US1698228A

US1698228A - Machine gun

Info

Publication number: US1698228A
Application number: US632103A
Authority: US
Inventors: Harry K Harring
Original assignee: MORGAN R MILLS
Current assignee: MORGAN R MILLS
Priority date: 1923-04-14
Filing date: 1923-04-14
Publication date: 1929-01-08
Anticipated expiration: 1946-01-08

Description

Jan. 8, 1929.

H. K. HARRING MACH I NE GUN Original Filed April 14,

1923 8 Sheets-Sheet 1 Jan. 8, 1929.

H. K. HARRING MACHINE GUN Original Filed April 14. 1925 8 Sheets-Sheet 2 wow Jan. 8, 1929.

H. K. HARRING MACHINE GUN Original Filed April 14, 1923 8 Sheets-Sheet 5 Jan. 8, 1929.

H. K. HARRING MACH I NE GUN Original Filed April 14, 1923 8 Sheets-Sheet 6 vwi wt NQ x? Qg Jan. 8, 1929.

H. K. HARRING MACHINE GUN Original Filed April 14, 1923 8 Sheets-Sheet 7 M M A l l l M. .fllk

iiiii. tlllh, .allh. vlllh .Illli; Allfl Patented Jan. 8,1929.

UNITED STATES PATENT OFFICE.

I HARRY K. EARRING, OF WASHINGTON, DISTRICT OF COLUMBIA, ASSIGNOR OF TWO- THIRDS T MORGAN R. MILLS, 0F RICHMOND, VIRGTNIA.

MACHINE GUN.

Application filed April 14, 1923, Serial No. 632,103. Renewed March 28, 1928.

This invention relates to machine guns.

An object of the invention is to provide a gun having a movable frame arranged at the rear of the barrel and a bolt mounted in said frame, said frame and bolt being adapted to be moved rearwardly by the recoil a predetermined distance, and the bolt being then adapted to be moved rearwardly in the frame to permit ejection of the fired cartridge and the insertion of anew one.

A furtherobject is the provision of improved operating means for the breech block controlled by the movement of the frame.

A further object is the provision of improved ejecting mechanism.

A further object is the provision of improved feeding mechanism for the cartridges.

In the accompanying drawings, I have shown one embodiment of the invention. In this showing:

Figure l is a side elevation of the frame and rear end of the barrel showing the bolt in firing position,

Figure 2 is a. plan view of the parts shown in Figure 1 with the bolt in firing position,

Figure 3 is a view similar to Figure 1 showing the position of the bolt after firing has taken place,

Figure a is a plan view with the parts in the position shown in Figure 3,

Figure 5 is a central vertical sectional view of the frame showing the bolt in firing position,

Figure 6 is a. similar view showing the bolt withdrawn.

Figure 7 is a. horizontal sectional view on line 7'T of Figure 1,

Figure 8 is a transverse sectional View on line 88 of Figure 2,

Figure 9 is a similar view on Figure 2.

Figure 10 is a horizontal sectional view on line 10-]() of Figure 7,

Figure 11 is a plan view of the bolt re moved.

Figure 12 is a horizontal sectional view on line 1212 of Figure 5.

Figure 13 is a vertical sectional view through the bolt taken on line 13 13 of Figure 11.

Figure 1% is a similar view on line 141 1. of Figure 11,

line S)-9 of forward end of the frame.

pair of arms forming a part of the cartridge feeding mechanism, v

Figure 20 is asimilar view of a block by means of which the movement of the arms is controlled,

Figure 21 is a transverse sectional view on line 21-21 of Figure 7,

Figure 22 is a similar view on line 22*22 of Figure 7,

Figure 23 is a detail side elevation of a portion of the mechanism for accelerating the rearward movement of the bolt,

Figure 24 is a similar view of the same parts at the end of the acceleration,

Figure 25 is a transverse sectional view on line 2525 of Figure 4, and,

Figure 26 is a transverse sectional view through the barrel of the gun showing the cartridge magazine in elevation.

General construction.

The gun forming the subject matter of the I a plate 10, having a depending portion."

