed piston of FIG. 9 to show the configuration thereof;

FIG. 10 is an enlarged cross-sectional broken away view of the explosive propellent which is used to accelerate the piston from the breach end of the gun; and

FIG. 11 is an enlarged view showing the configuration of the subprojectile.

While the gun of the invention may be used for the acceleration of any projectiles, and for any type of use, it was primarily designed for accelerating small projectiles to simulate micro-meteorites in flight, and hence it has been so illustrated and will be so described. However, it should be understood that the gun clearly could be used to accelerate armor piercing projectiles, or for any other suitable application.

With referece to the form of the invention illustrated in FIGS. 1 through 3 of the drawings, the gun is illustrated generally by numeral 10 and comprises the alignment of two barrels having bores of different calibers. Specifically, there is a discharge barrel 12, and a breach barrel 14. The discharge barrel 12 is positioned by any suitable means. In essence, the breach barrel 14 includes a uniform diameter bore 16 extending substantially the full length thereof, while the muzzle barrel 12 has a reduced diameter bore 18 at its discharge end and an enlarged bore in which the breach barrel 14 is received.

The breach barrel 14 and muzzle barrel 12 are slidably interlocked in limited movement in both directions by a raised annular ring 16A on breach 14, and two inwardly extending flanges 18A and 18B on the muzzle barrel 12, as clearly shown in FIG. 2. In order to maintain both barrels at the desired extended relationship to each other, a plurality of double wound helical springs 20, or equivalent means, are positioned between the flanges 16A and 18B, as most clearly shown in FIGS. 2 and 6.

The breach barrel 14 has an extending lip portion 22 which is adapted to act both as a stop for a projectile 24, and a projectile discharge mechanism, as will be more fully described hereinafter. The exact configuration of the extending lip 22 is more clearly seen in FIG. 4. The muzzle barrel 12 has a slotted cutout portion 26 extending partially around the circumference in proximity to the bore 16 in breach barrel 14, whereby the projectile 24 can be ejected, as is more clearly shown in FIG. 3, and will be more fully explained hereinafter. A gas passage 28 extends from behind the lip 22 through the breach barrel 14 to a point lying between the flanges 16A and 18A, as best seen in FIG. 2. A projectile discharging spring 30 also operatively extends through the lip 22 of breach barrel 14 to act in ejecting the projectile 24, as more clearly shown in FIG. 3, and defined in more detail hereinafter. FIG. rather clearly shows the projectile discharge opening 26, the gas passage 28, and the relationship of the muzzle barrel 12 relative to the breach barrel 14.

In association with the apparatus of the gun as shown and described in reference to FIGS. 1-6 the construction of the projectile 24 is quite critical to the proper operation of the apparatus. Specifically, the projectile and its operation in the gun is more clearly illustrated with reference to FIGS. 7, 8, and 9 and associated transverse cross-sec tional views.

The projectile or piston 24 comprises an outer housing or shell 40 which is made for a suitable plastic that can be readily formed to a desired accordion type shape in cross-section as shown in FIG. 7B and be extensible or moldable without failure under the force of impact which imparts the projecting force to the subprojectile. The base of shell 40 is formed with a raised annular flange 42 which provides sealing engagement with the bore 16. A tapered liquid ejector 44 is centrally positioned within the shell 40. This is preferably a metal rod and is interlocked with the shell by threadably receiving a locking cap 46 in the enlarged end thereof which effects a clamp ing action onto an inner lip 48 preferably formed as an integral molded part of the shell 40. A subprojectile indicated generally by numeral 50 comprises a plastic body 52 and a weighted metal nose 54, as best seen in FIG. 8. The inner central portion of the body 52 is formed with a somewhat spherically shaped recess 56 which snaps with a force fitted engagement over an enlarged ball end 45 of the ejector 44, thus holding the subprojectile 50 in position with respect to the shell 40. However, the skirt portion of the subprojectile 50 is also sealed to the shell 40 at a yielding base line 53 to provide a hydraulic seal before the firing of the piston 24.

