US3492913A

US3492913A - Open chamber gun ammunition feed system

Info

Publication number: US3492913A
Application number: US712214A
Authority: US
Inventors: Michael J Barnard
Original assignee: TRW Inc
Current assignee: Northrop Grumman Space and Mission Systems Corp
Priority date: 1968-03-11
Filing date: 1968-03-11
Publication date: 1970-02-03
Anticipated expiration: 1987-02-03

Description

Feb. 3., 1970 MQJ. BARNARD 3,492,913

OPEN CHAMBER GUN AMMUNITION FEED SYSTEM Filed March 11, 1968 3 Sheets-Sheet 1 El 2ML i4/cuasi. J2 .Bmeunnp Feb, 3, 1970 M. J. BARNARD 3,492,913

OPEN CHAMBER GUN AMMUNITI'ON FEED SYSTEM Filed March 1l, 1968 3 Sheets-Sheet 2 34N. *L 55s-'5 im() l Feb. 3., 1970 J. BARNRD 3,492,913

OPEN CHAMBER GUN AMMUNITION FEED SYSTEM Filed March 11, 1968 5 Sheets-Sheet 3 United States Patent O 3,492,913 OPEN 'CHAMBER GUN AMMUNITION FEED SYSTEM Michael J. Barnard, Torrance, Calif., assignor to I'RW Inc., Redondo Beach, Calif., a corporation of h10 Filed Mar. 11, 1968, Ser. No. 712,214 Int. Cl. F41d 9/06 U.S. 'Cl. 89-33 11 Claims ABSTRACT 0F THE DISCLOSURE An open chamber gun system having `ammunition infeed means, an open chamber gun with a rotary ammunition cylinder, and a transfer means for receiving open chamber ammunition rounds laterally in succession from the infeed means and transferring the rounds laterally in succession into the cylinder firing chambers. The rounds are releasably secured to a belt which is fed endwise through a transfer station where the rounds are stripped from the belt as they enter the firing chambers.

BACKGROUND OF THE INVENTION Field of the invention The invention relates generally to guns and more particularly to a novel open chamber gun system.

Prior Art Open chamber guns are known in the art. Such guns, for example, are disclosed in prior art Patent Numbers 2,865,126; 2,847,784; 2,983,223; 2,831,401; 3,041,939; and 3,046,890. Generally speaking, an open chamber gun is characterized by a breech frame having a ring strap and containing a rotary breech cylinder. This breech cylinder has a number of ii'ring chambers circumferentially spaced about and opening laterally through the cirmumference of the cylinder. During operation of the gun, the cylinder is driven in rotation to rotate the firing chambers in succession through ammunition infeed, tiring, and ejection positions. The open side of each firing chamber, when in infeed position, registers with a lateral ammunition infeed opening in the breech frame to permit lateral infeed movement of an ammunition round into the chamber. When in ring position. the open side of each firing chamber is closed by the breech frame firing strap, to condition the gun for firing of an ammunition round in the chamber. The open side of each firing chamber, when in ejection position, lregisters with a lateral ejection opening in the breech frame to permit lateral ejection of the spent cartridge case of a fired round, as well as an unred round, from the chamber. A characteristic feature of the open chamber guns disclosed in the aforementioned prior art patents resides in the complementary, generally triangular round shapes of the firing chambers and ammunition rounds. In this regard, it will be observed in the patent -drawings that each firing chamber and ammunition round has a generally triangular round shape in transverse cross-section, such that an ammunition round positioned in a firing chamber has one curved side exposed at the open side of the firing chamber. At least this exposed side of each round has substantially the same radius of curvature as the breech cylinder and is substantially ush with the cylinder circumference. The ring chambers and ammunition rounds may have either a generally equilateral triangular round shape, in which case, all three sides of each round and the two sides of each ring chamber have the same radius of curvature as the :breech cylinder, or a4 generally isosceles triangular round shape, in which case only the exposed side of each round has the same radius of curvature as the breech 3,492,913 Patented Feb. 3, 1970 cylinder. With this latter configuration, the two remaining side of each round and the two side Walls of each firing chamber have a common radius of curvature which differs from that of the cylinder. An open chamber gun may embody either a xed barrel or a rotary barrel construction. A xed barrel open chamber gun is one in which the gun barrel or barrels are secured to and remain stationary with the breech frame. During firing operation of such a fixed |barrel gun, the breech cylinder is driven in intermittent rotation in such a way that each cylinder tiring chamber is momentarily arrested in firing position, and a round is fired in the chamber while the latter remains stationary in this position. A rotary barrel open chamber gun, on the other hand, has a number of gun barrels which are secured to the breech cylinder, in coaxial alignment with its firing chambers, respectively, and rotate with the cylinder. During ring operation of such a rotary barrel gun, the breech cylinder and barrels are driven in continuous rotation, and an ammunition round is fired in each chamber during rotation of the latter through its ring position. The earlier mentioned Patent Number 3,041,939 discloses a rotary barrel open chamber gun. The remaining patents disclose xed barrel open chamber guns. As is well known to those versed in the art, a major advantage of a rotary barrel gun over a fixed barrel gun resides in the higher ring rate `of the rotary barrel gun. It will become evident as the description proceeds that the present invention may be utilized to advantage in connection with both fixed barrel and rotary barrel open chamber guns. However, the invention is particularly concerned with and will be disclosed in connection with its application to a rotary barrel open chamber gun.

Briefly, during firing operation of an open chamber gun, the open chamber ammunition rounds are fed laterally to the breech cylinder in such a way that each round undergoes lateral infeed movement into a cylinder firing chamber in infeed position, through the open side of the chamber. The round then rotates laterally with its containing chamber to firing position, where the round is red. After ring, the spent cartridge case of the round is rotated laterally to ejection position and ejected laterally from the firing chamber through the open side of the chamber.

The aforementioned prior art patents disclose various ammunition feed mechanisms for feeding open chamber ammunition rounds to the open chamber gun cylinders. These existing ammunition feed mechanisms, while capable of employment in relatively low firing rate guns, are ill-suited to or incapable of employment in high filing rate guns. In this connection it should be noted that a high firing rate open chamber gun, in the present context, is one which involves an ammunition infeed rate on the order of 36,000 rounds per minute into the firing chambers of a rotating breech cylinder whose rim velocity is on the order of 33 feet per minute. The stringent requirements imposed by these operating parameters on an ammunition feed mechanism are obvious and, as already noted, are incapable of satisfaction by the existing ammunition feed mechanisms.

