US3503300A

US3503300A - High firing rate hypervelocity gun and ammunition therefor

Info

Publication number: US3503300A
Application number: US665155A
Authority: US
Inventors: David Dardick
Original assignee: TRW Inc
Current assignee: Northrop Grumman Space and Mission Systems Corp; Tround International Inc
Priority date: 1967-09-01
Filing date: 1967-09-01
Publication date: 1970-03-31
Anticipated expiration: 1987-03-31
Also published as: SE353390B; IL30610A0; CA924553A; DE1728131A1; GB1248783A; BE720222A; FR1603740A; SE368083B; ES357767A1; CH503247A

Description

D. DARDICK March 31, 1970 HIGH FIRING RATE HYPERVELOCITY GUN AND AMMUNITION THEREFOR I Filed Sept. 1, 1967 3 Sheets-Sheet 1 March 31, 1970 o. DARDICK 3,503,300

HIGH FIRING RATE HYPERVELOCITY GUN AND AMMUNITION THEREFOR Filed Sept. 1, 1967 3 Sheets-Sheet 2 1 \"VENI'OR 04:00 04:04

Jrraemey March 31, 1970 D. DARDICK 3,503,300

HIGH FIRING RATE HYPERVELOCITY GUN AND AMMUNITION THEREFOR Filed Sept. 1, 1967 3 Sheets-Sheet 3 zg'yda INVENTOR. filly/0 04m United States Patent O 3,503,300 HIGH FIRING RATE HYPERVELOCITY GUN AND AMMUNITION THEREFOR David Dardick, Palos Verdes Peninsula, Calif., assignor to TRW Inc., Redondo Beach, Calif., a corporation of Ohio Filed Sept. 1, 1967, Ser. No. 665,155 Int. Cl. F41d 11/14 US. Cl. 89-8 20 Claims ABSTRACT OF THE DISCLOSURE A high firing rate hypervelocity gun having at least one barrel, a primary breech mechanism at the breech end of the barrel for successively transporting primary rounds to and firing each round in firing position to eiiect forward propulsion of its projectile through the barrel, and at least one secondary breech mechanism located at a booster station along the barrel forwardly of the primary mechanism for successively transporting booster rounds to firing position simultaneously with the primary rounds in such manner that the propellant charge in each booster round is exposed to and ignited by the propellant gas generated by the corresponding fired primary round upon forward travel of its projectile through the respective booster station, thereby to increase the propellant gas pressure behind the projectile and accelerate the latter through the barrel. Booster ammunition for the hypervelocity gun.

REFERENCE TO COPENDING APPLICATIONS Reference is made herein to copending applications, Ser. No. 671,910, filed Sept. 1, 1967, and entitled Sealed Open Chamber Breech Mechanism and Caseless Ammunition Therefor, and Ser. No. 665,136, filed Sept. 1, 1967, and entitled Semicombustible Ammunition for Open Chamber Breech Mechanism, now abandoned.

BACKGROUND OF THE INVENTION Field of the invention This invention relates generally to guns and more particularly to so-called hypervelocity guns. The invention relates also to novel ammunition for the guns.

Prior art Hypervelocity guns are known in the art and, as their name implies, are characterized by extremely high muzzle velocity, i.e., hypervelocity. Such hyper-muzzle velocity may be achieved in various ways. The present invention is concerned with the particular hypervelocity technique which involves ignition of a booster charge at one or more positions along the bore directly behind the advancing projectile to increase or boost the propellant gas pressure behind the projectile and thereby accelerate the latter through the bore to a hypervelocity.

Hypervelocity guns which utilize this booster firing technique to achieve hyper-muzzle velocities have been devised. Generally speaking, such guns comprise a barrel with a breech mechanism for firing a primary round at the breech end of the barrel. This primary round contains a projectile which is propelled forwardly through the barrel by the propellant gas pressure generated by firing of the round. Arranged along the barrel, forwardly of the breech mechanism, are one or more secondary or booster firing chambers containing a'booster propellant charge. Each booster chamber communicates to the bore in the gun barrel through ports in the barrel wall. As the projectile travels forwardly past each booster chamber, its contained booster charge is exposed to and ignited by the high temperature propellant gas of the fired primary round. The propellant gas generated by the burning booster charge then enters the bore to increase the total propellant gas pressure behind the projectile and thereby accelerate the latter through the bore.

While this type of gun achieves a hyper-muzzle velocity, it has certain inherent deficiencies. The major deficiency of the gun, for example, resides in the fact that reloading is very laborious and time consuming. As a consequence, hypervelocity guns of the characteristic described have never been adopted as a practical weapon.

SUMMARY OF THE INVENTION The present invention provides a hypervelocity gun which avoids the above-noted and other deficiencies of the existing hypervelocity guns. The major advantage of the present gun resides in its high firing rate and rapid reloading capabilities. In the regard, for example, it will become evident from the ensuing description that the present gun is uniquely adapted to automatic high rate firing. Generally speaking, the invention provides a hypervelocity gun characterized by a primary breech mechanism located at the breech end of a barrel for successively transporting primary rounds to firing position and firing each round to effect forward propulsion of its projectile through the gun bore. Located at at least one booster station along the barrel forwardly of its breech end is a secondary breech mechanism for successively transporting projectileless booster rounds to firing position. When in firing position, the propellant charge in each booster round is disposed for ignition by the propellant gas generated by firing of a primary round upon forward travel of its projectile through the respective booster station. The propellant gas generated by each ignited booster round enters the gun bore and increases the propellant gas pressure directly behind the projectile to accelerate the latter forwardly through the bore.

As will appear from the later description, the present hypervelocity gun may employ either closed chamber or open chamber breech mechanisms or both closed and open chamber breech mechanisms in various combinations. That is to say, both the primary and secondary breech mechanisms may embody a closed chamber breech action or an open chamber breech action, or one mechanism may embody a closed chamber action and the other an open chamber action. In this regard, it should be noted that a closed chamber breech action is one in which each ammunition round is inserted or rammed axially into a circumferentially closed firing chamber through one end of the chamber and the spent cartridge case of each fired round is extracted axially from the chamber. Examples of this type of breech mechanism are the conventional belt or clip fed mechanisms, the revolver mechanism, the Gatling mechanism, and the separate chamber mechanism. An open chamber breech action, on the other hand, is one in which each ammunition round is introduced laterally into a firing chamber through an open side of the chamber and the spent cartridge case of each fired round is ejected laterally through the open side of the chamber. Examples of such open chamber breech mechanisms are those disclosed in prior art Patents No. 2,983,223; 3,04l,938; 2,831,140; 2,847,784; and 3,044,890. Moreover, a hypervelocity gun according of the invention may have either a fixed barrel or a rotary barrel construction. A fixed barrel construction is one in which each gun barrel is stationary at all times and each firing chamber is stationarily aligned with the barrel, at least during firing of each ammunition round in the chamber. A rotary barrel gun, on the other hand, is one in which the gun barrel or barrels undergo continuous rotation about an axis parallel to and spaced laterally from the barrel or barrels, and each firing chamber is coaxially aligned with and undergoes rotation about the axis with a barrel during firing of each round in the chamber, thus to achieve a very high firing rate. The aforementioned Patent No. 3,041,939, for example, describes a rotary barrel open chamber gun, and the remaining patents listed disclose fixed barrel Open chamber guns. It will also appear that the primary and booster ammunition which is fired in an open chamber hypervelocity gun according to the invention may comprise fully cased open chamber ammunition having a cartridge case similar to that disclosed in the aforementioned prior art patents, semicombustible ammunition having a skeletonized cartridge case similar to that disclosed in the copending application entitled Semicombustible Ammunition for Open Chamber Breech Mechanism, or caseless ammunition similar to that disclosed in the copending application entitled Sealed Open Chamber Breech Mechanism and Caseless Ammunition Therefor.