The energy transferring objects of the invention are achieved by providing a hydraulic fluid in the open or hollow area between the shell 40 and ejector 44, this fluid being indicated by numeral 60. The fluid must be a nonexplosive substantially non-compressible hydraulic liquid such as water or glycol.

In essence, the invention contemplates that suitable means are provided to accelerate the entire projectile 24 under great speed down the large uniform diameter bore 16. The invention contemplates a suitable explosive charge for this purpose. For example, the invention illustrates in FIG. an explosive charge indicated generally by numeral 61 which has specific contours in spaced relation so as to give a maximum and uniform propelling explosive force thus giving the projectile 24 the greastest possible speed down the bore 16. A breach block 63 pivotally mounted to the end of the breach barrel 14 allows positioning of the charge 61, and directs the force thereof down the bore 16. In essence, the charge 61 is designed to provide an explosive unlimited mass which is able to burn within a time interval as small as possible.

Specifically, the explosive charge 61 constitutes successive layers of three different types of explosive materials distributed transversely and longitudinally along a curved medium profile with the center of curvatures of each successive layer located towards the muzzle of the gun. The explosives consist of an igniter 62 which acts as a fuse, and represents a very thin layer. Next is a primer explosive 64 which constitutes a small area adjacent on both sides of the layer of igniter 62. And lastly, is the bulk of the explosive charge 61 which comprises a propellant 66 which lies between the adjacent layers of the primer explosive 64. The entire explosive charge 61 is normally encased in a suitable metal shell 67. The mass of the explosive charge 61 is ignited from the front face, or in other words the face adjacent the base of the projectile 24 by a suitable electric igniter 68 connected through the housing or case 67 and to the central point of the fuse igniter 62.

Through the structured arrangement of the layers in the explosive the ignition progresses in a three dimensional process and the timing is obtained by selecting the number and thickness of the layers of the different explosives. The volume or cross sectional area of the explosive charge 61 and particularly the propellant 66 increases towards the rear of the breach in order to allow for a fast increase in the burning area. This is done to provide a burning mass rate as high as required to maintain a constant pressure application to the base of the projectile as the latter travels towards the muzzle through the bore 16. Normally, in most explosive propellant charges, the burning rate is uniform, and of the same cross section throughout its length so that in effect the pressure behind the projectile decreases as it moves down the muzzle.

FIGS. 7, 8, and 9 illustrate in sequence the impacting of the projectile 24 into the reduced diameter bore 18 in the muzzle barrel 12 of the gun 10 after its acceleration down the bore 16 by the explosive charge 61. Essentially, the high kinetic energy imparted by the explosive charge to the piston 24 in transmitting it down the bore causes the integral outer shell 40 which is formed with the accordion folds shown in FIGS. 7B and 7C to be compressed over the ejector 44 when the outer shell 40 contacts the tapered mating surfaces at the end of the inner bore 18. FIGS. 9B and 9C illustrate the compressed relation of shell 48 over the ejector 44. This causes high compressive pressure to be exerted upon the hydraulic layer 60 and since the layer 60 is essentially non-compressible the pressure is relieved by forcing the subprojectile 50 to pop off the ball end of ejector 44 and out and down through the inner bore 18, as clearly shown in FIG. 8. FIG. 9 illustrates the complete compression of the outer shell 40 over the ejector 44 which causes just enough fluid displacement to force the subprojectile 50 completely to the end of bore 18.