SUMMARY OF THE INVENTION The present invention provides a novel open chamber gun system of the class described. A particularly unique and important advantage of this system resides in its high firing rate capability. In this regard, it will become evident as the description proceeds that the invention is particularly adapted for embodiment in a high firing rate, rotary barrel open chamber gun of the kind discussed above. It will be recognized by those versed in the art as the description proceeds, however, that while the present gun system possesses the inherent and advantageous capability of high firing rate, it is not limited in usefulness to high tiring rate applications.

`In general terms, the present gun system is characterized by an open chamber gun and an ammunition feed mechanism for feeding open chamber rounds in succession to the firing chambers in the gun cylinder. According to one feature of the invention, the feed mechanism embodies an ammunition infeed means for conveying the rounds in succession along a prescribed path of motion from an ammunition storage facility, such as an article storage magazine, to an infeed transfer station, and an ammunition transfer means for receiving the rounds in succession from the infeed means at the infeed transfer station, transporting the rounds in succession to an outfeed transfer station with the rounds disposed in predetermined spaced and oriented relation to their direction line of movement between the Stations, and dispensing the rounds in succession to the gun cylinder at the outfeed station in the proper timed relation to the cylinder rotation and proper attitude to enter the cylinder ring chambers. In the particular embodiment of the invention which has been selected for illustration in this disclosure the transfer means is a rotary transfer wheel having axially extending ammunition receiving pockets which are spaced circumferentially about and open laterally through the circumference of the wheel in such a way that each pocket is conditioned to laterally receive an ammunition round through its open side from the infeed means and to position the contained round parallel to the transfer wheel axis. The transfer wheel and breech cylinder are generally tangently disposed at the outfeed transfer station and are driven in unison in such a way that the ammunition rounds are transferred laterally in succession from the transfer wheel into the cylinder firing chambers, through the open sides of these chambers.

As will appear from the ensuing description, the ammunition feed mechanism of the invention may be employed to handle and feed unattached or beltless ammunition rounds, which are not joined to one another in any way. A further aspect of the invention, however, is concerned with a unique web or belt-type ammunition feeding and dispensing mechanism for the present open chamber gun system. According to this inventive aspect, the ammunition rounds are adhesively bonded or otherwise releasably secured to one side of a conveyor web or belt which is trained about the transfer wheel in such a way that the rounds engage driving lugs on the wheel. Rotation of the transfer wheel drives the rounds and belt through the feed system to the gun. This belt-type feeding and dispensing mechanism serves both as a transport mechanism for transporting ammunition rounds laterally in succession from an ammunition magazine to the breech cylinder of the open chamber gun, and as an ammunition transfer mechanism for positively timing and orienting the incoming rounds for proper entrance into the breech firing chambers. The conveyor web or belt is stripped from each ammunition round as the latter enters its ring chamber, thus to release the round from the web for rotation with its containing tiring chamber to firing position.

BRIEF DESCRIPTION OF THE DRAWINGS In the drawings:

FIG. 1 is a side elevation of an open chamber gun system according to the invention, which, in this instance, consists of a rotary barrel open chamber gun and an ammunition feed system for feeding open chamber ammunition rounds to the gun;

FIG. 2 is an enlarged section taken on line 2-2 in FIG. 1;

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

FIG. 4 is a section taken on line 4-4 in FIG. 3;

FIG. 5 is a section taken on line 5-5 in FIG. 3; and

FIG. 6 is a section taken on line 6-6 in F-IG. 2.

4 DESCRIPTION OF THE PREFERRED EMBODIMENT In general terms, the invention provides an open chamber gun system 10, including an open chamber gun 34 having a rotary open chamber cylinder, and an ammunition feeding and dispensing mechanism 14 for transporting or feeding open chamber ammunition rounds 16 in succession from an ammunition storage facility 17 to the cylinder and dispensing the round in succession to the cylinder in such a way that the rounds are presented to the cylinder in accurately timed relation to the rotation of the cylinder with each round oriented in a predetermined attitude relative to the cylinder. The ammunition feeding and dispensing mechanism 14 illustrated, which will be enceforth referred to simply as a feed mechanism, comprises an infeed means 18 and a transfer means 20. The infeed means 18 conveys the rounds 16 in succession along a prescribed path of movement to an infeed transfer station Si. The transfer means 20 includes a driven transfer mechanism 22, in this instance a transfer wheel, having ammunition receiving means 24 which are movable through the infeed transfer station in succession. The transfer mechanism receives the rounds 16 in succession from the infeed means 18 at the infeed transfer station and transports the rounds to an outfeed transfer station So. Located at the outfeed transfer station is a transfer guide 26 for effecting outfeed transfer movement of each round 16 from the transfer mechanism to the gun cylinder 12 as the round travels through the outfeed station. Drive means 28 are provided for driving the cylinder 12 and the transfer mechanism 22 in synchronism. The ammunition receiving means 24 of the transfer mechanism are arranged to locate the rounds 16 in accurately spaced relation along and in a predetermined attitude relative to their direction line of movement from the infeed station S1 to the outfeed station So. As will appear presently, the motions of the gun cylinder 12 and the transfer mechanism 22 are so timed, and the rounds 16 on the transfer mechanism are so spaced and oriented, that the rounds are presented or transferred to the cylinder at the outfeed transfer station S0 in accurately timed relation to the cylinder rotation with the rounds disposed in a predetermined attitude relative to the direction line of movement of the cylinder through the outfeed station. The gun cylinder 12 has a number of firing chambers 30 spaced circumferentially about and opening laterally through the circumference of the cylinder. The rounds 16 are transferred laterally to the cylinder in such manner that each undergoes lateral infeed movement into a cylinder chamber 30 through the open side of the chamber as the latter rotates through the outfeed transfer station So.

As noted earlier, a further important aspect of the present invention is concerned with a unique web or belt-type article feeding and dispensing means for the ammunition rounds 16. According to this aspect of the invention, the rounds are releasably secured in spaced relation to a conveyor web 32 which which is trained about the transfer Wheel 22. As each round approaches the outfeed transfer station So, it is directed along a path of movement which diverges from the path of web movement through the station in such a way that the round is stripped from the web. According to the preferred practice of the invention, the rounds are releasably secured to the web by an adhesive bond having a sufiiciently high shear strength to effect transfer of the driving forces from the rounds to the web and a sufficiently low peel strength to permit stripping the rounds from the web.