This depending portion is provided with an opening for the reception of a bolt 12. As shown. the head 14 of the bolt is arranged in the rear of the plate 10. This bolt extends through a cylinder 16, carried by the stationary support, and a coil spring 18 is arranged around the bolt. The other end of the bolt is provided with a suitable enlargement 20, whereby the spring will be placed under tension when the bolt is moved rearwardly (see Figure 6). The ends of the cylinder are provided with'plugs 22, serving as cylinder heads. A barrel 24 is secured in the As shown. the frame is provided with a bore 26, adapted to aline with the rear end of the'bore 28 of the barrel.

A bolt 30 is mounted in the frame and is movable therein from the firing position shown in Figure 5 of the drawings, to the recoil position shown in Figure 6 of the drawings. hen the shell is fired, the recoil forces the frame backwardly on the support, placing the spring 18 under tension, as shown in Figure 6 of the drawings. Suitable means to be described, are provided for moving the bolt rearwardly within the frame in addition to its movement as a part of the frame. The bolt is thus brought to the position shown in Figure .6 of the drawings to permit the ejection of a fired cartridge and the insertion of a new one.

Bolt 0 aerating mechanism.

The means for moving the bolt independently of the frame consists of a rack 32 formed on the lower face of the bolt and adapted to mesh with a pinion 34, carried by a shaft 36, extending through the frame. This shaft is provided with a pinion 38 and is further provided with a segmental roller 40, having one tooth 42. The pinion 38 is adapted to mesh with a rack 44. The segmental wheel 40 is adapted to co-operate with a pair of plain surfaces 48, arranged adjacent each end of the rack 44. The level of the plain surfaces 48 is substantially the same as the top of the teeth 44. Between the plain surfaces 48, there is provided a surface 50, substantially in alinement with the rack 44, and

' arranged at a lower elevation. On each side of the tooth 42, the segmental wheel is provided with a substantially fiat surface 52. When the frame begins its rearward movement under the impulse of the firing, one of the surfaces 52 is in engagement with the surface 48 and the pinion 38 is in front of the rack 44, whereby the shaft 36 is not revolved and the bolt does not move independently of the frame. During this portion of the rearward movement, the breech bolt lock which holds the bolt in position, is moved to an inoperative position. lVhen the pinion 38 engages the rack 44, the shaft 36 is revolved and this movement is communicated to the bolt through the pinion 34 and rack 32, causing it to move from the position shown in Figure 5 of the drawings, to the position shown in Figure 6 of the drawings. Toward the end of the rearward movement of the frame, the pinion 38 passes off. the rack 44. At this time, the tooth 42 is substantially in the position shown in Figure 24 of the drawings and is about to engage a shoulder 54,

formed .at the end of the surface 48. This causes the flattened portion 52 of the wheel 40 to engage the plain surface 48 and slide over it, stopping the revolution of the shaft 36 and thus stopping the independent movement of the bolt in the frame. When the end of the rearward movement is reached, the

Breech bolt Z0070.

The breech bolt lock is also moved in and out of position by the movement of the frame on its support. As shown, the breech bolt lock consists of a substantially U-shaped member 56 having a pair of parallel arms 58, arranged on opposite sides of the bolt (see Figure 21). It is provided with a central, depending abutment 59. When the breech bolt lock is in closed position, the arms 58 are arranged beneath shoulders formed by guide flanges or ribs 60, adjacent the upper edge of the bolt. These flanges are received in grooves or recesses 62, formed in the top of the frame. The breech bolt lock engages a depending lug or shoulder 64 formed on the under face of the bolt to retain it in firing position. It is adapted to be lowered to an inoperative position, shown in Figure 6 of the drawings, to permit rearward movement of the bolt. This lowering of the breech bolt lock takes place prior to the revolution of the shaft 36 and before the rearward movement of the bolt in the frame is begun. As shown, the breech bolt lock is carried by a lever 66, which is pivotally mounted on a pin 68, eX- tending through the frame. The rear end of this lever is secured to an arm 70, which extends through an arcuate slot 71 (see Figure 22) in the frame and is provided with a roller 72 on its outer end. This roller is received in a slot 74, formed in a plate 76, carried by the stationary support. As shown, the forward end of the slot is substantially horizontal, as indicated at 78, and is then provided with an inclined portion 80. When the framemoves rearwardly, the roller 7 2 is in the horizontalportion at the beginning of the rearward movement. The lever 66 is in the position shown in Figure 5 of the drawings and the breech bolt is in operative position,holding the bolt in place. hen the roller 72 rides upwardly in the inclined portion 80, the lever is swung on its pivot to substantially horizontal position, as shown, in Figure 6 of the drawings, lowering the breech bolt lock to an inoperative position. This permits the bolt to move rearwardly and at this time, the pinion 38 engages the rack 44, as previously described. During the further rearward movement of the frame, the roller moves through the long horizontal portion of the slot 74 and the breech bolt lock and lever 66 remain in the lowered position shown in Figure 6 of the drawings. It will be noted that the rear portion of the support is provided with a longitudinal groove 82 for the reception of the abutment 59 of the breech bolt look when it is in lowered position. The forward end of this groove forms a shoulder 84. The frame" and bolt move rearwardly as a unit, with the roller 7 2 traveling in the lower portion 78 of the groove 74, until the depending abutment 59 of the breech bolt lock .clears the shoulder 84. When the breech bolt lock is raised, the

