Liquid propellant gun

• US 4,928,571 A
• Filed: 08/10/1989
• Issued: 05/29/1990
• Est. Priority Date: 10/06/1977
• Status: Expired due to Fees

• Current Assignee: General Dynamics Armament Systems, Inc. (General Dynamics Corporation)
• Original Assignee: General Electric Company
• Inventors: Bulman, Melvin J.
• Primary Examiner(s): BROWN, DAVID
• Application Number:
  US07/403,275
• Time in Patent Office: 292 Days
• Field of Search: 89/7, 89/8
• US Class Current: 89/7
• CPC Class Codes: F41A 1/04 Missile propulsion using the combustion of a liquid, loose powder or gaseous fuel, e.g. hypergolic fuel

Abstract

A liquid propellant gun system has an annular differential piston journaled for telescopic movement with respect to an annular control valve and to the chamber of the firing bore; uses the piston, the valve and the projectile as valve means for controlling the injection of liquid propellant into the combustion chamber of the gun system; uses a displacement type control means to limit the rate of the loading of liquid propellant and to provide a positive evacuation of misfired liquid propellant from the combustion chamber; and incorporates a vernier control circuit to give direct control over the performance of the gun.

Claims

1. A liquid propellant gun comprising:

a housing having a longitudinally extending first cavity therein;

a gun barrel having a firing bore with a projectile receiving chamber disposed along a longitudinal axis;

said gun barrel being disposed within said housing first cavity and with said housing defining a second closed cavity which is a portion of said first cavity and is of substantially annular, longitudinally extending shape and is coaxial with said barrel longitudinal axis;

a valve sleeve of substantially annular, longitudinally extending shape coaxial with said barrel longitudinal axis and disposed in said second cavity;

a piston sleeve of substantially annular, longitudinally extending shape coaxial with said barrel longitudinal axis and disposed in said second cavity;

said piston sleeve and said valve sleeve being journaled for relative motion with respect to each other and said gun barrel, said valve sleeve and said gun barrel mutually defining a supply chamber of variable volume for liquid propellant, and said piston sleeve and said valve sleeve mutually defining a pumping chamber of variable volume for liquid propellant;

obturating means for closing the aft end of said projectile receiving chamber;

supply means for supplying liquid propellant under pressure;

first conduit means for coupling and decoupling said supply means to said supply chamber;

second conduit means for coupling and decoupling said supply chamber to said pumping chamber;

p1 third conduit means for coupling and decoupling said pumping chamber to said projectile receiving chamber;

said valve sleeve, said piston sleeve, said first conduit means, said second conduit means and said third conduit means having a mode of operation such that;

initially said first conduit means, said second conduit means and said third conduit means are each decoupled and said pumping chamber is at its minimum volume,

subsequently said first conduit means is coupled and passes liquid propellant to said supply chamber,

subsequently said second conduit means is coupled and passes liquid propellant to said pumping chamber,

subsequently said pumping chamber is expanded to its maximum volume by inletted liquid propellant, and

subsequently said pumping chamber is reduced in volume, and said third conduit means is coupled, injecting liquid propellant into said projectile receiving chamber.

2. A gun according to claim 1 wherein:

said first conduit means includes said valve sleeve, and longitudinal movement of said valve sleeve relative to said gun barrel serves to decouple and couple said supply means to such supply chamber.

3. A gun according to claim 1 wherein:

said second conduit means includes said valve sleeve, and longitudinal movement of said valve sleeve relative to said gun barrel serves to decouple and couple said supply chamber to said pumping chamber.

4. A gun according to claim 1 wherein:

said third conduit means includes said valve sleeve and longitudinal movement of said valve sleeve relative to said gun barrel serves to decouple and couple said pumping chamber to said projectile receiving chamber.

5. A gun according to claim 1 further including:

a projectile disposed in said projectile receiving chamber, and

said third conduit means includes said projectile and longitudinal movement of said projectile relative to said projectile receiving chamber serves to decouple and couple said pumping chamber to said projectile receiving chamber.

6. A gun according to claim 1 wherein:

said supply chamber is so constructed and arranged as to undergo a cycle of change of volume from zero to maximum to zero as a function of reciprocation of said valve sleeve, and when said supply chamber passes through a predetermined intermediate volume as it approaches zero, it assumes the characteristic of a dash-pot to decelerate the velocity of said valve sleeve.