Briefly, in operation of the open chamber gun system 10, the gun cylinder 12 and transfer wheel 22 are driven in synchronism to drive the conveyor web 32 endwise through the infeed means 18 to the infeed transfer station Si. At this station, the rounds 16 and conveyor web pass from the infeed means to the transfer wheel and travel with this wheel from the latter station to the outfeed transfer station S0. During their transfer movement from the infeed means to the transfer wheel, the rounds enter the ammunition receiving means 24 on the transfer wheel and are thereby drivably engaged with the wheel as well as accurately spaced and oriented relative to their path of motion on the wheel. As each round 16 approaches the outfeed transfer station S0, the round engages the transfer guide 26. This transfer guide directs each round along a path of movement which diverges from the path of movement of the conveyor web 32 and merges with the path of movement of the gun cylinder chambers 30 in such a way that each round is stripped from the web and simultaneously undergoes outfeed transfer movement from the transfer wheel into a cylinder chamber.

The particular open chamber gun shown is a high firing rate, rotary barrel gun of the kind referred to earlier. The illustrated open chamber gun has a breech frame 36 in which` the breech cylinder 12 is rotatably mounted by front and

rear bearings

38, 40. The cylinder chambers 30 constitute firing chambers. As already noted and illustrated in the drawings, these firing chambers are circumferentially spaced about and open laterally through the circumference of the cylinder. The front end of the breech cylinder 12 projects forwardly through an opening in and is exposed at the front end of the breech frame 36. Secured to and extending forwardly from the front end of the cylinder are a number of gun barrels 42. These barrels are equal in number to and are coaxially aligned with the iiring chambers 30. Each barrel contains a bore which opens rearwardly to the corresponding firing chamber. It is evident at this point, therefore, that the breech cylinder 12 and barrels 42 rotate in unison.

It will be recalled that the present gun system embodies a drive means 28. In this instance, the drive means comprise a motor 46 mounted on the rear end of the breech frame 36. The shaft of this motor is coupled to the rear end of the breech cylinder 12 for driving the cylinder in rotation in a counterclockwise direction, as viewed in FIG. 2. Then the breech cylinder is thus driven, each cylinder firing chamber undergoes rotation through infeed, firing and ejection positions in sequence. When in infeed position, the open side of each firing chamber registers with an ammunition infeed opening 48 in the breech frame 36. This infeed opening is located at and faces the outfeed transfer station So of the article transfer means 20. When in firing position, the open side of each firing chamber is closed by the breech frame firing strap 50 to condition the gun for firing an ammunition round in the chamber. The gun is equipped with firing means (not shown) for firing a round in each firing chamber 30 during rotation of the latter through its firing position. When in ejection position, the open side of each firing chamber registers with an ejection chute 52 on the breech frame 36.

The illustrated ammunition rounds 16 comprise open chamber ammunition rounds to be fired in the open chamber gun 34. These ammunition rounds are conventional and, accordingly, need not be described in detail. Suffice it to say that each ammunition round has a generally triangular round shape in transverse cross-section. In this instance, the ammunition has a generally equilateral triangular round shape similar to that disclosed in the majority of the aforementioned prior art patents. Each side of a round has a radius of curvature substantially equal to the radius of the breech cylinder 12. The cylinder firing chambers 30 also have a generally triangular round shape in transverse cross-section and are sized to complement the ammunition rounds 16 in such a way that when a round is positioned in a firing chamber, the exposed side of the round is substantially flush with the cylinder circumference.

The ammunition rounds 16 are adhesively bonded to one side of the conveyor web 32, which thus serves as an ammunition belt. This belt may comprise various materials but is preferably a Mylar tape. As shown best in FIG. 2, the ammunition rounds 16 are secured to the belt 32 at spaced intervals with the longitudinal axis of each round extending normal to the length of the belt. The center distance between adjacent ammunition rounds is approximately equal to the circumferential spacing between the adjacent cylinder firing chambers 30. As may be best observed in FIG. 3, the ammunition rounds 16 have a length somewhat greater than the width of the belt 32 and are centered endwise relative to the belt, whereby the ends of each round project a distance beyond the longitudinal edges of the belt.

We turn now to the ammunition feed mechanism 14. The transfer mechanism or wheel 22 of this ammunition feed mechanism has a generally cylindrical drum 54 closed at one end by an integral end wall 56 and a shaft 58 integrally joined to and extending coaxially from the end wall. This shaft has a bearing shoulder 60 adjacent the end wall and an outer splined end 62. The end of the transfer wheel drum S4 remote from the end wall 56 is open.

Transfer wheel 22 is located directly opposite the ammunition infeed opening 48 in the breech rframe 36 of the open chamber gun 34. The axis of this transfer wheel parallels the axis of the breech cylinder 12. The circumference of the transfer wheel is disposed in close proximity to the circumference of the cylinder and the adjacent curved face of the firing strap 50. Extending laterally from the breech frame 36, at the -front and rear ends of the transfer wheel 22 are a pair of front and rear transfer

wheel mounting brackets

64, 66. The transfer wheel shaft 58 extends through the rear mounting bracket 66 and is rotatably supported in this bracket by a bearing 68, the inner face of which is secured to the shaft bearing shoulder 60. Concentrically positioned within the transfer wheel drum 54 is a generally cylindrical cam assembly 70 whose function will be explained presently. Suffice it to say at this point that the cam assembly 70 includes an inner supporting member 72 having a central bearing shoulder 74 and integral front and

rear shafts

76, 78 extending coaxially from opposite sides of the shoulder. The front shaft 76 extends through the front transfer wheel supporting bracket 64 and is threaded to receive a nut 80 for rigidly securing the supporting member 72 to the bracket. The bearing shoulder 74 of the supporting member 72 is positioned within the front end of the transfer wheel drum 54, and the rear shaft 78 of the member extends centrally through the drum into a blind bore in its rear end wall 56. Mounted on the bearing shoulder and the rear end of the shaft are

bearings

82, 84 which rotatably support the transfer wheel on the supporting member 72. The transfer wheel 22 is thus supported on the breech frame 36 lfor rotation on an axis parallel to the breech cylinder 12.

It will be recalled that the transfer wheel 22 is driven in synchronism with the breech cylinder 12 by the drive means 28. To this end, the drive means comprises a drive gear 86 which is coaxially keyed on the rear end of the cylinder so as to rotate with the latter when the cylinder is driven -by its motor 46. Rotatably supported on the transfer wheel shaft 58, between its bearing shoulder 60 and splined end 62, is a driven gear 88 which meshes with the drive gear 86. The splined end 62 of the shaft slidably mounts a drive dog or clutch collar having internal splines which mesh with the shaft splines to restrain the collar and shaft against relative rotation. Clutch collar 90 is movable axially of the transfer wheel shaft 58 between a left-hand or forward transfer wheel drive position and a right-hand or rear transfer wheel lock position in FIG. 3. Integrally formed on the confronting ends of the driven gear 88 and the clutch collar 90 are clutch drive teeth 92 which interengage to drivably couple the gear to the transfer wheel 22 when the collar occupies its forward drive position. Rigidly secured to the rear end of the breech frame 36, rearwardly of the clutch collar 90, is a mounting plate 94 to which the breech cylinder drive motor 46 is attached. On the front surface of this plate and the rear face of the clutch collar 90 are clutch lock teeth 96 which interengage to lock the transfer wheel against rotation when the clutch collar occupies its rear lock position. It is evident at this point that the breech cylinder 12 is driven continuously in rotation whenever its drive motor 46 is energized. The transfer wheel 22, on the other hand, is adapted to be selectively coupled to the drive motor for rotation in synchronism with the breech cylinder and locked against rotation while the breech cylinder continues to turn by shifting of the clutch collar 90 between its drive and lock positions.

