IL43158A - Burst firing single barrel rifle - Google Patents

Description

BURST FIRING, SINGLE BARREL RIFLE nmm irra nap ya nan Docket No. 52 -AR -1818 BURST FI RING, SINGLE BARREL, ARMAMENT SYSTEM The invention herein described was made in the course of or under a contract or subcontract thereunder with the Department of the Army.

BACKGROUND OF THE INVENTION 1. Field of the Invention This invention relates to high rate of fire, burst firing, single barrel, rifle mechanisms. 2. Prior Art Automatic rifles and machine guns are well known in many configurations. Other than the Gatling and revolver type guns, conventional guns do not fire at a rate in excess of 1, 000 rounds per minute. The earliest revolver type rifle may be the Colt Revolving Rifle produced in 1836. Gatling' patent No. 47631 issued on May 9, 1865.

SUMMARY OF THE INVENTION Accordingly, it is an object of this invention to provide a single barrel rifle capable of firing bursts at rates far in excess of 1 , 000 shots per minute.

A feature of this invention is the provision of a single barrel rifle, having a pk rality of chambers in a revolver drum which are loaded, chambere extracted and ejected concurrently, and fired sequentially, under the control of a central actuation rod.

BRIEF DESCRIPTION OF THE DRAWING These and other objects, features, and advantages will be apparent 52-AR - 1818 Fig. 14 is a detail transverse cross -section taken partially along the plane Α-Λ' external to the ammunition magazine, and partially along the plane B- B, internal to the magazine; Fig. 15 is a top view of the clip of Fig. 14 and Fig. 3; Fig. 16 is a detail view in elevation, looking aft, of the clip of Figs. 15, 14, and 3; Fig. 17 is a side view of the bolt of the rifle of Fig. 1 ; Fig. 18 is a front end view of the bolt of Fig. 17, and Fig. 19 is a partial perspective view of a composite of the basic mechanism, showing the actuator rod assembly in its forward position, the firing pin assembly on sear and safety, and the revolver drum with the last round aligned with the barrel before firing.

THE PREFERRED EMBODIMENT The rifle shown in Fig. 1 contains a burst firing mechanism. With each pull on the trigger, three rounds of ammunition are rapidly fired in succession through the single barrel. The mechanism includes : (1 ) a coaxial actuating rod and piston, revolver, and bolt; (2) a double and symmetrical actuating cam in the receiver including the stock which controls the actuating rod and thereby the revolver and the bo (3) a magazine which provides three rounds simultaneously to the bolt; (4 a continuous forward movement of the actuating rod to strip and chamber three rounds concurrently, and to eject three cases concurrently; arj (£·) a continuous rearward movement of the actuating rod to fire three rounds sequentially and to extract three cases concurrently.

The rifle com rises a receiver 10 which includes a shoulder stock 52- A R - 1 81 8 to the forward end of an actuating rod '26, which rod passes through a a gun bolt 30, and whose aft end is pinned to an actuati cam follower support 32 by means of an actuating cam follower 34 which is disposed through a diametral bore in the support and the rod. One end 36 of the follower rides in a shallow cam track 38 and the other end 40 rides in a deep cam track 42 formed into the inner wall of a longitudinal bore in the re-ceiver. The rod has three longitudinally spaced apart keys 44, 46 and 48 pro jecting radially therefrom at 90° included angles from the longitudinal axis, long fourth key 49 aligned with the key! 44, and a ball catching concavity 50.

] An actuating gas port 52 provides a conduit for gas between the forw. portion of the bore of the gun barrel and the forward portion of the bore of the gas cylinder. The aft end of the cylinder has a gas vent port 54.

The revolver drum 18 is disposed in a bore 29 in the receiver, and has three longitudinally extending, par?Vlel, 90° radially spaced apart chamb 56, 58, and 60; three, longitudinally diverging, 90° radially spaced ejection tunnels 62, 64, and 66; and three, longitudinally extending, parallel, 90° radially spu med apart keyways 68, 70 and 72 in a longitudinal bore 74 which will pass the actuating rod 26. An integral annular hoop 76 is provided on the aft end of the revolver 28 for additional strength over the chambers, and is interrupted between the chambers to form annular castellations. Each chamber includes an aft enlarged diameter 78 to accommodate the projectile and its rifling band, and a forward L-seal 82 to provide a gas seal between th chamber and the bore 83 of the barrel 18.