7. A gun according to claim 1 wherein:

said pumping chamber is so constructed and arranged as to undergo a cycle of change of volume from zero to maximum to zero as a function of reciprocation of said piston sleeve, and as the volume approaches zero, said pumping chamber provides the characteristic of a dash-pot to decelerate the velocity of said piston sleeve.

8. A gun according to claim 1 wherein:

said piston sleeve and said valve sleeve mutually define a first additional cavity; and

said piston sleeve and said housing mutually define a second additional cavity;

further including

control conduit means coupled to and between said first additional cavity and said second additional cavity;

wherein said gun has a cycle or operation including

a liquid propellant injection subcycle during which liquid propellant is admitted into said first and second additional cavities, and said first additional cavity has a progressive increase in its volume and said second additional cavity has a progressive decreases in its volume, and

a liquid propellant combustion subcycle during which said first additional cavity has a progressive decrease in its volume and said second additional cavity has a progressive increase in its volume, said control conduit means serving to pass liquid propellant at a controlled rate of flow from said first additional cavity to said second additional cavity and thereby control the rate of change of said volumes of said first and second additional cavities.

9. A gun according to claim 1 further including:

a primer disposed in said projectile receiving chamber;

a booster disposed in said projectile receiving chamber;

means for firing said primer, said primer when fired serving to ignite said booster to generate combustion gas;

conduit means for passing booster generated combustion gas to said piston sleeve for driving said piston sleeve to reduce the volume of said pumping chamber.

10. A gun according to claim 1 wherein:

said third conduit means includes a plurality of conduits having their outlets longitudinally spaced apart.

11. A gun according to claim 1 wherein:

said third conduit means includes

an annular row, in a transverse plane, of radial bores having their outlet ends opening into means for deflecting a flow through said bores of liquid propellant forwardly along the inner wall of said firing bore.

12. A gun according to claim 1 wherein:

said deflecting means comprises an annular groove formed in said inner wall of said firing bore and having an aft shoulder projecting partially into the passageway of each of said bores and a forward face sloping into said inner wall of said firing bore.

13. A gun according to claim 1 wherein:

said obturating means includes

a gun bolt

an annular seal extending between said gun bolt and said aft end of said projectile receiving chamber.

14. A gun according to claim 13 wherein:

said annular seal is a cartridge case.

15. A gun according to claim 13 further including:

a primer carried by said annular seal and disposed in said projectile receiving chamber;

a booster carried by said annular seal and disposed in said projectile receiving chamber;

means for firing said primer, said primer when fired serving to ignite said booster to regenerate combustion gas;

conduit means for passing booster generated combustion gas to said piston sleeve for driving said piston sleeve to reduce the volume of said pumping chamber.

16. A gun according to claim 1 wherein:

said piston sleeve has a first transverse face adjacent to said pumping chamber of a first cross-sectional area, and a second transverse face remote from said pumping chamber of a second cross-sectional area, said second area being greater than said first area.

17. A gun according to claim 16 wherein:

said obturating means includes

a gun bolt, and

a cartridge case carried by said gun bolt and projecting into said projectile receiving chamber; and

further including

a primer carried by said cartridge case;

a booster carried by said cartridge case;

means for firing said primer carried by said gun bolt, said primer when fired serving to ignite said booster to generate combustion gas; and

conduit means for passing booster generated combustion gas to and against said second transverse face of said piston sleeve for driving said piston sleeve to reduce the volume of said pumping chamber.

18. A gun according to claim 17 further including:

a projectile carried by said cartridge case.

19. A gun according to claim 18 wherein:

said third conduit means includes a plurality of conduits having their outlets longitudinally spaced apart, at least the forwardmost outlet being obturated by said projectile while it is carried by said cartridge case.

20. A gun according to claim 1 wherein:

said piston sleeve travels in a first direction to increase the volume of the pumping chamber under the pressure of inletted liquid propellant, and travels in a second, opposite to said first, direction to decrease the volume of the pumping chamber under the pressure of combustion gas, and further including

control means, coupled to said piston sleeve, for limiting the velocity of said piston sleeve in said first direction.

21. A gun according to claim 20 wherein:

said gun has a cycle of operation;

said travel of said piston sleeve in said first direction occurs at a first time in said cycle,

said travel of said piston sleeve in said second direction occurs at a second time which is subsequent to said first time, and

said control means additionally is for driving said piston sleeve in said second direction at a third, subsequent to said second, time in said cycle, if and only if, said piston sleeve has not traveled in said second direction prior to said third time.

