US3311021A

US3311021A - Feed mechanism

Info

Publication number: US3311021A
Application number: US452412A
Authority: US
Inventors: Frederick P Reed
Original assignee: Individual
Current assignee: Individual
Priority date: 1965-04-30
Filing date: 1965-04-30
Publication date: 1967-03-28
Anticipated expiration: 1984-03-28

Description

March 28, 1967 F. P. REED 3,311,021

FEED MECHANISM Filed April 30, 1965 6 Sheets-Sheet 1 8O El g l INVENTOR FreflerirfkEReefl.

ATTORNEYS 6 Sheets-Shet 2 F. P. REED FEED MECHANISM March 28, 1967 Filed April 30, 1965 INVENTOR F'IEflETIE-kiEREEfi.

K 8 ATTORNEYS BY M E, g I

March 28, 1967 F. P. REED 3,311,021

FEED MECHANISM Filed April 50, 1965 6 Sheets-Sheet 5 INVENTOR FrEflEriBkEREEi ATTORNEYS March 28, 1967 REED 3,311,021

v FEED MECHANISM Filed April 50, 1965 6 Sheets-Sheet 4 80 INVENTOR FIEflEIiEkEEEEEL ATTORN EYS March 28, 1967 Filed April 30, 1965 F. P. REED FEED MECHANISM 6 SheetsSheet 5 BY ALzuw /4. 5 1% INVENTOR IOO Freflan' Bk EREEIi W AG ATTORNEYS 2 March 28, 1967 F. P. REED 3,311,021

FEED MECHANISM Filed April 30, 1965 6 Sheets-Sheet 6 FE LLEL INVENTOR FrEHETiBkEREEEL ATTORNEYS United States Patent Office 3,311,021 FEED MECHANISM Frederick P. Reed, Ludlow, Mass., assignor to the United States of America as represented by the Secretary of the Army Filed Apr. 30, 1965, Ser. No. 452,412 9 Claims. (Cl. 89-33) The invention described herein may be manufactured and used by or for the Government for governmental purposes without the payment to me of any royalty thereon.

This invention relates to firearms and pertains more particularly to the feeding mechanisms thereof.

A type of cartridge has been developed for modern warfare use in which the nose of the projectile is very fragile. This creates problems when the cartridge is used in a machine gun type weapon as the cartridge must be moved from a belt into the barrel chamber without ramping, which might fracture the nose of the projectile, and without forward acceleration. This is accomplished by designing a machine gun in which the cartridges are fed radially to a position in alignment with the barrel, actuating the barrel to envelope the cartridge for firing, and then moving the enveloped cartridge slightly rearwardly for engagementwith the extractor.

It is the object of this invention to provide for such a machine gun a feed mechanism which will successively deliver a supply of cartridges radially into alignment with the barrel at an indexed position, hold the cartridges in the indexed position for envelopment by the reciprocating barrel, and then eject the fired case from the gun.

The specific nature of the invention as well as other objects and advantages thereof will clearly appear from a description of a preferred embodiment as shown in the accompanying drawings in which:

FIG. 1 is a fragmentary, laterally cross-sectioned view of the gun at the location of the feed mechanism;

FIG. 2 is a forward extension of FIG. 1;

FIG. 3 is a view taken along line 33 of FIG. 1;

' FIG. 4 is a view taken along line 44 of FIG. 1 and shows the barrel in its rearward battery position;

FIG. 5 is a view taken along line 55 of FIG. 4;

FIG. 6 is a view similar to FIG. 4 but shows the barrel located adjacent its forward loading position during the forward stroke thereof;

FIG. 7 is a view taken along line 77 of FIG. ,6;

FIG. 8 is a view similar to FIGS. 4 and 6 but shows the barrel located between the forward and rearward positions during the rear stroke thereof and a cartridge held in the indexed position; 7

FIG. 9 is a view taken along line 99 of FIG. 8;

FIG. 10 is a view taken along line 10-10 of FIG. 8;

and

FIG. 11 is a perspective exploded view of the feed pawl device.