The gun bolt 30 is disposed in a bore 84 in the receiver, coaxial with the bore 29, and is substantially cyl indrical with a longitudinal bore 85 which will pass the actuating rod 26. Within the bore are two lull length project but not to depart from the bore 92. The bolt has a front face 97 from which three extractor lips 98, 100, and 102 project radially at 90° included angles and are spaced from an annular shoulder 104. A firing pin actuator can-track 106 is formed into the outer periphery of the bolt as shown in Fig. 1 2.

A main spring 108 is also disposed in the bore 84 and is captured between the cam follower support 32 and a plug 110.

A single firing pin assembly 1 14 is disposed in a longitudinal bore 1 16 in the receiver 10. The firing pin assembly includes an actuator block 118 having a cam follower roller 1 20 journalled thereto and riding in the cam track 106 in the bolt, and a longitudinally aft extending neck portion 122 terminating in a head portion 1 24. A rod 126 is threaded into and extends longitudinally forward from the block to a firing pin support 128, from which firing pin 130 extends longitudinally forward. A main firing pin spring 132 is disposed on the rod 126, and a reflex spring 1 34 is disposed on the pin 1 30 The spring 134 is captured between the support 128 and a shoulder 136 in the bore 1 16. Tne spring 132 is captured between the support 1 28 and a shoulder 138 on the receiver. The bore 84 in the receiver has a centripetal proj ection 140 which extends longitudinally from shoulder 136 A to 138A, and transversely for 90°, to mate with a peripheral cut out 146 on the bolt which extends longitudinally from the shoulder 142 to the shoulder 148 transversely 360°, and to the shoulder 104 transversely 135°.

A trigger-sear assembly 150 is also disposed in the receiver. A trigger pivot shaft 152 is journalled in a transverse bore 154 through :he receiver. A trigger 156 is fixed at 158 onto the shaft 152. A lower, bifurcated main sear 160, with an upwardly directed hook 162 is fixed at 164 onto the disposed on the shaft 152 and partially in a blind, counterbore in the sear 1 60 with one end 176 c aptured by the receiver and the other end 178 captured in -the tail of the sear 166. The spring biases the tail of the sear 166 upwardly and via the shaft 170 biases the hook 168 downwardly and the hook 162 upwa The aft sear surface of the hook 162 is slightly forward of the aft sear surfa of the hook 168. A safety has a handle 180 extending transversely from the aft end of a main arm 182 which is journalled on the shaft 152 and extends forwardly into a transverse interposer bar 184 which extends into an auxiliary arm 186 which is also journalled on the shaft 152. When the handl 180 is up, the bar 184 is down and blocks forward movement of the firing pi actuator block 118. When the handle is down, the bar is up and clears the block.

A longitudina -horizontal slot 188 is formed in the right side of receiver, through to the bore 84, to receive a charger blade 190 having a horizontally extending handle 192 and two vertical guide pins 194 and 196. T pins ride in a longitudinal- vertical slot 198 intersecting the slot 188. The slot 198 has an off -set portion at its forward end, which permits the handle to be swung out from the disposition shown in Fig. 10A to the disposition of Fig. 10B whereat the aft inner corner 144 of the blade projects into the bore 84 whereat it may engage the forward face of the cam follower support 32. Rearward movement of the swung out charger handle will drive the cam following support 32 aft, compressing the main spring 108.

A vertical slot 200 is formed in the bottom of the receiver, th rough the bore 84, to receive a magazine 202 of ammunition. The magazine store three vertical columns of rounds. The magazine has a left wall 204, a right 52 -AR- 1818 of the left and right partitions are curved inwardly, to partially obturate the upper ends of the three columnar passageways, and thereby limit vertical movement and loss of rounds from the passageways. The left and right walls have respective shoulders 220 which abut respective projections 222 in the receiver to limit upward movement of the magazine into the slot. A bifurcated latch 224 is fixed on the aft wall 210 to engage a detent on the trigger guard 16, to releasably secure the magazine in the slot.