abutment 59 rests upon a surface 86 which prevents accidental displacement. The movement of the breech bolt lock onto the surface 86 takes place during thetime the roller 7 2 is traveling through the horizontal nels 90 for the reception of the breech bolt lock. The relative'width of this portion of the frame with respect to other portions will be apparent from an inspection of Figures 21 and 22 of the drawings. 1

Cartridge ejector.

Means are provided, controlled by the rearward movement of the bolt, to eject a used cartridge from the firing chamber. The fire ing chamber is formed by the bore 26 at the front of the frame and the rear portion 28 of the bore of the barrel. As shown, the hole is shaped to receive a cartridge 92 (seeFigure 7) and the head of the cartridge'94 projects slightly from the bore. An extractor 9.6 is pivotally mounted on one side of the bolt, as at 98, and the forward end ofthis extractor is normally pressed inwardly by a leaf spring 100. This extractor is provided with a finger 102 on its forward end, adapted to engage the groove in the heel of the cartridge to withdraw the cart-ridge from the bore when the bolt moves rearwardly in the frame. The

frame is provided with an opening 104 in its side through which the cartridge is adapted to be ejected. An ejector 106 is mounted on one side of the bolt and this ejector is adapted to be moved forwardly to engage the heclof the cartridge at the side opposite the opening 104 and tip the cartridge through the opening. As shown. the rear end of the ejec tor is extended upwardly at right angles, as indicated at 108 and is provided with a pin 110 on its upper end. This pin is received in a slot 112. formed in a bell crank lever 114. pivoted on the top of the bolt. as at 116. A roller 118 is mounted on the other end of the bell crank lever. The extension 108 is further provided with a stud or screw 120 passing through a slot in the side of the bolt and received in a plunger 122. The plunger is slidably mounted in a bore 124, formed within the bolt. A spring 126 is arranged behind the plunger and engages a plug 128 which closes the rear end of the bore. The

top of the bolt is provided with a recess 130,

adapted to receive the body portion of a latching mechanism 132, which controls the bell crank lever 114. As shown, this-latching mechanism is provided with a forward arm 134 and a rear arm 136. Upon rearward movement of the/bolt, the rear arm is adapted to engage a pin 138 to move the latch mechanism forwardly to an operative position. Upon forward movement of the bolt, the end .of the forward arm engages the inner face 140 of the front of the frame to release the latching mechanism. The latching mechanism is shown, in operative position, in Figure 11 of the drawings, with the forward end 142 of'the arm 136 engaging the bell crank lever to retain it-inthe full line position. The bell crank lever is retained in this position during the forward movement of the bolt which retains the spring 126 under tension and retains the ejector 106 in a withdrawn position. As soon as the bolt reaches its forward position. the latch mechanism is released. The bell crank lever is prevented from swinging on its pivot immediately by a plate 144, arranged in the top of the frame and engaged by the roller 118. The bell crank leveris retained in set position during the rearward-movement of the plate until the roller passes beyond the rear end of plate 144, when the bell crank lever assumes the dotted iine position shown, due to the force ofthe spring 126. This forces the ejector forwardl at a time when the bolt has moved baekwar ly a sufficient distance for the forward end of the spent shell to clear the forward end of the spring 104. The engagement of the ejector with the heel of the cartridge forces it through the ejecting opening. Upon further rearward movement of the bolt, the roller engages an inclined edge 146 of a plate 148 arranged in the top of the frame and is again moved to its operative position, placing the spring 126 under tension. At this time, the rear arm 136 of the latching mechanism engages the pin 138 to move the latching mechanism forwardly and thus retain the bell crank lever in inoperative position during the forward movement of the bolt, independently of the

plates

144 and 148.