BRIEF DESCRIPTION OF THE DRAWINGS In the drawings:

FIG. 1 is a perspective view of a fixed barrel open chamber hypervelocity gun according to the invention;

FIG. 2 is an enlarged, fragmentary longitudinal section through the gun;

FIG. 3 is a section taken on line 3--3 in FIG. 2;

FIG. 4 is an enlargement of the area encircled by the arrow 4-4 in FIG. 2;

FIG. 5 is a perspective view, partly broken away, of a booster ammunition round to be fired in the gun;

FIG. 5a diagrammatically illustrates an electrical firing circuit and cylinder drive for the gun of FIGS. 14;

FIG. 6 is a longitudinal section through a modified hypervelocity gun according to the invention;

FIG. 7 is an enlarged section taken on line 77 in FIG. 6;

FIG. 8 is a perspective view, partly broken away, of a booster ammunition round to be fired in the hypervelocity gun of FIG 6;

FIG. 9 is a perspective view of a rotary barrel open chamber hypervelocity gun according to the invention; and

FIG. 10 is a longitudinal section through the gun of FIG. 9.

DESCRIPTION OF THE PREFERRED EMBODIMENTS In general terms, the invention provides a hypervelocity gun, represented in FIGS. l-5 of the drawings by the gun 10, having a barrel 12 containing a bore 1 4. Spaced along the barrel 12 are a number of breech mechanisms 16 and 18. Breech mechanism 16 is located at the breech end of the barrel and is hereinafter referred to as the primary breech mechanism. Breech mechanism 18, which is hereinafter referred to as a secondary breech mechanism is located at a booster station S spaced forwardly along the barrel from the primary breech mechanism. As will appear from the ensuing description, a hypervelocity gun according to the invention may embody any number of booster stations and secondary breech mechanisms, depending upon the muzzle velocity to be obtained. For the sake of simplicity, the illustrated hypervelocity gun of the invention has been shown to comprise a single secondary breech mechanism. As will appear presently, the primary breech mechanism 16 operates to transport primary ammunition rounds in succession to firing position at the breech end of the barrel 12 and to fire each round in this position. The projectile of each fired round is propelled forwardly through the barrel by the high pressure propellant gas which is generated by the burning primary propellant charge in the round. The secondary breech mechanism 18 operates to transport secondary or booster ammunition rounds in succession to firi g position at the booster station .8 in

such a way as to locate each boster round in firing position simultaneously with a primary round. Each booster round is a projectileless round containing a booster propellant charge which, in firing position, is disposed to be ignited by the hot propellant gas of the respective fired primary round upon forward travel of its projectile through the booster station. The propellant gas generated by the booster propellant enters the barrel bore 14 behind the advancing projectile to accelerate the latter through the bore.

It will be recalled that the present hypervelocity gun may employ various types of primary and secondary breech mechanisms. Each of the illustrated breech mechanisms 1-6, 18 has a breech frame 20 supporting a movable ammunition carrier 26 containing at least one firing chamber 28. Carrier 26 is movable along a prescribed path of motion relative to its breech frame 20 to locate its firing chamber successively in an ammunition infeed position, a firing position, and an injection position.

When in infeed position, the carrier 26 is disposed to receive an ammunition round to be fired. When in firing position, the carrier firing chamber 28 locates its contained ammunition round in firing relation to the gun bore 14. Finally, when in ejecting position, the carrier is disposed for ejection of the spent cartridge case of the fired round from the firing chamber after firing. Means 30 are provided for driving the two carriers 26 of the breech mechanisms 16, 18 in unison to infeed, firing and ejection positions.

The primary breech mechanism 16 is designed to fire primary ammunition rounds 32 including a projectile 34. The particular primary ammunition illustrated is cased ammunication having a cartridge case 36 containing the projectile 34, a primary propellant charge 38, and a primer 40. The'secondary breech mechanism 18 is designed to fire ammunition booster rounds 42 including a booster propellant charge 44 only. The illustrated booster rounds also comprise cased ammunition having a cartridge case 46 containing the propellant 44.

Briefly, in operation of the present hypervelocity gun 10, the carriers 26 of the breech mechanisms 16, 18 are first driven to infeed position. A primary ammunition round 32 is then introduced into the firing chamber 28 of the primary breech mechanism 16 and a booster round 42 is introduced into the firing chamber of the secondary breech mechanism 18. Thereafter, the carriers are driven to firing position and the firing means 48 of the primary breech mechanism is actuated to fire the primary round in the latter mechanism. The firing chamber 28 of the primary breech mechanism 16, when in firing position, is coaxially aligned with and opens forwardly to the gun bore 14. Accordingly, when the primary round 32 is fired, its projectile 34 is propelled forward through the gun bore 14 by the propellant gas generated by the burning propellant charge 38 in the round. The firing chamber of the secondary breech mechanism 18, when in firing position, opens to the gun bore 14 in such a way that the propellant charge 44 in the booster round 42 contained within the chamber is exposed to and ignited by the hot propellant gas of the fired primary round upon forward travel of its projectile through the booster station S. The propellant gas generated by the fired booster round then enters the gun bore 14 to increase the total propellant gas pressure behind the projectile and thereby accelerate the latter forwardly through the gun bore. At this point, it is significant to recall that while the illustrated hypervelocity gun of the invention has a single secondary breech mechanism 18, a present gun may embody any number of secondary breech mechanisms spaced along the barrel 12. In the event that a present gun is equipped with more than one secondary breech mechanism, the action of each additional secondary mechanism is identical to that described above. Accordingly, the propellant gas pressure behind the projectile of a fired primary round is increased a number of times as the projectile t avels forwardly through the bore and exposes the booster rounds in the successive secondary breech mechanisms to the hot propellant gas of the primary round.