The receiver also includes three longitudinally extending, parallel, 90° angularly spaced apart, loading grooves 226, 228, and 230; three longitudinally extending, parallel, 90° angularly spaced apart, extraction grooves 232, 234, and 236 alternating with the loading grooves at 45°; and three longitudinally extending but diverging, 90° angularly spaced apart, ejection tunnels 238, 240, and 242. The receiver also includes a groove 244 adapted to receive a portion qf the ball 96 disposed in the bore 92 in the bolt.

In operation, a loaded magazine of ammunition is thrust into the slot 200 and the latch 224 is locked to the guard 16. The charger 190 is swung! to engage the actuating cam follower support 32, and is pulled aft to push the actuating rod 26 aft. The rod carries the bolt aft and compresses the main spring, as will be described in more detail below, until the face 104 of the bolt is aft of the magazine ammunition. The respective topmost round in each of the three columns are biased up within their respective passageway and when the charger handle is released, the main spring drives the bolt forward, with the annular shoulder 104 tbuting the bases of the three rounds and stripping them forward out of the magazine and into the respective loading rooves 226, 228, and 230. The rod and bolt continue forward rammin the rod, the bolt, and the revolver rotate 90° clockw ise to the batter -first round - start of burst disposition, shown in Fig. 1. As shown in Fig. 1 1 , the actuating rod cam follower 42 is at disposition_A_ and as shown in Fig. 1 2 the firing pin cam follower roller 120 is at disposition a_. The trigger 156 is forward, the lower sear hook 162 is engaged with the firing pin actuator head, the upper sear hook 168 is above and clears the head, and the firing pin spring 132 is compressed.

When the trigger is pulled aft, the longer, lower, sear hook is disengaged from the firing pin actuator head 124. The shorter, upper hook is resiliently pulled down, but only abuts the head 1 24 and does not engage it, and the firing pin 130 is driven forward by the spring 132 to fire the round in the chamber 56, with roller 1 20 travelling to disposition b. After the fired bullet passes the actuating gas port 52, combustion gas enters the gas cylinder 20 and drives the piston 24 and the rod 26 aft. The follower 40 travels aft to disposition B, providing a dwell period for gas pressure to decline the chamber, and then travels through a 90° rotation to disposition C , rotating the revolver and the bolt 90° to align the chamber 58 with the gun barrel bore 83, and driving the roller 120 up the ramp to disposition £, and compressing the spring 132. The head 1 24, however, is not far enough a aft to be engaged by either hook. The trigger is still aft, the lower .sear hook is still down, and the upper sear hook is still too short to engag e behind the head 1 2 Γ. The roller 120 falls to disposition d, and the spring 1 2 drives the firing pin to fire the round in the chamber 58. Combustion gas again drives the piston and the rod aft. The follower 40 travels aft to disposition _D, providing a dwell period or gas pressure to decline, and then ° o the bolt 90 , to align the chamber 60 with the gun barrel bore, and driving the roller 1 20 up the ramp to disposition e, and compressing the spring 132. The trigger is still aft, the lower sear hook is still down, and the upper sear hook is still too short to engage behind the head 124. The roller 120 falls to disposition f_, and the spring 132 drives the firing pin to fire the round in the chamber 60. Combustion gas again drives the piston rod aft. The follower 40 travels aft to disposition _F_, providing a dwell period for gas pressure to decline, and then travels through a 45° rotation to disposition G, rotating the revolver and the bolt 45° to align the chambers 56, 58, and 60 with the extraction grooves 232, 234, and 236. The roller 120 travels to disposition g. The ball 96 carried in the bore 92 in the bolt, and partially* disposed in the concavity 244 in the receiver, is aligned with the concavity ^0 in the actuating rod and the key 46 in the rod is bottomed in the blind keyway 90 in the bolt. As the follower 40 travels aft to disposition the rod drives the bolt aft, shifting the ball 96 in the bolt from the concavity 244 in the receiver to the concavity 50 in the rod, thereby interlocking the bolt to the rod. Further, the extractor lips 98, 100, and 102 pull thy respective cases partially out of the chambers 56, 58, and 60 and partially into the extraction grooves 232, 234, and 236 in the receiver. The roller 12C travels to disposition h. The follower 40 continues to disposition I_ fully pulling the cases (or misfired cartridges) into the extractor grooves and rotating 45° to align the chambers 56, 58, and 60, as seen in Fig. 5, with the loading tunnels 226, 228, and 230, as seen in Fig. 6, and the ejection tunnels 62, 64. and 66 with the extraction grooves 232, 234, and 236 and the ejection tunnels 238, 240, and 242. The roller 120 travels to disposition i_ and is 52-AR -1818 trigger is still aft, the shorter, upper hook 168 will engage. If the trigger is forward, the longer, lower hook 162 will engage. The firing pin spring 13; is compressed. The follower 40 continues aft to disposition J, at which the annular shoulder 104 on the bolt is immediately aft of the magazine. The three topmost rounds in the magazine rise to the top of the magazine and are tilted forwardly- upwardly. The roller 120 is at disposition j_. The piston 24 is aft of the gas vent 54 and much of the combustion gas vents to the atmosphere through the vent, reducing the gas pressure in the cylinder.