Cartridge feeding mechanism. The cartridges to be fed to the gun are 211- ranged in a substantially circular magazine 150, secured to the forward end of the support. As showmthc magazine-is sul'istantially frustro-oonical in shape, whereby cartridges arranged therein will abut each other substantially throughout their length. A spring 152 is secured to the magazine support 154 and this spring is provided with an offset end 156 which extends through aslot in the inner wall of the magazine. This-offset end of the spring is adapted to be arranged behind the last cartridge as shown in Figure 26 of the drawings, and is sufliciently strong to force the cartridges around the magazine as they are Withdrawn until the lastcartridge is removed from the magazine. Adjacent the outlet end of the magazine, the walls are arranged parallel to each other, as indicated at 158 and 160, whereby the cartridge to be removed from the magazine is disposed in a plane substantially parallel to the bore of the gun. A block 162 is secured to the bolt adj acent its forward end and this block projects laterally through an opening 164 in the frame of the gun. This opening forms the inlet or feed opening through which the cartridges are delivered to the gun and, as shown in Figure 7 of the drawings, is of greater length than the ejecting opening. The block 162 is provided with a pair of spring fingers 166 which are adapted to engage the cartridge at the outlet end of the magazine each time the bolt is moved forwardly and carry it rearwardly when the bolt recoils to properly position it for insertion in the gun. As shown, the cartridge is fed rearwardly over a shelf 168 which extends through the opening 164 into the barrel of the gun to support the cartridge in the frame until it is forced into the bore or firing chamber by the bolt.

The mechanism for feeding the cartridge laterally across the shelf 168 into the gun consists of a pair of arms 170 shown in detail in Figure 19 of the drawings. As shown. these arms are crossed and are provided with laterally extending heads 172 which engage the side of the cartridge to feed it inwardly. The outer ends of the arms are provided with openings 174 adapted to receive bolts or pins 176 by means of which the arms are pivoted on the shelf. The shelf is provided with a pair of arcuate slots 178 and the arms are provided with pins 180, extending through these slots. These pins are received in slots 182, formed in the arms 184 carried by a cross head 186. The cross head is mounted in guides 187. A plate 188, carried by the stationary support, is arranged beneath the cross head and a pin 190, carried by the cross head, is received in a slot 192 in this plate. Adjacent its rear end, the slot is inclined, as at 194, and is then provided with a substantially straight portion 196. hen the bolt moves rearwardly, the cartridge is first positioned on the shelf 168 inwardly of the ends of the arms 170. During this time. the cross head 186 is moving longitudinally of the plate 188, with the pin 190 in the longitudinal portion of the slot 192. The pin engages the inclined portion 19-1 of'the slot at substantially the same time the llat face 52 of the segmental wheel 40 engages the plain surface 48, so that the bolt and frame are moving as a unit. The cartridge being fed is thus stationary on shelf 168. W hen the pin rides through the inclined portion 191 of the slot. the cross head is moved laterally to ward the frame aiid'the pins'180 are caused to move in the arcuate slots 178. This swings the arms 170 on their pivots and forces their inner ends to the position shown in Figure 4 of the drawings, feeding the cartridge into the frame in position to be'moved forwardly into the firing chamber by. the bolt.

Firing mechanism.

