US3138990A

US3138990A - Liquid propellant machine gun

Info

Publication number: US3138990A
Application number: US143983A
Authority: US
Inventors: Roy A Jukes; Bernard A Niemeier
Original assignee: Individual
Current assignee: Individual
Priority date: 1961-10-09
Filing date: 1961-10-09
Publication date: 1964-06-30
Anticipated expiration: 1981-06-30

Description

Filed Oct. 9, 1961 W m 5, W E m MA J Z A.A.. am w mi mm m wv %\A 1 Am WY A v m/.|| fi k Nu 0 o United States Patent 3,138,990 LIQUID PROPELLANT MACHINE GUN Roy A. Jukes, Knoxville, Tenn, and Bernard A. Niemeier,

Richmond, Va., assignors, by mesne assignments, to

the United States of America as represented by the Secretary of the Army Filed Oct. 9, 1961, Ser. No. 143,983 3 Claims. (Cl. 89-7) This invention relates to a liquid propellant gun and more specifically to a liquid propellant gun adapted for high rates of fire utilizing hypergolic propellants.

Briefly, our invention comprises a block having an axially slidable differential piston which has an axial passage for the feed of the projectiles to be fired. The piston has two shoulder portions which slide in two bores in the block to act as feed means for two hypergolic propellants which are fed into said bores. The forward face of the differential piston forms one wall of a combustion chamber and the hypergolic propellants are fed to the combustion chamber through orifice passages in the differential piston. These passages are made small enough to obviate any necessity for propellant valves. Projectiles are fed axially from a magazine through the block and differential piston into the gun barrel by a feed piston actuated by the gun. The projectile in the barrel is propelled by the pressure generated by the burning of the hypergolic propellants and the other projectiles in the feed line act as an obturator and take the place of a breech block.

An object of this invention is to provide a liquid propellant gun utilizing .hypergolic propellants.

Another object of the invention is to provide a liquid propellant gun having a differential piston to feed separate propellants to a combustion chamber through metering orifices in the piston.

Yet another object is to provide a liquid propellant gun having a differential piston for supplying the propellants and a projectile feed mechanism operated by the differential piston.

A further object is to provide a gun in which projectiles are fed in an axial line to the barrel and act as an obturator to obviate the necessity of a breech block.

These and other objects will become more apparent when reference is had to the following detailed description and drawing in which:

FIGURE 1 is an axial sectional view of our liquid propellant gun.

FIGURE 2 is a sectional view taken on the line 2- 2 of FIGURE 1 looking in the direction of the arrows and illustrating the means which prevents retrograde projectile movement, and

FIGURE 3 is a sectional view taken on the line 3--3 of FIGURE 2.

With reference to the drawing there is shown a liquid propellant gun having a block made up of three sections 1, 2, 3 which are rigidly secured together by any suitable means such as through bolts (not shown). The forward block section 3 has the internally threaded bore 4 in which is received the gun barrel 5 and is further provided with the bore 6 which receives the collar 7 having an internal diameter equal to the diameter of the barrel bore. The central block sectionZ is bored and receives the sleeve member 8 which is provided with the internal shoulder 9 and the bores 10 and 11. The block section 1 is provided with the bore 12 which is coaxial withbores 10 and 11 in the sleeve 8. Slidably received within the bores 1f), 11, 12 is the differential piston 13 having integral shoulder 14 slidable in bore 10 and attached shoulder 15 slidable in bore 11. The differential piston 13 has the central longitudinal passage 16 for the passage therethrough of projectiles 3,138,990 Patented June 30, 1964 and reduced end portion 17. The forward portion of the differential piston is flared as indicated at 18 and is provided with orifice channels 19 and 21) which pro vide communication between the forward face of the piston and the bores 10 and 11, respectively. The volume between the front face of the differential piston 13 and the block section 3 forms a combustion chamber 21.