The end of the bore 18 is reduced in diameter such that the subprojectile 50 is lodged at the end of the bore, at the same time the final stage projectile pellet 54 is ejected at high velocity. In order that the hydraulic fluid utilized to propel the subprojectile 50 down the bore 18 does not rupture the muzzle, the invention contemplates that liquid discharge ports 57 are positioned around the bore 18 to provide the pressure relief and discharge of the liquid as shown in FIG. 9.v

Another method of exiting the projectile is shown in FIG. 11 wherein the final stage projectile is also the subprojectile 50. The end of the muzzle bore 18a is shaped to fold back the skirt 52 of the subprojectile 50 to an inflight aerodynamic shape. The subprojectile is expelled from the muzzle along with the fluid as shown in FIG. 11. In this variation, no exit ports 57 are needed as the fluid exiting with the subprojectile provides aerodynamic stability to the projectile. However, exit ports 57a are provided in the subprojectile skirt 52 to relieve the fluid pressure when the skirt 52 is drawn back to form the teardrop shape shown in FIG. 11. The shape of the front end of the muzzle is changed to provide an airstream contour 56 which will not impede the velocity or aerodynamic stability of the subprojectile 50.

The invention contemplates that the outer shell 40 and the ejector 44 and cap 46 will comprise approximately to of the complete weight of the projectile 24. This portion of the projectile acts as an accumulator of kinetic energy. The second stage of the projectile essentially comprises the liquid or hydraulic mass or layer 60 which is a receptor-transmitter of kinetic energy. Its function consists of transferring, with a high efficiency, the energy from the outer shell and ejector to the solid third and final stage comprising the subprojectile 50. The hydraulic mass or layer 60 will weight between 10 to 15% of the complete projectile weight, and will always constitute sufiicient volume to completely push the member 50 down the entire length of bore 18. The subprojectile 50 Weights approximately of the complete projectile weight.

With reference to FIGS. 2 and 3 of the drawings, the operation of the gun to eject the projectile 24 after the subprojectile 50 has been discharged will be described. Specifically, the hot gases of combustion utilized to propel the projectile 24 down the bore 16 enter through the port 28 and are deposited thereby between the flange 16A and 18A. This pressure thus causes a spreading between barrels 12 and 14 which allows the projecting finger or arm 22 to draw the projectile 24 back out of its seated position into the reduced diameter portion of bore 18. The gas pressure operates against the springs 20, but is suflicient to overcome the force of such springs. The rapidly applied high pressure of the gas causes substantially equal and opposite movement of each barrel 12 and 14 to a position indicated in FIG. 3 until the spring 30 bottoms against flange 18a causing it to discharge the projectile 24 out the port 26. At the same time, all gas pressure is exhausted from the bore 16 through the opening 26, and with this pressure relieved, the springs 20 force the barrels back to their original position shown in FIG. 2. If, however, some catch means are associated with the recoil, the barrel 12 and 14 can be held in the position shown in FIG. 3. This may be desirable to allow any type of cleaning probe or other mechanism to discharge the member 54 from its wedged position in bore 18. However, the invention contemplates that if suitable ablative material is used for member 54, it will burn up from the hot gases of combustion impinging thereon when the projectile 24 is discharged.

It is found that this particular method of transferring kinetic energy from a large mass to a small mass through a liquid medium has great efliciency. In fact, the loss of kinetic energy is normally less than about 5 percent, and extremely high muzzle velocities for the reduced size projectile can be achieved. In fact, velocities much greater than are available with any known gun today have been demonstrated as feasible. In other words, the hydraulic accelerator stage or layer operates through a change of fluid volume configuration to which it opposes only inertia and viscosity forces. The configuration conversion is independent of all wave formations and motion which may happen within the fluid. It has been found that the loss of efliciency due to fluid elasticity, if water or glycol are used as the hydraulic layer, is a maximum of only about 4 percent of the volume.

While in accordance with the patent statutes only one best known embodiment of the invention has been illustrated and described in detail, it i to be particularly understood that the invention is not limited thereto or thereby, but that the inventive scope is defined in the appended claims.