The tiring mechanism consists of. a plunger 198 arranged in a bore 200 within the bolt. The bore is provided with a reduced portion 202 adjacent its forward end and the plunger is provided with a collar 204 arranged rearwardly of this reduced portion. The rear end of the bore is closed by a'plug 206, having a central opening for the passage of the plunger. A spring 208 is arranged between the plug and the collar 204 to normally retain the plunger in its forward position. The forward end of the plunger is reduced, as at 210, forming a firing pin, which extends through an opening in the face of the bolt. Exteriorly of the bolt, the plunger is provided with a cross head 212, one edge of which is received in a groove 214 in the frame. A groove 215, on the opposite side of the frame is adapted to receive the extractor 96 when the bolt moves rearwardly in the frame. The laterally moving latch bar 216 is mount ed in a suitable chamber 218, and is provided with a tooth 220 in its inner end. When the bolt moves rearwardly in the frame, the cross head 212 rides over this latch. Upon the forward movement of the bolt, the latch tooth 220 engages the cross head to retain it in the dotted line position shown in Figure 7 of the drawings, and thus retain the spring 208 under tension. Suitable trigger operated mechanism is provided to release the cross head. from the'latch tooth and permit the spring 208 to force the firing pin into engagement with the cartridge. Asshown (see Figures 8 to 10), the trigger 222 is pivotally mounted in a trigger guard 224 arranged on the frame and is normally held in inoperative position by a spring 226.v A slide 228 is mounted on the side of the frame and this slide is provided with a downwardly extending arm 230, having a slot 232 for the reception of a pin 231,0arried by the trigger. When the trigger is actuated, the slide 228 is moved rearwardly. The forward end of the slide is provided with a cam surface 236, forming a cam face 238. This cam face is adapted to engage an inclined surface 240, formed on the bottom of a vertically movable slide 242. This slide 212 is provided with a pin 21-i,*adapted to be received in an inclined slot 216, formed in the latch lever 216. "When the triggeris pulled, and the slide 228 moved.rearwvardly, the. slide .212 is raisediwhich withdraws the.latchlever 216 andreleases the plunger, causmgthe tiri l i mg p n tostr lge the cartr dge, ilQSlltiQ 21; is normally retained in lowered position to retain the latch lever 210 in operative position by means of a spring 248. One end of this spring is secured to a pin 250 in the frame and the other end is secured to a pin 252 carried by the slide 242.

The slotted plate 76, carried by the frame is extended rearwardly and is provided with a handle 254, which may be employed for pointing or aiming the gun. The support is provided with ears 250 by means of which the gun may be mounted on a tripod or other suitable support in any desired manner.

General operation.

With the parts in the position shown in Figures 1 and 2 of the drawings, the cartridge in the firing chamber is fired by pressing the trigger 222, moving the slide 228 rearwardly and raising the slide 242 by the engagement of its inclined lower end with the cam surface 238 of the slide 228. The cross head 212 is released from the latch lever 216 and the spring 208 forces the firing pin 210 against the butt of the cartridge to fire it. The force of the explosion causes the breech frame to move rearwardly on the support 2. The pinion 34 is in mesh with the rack 32 and at the beginning of the rearward movement, one of the flat surfaces 52 of the segmental roller 40 is in engagement with the forward plain surface 48. The shaft 36 is thus prevented from revolving and the bolt remains stationary in the frame, moving rcarwardly as a part of the frame. As the segmental roller passes off of the flat surface 48, the pinion 38 meshes with the rack t-t to revolve the shaft 36 and thus cause the bolt to move rearwardly independent of the frame. The bolt is thus moved from the position shown in Figure 5, to the position shown in Figure 6 of the drawings. Toward the end of the rearward movement, the tooth 12 engages the shoulder 54, and the other flat surface 52 of the segmental roller passes onto the plain surface 48 just as the pinion 38 passes off the end of the rack 44. This stops the independent movement of the bolt and during the remainder of the movement of the frame, the bolt is stationary with respect to the frame and moves as a part of it.

The breech bolt lock 56 is moved from the operative position shown in Figure 5 of the drawings to the inoperative position shown in Figure 0 of the drawings, prior to the movement of the bolt. Vhen the frame begins its rearward movement, the pin 72 is in the lower horizontal portion 78 of the slot 74. \Vhile the pin is moving through the horizontal portion 78 of the slot, the breech bolt lock is moving rearwardly over the surface 86. Vhcn the pin begins to ride up the inclinedportion 80 of the slot, the breech bolt lock is lowered into the groove 82. It is then disposed below the lug or shoulder 64 on the bolt and the bolt is free to pass it.

At this time, the rack 44 is engaged by the pinion 38, as previously described, to move the boltrearwardly.