Shown in the figures is a machine gun 12 having a receiver 14 which slidingly supports a barrel 16 for reciprocation between a forward loading position and a rearward battery position. Mounted on the top of receiver 14 is a sprocket device 18 which is operated in synchronization with barrel 16 by a separate power means (not shown) and which engages with a cartridge belt 20 for pulling cartridges 22 carried therein to a feed trough 24 within a housing 26. Provided in housing 26 is a stripper 28 for removing the cartridges 22 from cartridge belt 20 so that the cartridges are free thereof when delivered to a pickup station Y in feed trough 24 as best shown in FIG. 3. The cartridges are releasably held in pickup station Y by a pair of spring-pressed plungers 29.

Cartridges 22 are moved from pickup station Y to an indexed position X in receiver 14, in axial alignment with barrel 16, by means of a feed mechanism 30. Feed mechanism 30 includes a feed lever 32 which is mounted for pivotal displacement by means of an axle 34 which extends laterally into receiver 14 from the left side thereof, looking towards the front of the machine gun 12 from the rear end. Formed in feed lever 32 is a cam slot 36 which cooperates with a stud 38 fixed to barrel 16 for converting longitudinal displacement thereof to pivotal displacement of the feed lever so that the feed lever is raised during the forward stroke of the barrel and lowered during the rearward stroke. Formed in the rear end of feed lever 32 is a modified dolls head the sides of which are flattened to form an arcuate bearing surface 48 and a finger 42 extends rearwardly therefrom, which bearing surface and finger have functions which will be explained hereinafter.

Cartridges 22 are successively moved from pickup station Y to indexed position X by means of a feed pawl device 44 which includes a slide 46 of T-configuration in cross-section. Slide 46 is slidingly received in a mating T-slot 48 vertically formed in the left side of receiver 14 and such slide includes a plate 50, an arm 52 which extends outwardly from the top of the plate, and a tang 54 which extends outwardly from the bottom end of the plate. A rectangular opening 56 is provided in plate 50 approximately midway the length thereof and a channel 58 extends downwardly in the back of plate 50 from the top thereof to such opening. Mounted on arm 52 is a feed pawl 60 which is arranged to pass over cartridge 22, when in pickup station Y, during upward travel of slide 46 and to drive the cartridge downwardly to indexed position X during downward travel. T-slot 48 is located so that feed pawl 60 contacts cartridge 22 at the center of gravity thereof.

Feed pawl device 44 is reciprocal in upward and downward strokes. The upward stroke is effected by feed lever 32 through the contact of bearing surface 40 thereon with a release pawl 68 which is rotatingly mounted on slide 46 in opening 56 by means of a pin 70 that extends longitudinally thereacross. Release pawl 68 includes a bottom arm '72 which is pressed inwardly by spring 74 so that the end is c'ontactable by bearing surface 40 to transfer upward displacement of feed lever 32 to feed pawl device 44. Release pawl 68 also includes an arcuate surface 76 formed on the release pawl above pin 78. Arcuate surface 76 is engageable during the upward stroke of slide 46, with a cam surface 78 which is formed on a removable stop pawl plate 88 so as to be in registry with channel 58 and receivable thereby, as shown in FIG. 3. Contact of arcuate surface 76 with cam surface '78 rotates release pawl 68 so as to be disengaged from bearing surface 40 for release of feed pawl device 44 from feed lever 32.

A bore 82 is formed in the left side of receiver 14 in back of T-slot 48 and parallel therewith for receiving a compressible coil spring 84. A month 87 provides communication between T-slot 48 and bore 82 along the length thereof and such mouth receives a tang 88 extending from the bottom end of slide 46 into the bore for contact with the bottom end of spring 84. The top end of spring 84 butteresses against stop pawl plate 80. Thus, spring 84 is loaded during the upward stroke of feed pawl device 44 and the stored energy therein drives the feed pawl device downwardly when release pawl 68 is disengaged from bearing surface 40.

Cartridge 22 is held in indexed position X, after being displaced thereto by feed pawl device 44, through the three-point contact of case 66 by feed pawl 60, a stop pawl 90 and a holding pawl 92. Stop pawl 90 is rotatingly mounted on the bottom end of stop pawl plate by means of a longitudinally disposed pin 94 and is biased in a counterclockwise direction, looking towards the Patented Mar. 28, 1967 I front end of gun 12 from the rear end thereof, by a spring 96. Stop pawl 90 includes a first arm 98 which extends upwardly into receiver 14 for terminal contact with case 66 of cartridge 22, when in indexed position X, at the same cross-sectional area contacted by feed pawl 60, and an arcuately formed second arm 100' which extends downwardly from pin 94 so as to be positionable under slide 46.