The gun of this invention utilizes liquid propellants and preferably propellants of the hypergolic type, i.e. those which spontaneously ignite upon contact with one another. An example of hypergolic reactants is hydrogen peroxide (H 0 and hydrozine (N H Obviously, such reactants cannot be premixed and must be fed to the combustion chamber 21 separately.

The block section 1 is provided with recess 22 and block section 2 has a mating recess 23. Mounted within the

recesses

22 and 23 is the valve plug 24 having inlet passage 25 for one of the hypergolic reactants. Check ball 26 is received in the valve plug 24 and urged to closed position by spring 27 seated in cup 28. The sleeve 8 is provided with passage 29 which affords communication between inlet passage 25 and bore 10. The block sections 2 and 3 are provided with corresponding mating recesses 30 and 31, respectively, which receive the valve plug 32 having inlet passage 33 for admission of the second hypergolic reactant. Check ball 34 is received in the valve plug 32 and urged to closed position by spring 35 received in cup 36. Passage 37 affords communication between the inlet passage 33 and bore 11.

A piston stop mechanism is indicated in its entirety by referencecharacter 38. Threadedly received in the block section 2 is the cup shaped member 39 having central post 40. Slidably mounted in the block and sleeve 8 is the stop member 40 having the piston 41 formed on its upper end. The spring 42 surrounds the post 40 and reacts against the piston 41 to urge the stop member 40 downwardly. When the differential piston 13 is moved to the left from the position shown in FIGURE 1 the stop member 40 may move downwardly under the influence of spring 42 in front of shoulder 14 to lock the piston in rearward position. The block section 2 is provided with passage 43 by which pressure fluid can be admitted below the piston 41 to raise the stop member 40 against the action of spring 42.

Threadedly connected to the rearward end of block section 1 is the projectile feed mechanism 44. This feed mechanism forms the subject matter of a separate patent application butit will be described here in its relationship to the remainder of the gun.

The feed mechanism comprises a housing 45 having a centrally disposed projectile feed channel 46 and integrally formed cylinder 47 coaxial with the feed channel. The forward end of the housing 45 is provided with a pilot extension 48 which slidably receives the rear end of differential piston 13. A fluid tight projectile magazine 49 is mounted on the housing and communicates with the feed channel 46. The magazine is provided with a follower 50 slidable therein in sealed engagement and port 51 by which pressure fluid may be admitted to force the follower downwardly. Slidably mounted in the housing is the feed plunger 52 having the piston 53 connected thereto and. slidable in the cylinder 47. Gas pressure may be applied to the rear side of piston 53 through the port 54 in the cylinder.

1 47. Communication is provided between the front face of piston 53 and the rear face of differential piston 13 by means of channels 55 in the housing 45 and these channels are filled with an incompressible fluid.

As shown in FIGURES 2 and 3 the projectile feed mechanism is provided with means to prevent retrograde motion of the projectiles after they are fed. The houstherein begins to rise.

3 ing 45 is provided with a plurality of radially slidable stop plungers 56. These .plungers are urged into the feed channel by gas pressure applied to the upper sides thereof through ports 57 and the lower ends thereof are rearwardly bevelled as shown at 58. When a projectile is fed forwardly the plungers are cammed outw Wardly to permit passage of the projectile and then snap inwardly by gas pressure to prevent reverse projectile movement. I I

Operation In idle condition the differential piston 13 will be moved to left from the position shown in FIGURE 1 and locked by stop member 46. To place the gun in operation, gas pressure is supplied to channel 43 to raise thestop member 40 and also to the ports 51, 54 and 57 of theprojectile feed mechanism. Gas pressure applied to the feed plunger piston 53 will move the plunger 52 to the right and feed a projectile into the gun barrel 5. When the piston 53 moves to the right the liquid in channels 55 will act as a hydraulic link and move the differential piston 13 to the position shown in FIG- URE 1 by acting on the rear face thereof.

The hypergolic reactants are supplied under pressure to theinlet passages .25 and 33 and flow past the check valves into bores and 11, respectively. The volume of these bores is proportioned to provide a measured amount of the propellants. The sleeve 8 is provided with an annular air channel 59 and the block section 2 has the scavenging port 60 therein to prevent the passage of propellants from one bore to the. other.