\Vhen the bolt moves rcarwardly, the extractor 90 withdraws the spent cartridge from the firing chamber and positions it within'the frame in alinement with the ejector opening 104. During this rearward movement, the bell crank lever 114 is in the operative full line position shown in Figure 11 of the drawings and the spring 126'is under tension. The latch member 122, has been moved to its inoperative position by the engagement of its forward end with the forward inner wall of the frame. Operation of the bell crank lever is prevented by the plate 144, as shown in Figure 12 of the drawings, until the bolt has moved rearwardly in the frame a sufficient distance to properly position the spent'cartridge in alinement with the ejector opening. At this time, the roll-er 118 passes the rear end of the plate 144 and swings to the dotted line position shown in Figure 12 of the drawings. The spring 120 swings the bell crank lever on its pivot and projects the ejector 106 at the front of the bolt to engage the top of the cartridge at one side and force it through the ejector opening. It will be noted (see Figure 7 that the ejector opening 104 is consider-a ly smaller than the cartridge feeding opening 104, which prevents the fresh cartridges fed to the gun from passing through the ejector opening.

. After the bell crank lever is released to operate the ejector, it is again moved to its operative position by the plate 148, placing the spring under tension. At the end of the ran-ward movement of the bolt, the latching mechanism is moved to operative position by the engagement of the arm 130 and pin 138, which retains the bell crank lever in operative position during the forward movement of the bolt.

The feeding mechanism draws the cartridge rearwardly onto the shelf 168 by the rearward movement of the bolt, the block 102 being carried by the bolt. The rearward movement of the frame causes the cross head 186 to be fed laterally at an angle when the pin 190 pas es through the inclined portion 194 of the slot 192. This causes the pins 180 to move in the arcuate slots 178' and swings the levers 170 on their pivots to the position shown in Figure 4 of the drawings, feeding the cartridge into the frame in front of the bolt, and thus positioning it to be fed into the firing chamberupon the forward movement of the bolt. The pin 190 enters the inclined portion of the slot 192 after the independent movement of the bolt has been completed and the bolt is in withdrawn po sition.

tion'by the spring 18 which has been placed under tension by the rearward movement of the frame. The cross head 212 is engaged by the latch lever 216 and retained in the dotted line position shown in Figure 7 of the drawings to place the gun in proper position for firing.-

It is to be understood that the form of the invention herewith shown and described is to be taken as a preferred example of the same, and that various changes in the shape, size, and arrangement of parts may be resorted to without departing from the'spirit of the invention or the scope of the subjoined claims.

Having thus described my invention, I

claim jacent said bolt, a racli formed on said bolt carried by said support exteriorly of saidframe and engaging said shaft to restrain revolution of said shaft during a part of the rearward movement of said frame.

2. In a machine gun, a stationary support, a frame movably mounted thereon, a barrel secured to said frame, a bolt mounted in said frame, a shaft mounted in said frame, a pinion carried by said shaft adjacent said bolt, a rack formed on said bolt and meshing with said pinion, means carried by said support I exteriorly of said frame to engage said shaft and restrain revolution of said shaft during a part of the rearward movement of the frame, a breech bolt lock mounted in said frame, and means controlled by the movement of the frame to move said breech bolt lock to an inoperative position during the period when said shaft is restrained from revolution.

3. In a machine gun, a stationary support, a frame movably mounted thereon, a barrel secured to said frame, a bolt mounted in said frame, means operable by the movement of the frame to move said bolt independently of said frame during a part of the movement of said frame, a breech bolt lock mounted in said frame, and means controlled by the movement-of the frame to move said breech bolt lock to an inoperative position prior to the independent movement of said bolt.

4. In a machine gun, a stationary support, a frame movably mounted thereon, a bolt mounted in said frame, a vertically movable breech bolt lock mounted in said frame and adapted to lock said bolt in position, a lever connected to said breech bolt lock, said lever being pivotally mounted insaid frame, aplate mounted on said support, said plate being provided with a slot having an inclined portion, and a roller carried by said lever and arranged in said slot.

and meshing with said pinion, a second pinion mounted on said shaft exteriorly of said frame, and a rack formed on said support and meshing with said second pinion during a part of the rearward moitement of said frame.