Clutch collar 90 is shifted back and forth between its drive and lock position by a clutch collar actuating means 9S. In this instance, the actuating means comprises an electrical solenoid 100 mounted on the breech frame 36 adjacent the clutch collar. Pivotally mounted intermediate its ends on a pin 101 secured to the frame in the region between the clutch collar 98 and the solenoid 101') is a collar actuating lever 102. One end of this lever is shaped to provide a fork 104 which straddles the collar within an external groove 106 extending circumferentially about the collar. The opposite end of the lever 102. is pivotally attached to the solenoid plunger S. Embodied in the solenoid 100 are means, such as a spring, for axially urging the solenoid plunger 108 in a direction to shift the clutch collar 90 to its transfer wheel locking position when the solenoid is de-energized. Energizing of the solenoid drives the plunger in the opposite direction to shift the clutch collar to its transfer wheel driving position.

It will be recalled that in addition to the ammunition transfer means 20, the ammunition feed mechanism 14 includes an ammunition infeed means 18 for conveying the ammunition rounds 16 in succession to the infeed transfer station Si of the transfer means. Referring to FIG. 2, it will be observed that this infeed station is located generally diametrically across the transfer wheel 22 from the outfeed transfer station S0. The illustrated ammunition infeed means 18 includes an ammunition infeed guide 110 having rigid -walls defining an interior infeed guide passage 112 of rectangular cross-section. The infeed guide is rigidly secured to the breech frame 36 in such a way that the outfeed end of the interior guide passage opens to the infeed transfer station Si in the direction of rotation of the transfer wheel 22 through this station and in general tangential relation to the drum. Extending circumferentially about the transfer wheel drum 54 in radially spaced relation thereto and in the direction of rotation thereof, from the outfeed end of the infeed guide 110 to the breech frame 36 of the gun 34 is a curved ammunition retaining guide 114. This retaining guide is rigidly joined to the infeed guide and breech frame and is cylindrically curved about the rotation axis of the transfer wheel 22. Along the longitudinal edges of the retaining guide 114 are ammunition retaining flanges 116 which extend inwardly toward the axis in endwise straddling relation to the transfer wheel drum 54.

The infeed guide 110 is connected, either directly or through an intervening feed chute (not shown), to the ammunition magazine 17 or the like for containing a supply of the ammunition rounds 16. The interior passages within the feed chute and/or infeed guide 110, as the case may be, are sized to slidably receive the ammunition rounds 16 with the axes of the rounds extending normal to the length of the passages. It will be understood, therefore, that these passages are sized to permit lateral movement of the rounds to the infeed transfer position S1 of the transfer wheel 22.

As will be described in greater detail presently, the ammunition rounds 16 move laterally in succession from the infeed guide 110 to the ammunition transfer wheel 22 and are then conveyed or transported by this wheel from the infeed transfer position Si to the outfeed transfer position So. In this regard, it will be recalled that the transfer wheel is equipped with article receiving means 24 into which the ammunition rounds enter in succession at the infeed station. These article receiving means serve to drive the rounds with the transfer wheel as well as to accurately space the rounds along and orient the rounds in a predetermined attitude relative to their direction line of movement with the transfer wheel. In this instance, the article receiving means comprise ammunition receiving pockets 118 which are spaced circumferentially about and open laterally through the circumference o-f the transfer wheel and are defined by a number of circumferentially spaced, ammunition drive pawls 120 carried by the wheel. The several drive pawls 120 are arranged in pairs 120H. AS shown best in FIG. 3, the two pawls of each pair are aligned lengthwise of and located adjacent opposite ends of the transfer wheel drum 54. The several pawl pairs are uniformly circumferentially spaced about the drum.

The several drive pawls 120 at each end of the transfer wheel drum 54 are identical and the two pawls of each pawl pair are mirror images of one another. Accordingly, the same description will apply, with certain hereinafter noted minor exceptions to all of the pawls With this in mind, each drive pawl will be seen to have a generally L-shape and to comprise a pair of arms 1200, 120i which are joined end-to-end in generally mutually perpendicular' relation. For reasons which will appear as this description proceeds, the two arms 1200, 120i of each pawl are hereinafter referred to as outer and inner arms, repsectively. Integrally formed on and extending inwardly from the inner edge of the outer arm 120o of each pawl, adjacent the free end of this arm, is an apertured lug 122. This lug has the same thickness as and is disposed in the common plane of the arms. The free end of each outer pawl arm 1200, beyond its lug 122, is contoured to define a concave ammunition seating face 124. The inner end of the seating face 124 on each pawl merges tangentally with the adjacent edge of the respective lug 122. The outer end of the seating face on each pawl curves outwardly to provide the pawl with a generally tapered and terminally rounded tip 126. Referring to FIG. 3, it will be observed that the two drive pawls 120 in each pawl pair 120a have confronting surfaces. Secured to the free or inner ends of the inner arms 120, of the pawls in each pair are cam followers 128 which project laterally from the confronting surfaces of the pawls. It will now be recognized therefore, that the several ammunition drive pawls 120 are identical except for the fact that the cam followers 128 on the pawls adjacent the front end of the transfer wheel drum 54 project from the rear sides of the pawls, while the cam followers on the rear pawls project from the front sides of the latter pawls.

The transfer wheel drum 54 has a number of circumferential slots 130, one for each of the drive pawls 120. Each slot receives the inner arm 120i and lug 122 of its respective pawl. The pawls are pivotally mounted in their respective transfer wheel slots by pins 132 which are press fitted in the transfer wheel drum and extend across the drum slots 130 and through the apertured pawl lugs 122. The several drive pawls are oriented in the same general position relative to the transfer wheel. In this connection, it will be observed that the lugs 122 and inner arms 120o of the pawls are located within the front and rear ends, respectively, of the respective wheel slots 130, relative to the direction of rotation of the transfer wheel 22. Accordingly, the ammunition seating face 124 of each pawl is located at the leading end of the pawl and faces forwardly relative to the direction of transfer wheel rotation. It is also significant to observe that the arnmunition seating face of each pawl projects beyond the outer surface of the transfer wheel drum 54. The breech cylinder 12, breech frame firing strap 50, and infeed guide have clearances lots 12a, 50a, and l10n, respectively, through which the projecting leading ends of the pawls pass during rotation of the transfer wheel.