In the particular hypervelocity gun of the invention under discussion, the primary and secondary breech carriers 26 are cylinders which contain the firing chambers 28. These cylinders are rotatably mounted within chambers 22 in the primary and secondary breech frames 20, respectively, for turning on axis 24, parallel to and spaced laterally from the barrel 12. The carrier drive means 30 drives the cylinders in rotation in unison to locate the primary and secondary firing chambers in their infeed, firing, and ejection positions.

Referring now in more detail to the hypervelocity gun 10 of the invention which has been selected for illustrati n in FIGS. l5 of the'drawings, it will be seen that the" breech frames of the primary and secondary breech mechanisms 16, 18 are rigidly joined to one another by top and

bottom connecting straps

48, 50 to form a rigid breech structure. At the front end of this breech structure is a trunnion support or boss 52. A trunnion 54 extends through this boss, laterally of the gun, and projects a distance beyond opposite sides of the boss. The projecting ends of the trunnion 54 are rotatably received in bearings 56 fixed within the upstanding arms 58 of a gun carriage bracket 60. The gun is thus pivotally supported for training of the gun in elevation. The bracket 60, in turn, may be pivotally supported for training of the gun in azimuth. It is obvious, of course, that the gun may be supported in a fixed mount, if desired.

As noted earlier, a hypervelocity gun according to the invention may utilize either or both an open chamber breech action and a closed chamber breech action. The particular gun under discussion is an open chamber gun which employs an open chamber breech action in both its primary and secondary breech mechanisms 16, 18. In this regard, it will be observed that each breech mechanism is essentially a conventional open chamber breech mechanism of the type disclosed in the aforementioned prior art patents. Thus, the breech frame 20 of each breech mechanism has the characteristic, generally fiat rectangular shape and contains a generally rectangular central opening which opens laterally through opposite sides of the frame to form the chamber 22. As is wellknown to those versed in the open chamber gun art, the cylinder of an open chamber breech mechanism may contain one or more firing chambers and may be driven in unidirectional rotation or in oscillation. Each breech cylinder 26 of the illustrated open chamber hypervelocity gun 10 of the invention contains a number of uniformly spaced firing chambers 28 and is driven in unidirectional rotation to locate each firing chamber in its infeed, firing, and ejection position. In accordance with a characteristic feature of open chamber mechanisms, each firing chamber 28 opens laterally through the circumference and longitudinally through the front and rear ends of its respective cylinder. The open sides of each chamber 22 define ammunition infeed and ejection openings with which each firing chamber of the contained breech cylinder 26 registers when in infeed and ejection positions, respectively. When in firing position, the open side of each firing chamber is closed by the firing strap 62 of the corresponding breech frame.

A further characteristic feature of open chamber breech mechanisms resides in the complementary, generally triangular shapes of the open firing chambers and ammunition in transverse cross-section. In this regard, it will be observed that the firing chambers 28 of the illustrated open chamber gun 10 and the ammunition rounds 32, 42 which are fired in the gun have the same generally triangular round shape in transverse cross-section as the firing chambers and ammunition disclosed in the aforementioned prior art patents. The side walls of each firing chamber and the sides of each ammunition round are cylindrically curved to the same radius of curvature as the breech cylinders 26.

When an ammunition round is positioned in a firing chamber of either breech mechanism 16 or 18, two sides of the round seat flush against the side walls of the chamber and the third, exposed side of the round is fiush with the cylinder circumference. The inner surface of the firing strap 62 of each breech frame 20 is also cylindrically curved to the same radius as and slidably engages the circumference of its contained cylinder 26.

In the particular open chamber gun under discussion, the barrel means 12 Comprises front and rear barrel sections 12a and 12b, respectively. Front barrel section 12a is secured at its rear end to and extends forwardly from the front end of the secondary breech frame 20. The rear barrel section 12b extends between and is secured at its ends to the front end of the primary breech frame and the rearend'of the secondary breech frame. These barrel" 7 sections are coaxially disposed in spaced parallel relation to the common axis 24 of the breech cylinders 26.

It will be recalled that the illustrated open chamber hypervelocity gun 10 is equipped with drive means 30 for driving the primary and secondary breech cylinders 26 to sequentially locate each of their respective firing chambers 28 in infeed, firing, and ejection positions. The illustrated drive means comprise a connecting drive shaft 64 which extends between the cylinders along their common axis 24 of rotation. The rear end of this shaft extends rotatably through the forward end of the primary breech frame 20 and is coaxially secured to the forward end of the primary breech cylinder 26. The forward end of the shaft extends rotatably through the rear end of the secondary breech frame and is coaxially secured to the rear end of the secondary breech cylinder. Accordingly, the connecting shaft joins the cylinders for rotation thereof in unison. Shaft 64 extends through the cylinders to rotatably support the latter on their respective breech frames. It is significant to note here that the cylinders are so oriented on their common axis 24 that their firing chambers are axially aligned. The coresponding firing chambers of the two cylinders thus rotate in unison to their infeed, firing, and ejection positions.

The illustrated cylinder drive means 30 further comprise an electric drive motor 66, the shaft of which is drivably coupled to the rear end of the cylinder shaft 64 through in intermittent rotary drive mechanism 68 (FIG. 5a). The particular drive mechanism illustrated is at Geneva drive having an input member 70 coupled to the motor shaft and an output member 72 coupled to the cylinder shaft. This Geneva drive is so constructed and arranged as to drive the breech cylinders 26 in intermittent rotation in such a way that the cylinder firing chambers 28 are momentarily arrested in their firing positions. As noted earlier, the primary ammunition rounds 32 are fired in firing position by the primary breech firing means 48. This firing means is an electrical firing means actuated by a firing switch 74. Referring to FIG. 5a, it will be seen that the firing switch 74 is operated by a rotary cam 76 which is coupled to the input member 70 of the Geneva drive 68. This cam is oriented to close the firing switch and thereby energize the electrical firing means 48 during that portion of each revolution of the input member in which the breech cylinders 26 are retained stationary in firing position by the output member 72 of the Geneva drive. The cylinder drive motor 66 may be controlled by a trigger switch 78 operated by a trigger mechanism (not shown) to permit selective firing of the gun.