What is claimed is:

1. In a high velocity gun the combination of an elongated barrel having a uniform diameter bore from one end through most of the length thereof, but a reduced diameter bore coaxially aligned with and extending from the other end to the uniform diameter bore,

a piston slidably received in the uniform diameter bore,

means to propel the piston down the uniform diameter bore,

a non-explosive liquid carried by the piston in the end thereof nearest the reduced diameter bore, and

a pellet of substantially the same diameter as the reduced diameter bore carried by the piston in such a manner whereby the kinetic energy of the propelled piston is transferred to the liquid when the piston reaches the reduced diameter bore, and the liquid transfers the kinetic energy to the pellet causing it to expelled from the end of the reduced diameter bore.

2. In a high velocity gun the combination of an elongated gun barrel having a bore,

a piston slidably received in the bore from one end of the barrel,

means to limit the sliding movement of the piston in the bore towards the other end of the barrel,

means to propel the piston through the bore from said one end of the barrel towards the other end,

a pellet slida-ble through the bore from the other end of the barrel, said pellet being much smaller in mass than the piston, and operatively carried by said piston, and

non-explosive liquid means operatively carried by said piston to effectively transfer the kinetic force of the piston to the pellet when the piston is limited in its propelled movement through the bore.

3. A combination according to claim 2 wherein explosive means are utilized to propel the piston down the bore, with such explosive means providing a constant pressure behind the piston as it translates down the bore.

4. A combination according to claim 2 where the liquid is water.

5. A combination according to claim 2 where the liquid is glycol.

6. A combination according to claim 2 wherein there are liquid dispersion holes located around the muzzle of the bore to discharge the liquid means after an effective transfer of the kinetic energy of the piston to the pellet.

7. A combination according to claim 2 where the bore includes a conversion breach which tapers from a constant large diameter to a constant smaller diameter and wherein the piston consists of:

an appropriately shaped hollow first stage housing shell having a nose and a bottom made of any convenient material able to be squeezed without appreciable structural resistance,

a rigid structure internally extended from the bottom of the shell to the apex of the nose, having a profile shape designed in connection with that one of the conversion breach whereby, as the piston is propelled into the conversion breach the housing shell is jammed between the structure and the conversion breach,

a hydraulic liquid between the shell and the rigid structure, and

a subprojectile hydraulically sealed to the nose of the shell, but designed to break free and be propelled down the bore upon an increase in the hydraulic fluid pressure.

8. A combination according to claim 7 where the shell is provided with longitudinally extending accordion folds to enhance its ability to compress an elongate upon jamming between the conversion breach and the complementary rigid structure.

9. An apparatus according to claim 2 where the elongated gun barrel consists of two sub-barrels interlocked in limited sliding relationship to each other, and normally biased to one end of the limit, and where one of the subbarrels has a piston discharge port whereby the hot gases of combustion propelling the piston down the barrel effectively cause sliding movement of the sub-barrels in a direction opposite to the bias to discharge the piston from the piston discharge port after the piston has transmitted its kinetic energy to the liquid means.

10. In a hypervelocity gun the combination of a first energizing gun having a constant caliber bore extended from the breach to the muzzle end, said muzzle end connected in a continuous manner with a conversion breach and a second barrel extending from, and coaxially aligned with the energizing gun barrel, said conversion breach and barrel having a variable decreasing bore caliber extending from said muzzle end to an appropriate distance where said caliber becomes constant, but small comparing to the caliber of the energizing gun barrel bore, a

compound multi-stage projectile slidably received in the uniform caliber bore, means to energize the compound multistage projectile inside the constant caliber bore barrel, multistage projectile comprising a first stage which stores most of the energy provided by the energizing gun, a non-explosive liquid stage carried by the compound multistage projectile to the conversion breach, and a subprojectile carried by the compound multi-stage projectile in such a manner whereby the kinetic energy of the first stage accumulator is transferred to the liquid when the compound projectile enters the conversion breach while the liquid transfers the energy to the subprojectile causing it to be expelled with high velocity from the muzzle of the second gun barrel.

References Cited SAMUEL W. ENGLE, Primary Examiner US. Cl. X.R.

Images