As noted earlier, the transfer wheel drum surrounds a cam assembly 70 including an inner xed drum supporting mem-ber 72. In addition to this supporting member, the cam assembly comprises an annular can 134 which surrounds and is keyed to the rear shaft 78 of the supporting member. This lcam is straddled in the endwise direction by the inwardly projecting inner arms 120i of the ammunition drive pawls 120. Machined or otherwise formed in the end faces of the cam 134 are annular cam grooves or tracks 136 which receive the cam followers 128 on the pawls. It is evident from the description thus far, therefore, that when the ammunition transfer wheel 22 is driven in rotation by the breech cylinder drive motor 46, the drive pawl cam followers travel along their respective receiving cam tracks 136. These cam tracks are shaped to pivot or rock the pawls 120 on their respective pivot axes in the manner to be explained presently.

It will be recalled that the ammunition rounds 16 are adhesively bonded to one side of the conveyor web or ammunition belt 32. This belt is trained through the ammunition feed mechanism 14 in the manner best illustrated in IFIGS. 2 and 3. In this regard, it will be observed that the belt extends through the ammunition infeed guide 110 to the infeed transfer station Si, around the transfer wheel drum 54 from the infeed station to the outfeed transfer station S0, and finally emerges through a narrow clearance gap between the drum and the breech frame ring strap 50 of the open chamber gun 32. It is significant to recall here that the ammunition rounds 16 are somewhat longer than the width of the belt 32 and that the ends of the rounds project a distance beyond the longitudinal edges of the belt. In this regard, it will be observed that the width of the belt approximates or is slightly less than the spacing between the ammunition drive pawls 120 in each vof the pawl pairs 120a on the ammunition transfer wheel 22. The length of the ammunition rounds, on the other hand, is somewhat greater than this spacing. According to the present invention, the ammunition belt is trained about the transfer wheel in such a Way that the belt passes between the drive pawls in direct seating contact with the surface of the transfer Wheel drum 54, and the leading ammunition seating faces 124 of the pawls engage the extending ends of the ammunition rounds on the belt. Accordingly, when the transfer wheel 22 is driven in rotation by the breech cylinder drive motor 46, the pawls 120 drive their respective engaged ammunition rounds 16 in rotation with the transfer wheel. The driving forces thus exerted on ammunition rounds are transmitted to the belt 32 and serve to pull the latter, and the incoming ammunition rounds secured thereto, from the ammunition magazine 17 through the infeed guide 110, to the transfer wheel. It will be understood, of course, that the spacing between the rounds approximates the circumferential spacing between the drive pawl ammunition seating faces 124 such that the rounds are properly located on the ammunition belt 32 for driving engagement by the pawls. At this point, it is evident that the articles or ammunition rounds 16, transfer wheel 22, and web or belt 32 together constitute an article transport mechanism for transporting the articles, i.e., ammunition rounds, in the endwise direction of the belt. The transfer wheel functions as a sprocket-like drive wheel for driving the belt endwise. As noted earlier, and hereinafter explained in greater detail, the ammunition rounds are stripped from the belt at the outfeed transfer station So and simultaneously transferred into the firing chambers 30 of the currently rotating breech cylinder 12.

The ammunition feed mechanism 14 is equipped with disposal means 138 for receiving and disposing of the stripped end of the conveyor web or ammunition Fbelt 32 emerging through the narrow gap between the breech frame ring strap 50 and the transfer wheel drum 54 when the open chamber gun 34 is fired. Various disposal means may be utilized for this purpose. In this instance,

the disposal means comprises a disposable takeup reel 140. Referring particularly to FIGS. 2 and 3, it will be Dbserved that the takeup reel is positioned between a pair of integral laterally projecting

lugs

142, 144 on the gun frame 36, just below the ejection chute 52. Mounted on the front lug 142 is a constant torque motor 146 having a shaft 148 which extends rotatably through the lug. The rear projecting end of the shaft is squared and fits slidably within a square socket 150 in the front of the takeup reel 140. Entering the rear end of the reel is a socket 152 which slidably receives the front end of a reel supporting shaft 153. Shaft 153 is supported for rotation and axial movement in the rear frame lug 144. Surrounding the shaft adjacent the reel is an enlarged shoulder 154 which slides within a front counterbore in the lug, as shown. A spring 155 acting between the shoulder and the rear wall of the counterbore urges the shaft 153 forwardly to its position of FIG. 3. In this position, the front end of the shaft lits in the rear reel socket 152 and the shaft shoulder 154 seats against the reel. The takeup reel is then supported lby the motor shaft 148 and shaft 153 with its axis parallel to the rotation axes of the breech cylinder 12 and the transfer wheel 22. The constant torque motor 146, when energized, drives the reel in the clockwise direction in FIG. 2. On the rear end of the reel shaft 153 is a knurled grip 156 by which the shaft may be retracted to release the takeup reel 140 for removal. In this regard, it would be noted that the spacing between the frame lugs 142, 144 is sucient to permit removal and reinsertion of the takeup reel. The hub of the takeup reel has a slot 158 to receive the leading end of the belt 32 for securing the latter to the reel. Rotatably mounted :between the frame lugs, in the region between the transfer wheel 22 and the takeup reel 140, is a roller 160 about which the belt passes from the wheel to the reel as shown.

The operation of the gun system 10iy will now be described. The system is conditioned for firing by initial threading the ammunition belt 32 through the infeed guide 112, around the transfer wheel 22, through the clearance gap between the transfer wheel and the breech frame firing strap 50, and around the roller 160` to the takeup reel 140. The leading end of the belt is then inserted into the reel slot 158 to secure the belt to: the takeup reel. In this regard, it will be understood that the ammunition belt 32 will be provided with a leader portion which may be threaded through the system and secured to the takeup reel, in the manner just explained. When thus threading the ammunition belt through the system, at least the leading ammunition round 16 on the belt is located to be engaged by a pair of the drive pawls 120 on the transfer wheel 22 when the latter is driven in rotation. At this point, the breech cylinder drive motor 46 and the takeup reel drive motor 146 are energized. Motor 46, when energized, drives the breech cylinder 12 in rotation in a counterclockwise direction in FIG. 2. However, assuming that the transfer wheel clutch actuating solenoid 100 is deenergized, the transfer wheel 22 remains stationary so that no ammunition rounds are fed to the cylinder. Under these conditions, the takeup reel 140 remains stationary even though its drive motor 146 is energized. This is due, of course, to the constant torque characteristics of the motor. The gun system 10 is now conditioned for 4tiring operation.