It is now evident that when the trigger switch 78 is closed, the breech cylinders 26 are driven in intermittent rotation in such a way that the cylinder firing chambers 28 rotate in succession through their infeed, firing, and ejection positions. Indicated at 80 in the drawings are ammunition infeed means for feeding primary ammunition rounds 32 laterally in succession to the primary breech firing chambers and feeding booster ammunition rounds 42 laterally in succession to the secondary breech firing chambers upon rotation of these chambers to infeed position. It will be obvious to those versed in the art that various ammunition infeed means may be employed in the gun. The particular infeed means shown comprise ammunition hoppers which feed their respective rounds to their corresponding cylinders through the amunition infeed openings in the breech frames 20. These hoppers may be equipped with spring loaded followers or the like for urging the rounds toward the cylinders. After entrance of each pair of the ammunition rounds 32, 42 into aligned primary and secondary firing chambers 28, the rounds rotate with the chambers to firing position. In the hypervelocity gun 10 under discussion, both the primary and secondary firing chambers, when in firing position, are coaxially aligned with the gun bore 14. Thus, each primary firing chamber, when in firing position, is coaxially aligned with and opens forwardly to the breech end of the bore. Each secondary firing chamber, when in firing position, is coaxially disposed between the front and rear barrel sections 12a, 12b and opens forwardly to the bore in the front barrel section and rearwardly to the bore in the rear barrel section.

The primary ammunition rounds 32 are identical to those disclosed in the aforementioned prior art patents. Accordingly, there is no need to describe these rounds in any greater details than presented earlier. The construction of the booster ammunition rounds 42, however, is novel and constitutes an important feature of the invention. One of these rounds is shown in detail in FIG. 5. Each illustrated booster round has an outer yieldable noncombustible cartridge case 46. This cartridge case, and that of each primary round, have a generally triangular round shape in cross-section and are sized to complement and seal their respective primary and secondary breech cylinder firing chambers against propellant gas leakage during firing, in the same manner as explained in the earlier listed patents. Extending centrally through the cartridge case 46 of each booster round 42 is a perforated tube 86. The ends of this tube are sealed to the end walls of the cartridge case 46. As explained below, the tube 86 of each booster round 42, when in firing position, forms a section of the gun bore 14 and serves to guide the projectile 34 of a fired primary round 32 during its travel through the booster station 5. To this end, the internal diameter of the tube is the same as that of the gun bore 14, proper, and the tube is made of non-combustible material suitable to its projectile guiding function. The interior space of each booster round 42, between the outer cartridge case 46 and inner tube 86 of the round, is filled with the booster propellant 44. A combustible cover sleeve 88 may be disposed about the tube 86, particularly if the booster propellant 44 is a loose grain propellant, to shield the propellant and prevent its loss through the tube ports during handling and infeed.

The operation of the illustrated open chamber hypervelocity gun 10 will now be explained. The gun is initially conditioned for firing by filling the ammunition infeed means or hoppers 80 of the primary and secondary breech mechanisms 16, 18 with primary and booster ammunition rounds 32, 42, respectively.

The trigger switch 78 is then closed to energize the breech cylinder drive motor 66 and thereby effect driving of the primary and secondary breech cylinders is intermittent rotary motion through their respective infeed, firing, and ejection positions. As each pair of corresponding primary and secondary firing chambers 28 rotate to infeed position, a primary round 32 is fed laterally into the primary chamber and a booster round 42 is fed laterally into the secondary chamber from the ammunition hoppers 80 and through the infeed openings in the breech frames 20 and the open sides of the firing chambers. Thereafter, the rounds are rotated to firing position in their respective breech mechanisms 16, 18 and the primary round is electrically fired in the primary breech mech nism by closure of the cam actuated firing switch 74. Each booster round 42, when in firing position, is located with its inner perforated tube 86 in coaxial alignment with the gun bore 14, so as to effectively form a section of the bore, as shown in the drawings.

When each primary ammunition round 32 is fired in firing position, in the manner just explained, its projectile 34 is propelled forwardly through the gun bore 14 by the propellant gas pressure generated by the fired primary round. During its forward travel through the gun bore, the projectile passes through and uncovers the ports in the central perforated tube 86 of the booster round 42 currently in firing position within the secondary breech mechanism 18. The booster propellant 44 in the booster round is thereby exposed to an ignited by the hot propellant gas of the fired primary round. In this regard, attention is directed to the fact that the combustible sleeve 88 in the booster round serves merely to prevent escape of the booster propellant through the tube ports during storage and handling of the round, and is consumed by the hot propellant gas of the fired primary round to permit exposure of the booster propellant to the gas as just explained. The propellant gas generated by the burning booster propellant then enters the gun bore to increased the propellant gas pressure in the bore behind the advancing projectile of the fired primary round 32 and thereby accelerate the projectile to the desired hyper-muzzle velocity. At this point, it is significant to recall that a hypervelocity gun according to the invention may be provided with any number of booster stages. It will be understood that the booster propellants of the successive booster stages are ignited in essentially the same way as described above in connection with the illustrated gun 10 upon forward travel of the projectile of the fired primary round through the successive booster stages.

During firing of the gun 10, the

cartridge cases

38 and 46 of the fired primary and booster rounds 32, 42, are expanded by propellant gas pressure outwardly against the walls of their respective firing chambers 28 and breech frames 20 to seal the breech interfaces against propellant gas leakage, in the manner explained in the aforementioned prior art patents. After firing, the firing chambers 28 currently in firing position are rotated to ejection position to eject the spent cartridge cases of the fired primary and booster rounds, and a pair of live primary and booster rounds are rotated to and fired in firing position. This firing action continues as long as the breech cylinder drive motor 66 remains energized and the ammunition hoppers contain primary and booster ammunition rounds.

Turning now to FIGS. 6 through 8, there is illustrated a modified hypervelocity gun according to the invention having a primary breech mechanism 102 which utilizes a closed chamber breech action and a secondary breech mechanism 104 which utilizes an open chamber breech action. In the interest of simplicity of description and illustration, only the breech means and barrel of the modified gun have been shown and will be described. It will be understood, of course, that the actual gun will be provided with cylinder drive means, and ammunition infeed means for each breech mechanism. In this regard, it should be noted that the open chamber breech mechanism may have a hopper feed like that just described. The closed chamber primary breech mechanism may be equipped with any conventional ammunition infeed means suitable for use with the illustrated mechanism.

The primary breech mechanism 102 has a breech frame 106 containing a breech chamber 108 in which is rotatable mounted a revolver cylinder 110. Extending through the cylinder 110, parallel to its rotation axis 112, are a number of laterally closed firing chambers 114. These firing chambers are uniformly spaced about the axis of and open through the front and rear ends of the cylinder 110. Each firing chamber is conventionally shaped and dimensioned to receive a standard ammunition cartridge 116, hereinafter referred to as a primary round. Breech chamber 108 opens through opposite sides of the breech frame 106. Secured at its rear end to an extending forwardly from the front end of the breech frame 106 in spaced and parallel relation to the cylinder axis 112 is a barrel 118 containing a bore 120.