The spring 108 starts to expand, driving the actuating rod and the bolt forward, the annular shoulder 104 stripping the three rounds out of the magazine and into the grooves 226, 228, and 300. As the rounds enter the grooves, they tilt to the longitudinal and engage the extractor lips. When the follower 40 is at disposition K, the rounds have been pushed into the loading grooves 226, 228, and 230. The roller 120 is at disposition k . When the follower 40 is at disposition L, the rounds have been fully chambered, the empty c s ar have been impelled forward by the annular shoulder of the bolt and ejected, and the ball 96 is aligned with and enters the groove 244, releasing the bolt from the rod. As the follower 40 travels to disposition M, the roller 120 travels to disposition JL The follower 40 finally travel s to disposition A' rotating the bolt and the revolver 90° to align the chamber 56 with the gun bore, The roller 120 rotates 90° to disposition a' . The rifle is now at ba*tery, and awaits another pull of the trigger to fire another burst of three rounds.

Claims (3)

1. 52 -AR- 1818 What is claimed is : 1. A rifle including: a receiver; a single barrel coupled to said receiver; a revolver drum within said receiver having a plurality of chambers; of passageway a magazine coupled to said receiver having a like plurality / of means for supplying a train of rounds of ammunition; and control means within said receiver for causing each of said chambers to be concurrently loaded with a respective round of ammunition passageways from a respective one of said si^piyxmeawe, for sequentially firing each round in the respective one of said chambers, for concurrently extracting each fired round from the respective one of said chambers, and for concurrently ejecting each fired round from said receiver.

2. A rifle according to claim 1 wherein: said control means includes a main spring loaded, gas operated actuation rod journalled for rotation and longitudinal reciprocation; a bolt journalled fo: rotation and longitudinal reciprocation and a single firing pin assembly.

3. A rifle according to claim 2 wherein: said bolt and said revolver drum are concentric about said actuation rod. 1. A rifle according to claim 3 further including: a cam follower fixed to the ait end of said actuation rod, and 8. A rifle accordin to claim 7 wherein: 52-AR -1818 said revolver drum has : throe of said chambers spaced a first number of degrees apart, and three of said passageways spaced said first number of degrees apart; and said bolt has three bolt face areas and extractors spaced said first number of degrees apart; said magazine has three of said passageways for providing three of said trains of rounds ; and said receiver has : three of said first passageways spaced said first number of degrees apart, and three of said third passageways spaced said first number of degrees apart. 9. A rifle according to claim 8 wherein: said control means provides the following firing cycle: (1 ) in battery and charged, said revolver drum has its first chambe aligned with said barrel; (2) on firing said revolver drum is rotated to sequentially align each of said chambers with said barrel and to fire the respective round within each said chamber when aligned with said barrel, (3) said revolver drum is further rotated to align said chambers with said se cond passageways of said receiver, (4) said bolt is moved aft to extract the fired rounds from said chambers into said second passageways of said receiver, , (5 said revolver drum is further rotated to align said chambers wit