Actual ring operation of the gun system 10 is initiated by energizing the transfer wheel clutch actuating solenoid 100 to effect driving of the ammunition transfer wheel 22 in synchronism with the currently rotatably breech cylinder 12. This rotation of the transfer wheel results in driving engagement of the transfer Wheel pawls 120 with one or more of the leading ammunition rounds 16 on the ammunition belt 32. The ammunition belt and the ammunition rounds attached thereto are thereby driven in the endwise direction of the belt from the ammunition magazine 17, through the infeed guide 112, to the infeed l 1 transfer station Si. At this station, the belt and ammunition rounds enter onto the transfer wheel and travel with the latter from the infeed transfer station to the outfeed transfer station So. As noted earlier and hereinafter explained in detail, the ammunition rounds and ammunition belt are directed along divergent paths as they approach and then travel through the outfeed station. In this regard, it will become evident from the ensuing description that each ammunition round, upon approaching the outfeed station, enters a breech cylinder firing chamber 30 and then travels with the chamber, along its circular direction line of movement, from the outfeed station, through firing position opposite the breech frame firing strap 50, to ejection position opposite the ejection chute 52. The ammunition belt, .on the other hand, follows an exit path from the outfeed transfer station which leads through the narrow exit gap between the transfer wheel and firing strap, then around the idler roller 1601, to the takeup reel 140. This movement of the ammunition round and ammunition belt along divergent paths results in stripping of the rounds from the belt, thus to release the rounds from the belt for firing in the open chamber gun 34. Endwise movement of the stripped end of the ammunition belt along its exit .path permits rotation of the takeup reel 140 by its constant torque drive motor 146, whereby the belt is wound on the reel. Thus, during firing operation of the gun system 10, the ammunition rounds 16 are dispensed or transferred laterally in succession from the ammunition belt 32 to the rotating breech cylinder firing chambers 30, while the ammunition belt is continuously disposed of by winding of the belt on the takeup reel 140. Each ammunition round is fired as it rotates through ring position, after which the spent cartridge case of the round is rotated to ejection position and there ejected through the ejection chute 52. In this connection, attention is directed to FIG. 2, in which it will be observed that the gun 34 is equipped with a pair (only one shown) of cartridge case ejection cams 162. These cams are secured to the breech frame 36, along the trailing edge of the ejection chute 52 relative to the direction of rotation of the breech cylinder 12, and project radially inward into the transfer wheel drive pawl clearance grooves 12a. The leading edges of these cams are disposed at an acute angle relative to the circular direction line of movement of the breech cylinder firing chambers 30. Accordingly, the cams are effective to cam the cartridge cases of the fired ammunition rounds laterally from their containing firing chambers 30 into the ejection chute 52 during rotation of the chambers through ejection position.

At this point, attention is directed to the fact that the breech cylinder 12 and transfer wheel 22 are driven at substantially the same rim velocity. In this regard, it will be observed that the transfer wheel is smaller in diameter than the cylinder and is thus driven at a higher angular velocity than the cylinder. To this end, the transfer wheel drive gears 86, 88 are selected to have the correct ratio to drive the wheel at the same rim speed as the cylinder. Moreover, the numbers and spacings of the cylinder firing chambers 30 and transfer wheel drive pawls 120 and the cylinder and transfer wheel diameters are so related that each ammunition round 16 will arrive at the outfeed transfer station So concurrently with a firing chamber and then undergo lateral infeed movement into the chamber in the manner shown in FIG. 2 as the chamber and round travel in unison through the station.

The above-described firing operation of the gun system continues as long as the transfer wheel clutch actuating solenoid 100 remains energized. De-energizing of this solenoid terminates rotation of the transfer wheel 22 and hence feeding of the ammunition rounds 16 to the rotating breech cylinder 12. Under these conditions, firing of the open chamber gun 34 ceases. Accordingly, it is evident that the gun 34 may be fired continuously or in bursts, as desired, by appropriately controlling the transfer wheel clutch actuating solenoid. It should be noted here that the

drive mechanism

86, 88, 90, and 92 for the transfer wheel 22 is so constructed and arranged, as by selection of the proper number and spacing of the clutch teeth 92, that the rotation of the breech cylinder and transfer wheel will be correctly synchronized in every engaged position of the clutch teeth for proper entrance of the ammunition rounds into the firing chambers. After the ammunition magazine 17 has been emptied, the takeup reel 140, which will then contain the entire length of the spent ammunition belt 32, is removed and replaced by an empty reel to permit reloading of the gun.

Returning now to the transfer wheel 22, it will be recalled that its drive pawls have cam followers 148 which travel along the cam grooves 136 during rotation of the transfer Wheel. In FIG. 2, it will be observed that the cam grooves are shaped to rock the pawls back and forth on their pivot aXes in timed relation to rotation of the transfer wheel. Thus, as each pawl approaches the outfeed transfer station S10, the pawl is rotated in the counterclockwise direction in FIG. 2 to the position illustrated at the upper left-hand portion of the transfer wheel in the figure. In this position, the front ammunition seating face 124 of each pawl is disposed substantially normal to or inclined rearwardly at a slight angle relative to the circular direction line of movement of the pawl With the transfer wheel. Each drive pawl remains in this position until it emerges from the outfeed transfer station. The pawl is then rotated in the clockwise direction in FIG. 2 to the position occupied by each pawl on the lower half of the transfer wheel in the figure. In this latter position, the ammunition seating face of each pawl inclines forwardly at a small angle relative to its circular direction line of movement so as to define, with the cylinder surface of the transfer wheel drum `54, a forwardly opening generally V-shaped pocket for receiving the radially inner trailing apex edge of the adjacent ammunition round 16.