Revolver or cylinder 110 is rotatable in the breech chamber 108 to locate each of its firing chambers 114 in ammunition infeed, firing, and cartridge case ejection positions. Each firing chamber, when in infeed position, is exposed through one open side of the breech chamber to permit axial insertion of a primary cartridge or round 116 into the chamber. When in firing position, each firing chamber is coaxially aligned with and opens forwardly to the gun bore 120 to condition a primary round to be fired in the chamber. Each firing chamber, when in ejection position, is exposed through one open side of the breech chamber to permit axial extraction of a spent cartridge case from the chamber after firing. Secured to and extending coaxially from the cylinder 110 and rotatably through the rear end of the breech frame 106 is a shaft 122 by which the cylinder may be rotated to sequentially locate each of its firing chambers in infeed, firing, and ejection positions. Mounted in the rear end of the breech frame 106, on the axis of the gun bore 120, is a firing pin 124.

The secondary breech mechanism has a breech frame 126 containing a bore 128 receiving the barrel 118. The secondary breech frame is rigidly secured to the barrel in any convenient way and is sealed to the barrel. Breech frame 126 contains a chamber .132 which is laterally offset from the frame bore 128. Rotatably mounted within the chamber 132, for turning on an axis 134 parallel to and spaced from the axis of the gun bore 120, is an open chamber carrier or cylinder 136. Cylinder 136 contains a number of uniformly spaced longitudinal firing chambers 138 which open laterally through the circumference of the cylinder. Each of these firing chambers has the same generally triangular round shape in transverse crosssection as the firing chambers in the earlier described hypervelocity gun of the invention. Breech chamber 132 opens through opposite sides of the secondary breech frame 126 to define ammunition infeed and ejection openings. Breech frames 106, 126 are rigidly joined by connecting plates 139, 193a.

The secondary breech cylinder 136 is rotatable to locate each of its firing chambers 138 in ammunition infeed, firing, and ejection positions. Each firing chamber, when in infeed position, opens laterally through one open side of the chamber 132 to permit lateral infeed movement of a booster ammunition round 140 into the chamber. When in firing position, each firing chamber is closed by the secondary breech frame 126 to permit firing of the booster round in the chamber. When in ejection position, each firing chamber opens laterally through one open side of chamber 132 to permit lateral ejection of the spent cartridge case of a fired booster round from the chamber. Extending through the wall of the barrel 118 and the secondary breech frame 126 are a number of propellant gas ports 142 which communicate each firing chamber 138, when in firing position, to the gun bore 120.

As in the earlier hypervelocity gun 10 of the invention, the

breech cylinders

110, 136 of the modified hypervelocity gun 100 are drivably coupled for unified rotation of the firing

chambers

114, 138 to firing position. To this end, the shaft 122 of the primary breech cylinder 110 extends forwardly from the cylinder and rotatably through the front end of the primary breech frame 106. Fixed to the forward end of this shaft is a gear 144. Fixed to and extending coaxially from the secondary breech cylinder 136 and rotatably through the rear end of the secondary breech frame 126 is a shaft 146. A gear 148 fixed on the end of the shaft 146 meshes with the gear 144 to drivably couple the primary and

secondary breech cylinders

110, 136.

It is significant to note at this point that in the earlier described gun 10 of the invention, the primary and secondary breech cylinders are required to contain the same number of firing chambers. This results from the fact that the cylinders are directly connected to the same interconnecting shaft. In the modified gun under discussion, on the other hand, the primary and secondary cylinders may contain the same number or a different number of firing chambers. In the event that the cylinders contain the same number of firing chambers, the cylinder drive gears 144, 148 will mesh in a l to 1 ratio. On the other hand, if the number of firing chambers in the cylinders differ, the

gears

144, 148 will mesh in other than a 1 to 1 ratio depending upon the particular number of firing chambers in each cylinder. In any event, the ratio of the gears is such as to effect rotation of each secondary firing chamber 138 to firing position simultaneously with rotation of each primary firing chamber 114 to firing position. It is obvious, of course, that the primary and

secondary breech cylinders

110, 136 of the modified gun 100, unlike the breech cylinders of the earlier described gun 10, rotate in opposite directions.

As already noted, the primary ammunition cartridges or rounds 116 which are fired in the primary breech mechanism 102 are conventional. Accordingly, these primary rounds need not be described in detail. Suffice it to say that each primary round comprises a generally cylindrical metallic cartridge case 116a containing a primary propellant charge (not shown) and a projectile 116b which is secured to and extends forwardly from the front end of the cartridge case. The primary firing chambers 114 are shaped to complement the cartridge case 116a, as shown.

The booster ammunition rounds 140 which are fired in secondary breech mechanism 126 comprise a yieldable, non-combustible cartridge case 140a which is shaped to complement the secondary firing chambers 138. Contained within the cartridge case is a booster propellant charge 14%. Formed in at least the side of the cartridge case which is exposed when the booster round is positioned in a secondary firing chamber 138 is an opening 1400 closed by a combustible cover sheet 140d.

As in the previous embodiment of the invention, the sides of each firing chamber and the inner wall of the breech frame firing strap of the secondary breech mechanism 104, as well as the sides of the booster rounds 140, are cylindrically curved to the same radius as the circumference of the secondary breech cylinder 136. Moreover, when a booster round is positioned in a firing chamber 138, the exposed, apertured side of the round is flush with the cylinder circumference.

The modified hypervelocity gun 100 is conditioned for firing by rotating the primary and

secondary breech cylinders

110, 136 to locate firing

chambers

114, 138 of the respective cylinders in infeed position. Primary and

booster rounds

116, 140 are then inserted into the respective firing chambers, after which the cylinders are rotated to locate these rounds in firing position. At this point, the firing pin 124 is actuated to fire the primary round. The projectile 116b of the fired primary round is thereby propelled forwardly through the gun bore by propellant gas pressure. During its forward travel through the gun bore, the projectile uncovers the propellant gas ports 142 in the wall of the barrel 118. The booster round currently in firing position within the secondary breech mechanism 104 is thereby exposed to the hot propellant gas generated by the fired primary round. As in the previous embodiment of the invention, the hot propellant gas consumes the combustible cover sheet 140d and ignites the booster propellant charge 140b in the round. The propellant gas then generated by the booster propellant enters the gun bore 120 through the ports 142 to increase the propellant gas pressure behind the advancing projectile 116/5 of the fired primary round and thereby accelerate the projectile to the desired muzzle velocity. It will be understood that the modified hypervelocity gun 100, like the earlier described gun 10 of the invention, may be provided with as many booster firing stations along the barrel 118 as necessary to accelerate the projectile to the desired muzzle velocity. After firing, the primary and

secondary firing chambers

114, 138 currently in firing position are rotated to ejection position to permit ejection of the spent cartridge cases of the fired rounds from the chamber.