6. In a machine gun,'a support, a frame movably mounted on said su port, a bolt mounted in saidframe, a shaft mounted in said frame, a pinion carriediby said shaft adjacent said bolt, a rack formed on said bolt and meshing with said pinion, a second pinion mounted on said shaft cxtcriorly of said frame, a rack formed on said support and meshing with said second pinion during a part of the rearward movement of said frame, and means for restraining the revolution of said shaft when said rack and second pinion are disengaged.

7 In a machine gun, a support, a frame movably mounted on said support, a bolt mounted in said frame,a shaft mounted in said frame, a pinion carried by said shaft adjacent said bolt, a rack formed on said bolt and meshing with said pinion, a second pinion mounted on said shaft eXteriorly of said frame, a rack formed on said support and meshing with said second pinion during/a part of the rearward movement of said frame, a segmental roller mounted on said shaft adjacent said second pinion, and a plain surface arranged on said support beyond each endof said rack and adapted to be engaged by a portion of said roller to restrain revolution of said shaft.

8. In a machine gun, a frame having an ejector opening, a bolt movablymounted in said frame, an ejector movably mounted in said bolt, a spring to force said ejector forwardly to an operative position, a lever to normally restrain the operation of said ejector, and means controlled by the movement of the bolt to release said lever.

9. In a machine gun, a frame having an ejector opening, a bolt movably mounted in said'frame, an ejector movably mounted in said bolt, a spring to force said ejector for-v wardly to an operative position, a bell crank lever to retain said spring under tension, a latch engaging said lever, and means for releasing said latch.

10. In a machine gun, a frame having an ejector opening, a bolt movably mountedin said frame, an ejector movably mounted in said bolt, a spring to force said ejector forwardly to an operative position, a bell crank lever to retain said spring under tension, a latch engaging said lever, means for releasing said latch, and independent means for resetting said bell crank lever.

11. Ina machine gun,a frame having an ejector opening, a'bolt movably mounted n said frame, an ejector movably mounted in said bolt, a spring to force said e ector forwardly to an operative position, a bell crank lever to retain said spring under tension, a latch engaging said lever, means for releasing said latch, independent means for resetting said bell crank lever, and means for returning said latch to operative position.

12. In a machine gun,.-a frame having a cartridge feeding opening, a bolt movably mounted in said frame, a gripping member carried by said bolt and adapted'to pos tlon a cartridge adjacent said opening, a pair of arms arranged adjacent said opening and adapted to force saidcartridge through said opening, and means for moving said arms inwardly toward said opening.

13. In a machine gun, a support,;a frame movably mounted on said support and provided with a cartridge feeding opening, a bolt movably mounted in said frame, means controlled by the movement of the bolt for positioning a cartridge adjacent said opening, a pair of cross arms pivoted at their outer ends arranged adjacent said opening, and means controlled by the movement of the frame for swinging said arms on their pivots to feed a cartridge through said opening.

14:. In a machine gun, a support,;a frame movably mounted on said support and provided with a cartridge feeding opening, a shelf carried by said frame and arranged adjacent said opening, a bolt movably mounted in said frame, a cartridge gripping member carried by said bolt and adapted to position a cartridgeon said shelf adjacent said opening, said shelf being provided with apair of arcuate slots, a pair of crossed arms pivotally mounted on said shelf,pins carried by said arms and extending through said slots,:and

means controlled by the movement of the frame for swinging said arms on their pivots to feed a cartridge through said opening.

' 15. In a machine gun, a support, a frame movably mounted on said support and provided with a cartridge feedingopening, a shelf carried by said frame and arranged adjacent said opening, a bolt movably, mounted in said frame, a cartridge gripping member carried by said bolt and adapted to position a cartridge on said shelf adjacent said opening, said shelf being provided with a pair of arcuate slots, a pair of crossed arms pivotally mounted on said shelf, pins carried by said.

arms and extending through said slots, a plate carried. by said sup-port and arranged beneath said shelf, said plate being provided with a slot having an inclined portion, a cross head arranged over said plate, the ends'of said pins being received 1n said cross head, and a roller carried'by said cross head and arranged in said slot.

In testimony whereof, aflix my signature.

HARRY EARRING.