First arm 98 is biased by spring 96 to a normal position in contact with the inside surface of the left side of receiver 14, as shown in FIG. 6, so as to be 'out of the way of case 66 when ejected therefrom as hereinafter explained. First arm 98 is actuated from its normal position by contact of a cam surface 102 formed on the bottom of tang 54 with a rounded protuberance 104 on the first arm when feed pawl device 44 is adjacent the end of its downward stroke. Through the cooperation of cam surface 102 with protuberance 104, the end of first arm 98 is positioned for holding contact with cartridge 22 and for contact with a ramp 106 which extends outwardly and forwardly from the rear end of barrel 16 so that the first arm is cammed out of the way when the barrel moves into battery position. A shaft 108 extends downwardly from the bottom end 'of slide 46 for contact by second arm 100 during displacement of stop pawl 90 by ramp 106 so that the displacement of the stop pawl by barrel 16 is transferred to slide 46 for moving feed pawl 60 also clear of interference with the rearward displacement of the barrel.

Holding pawl 92 is pivotally mounted on the upper end to the right side of receiver 14 by a laterally disposed pin 110 so as to depend into the receiver to make the third point of contact with cartridge 22 and hold such cartridge in indexed position X in registry with the bore of barrel 16. Holding pawl 92 is biased to the cartridge holding position by a torsion spring 112 and is arranged to be swung upwardly out of interference with barrel 16 by contact of the rear end thereof when proceeding to battery position. After cartridge 22 is fired, case 66 is ejected downwardly through an opening 114 in the bottom of receiver 14 by an ejector device 116. Ejector device 116 includes a carrier 118 which is of T-configuration in cross-section and which is slidingly mounted for vertical displacement in 'a mating slot 120 in the left side of receiver 14 rearwardly of slide 46. Pivotally mounted on the top end of carrier 118 is a springbiased ejector pawl 122 which is arranged to slip over case 66 during upward displacement of carrier 118 and to drive the case downwardly during the downward displacement thereof. Slot 120 is located so that ejector pawl 122 contacts fired case 66 at the center of gravity thereof to facilitate ejection.

A bore 124 is formed in back of slot 120 parallel therewith for housing a spring 126 and a mouth 128 provides communication between the bore and slot so that a lug 130 on the bottom of the carrier is etxendable into such bore for contact with the bottom end of the spring. Thus, spring 126 is loaded when ejector device 116 is moved upwardly and drives the ejector device downwardly when released.

Ejector device 116 is actuated upwardly by finger 42 on feed lever 32 through the contact of the finger with a downwardly facing lip 131 formed on a spring-biased latch 133 mounted on carrier 118 so as to extend therefrom. Finger 42 and lip 131 are so arranged that the lip passes dead center, respective to the radius of feed lever 32, while the feed lever is driving ejector device 116 upwardly. After passing dead center, finger 42 begins to move off lip 131 and, when ejector device 116 is displaced upwardly to where ejector pawl 122 has slipped over case 66 and into driving engagement therewith, the finger is finally moved out of contact with the lip, whereby the ejector device is freed to be snapped downwardly by spring 126 to eject the case through opening 114.

Fired case 66 is held back during forward stroke of barrel 16, so as to be extracted therefrom, by an extractor 132. Extractor 132 is mounted in the left side of receiver 14 rearwardly of ejector device 116 for limited lateral displacement. A spring 134 presses extractor 132 inwardly to an engaging position. A cam face 136 on the front edge of the extractor 132 is contactable by the rim of case 66 so that, when cartridge 22 is pressed rearwardly against su h face by barrel 16 during envelopment, the extractor is actuated outwardly to ride over the rim and then pops inwardly to engage extractor groove 138 for extracting the case from barrel 16 when the barrel is displaced forwardly.

Operation When machine gun 12 is ready to be fired, barrel 16 is in battery position with cartridge 22 enveloped thereby. Extractor groove 138 of the enveloped cartridge 22 is engaged by extractor 132 and, as shown in FIG. 1, holding pawl 92 is cammed upwardly out of the way of barrel 16, stop pawl is cammed downwardly out of interference therewith, and feed pawl 60 is raised by the stop pawl out of contact with the barrel. I

After the enveloped cartridge 22 is fired, barrel 16 is actuated forwardly by the outside power source (not shown), moving stud 33 along cam slot 36 to convert forward displacement of the barrel to upper displacement of feed lever 32. When forward displacement of barrel 16 is initiated, fired case 66 is held back by extractor 132 to be extracted from the barrel. With the upward pivotal displacement of feed lever 32, feed pawl device 44 and ejector device 116 are also displaced upwardly, the feed pawl device through the contact of bearing surface 40 with release pawl 68 and the ejector device through the contact of finger 42 with the lip 131.