Each of the hypervelocity guns of the invention described thus far are fixed barrel guns in which the gun barrel remains stationary at all times and the primary and secondary firing chambers are retained stationary in firing position relative to the barrel during firing of each pair of primary and booster ammunition rounds in the chambers. As noted earlier, however, a hypervelocity gun according to the invention may embody a rotary barrel construction. FIGS. 9 and 10 illustrate such a rotary barrel hypervelocity gun 200. Gun 200 has a primary breech mechanism 202 and a secondary breech mechanism 203 each including a breech frame 204. Breech frames 204 are rigidly joined by top and bottom connecting straps 206. Each frame has a central portion 208 with generally fiat parallel sides and flange-like bearing rings 210 at the ends of the frame. The several bearing rings on the two breech frames have a common axis located in the plane of the connecting straps and extending parallel to the straps, approximately midway therebetween. Within each breech frame 204 is a chamber 212 which opens longitudinally through the front and rear ends of the frame and laterally through opposite sides of the central frame portion to form ammunition infeed and ejection openings, as in the gun of FIG. 1. The rear end of the top connecting strap 206 provides the firing strap for the primary breech frame 204, and the front end of this strap provides a firing strap for the secondary breech frame 204.

Rotatable within each breech frame 204, on the common axis of the breech frame bearingrings 210, is a carrier or cylinder 214. The ends of each cylinder are exposed through the open ends of its respective chamber 212. Each cylinder is rotatably supported in its respective breech frame 204 by bearing units 216 which surround the ends of the cylinder in the planes of the corresponding breech frame bearings rings 210.

Within each cylinder 214 is at least one firing chamber 218. In this instance, each cylinder contains a number of uniformly spaced firing chambers. These firing chambers have the same generally triangular round shape in transverse cross-section as those in the gun of FIG. 1. Each chamber opens laterally through the circumference of its respective cylinder 214, in the region between the bearing rings 210 of the corresponding breech frame 204. The ends of the firing chambers terminate short of the cylinder ends and are closed by front and

rear end walls

222, 224 on the cylinders.

The rotary barrel gun 200 has a barrel 226 for each firing chamber 218. The several barrels 226 parallel the rotation axis of the breech cylinders 214 and are coaxially aligned with the respective firing chambers. Each barrel has a front section 22611 and a rear section 22Gb. Each front barrel section 226a extends forwardly from the front end of the secondary breech cylinder 214 and is threaded or otherwise secured in the front wall 222 of its respective secondary firing chamber. Each rear barrel section 22617 extends between the primary and secondary breech cylinders 214 and is secured in the front wall 222 of its respective primary firing chamber and in the rear wall 224 of its respective secondary firing chamber. The bores 228 in the barrels are coaxially aligned with and open longitudinally to the firing chambers, as shown. Fixed to the muzzle ends of the barrels is a collar 230 for restraining the barrels against relative lateral deflection.

It is evident at this point that the primary and secondary breech cylinders 214 are connected by the rear barrel sections 2261) for rotation of the cylinders in unison to locate their firing chambers 218 in ammunition infeed, firing, and ejection positions in much the same way described earlier in connection with the gun of FIG. 1.

When in infeed position, the open sides of the corresponding primary and secondary firing chambers register with the ammunition infeed openings in the primary and secondary breech frames, respectively, to permit lateral infeed movement of primary and booster ammunition rounds into the chambers from ammunition infeed means 234. In this instance, as in the gun of FIG. 1, the ammunition infeed means 234 comprise ammunition hoppers. When in firing position, the open sides of the corresponding primary and secondary firing chambers 218 are closed by the breech frame firing straps to condition the gun for firing the primary and booster ammunition rounds. When in ejection position, the open sides of the corresponding primary and secondary firing chambers register with the ejection openings in the primary and secondary breech frames 204 to permit lateral ejection of the spent cartridge cases of the fired rounds from the chambers. Unlike the gun of FIG. 1, however, the breech cylinders 214 in the rotary barrel gun 200 are driven continuously in rotation, even during firing, by a motor 232 at the breech end of the primary breech frame 204. Also unlike the gun of FIG. 1, the barrels 226 in the gun 200 rotate with the cylinders.

The rotary barrel gun 200 fires primary open chamber ammunition rounds 236 which, like the primary rounds 32 fired in the gun of FIG. 1, have an electrical primer. The gun 200 fires booster ammunition rounds 238 which are identical to the booster rounds 42 which are fired in the gun of FIG. 1. Gun 200 has an electrical firing means 240' for firing each primary round in firing position.

The rotary barrel hypervelocity gun 200' of the invention operates in much the same way as the fixed barrel gun of FIG. 1. Thus, during unified rotation of the primary and secondary breech cylinders 214 of the gun 200 by the cylinder drive motor 232, the primary and secondary firing chambers 218 rotate in succession through their infeed, firing, and ejection positions. As the corresponding firing chambers rotate through infeed position, they receive primary and booster ammunition rounds 236, 238, respectively, from the ammunition infeed means 234. During subsequent rotation of the chambers through firing position, the primary round is fired by the electrical firing means 240. The projectile of the round is thereby propelled forwardly through the corresponding gun bore 228 by the high pressure propellant gas generated in the fired round. The booster propellant charge in the booster ammunition round 238 currently in firing position in the secondary breech mechanism 203 is ignited by this hot propellant gas, in the same manner as explained earlier in connection with FIG. 1, as the advancing projectile travels forwardly though the secondary mechanism. The high pressure propellant gas generated by the booster propellant then enters the corresponding gun bore 228 behind the advancing projectile to accelerate the latter through the bore. The spent cartridge cases of the fired primary and

booster rounds

236, 238 are ejected from the fired chambers during subsequent rotation of the chambers through ejection position. This same firing action or cycle is repeated for each pair of corresponding primary and secondary firing chambers 218 during continuous firing operation of the gun.

It is now evident, therefore, that the rotary barrel hypervelocity gun 200, just described, operates in much the same way as the fixed barrel hypervelocity gun of FIG. 1. The major difference between the two guns, of course, resides in the fact that the primary and secondary breech cylinders 214 and the gun barrels 226 of the gun 200 undergo continuous rotation, even during firing. The primary advantage of this rotary barrel gun construction is its extremely high firing rate. Accordingly, the gun 200- is characterized by both hyper-muzzle velocity and extremely high firing rate.

At this point, it is significant to recall that While the invention has been disclosed in connection with hypervelocity guns having certain specific primary and secondary breech mechanisms, other types of breech mechanisms, such as those referred to earlier, may be employed in the invention. Moreover, a present hypervelocity gun may employ other cylinder drive means, firing means, and ammunition infed means than those shown.