The propellants now begin to feed from the bores 10 and 11 to the combustion chamber 21 by way of the orifice channels 19 and 20, respectively. The diameter of these channels is selected to restrict the feed rate to give the desired burning rate. In this manner the necessity of valves in these channels is obviated. As soon as the hypergolic reactants meet in combustion chamber 21 combustion is initiated and the pressure When this pressure has risen sufiiciently to overcome the gas pressure acting on piston 53 of the feed plunger and the inlet pressure of the .propellant, the differential. piston begins to move backwardly. This increases the pressure in the bores 10 and 11 and closes the inlet check valves. The increased pressure on the propellants in the bores 10 and 11 accelerates the feed thereof through the orifice channels 19 and 2 0 and increases the rate of combustion until the piston has moved to the rearward end of its travel. Incident to the rearward movement of the differential piston 13, the hydraulic link causes retraction of the feed plunger to permit another projectile to feed from the magazine 49 into the feed channel 46.

When gas pressure is built up combustion chamber I 21 the projectile which is in the barrel is propelled forwardly at high speed. The projectiles occupying the space between the combustion chamber and feed mechanism are prevented from rearward movement by the plungers 56. It will be noted that the diameter of the projectiles and the diameter of the passage 16 are sub stantially the same so that the projectiles in the passage act as an obturator and preclude the necessity of any breech block mechanism.

' When the projectile clears the barrel of the gun the pressure in the combustion chamber immediately drops off. The gas pressure acting on the feed piston 53 now moves the feedplunger forward and through the hydraulic link also moves the differential piston 13 forwardj 1y so that the firing may automatically repeat.

'It will be apparent that the embodiment shown is only exemplary and that various modifications in construction and arrangement may be made without departing from thescope of the invention as defined in the subjoined claims.

We claim:

1. In a liquid propellant gun, the combination comprising, a composite block including an intermediate section, a forward section and a rearward section, said sections having axial, aligned bores therethrough, a sleeve in said central section and having an internal annular shoulder therein, there being forward and rearward axial bores therein and disposed, one each, on each side of said shoulder, said last named bores being coaxial with respect to said bores in said forward and rearward sections; a single differential piston mounted for axial re ciprocation in said bores in said sleeve and said bore in piston having metering orifice channels communicating.

between said combustion chamber and said bores in said sleeve; valve means in said block for admitting hypergolic reactants to said combustion chamber through said channels, the increase in pressure from combustion of the hypergolic reactants in said combustion chamber being effective to move said'piston' rearwardly to accelerate, the

feed of said reactants into said combustion chamber; a

barrel connected to said forward section, said barrel having an axial bore of the same diameter as said passage in said piston and in alignment therewith; means connected to the rearward section for feeding'projectiles into said passage in said piston and barrel; a differential piston stop mechanism in said block for locking said piston in a rearwardcocked position; scavenging means for said gun disposed in said block sections for preventing passage of propellants from one of said bores in said sleeve'to the other; and means for preventing retrograde motion of the projectiles after being fed into said piston and disposed between said feeding means and said rearward section comprising a series of inwardly urged, radially disposed plungers having beveled inner endswhereby when a projectile is fed forwardly, said plungers are cammed outwardly and snap inwardly upon forward clearance of'a projectile. l

2. In a liquid propellant gun as defined in claim 1, wherein said differential piston stop mechanism comprises a plunger radially slidable in said intermediate block,=said plunger being projected in front of said shoulder on said differential piston when said piston is in a rearward position and spring means to urge said plunger inwardly, said plunger being movable outwardly to free said shoulder by the application of fluid pressure to the under side thereof. a I j 3. In a liquid propellant gun as defined in claim 1,

I wherein said scavenging means comprises an annular UNITED STATES PATENTS 2,965,000 Skinner Dec. 20, 1960 2,981,153 Wilson et a1 Apr. 25, 1961 2,986,072 Hudson May 30, 1961