22. A gun according to claim 21 further including:

conduit means coupled to said pumping chamber for discharging liquid propellant from said pumping chamber if and when said control means drives said piston sleeve in said second direction.

23. A gun according to claim 21 wherein:

said control means includes

a timing cam driven by said gun, and

a cam follower coupled to said piston sleeve.

24. A gun according to claim 23 wherein:

said timing cam is a cam track in which said follower rides and is thereby provided with a positive rectilinear displacement with respect to time in said gun cycle, and

said piston sleeve normally undergoes a positive rectilinear displacement with respect to time, and further including

clutch means coupled to an between said piston sleeve and said follower and engaged at a predetermined mutual relationship of said piston sleeve and said follower.

25. A liquid propellant gun comprising:

a combustion chamber extending longitudinally into the firing bore of a gun barrel;

a first conduit outlet means for providing liquid propellant into said combustion chamber;

means for igniting liquid propellant from said first conduit outlet means to provide a longitudinally forward flow of combustion gas through said combustion chamber and firing bore; and

a second conduit outlet means, longitudinally forward of said first conduit outlet means, for providing liquid propellant into said combustion chamber including means in conjunction with said flow of combustion gas for deflecting the flow of liquid propellant longitudinally forwardly as a surface film along the inner wall of said combustion chamber and firing bore.

26. A liquid propellant gun comprising:

a gun barrel fixed to said housing having a firing bore with a projectile receiving chamber disposed along a longitudinal axis;

a valve sleeve of substantially annular, longitudinally extending shape coaxial with said barrel longitudinal axis;

a piston sleeve of substantially annular, longitudinally extending shape coaxial with said barrel longitudinal axis;

means for supplying liquid propellant;

conduit means for passing liquid propellant from said supply means into said firing bore;

said valve sleeve serving to open and close said conduit means;

said piston sleeve serving to pass liquid propellant through said conduit means when it is open.

27. A gun according to claim 26 wherein:

said conduit means includes a plurality of longitudinally spaced apart conduits each for passing liquid propellant to longitudinally spaced apart portions of said firing bore;

said valve sleeve serving to initially close all of said conduits and to subsequently open said conduits in sequence, the aftmost conduit first and the forwardmost conduit last.

28. A liquid propellant gun according to claim 26 wherein:

said piston sleeve is a differential piston having a longitudinally extending medial portion integral with a first transverse annular portion at one end thereof and a second transverse annular portion at the other end thereof,

said first portion having a transverse surface for displacing liquid propellant through said conduit means, and an interior peripheral surface for journaling said piston for longitudinal movement,

said second portion having an interior peripheral surface and an exterior peripheral surface for journaling said piston for longitudinal movement.

29. A gun comprising:

a gun barrel having a firing bore, having an aft end and a forward end, for guiding a projectile;

a first chamber for generating combustion gas coupled to the aft end of said firing bore to provide initial acceleration to a projectile disposed in said firing bore; and

a projectile velocity assistance mechanism coupled to said firing bore;

said projectile velocity assistance mechanism comprising;

a housing secured to said gun barrel;

injector means, for injecting liquid propellant into said firing bore of said gun barrel, disposed in said housing, including;

a cavity in housing;

a piston, disposed in said cavity to divide said cavity into a liquid propellant receiving chamber and a combustion receiving chamber, and slidably mounted for movement to and between a first and a second position;

a first conduit means in fluid communication between (i) said firing bore at a first point along said firing bore which is forward of said aft end whereat said first chamber is coupled, and (ii) said combustion gas receiving chamber;

a second conduit means in fluid communication between (i) said firing bore at a second point along said firing firing bore which is forward of said first point, and (ii) said liquid propellant receiving chamber;

a liquid propellant supply under pressure in fluid communication with said liquid propellant receiving chamber;

valve means controlling said second conduit means and normally biased to close said second conduit means against the pressure of said liquid propellant supply;

said valve means constructed to open under increased pressure in said liquid propellant receiving chamber caused by combustion gas passing from said first chamber, into said firing bore, through said first conduit means, into said combustion gas receiving chamber to apply pressure against said piston to increase the volume of said gas receiving chamber and to decrease the volume of said liquid propellant receiving chamber;

whereby liquid propellant flows from said liquid propellant receiving chamber, through said second conduit means, into said firing bore, aft of the previously accelerated projectile, and ignites to provide additional combustion gas to provide subsequent acceleration to the projectile before it exits the forward end of the firing bore.