It should also be noted that while the invention has beendisclosed in connection with the firing of cased primary and booster ammunition, the present hypervelocity gun may fire uncased ammunition. In this regard, attention is directed to the earlier mentioned copending application entitled Sealed Open Chamber Breech Mechanism and Caseless Ammunition Therefor, which discloses uncased open chambertarnmunition which may be fired in the primary breech mechanism of the gun. ,The uncased booster ammunition to be fired in the present gun will be like that illustrated in the present drawings, except that the outer cartridge case will be eliminated and replaced by an additional quantity of molded booster propellant. When firing uncased ammunition of this type, of course, the primary and secondary breech mechanisms of the gun will be equipped with suitable obturator means, such as those disclosed in the application, for sealing the breech interfaces against propellant gas leakage. In addition, semicombustible open chamber ammunition of the type disclosed in the aforementioned copending application entitled semicombustibleAmmunition for Open Chamber Breech Mechanism may be fired in the present gun.

While the invention has been disclosed in connection with certain of its physical embodiments, it will be understood that various modifications of the invention are possible within the spirit and scope of the following claims.

The embodiments of the invention in which an exclusive property or privilege is claimed are defined as follows:

1. A hypervelocity gun for firing individual elongate fixed charge primary ammunition rounds of fixed size and shape each containing a primary propellant and a projectile and individual elongate fixed charge booster ammunition rounds of fixed size and shape and containing a booster propellant, comprising:

a barrel having a bore;

a primary breech mechanism at the breech end of said barrel including a breech frame member, a primary ammunition carrier member having a primary firing chamber for receiving said primary ammunition rounds in succession, means supporting said carrier member on said frame member for movement of said firing chamber with said carrier member along a prescribed path of motion and through an ammunition infeed position wherein said firing chamber is disposed to receive a primary ammunition round to be fired, a primary firing position wherein said firing chamber locates its contained primary round in firing relation to the breech end of said bore to permit firing of the contained round in said firing chamber, and an ejection position;

a secondary breech mechanism along said barrel at a booster station forwardly of said primary breech mechanism including a secondary breech frame member, a secondary ammunition carrier member containing at least one secondary firing chamber for receiving said booster ammunition rounds in succession, means supporting said secondary carrier member on said secondary frame member for movement of said secondary firing chamber with said secondary carrier member along a prescribed path of motion and through an ammunition infeed position wherein said secondary firing chamber is disposed to receive a booster ammunition round to be fired, a firing position wherein said secondary firing chamber locates the booster propellant of its contained booster round in ignition relation to said bore, and an ejection position; and

means for driving said carrier members in timed relation to locate a booster ammunition round in secondary firing position concurrently with location of each primary ammunition round in primary firing position, whereby when a primary ammunition round is fired in primary firing position, the projectile of the fired primary round is propelled forwardly through said bore by the high pressure propellant gas generated by the fired primary round, and the booster propellant of the booster round in secondary firing position is ignited by said propellant gas upon forward travel of the advancing projectile through said booster station, thereby to generate additional high pressure propellant gas which enters said bore behind the advancing projectile for accelerating the latter through said bore.

2. A hypervelocity gun according to claim 1,wherein:

said carrier driving means comprise means for driving said carrier members in timed relation to said infeed, firing, and ejection positions.

3. A hypervelocity gun comprising:

a barrel containing a bore;

a primary breech mechanism at the breech end of said barrel;

a secondary breech mechanism along said barrel forwardly of said primary breech mechanism;

each of said breech mechanisms including a breech frame containing a chamber and an ammunition infeed opening to said chamber, and an ammunition carrier supported on said frame within said chamber for rotation on an axis parallel to and laterally spaced from said bore;

the carrier of said primary breech mechanism containing a primary firing chamber and being rotatable to locate said primary firing chamber in an ammunition infeed position wherein said primary firing chamber registers with the infeed opening in the primary breech frame, and a firing position wherein said primary firing chamber is coaxially aligned with and opens forwardly to the breech end of said bore;

the carrier of said secondary breech mechansm containing a secondary firing chamber and being rotatable to locate said secondary firing chamber in an ammunition infeed position wherein said secondary firing chamber registers with the infeed opening in the secondary breech frame, and a firing position wherein said secondary firing chamber is coaxially aligned with and opens forwardly and rearwardly to said gun bore; and

means for driving said carriers in rotation to simultaneously locate said primary and secondary firing chambers in their respective firing positions.

4. A hypervelocity gun according to claim 3, wherein:

said barrel is secured to and remains stationary with the frames of said breech mechanisms; and

said carriers are driven in intermittent rotation in such a way that said firing chambers are momentarily arrested in firing position.

5. A hypervelocity gun according to claim 3, wherein:

said barrel is secured to said carriers in coaxial alignment with said firing chambers and rotates with said carriers; and

said barrel and carriers are driven in continuous rotation.

6. A hypervelocity gun, according to claim 3, wherein:

at least one of said breech mechanisms comprises an open chamber breech mechanism; and

the firing chamber of said open chamber breech mechanism opens laterally through the circumference of the respective carrier.

7. A hypervelocity gun according to claim 3, wherein:

one of said breech mechanisms comprises a closed chamber breech mechanism; and

said firing chamber of said colsed chamber mechanism is closed about its entire circumference and opens axially through one end of the respective carrier.

8. An open chamber hypervelocity gun comprising:

a barrel containing a bore;

a primary open chamber breech mechanism at the breech end of said barrel;

a secondary open chamber breech mechanism along said barrel forwardly of said primary breech mechanrsm;

each of said breech mechanism including a breech frame containing a chamber and a lateral ammunition infeed opening to said chamber, and an open chamber cylinder supported on said frame within said chamber for rotation on an axis parallel to and laterally spaced from said bore;

the cylinder of said primary breech mechanism containing a primary firing chamber opening laterally through the circumference and longitudinally through the front end of the primary cylinder and being rotatable to locate said primary firing chamber in an ammunition infeed position wherein the open side of said primary firing chamber registers with the infeed opening in the primary breech frame, and a firing position wherein the open side of said primary firing chamber is closed by the primary breech frame and the primary firing chamber opens forwardly to the breech end of said bore;

the cylinder of said secondary breech mechanism containing a secondary firing chamber opening laterally through the circumference and longitudinally through the front and rear ends of the secondary cylinder and being rotatable to locate said secondary firing chamber in an ammunition infeed position wherein the open side of said secondary firing chamber registers with the infeed opening in the secondary frame and a firing position wherein the open side of said secondary firing chamber is closed by the secondary breech frame and said secondary firing chamber is coaxially aligned with and opens forwardly and rearwardly to said gun bore;

means for driving one cylinder in rotation to locate the corresponding firing chamber in infeed and firing position; and

means drivably coupling said primary and secondary cylinders for rotation of said cylinders in unison to simultaneously locate said primary and secondary firing chambers in their respective infeed and firing positions.