Claims

1. IN A LIQUID PROPELLANT GUN, THE COMBINATION COMPRISING, A COMPOSITE BLOCK INCLUDING AN INTERMEDIATE SECTION, A FORWARD SECTION AND A REARWARD SECTION, SAID SECTIONS HAVING AXIAL, ALIGNED BORES THERETHROUGH, A SLEEVE IN SAID CENTRAL SECTION AND HAVING AN INTERNAL ANNULAR SHOULDER THEREIN, THERE BEING FORWARD AND REARWARD AXIAL BORES THEREIN AND DISPOSED, ONE EACH, ON EACH SIDE OF SAID SHOULDER, SAID LAST NAMED BORES BEING COAXIAL WITH RESPECT TO SAID BORES IN SAID FORWARD AND REARWARD SECTIONS; A SINGLE DIFFERENTIAL PISTON MOUNTED FOR AXIAL RECIPROCATION IN SAID BORES IN SAID SLEEVE AND SAID BORE IN SAID REARWARD SECTION, THERE BEING AN INTEGRAL SHOULDER THEREON, SAID SHOULDER SLIDABLE IN THE REARWARD BORE OF SAID SLEEVE, A DETACHABLE SHOULDER SECURED ON THE FORWARD END OF SAID PISTON AND SLIDABLE IN THE FORWARD BORE IN SAID SLEEVE, THERE BEING A CENTRAL AXIAL PASSAGE THROUGH SAID PISTON AND BEING IN ALIGNMENT WITH THE BORES IN SAID FORWARD AND REARWARD SECTIONS, SAID DETACHABLE SHOULDER BEING FLARED TO FORM A COMBUSTION CHAMBER BETWEEN THE FORWARD FACE OF SAID PISTON AND SAID FORWARD SECTION, SAID PISTON HAVING METERING ORIFICE CHANNELS COMMUNICATING BETWEEN SAID COMBUSTION CHAMBER AND SAID BORES IN SAID SLEEVE; VALVE MEANS IN SAID BLOCK FOR ADMITTING HYPERGOLIC REACTANTS TO SAID COMBUSTION CHAMBER THROUGH SAID CHANNELS, THE INCREASE IN PRESSURE FROM COMBUSTION OF THE HYPERGOLIC REACTANTS IN SAID COMBUSTION CHAMBER BEING EFFECTIVE TO MOVE SAID PISTON REARWARDLY TO ACCELERATE THE FEED OF SAID REACTANTS INTO SAID COMBUSTION CHAMBER; A BARREL CONNECTED TO SAID FORWARD SECTION, SAID BARREL HAVING AN AXIAL BORE OF THE SAME DIAMETER AS SAID PASSAGE IN SAID PISTON AND IN ALIGNMENT THEREWITH; MEANS CONNECTED TO THE REARWARD SECTION FOR FEEDING PROJECTILES INTO SAID PASSAGE IN SAID PISTON AND BARREL; A DIFFERENTIAL PISTON STOP MECHANISM IN SAID BLOCK FOR LOCKING SAID PISTON IN A REARWARD COCKED POSITION; SCAVENGING MEANS FOR SAID GUN DISPOSED IN SAID BLOCK SECTIONS FOR PREVENTING PASSAGE OF PROPELLANTS FROM ONE OF SAID BORES IN SAID SLEEVE TO THE OTHER; AND MEANS FOR PREVENTING RETROGRADE MOTION OF THE PROJECTILES AFTER BEING FED INTO SAID PISTON AND DISPOSED BETWEEN SAID FEEDING MEANS AND SAID REARWARD SECTION COMPRISING A SERIES OF INWARDLY URGED, RADIALLY DISPOSED PLUNGERS HAVING BEVELED INNER ENDS WHEREBY WHEN A PROJECTILE IS FED FORWARDLY, SAID PLUNGERS ARE CAMMED OUTWARDLY AND SNAP INWARDLY UPON FORWARD CLEARANCE OF A PROJECTILE.