The reason for this rocking motion of the transfer wheel ammunition drive pawls 120 will now be explained. As noted earlier, the ammunition belt 32 travels around the transfer wheel 22 in seating contact with the transfer wheel drum 54 in the region between the pawls. Accordingly, each ammunition round 16 on the transfer Wheel is disposed with one curved face of the round adjacent and facing the drum and with the opposing apex edge of the round located radially outward of the drum surface. Referring to FIG. 2, it will be seen that as each ammunition round approaches the outfeed transfer station So, the round undergoes lateral infeed movement into a breech cylinder firing chamber 30, through the open side of the chamber, in such a way that the trailing wall of the chamber initially contacts the outer apex of the round. During continued rotation of the round and firing chamber through the outfeed transfer station, the trailing chamber wall exerts a clockwise moment, as viewed `in FIG. 2, on the round which rotates or pivots the round forwardly in the direction of its rotation, about the inner leading apex edge of the round as a fulcrum, to a position wherein the round is disposed for full seating engagement within the chamber. This forward rotation of each round swings the inner trailing apex edge of the round radially outward away from the transfer wheel. The ammunition seating faces 124 of the transfer wheel ammunition drive pawls 120 are rotated rearwardly, in the manner just explained, as they approach the outfeed transfer station in order to accommodate this forward pivoting of their engaged ammunition rounds 16 without jamming of the ammunition rounds against the pawls. The drive pawl ammunition seating faces are then rotated forwardly as they emerge from the outfeed transfer station to provide the aforementioned forwardly open, generally V-shaped pockets for receiving the inner trailing apex edges of the following incoming ammunition rounds. Referring to the lower half of the transfer wheel in FIG.

2, it will be seen that these pockets are shaped to generally complement the apex edges of the ammunition rounds, thus to effect secure driving engagement of the drive pawls with the ammunition rounds.

As noted earlier, the ammunition rounds 16 and ammunition belt 32 are directed along divergent paths as they approach and travel through the outfeed transfer station 22 in such a way that the rounds are stripped from the ammunition belt, or the belt is stripped from the rounds, to free the rounds from the belt for rotation of the rounds with their containing tiring chambers through ring position to ejection position in the manner explained earlier. The transfer guide 26 aids or effects this stripping action. In this instance, the transfer guide comprises a relatively sharp tapered leading edge of the bree-ch frame tiring strap 50. Referring to FIG. 2, it will be seen that the tapered transfer Iguide or edge 26 functions, effectively, as a wedge which enters between the ammunition belt 32 and each ammunition round 16, as the latter travels through the outfeed transfer station. This wedge directs each round laterally upwardly in FIG. 2 into and then along the curved path of motion of its containing tiring chamber 30l and the belt downwardly along its curved exit path. Each round is thereby separated from the belt by a stripping action. In this regard, it is significant to recall that the ammunition rounds 16 are secured to the ammunition belt 32 by adhesive having a relatively high shear strength and a relatively low peel strength, such that the driving forces exerted on the rounds by the transfer wheel drive pawls 120 are effectively transmitted to the ammunition belt, for driving the latter and the incoming ammunition rounds attached thereto, while permitting stripping of the rounds from the belt at the outfeed transfer station.

What is claimed is:

1. An open chamber gun system comprising:

:an open chamber gun including a breech frame, a rotary ammunition cylinder inV said frame having circumferentially spaced ring chambers extending longitudinally of and opening laterally through the circumference of said cylinder and rotatable in succession through an ammunition infeed station and a following firing station, and means for driving said cylinder in rotation; and

an ammunition feed mechanism including an ammunition belt, open chamber ammunition rounds extending laterally of said belt in generally uniformly spaced relation along said belt, said ring chambers and ammunition rounds having complementary generally triangular round shapes in transverse crosssection and said rounds having curved sides releasively adhesively bonded to one surface of said belt, means for feeding said belt and ammunition rounds in one endwise direction of said belt along a prescribed path of motion merging generally tangentially with said cylinder at said infeed station with said one surface of said belt facing said cylinder at said infeed station in such a way that said ammunition rounds and firing chambers undergo unified lateral movement in the same direction through said infeed station and each ammunition round enters the corresponding firing chamber laterally apex rst at said infeed station, and a wed-ge shaped formation on said breech frame for stripping each ammunition round from said belt at said infeed station, directing each stripped round laterally into its respective firing chamber for movement with the chamber along its circular path of motion to said ring station, and directing said belt :along an exit path divergin-g from said circular path.

2. An open chamber gun system comprising:

an open chamber gun including a breech frame having a firing strap, a cylinder rotatable in said frame and containing axially extending circumferentially spaced firing chambers opening laterally through the circumference of said cylinder, and means for driving said cylinder in rotation whereby said firing chambers undergo rotation in succession through an arnmunition infeed position wherein the open side of each ring chamber registers with an ammunition infeed opening in said frame, a firing position wherein the open side of the respective chamber is closed by the breech frame firing strap, and an ejection position wherein the open side of each chamber registers with an ejection opening in said breech frame; and

an ammunition feed mechanism including a rotary transfer wheel disposed in generally tangential relation to said cylinder through said infeed opening with the axis of said wheel parallel to the axis of said cylinder, an ammunition belt trained about said transfer wheel with one surface of said belt disposed in seating engagement with said wheel, open chamber ammunition rounds extending laterally of and adhesively bonded to the other surface of said belt in generally uniformly spaced relation along said belt, the ends of said rounds projecting beyond the longitudinal edges of said belt, radially projecting `drive pawls circumferentially spaced about said transfer wheel at opposite sides of said belt and disposed in driving engagement with the extending ends of the ammunition rounds on said wheel, whereby during rotation of said transfer wheel said pawls exert on said rounds driving forces which are transmitted to said belt for transporting said belt and its attached ammunition rounds in the endwise direction of said belt, means for driving said transfer wheel in rotation in unison with and in a `direction opposite the direction of rotation of said cylinder, whereby said ring chambers and ammunition rounds undergo unied rotation in the same direction through said infeed position, and transfer means at said infeed position for stripping each round arriving at said latter position from said belt and laterally transferring the stripped round from said transfer wheel into the corresponding firing chamber of said cylinder.

3. A gun system according to claim 2, wherein:

said firing chambers and ammunition rounds have complementary generally triangular round shapes in transverse cross-section;

said ammunition rounds have curved sides thereof adhesively bonded to said web, whereby each ammunition enters its respective firing chamber apex first in such a way that the trailing wall of each ring chamber exerts a moment on its respective entering round for rotating the round forwardy in the direction of its rotation with said transfer wheel to a position wherein the respective round is disposed for proper entrance into the tiring chamber;

said pawls have forward ammunition seating faces disposed for seating engagement with said ammunition rounds, and said pawls are rotatable relative to said transfer wheel on pivot axes parallel to the axis of said transfer wheel between extended positions wherein said seating faces incline forwardly relative to the direction of rotation of said transfer wheel to define generally V-shaped pockets for receiving the trailing apex edges of said ammunition rounds and retracted positions wherein said seating faces extend generally radially of said transfer wheel, means pivotly supporting said pawls on said transfer wheel for rocking between said positions, and a cam means for rocking said pawls between said positions in timed relation to rotation of said transfer wheel in such a way that said pawls are rocked to their retracted positions as they approach an outfeed transfer station wherein said ammunition rounds undergo transfer movement from said transfer wheel to said cylinder and to their extended positions as said pawls approach and infeed transfer station wherein said belt enters onto said transfer wheel.