9. An open chamber gun according to claim 8, wheresaid cylinders have a common axis of rotation; and

said coupling means comprise a shaft extending between and coaxially secured to said cylinders.

10. A hypervelocity gun comprising:

a barrel containing a bore;

a primary breech mechanism at the breech end of said barrel;

each of said breech mechanisms including a breech frame containing a breech chamber and an ammunition infeed opening to said chamber, and an ammunition carrier supported on said frame within said chamber for rotation on an axis parallel to and laterally spaced from said bore;

the carrier of said secondary breech mechanism containing a secondary firing chamber and being rotatable to locate said secondary firing chamber in an ammunition infeed position wherein said secondary firing chamber registers with the infeed opening in the secondary breech frame, and a firing position wherein said secondary firing chamber communicates laterally with said bore through ports in the wall of said bore; and

means for driving said carriers in rotation to simultaneously locate said firing chambers in their respective firing positions.

11. An open chamber gun according to claim 10,

wherein:

said carriers rotate on spaced parallel axes; and

said coupling means comprise meshing gears secured to said carriers, respectively.

12. An open chamber gun according to claim 10,

wherein 13. A hypervelocity gun according to claim 12, wheresaid primary breech mechanism comprises a closed chamber breech mechanism wherein the corresponding carrier is a revolver cylinder and the corresponding firing is circular in cross-section in planes normal to the axis of said cylinder and opens through the ends of said cylinder.

14. A hypervelocity gun comprising:

a barrel containing a bore;

a primary breech mechanism at the breech end of said barrel;

each of said breech mechanisms including a breech frame containing a chamber and an ammunition infeed opening to said chamber, and a cylinder supported on said frame within said chamber for rotation on an axis parallel to and laterally spaced from said bore;

the cylinder of .said primary breech mechanism containing a number of uniformly spaced primary firing chambers and being rotatable to locate each primary firing chamber in an ammunition infeed position wherein the respective primary firing chamber registers with the infeed opening in the primary breech frame, and a firing position wherein the respective primary firing chamberis coaxially aligned with and opens forwardly to the breech end of said bore; and

the cylinder of said secondary breech mechanism containing a number of uniformly spaced secondary firing chambers and being rotatable to locate each secondary firing chamber in an ammunition infeed position wherein the respective secondary firing chamber registers with the infeed opening in the secondary breech frame, and a firing position wherein the respective secondary firing chamber opens to said bore.

15. A hypervelocity gun according to claim 14, whereat least one of said breech mechanisms comprises an open chamber breech mechanism; and the firing chambers of said open chamber breech 1 7 mechanism open laterally through the circumference of the corresponding cylinder.

16. A hypervelocity gun according to claim 14, whereeach of said breech mechanisms comprises an open chamber breech mechanism; and

the firing chambers of each breech mechanism open laterally through the circumference of the corresponding cylinder.

17. A hypervelocity gun according to claim 14, whereone of said breech mechanisms comprises a closed chamber breech mechanism; and

the cylinder of said closed chamber breech mechanism comprises a revolver cylinder, the firing chambers of said closed chamber breech mechanism are circular in cross-section in planes normal to the cylinder axis and open through the ends of said revolver cylinder.

18. In combination:

a hypervelocity gun including a barrel containing a bore, a primary breech mechanism at the breech end of said barrel including a primary firing chamber, located in a primary firing position wherein said chamber is coaxially aligned with and opens forwardly to said bore, and a secondary breech mechanism along said barrel at a booster station forwardly of said primary breech mechanism including a secondary firing chamber located in a secondary firing position wherein said secondary chamber is coaxially aligned with and opens forwardly and rearwardly to said bore;

a primary ammunition round within said primary firing chamber including a projectile and a primary propellant adapted to be ignited to generate a high pressure propellant gas for propelling said projectile forwardly through said bore;

a unitary fixed charge booster ammunition round within said secondary firing chamber including a central perforated tube coaxially aligned with said bore and containing a central passage of approximately the same diameter as and opening forwardly and rearwardly to said bore so as to form a continuation of said bore, a booster propellant surrounding said tube, and said tube having ports through which said booster propellant is disposed in ignition relation to said bore, whereby when said primary round is fired said projectile travels forwardly through said tube to expose said booster propellant to the propellant gas behind the advancing projectile and thereby effect ignition of said booster propellant to generate additional high pressure propellant gas which enters said bore behind said projectile to accelerate the latter through said bore; and

said breech mechanisms including means for emptying and reloading said firing chambers.

19. A hypervelocity gun for firing individual elongate fixed charge primary ammunition rounds of fixed size and shape each containing a primary propellant charge and a projectile and individual elongate fixed charge booster ammunition rounds of fixed size and shape each containing a booster propellant, comprising:

a barrel containing a bore;

a primary breech mechanism at the breech end of said barrel including means for transporting said primary ammunition rounds in succession to a primary firing position wherein each primary round is coaxially aligned with said bore;

a secondary breech mechanism along said barrel at a booster station forwardly of said primary breech mechanism including means for transporting said booster ammunition rounds in succession to a secondary firing position wherein the booster propellant within each booster round is disposed in ignition relation to said bore at said booster station, whereby when a primary round is fired in said primary firing position with a booster round in said secondary firing position, the projectile of the fired primary round is propelled forwardly through said bore by the high pressure propellant gas generated by the fired primary round and the booster propellant within the booster round currently in said secondary firing position is ignited by said gas upon forward travel of the advancing projectile through said booster station to generate additional high pressure propellant gas which enters said bore behind the advancing projectile for accelerating the latter through said bore; and

means for driving said primary and secondary ammunition transport means in timed relation to simultaneously locate primary and secondary rounds in firing position.

20. A hypervelocity gun comprising: a barrel containing a bore; a primary breech mechanism at the breech end of said barrel;

a secondary breech mechanism along said barrel forwardly of said primary breech mechanism; each of said breech mechanisms including an ammunition carrier;

the carrier of said primary breech mechanism containing a primary firing chamber and being movable to locate said primary chamber in an ammunition infeed position and a firing position;

the carrier of said secondary breech mechanism confiring position; means for driving said carriers in timed relation to simultaneously locate said firing chambers in firing position; and

means for operating said driving means and firing means in timed relation in such manner as to actuate said firing means in response to arrival of said firing chambers in firing position.

References Cited UNITED STATES PATENTS McArthur 89-8 Stafford 89-8 Stanley 89-8 Schwager et al 89-155 Dardick 42-395 Treat 89-7 SAMUEL W. ENGLE, Primary Examiner US. Cl. X.R.