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

said transfer means comprises a relatively sharp wedgelike edge on said breech frame firing strap which enters between said belt and each ammunition round arriving at said outfeed transfer station; and

an infeed guide opening tangentially to said transfer wheel at said infeed transfer station for guiding said ammunition belt and ammunition rounds along a prescribed path of motion merging tangentially with said transfer wheel at said infeed transfer station.

5. An open chamber gun system comprising:

an open chamber gun including a breech frame, a rotary ammunition cylinder in said frame having circumferentially spaced firing chambers extending longitudinally of and opening laterally through the circumference of said cylinder and rotatable in succession through an ammunition infeed station and a following firing station, and means for driving said cylinder in rotation; and

an ammunition feed mechanism including an ammunition belt, open chamber ammunition rounds extending laterally of said belt in generally uniformly spaced relation along said belt, said firing chambers and ammunition rounds having complementary generally triangular round shapes in transverse crosssection and said rounds having curved sides releasively adhesively bonded to one surface of said belt, means for feeding said belt and ammunition rounds in one endwise direction of said belt along a prescribed path of motion merging generally tangentially with said cylinder at said infeed station with said one surface of said belt facing said cylinder at said infeed station in such a way that said ammunition rounds and tiring chambers undergo unitied lateral movement in the same direction through said infeed station and each ammunition round enters the corresponding firing chamber laterally apex first at said infeed station, and means at said infeed station for stripping each ammunition round from said belt, directing each stripped round laterally into its respective firing chamber for movement with the chamber along its circular path of motion to said tiring station, and directing said belt along an exit path diverging from said circular path.

6. An open chamber gun system according to claim 5,

wherein:

said belt feeding means is intermittently operable to effect selective intermittent feeding of said ammunition rounds to said gun.

7. An open chamber gun system according to claim 5,

including:

a take-up reel rotatably supported on said breech frame and secured to the stripped end of said belt, and means for driving said take-up reel to Iwind said belt on said reel.

8. An open chamber gun system according to claim 7,

including:

a releasable driving connection between said take-up reel and reel driving means, whereby said take-up reel may be removed from said gun when said belt is fully wound on said reel.

9. An open chamber gun system comprising:

an open chamber gun including a breech frame having a tiring strap, a cylinder rotatable in said frame and containing axially extending circumferentially spaced ring chambers opening laterally through the circumference of said cylinder, and means for driving said cylinder in one direction of rotation;

an ammunition transfer wheel rotatably supported on said frame with the axis of said wheel parallel to the axis of said cylinder and protruding through an ammunition infeed opening in said frame into generally tangential relation with said cylinder within a first transfer station, said transfer wheel including means defining a number of ammunition receiving pockets spaced circumferentially about and opening laterally through the circumference of said wheel, whereby a firing chamber and an ammunition pocket situated at said station open laterally toward one another;

said cylinder being rotatable in said one direction to rotate said tiring chambers in succession through said transfer station and a following firing station, wherein the open side of each firing chamber is closed by said breech frame firing strap, and said transfer wheel being rotatable in the opposite direction to rotate said ammunition pockets in succession through said transfer station and a second transfer station wherein each pocket is disposed to receive an ammunition round;

means for driving said cylinder and transfer wheel in unison to cause unified lateral movement of said firing chambers and ammunition pockets in the same direction through said rst transfer station in a manner such that each firing chamber and an ammunition pocket undergo lateral movement through said first transfer station in unison with the respective chamber and pocket opening laterally toward one another; a supply of open chamber ammunition rounds, said rounds and tiring chambers having complementary generally triangular round shapes in transverse crosssection;

infeed means for feeding said ammunition rounds laterally in succession to said transfer wheel at said second transfer station in such a way that each ammunition round enters a transfer pocket at said second transfer station and thereafter rotates with its containing pocket to said first transfer station;

said transfer wheel pockets being generally tapered in transverse cross-section to orient their contained ammunition rounds with apicies of the respective rounds disposed radially outward relative to said transfer wheel in such a way that each ammunition round on said transfer wheel approaches said rst transfer station concurrently with a cylinder firing chamber and enters the respective tiring chamber laterally apex first as the respective -chamber and round travel through said first transfer station;

means at said first transfer station for effecting lateral movement of each ammunition round arriving at said first transfer station from said transfer wheel into its receiving cylinder firing chamber for subsequent rotation of the respective round with its receiving chamber to firing position; and

said gun including means for tiring each ammunition round in said firing position.

10. An open chamber gun system according to claim 9, wherein:

said driving means comprises means for selectively intermittently driving said transfer wheel in unison with said cylinder to effect selective intermittent feeding of said ammunition rounds to said gun.

11. The method of feeding open chamber ammunition rounds of generally triangular round shape in transverse cross-section to an open chamber gun, said rounds having one curved side adhesively bonded to one surface of an ammunition belt with the rounds extending transversely of said belt in generally uniformly spaced relation along the belt, and said gun including a rotary cylinder having firing chambers of said triangular round shape in transverse cross-section spaced circumferentially about and opening laterally through the circumference of said cylinder, said method comprising the steps of:

driving said cylinder in one direction of rotation to cause lateral movement of said firing chambers in succession through an ammunition infeed station and a following tiring station; and

feeding said belt endwise through said infeed station along an arcuate path of motion which merges tangentially with the circumference of said |cylinder at said station With said one surface of said belt facing said cylinder with apices of the rounds presented toward and in a predetermined attitude relative to said 'circular path in such a Way that each ammunition round approaches said station concurrently with a ring chamber and enters the tiring chamber laterally, apex rst, through the open side of the respective ring chamber during7 lateral movement of the firing chamber and ammunition round through said station, each round is then stripped from said belt at said station and transported by its containing firing chamber from said infeed station to said firing station, and said belt emerges from said station along an exit path which diverges from said cylinder.

References Cited UNITED STATES PATENTS 8/1885 Allender 89-12 3/1891 Skoda 89-3'3 X 8/1892 Garland 89`35 4/ 1958 Dardick 89-33 X 9/1958 Otto 89-12 11/1960 OBrien 89-33 X .8/ 1961 Kunz.

7/1964 Double 221-73 7/1967 Kraus 89-33 7/1962 Dardick 89-160 X FOREIGN PATENTS Y 1888 Great Britain. 8/1938 Great Britain.

SAMUEL FEINBERG, Primary Examiner S. C. BENTLEY, Assistant Examiner