During upward displacement of feed pawl device 44, feed pawl 60 moves over the cartridge 22 which has been moved to pickup station Y by sprocket device 18 and; during upward displacement of ejector device 116, ejector pawl 122 moves over fired case 66. When ejector pawl 122 is located above fired case 66 and the rear end of barrel 16 is clear thereof, finger 42 slips out of contact with lip 131 to release ejector device 116 which is imme diately snapped downwardly by the loaded spring 126 causing ejector pawl 122 to eject the case held by extractor 132 out of receiver 14 through opening 114. After case- 66 is ejected and feed pawl device 44 approaches the end of its upper stroke, cam surface 78 is contacted by arcuate surface 76 on release pawl 68 causing the release pawl to be pivoted free of bearing surface 40. Thus, feed pawl device 44 is freed to be driven downwardly by spring 84 causing cartridge 22 in pickup station Y to be moved to index position X and cam surface 102 on tang 54 acts on protuberance 104 to move first arm 98 of stop pawl 90 to the holding position.

While barrel 16 was moved forwardly, holding pawl 92 was snapped down into holding position as the end of the barrel moved thereby. Also, before fired case 66 was ejected, ramp 106 moved out of contact with stop pawl 90 which was thereby freed to be biased to its normal position clear of opening 114 so that it would not interfere with the ejection of case 66. Thus, when cartridge 22 was displaced to the indexed position X by feed pawl device 44, it was contacted at three points by feed pawl 60, holding pawl 92, and stop pawl 90 to be firmly held thereby in alignment with the bore of barrel 16. When feed pawl device 44 reached the end of its downward stroke, bearing surface 40 snapped under release pawl 68 readying the feed pawl device for the next cycle.

During the ensuing rearward stroke of barrel 16, when the projectile of index position cartridge 22 is safely inclosed within the barrel, holding pawl 92 is cammed out of the way of barrel 16 through the contact of the holding pawl by the rear end of the barrel and ramp 106 contacts stop pawl 90 which is thereby also pivoted out of interference with the barrel. The pivotal displacement of stop pawl 90 moves second arm against the end of shaft 108, whereby slide 46 is actuated to raise feed pawl 60 clear of barrel 16. As barrel 16 moves rearwardly, feed lever 32 is pivoted downwardly and, when adjacent the end of the downward stroke, bearing surface 40 moves by release pawl 68 and finger 42 past latch 133 readying feed mechanism 30 for the next feed cycle. During the final envelopment of cartridge 22, it is forced back by barrel 16 from indexed position X to a firing position in contact with a breech-block face 140 in receiver 14 causing extractor 132 to snap into extractor groove 138.

Although a particular embodiment of the invention has been described in detail herein, it is evident that many variations may be devised within the spirit and scope thereof and the following claims are intended to include such variations.

I claim:

ll. In a machine gun having a receiver, a barrel supported by the receiver for reciprocation in forward and rearward strokes between a forward loading position and a rearward battery position, means for delivering a cartridge with a case to a pickup station outside the receiver and an extractor for removing the fired case of the cartridge from the barrel during the forward stroke thereof, a feed mechanism including a feed pawl device for transferring the cartridge from the pickup station to an indexed position in the receiver forward of the extractor and in axial alignment with said barrel, other pawl devices cooperating with said feed pawl device to releasably hold the cartridge in the indexed position for envelopment by the barrel during the recoil stroke thereof to the battery position, cooperating means on said feed pawl device and said other pawl devices to effect displacement thereof out of interference with the barrel during envelopment of the cartridge thereby, an ejector device arranged to eject the fired case from the receiver, means for slidingly mounting said feed pawl device in the receiver to contact the cartridge at the center of gravity thereof, and means for mounting said ejector device in the receiver to contact the fired case at the center of gravity thereof.

2. In a machine gun having a receiver, a barrel supported by the receiver for reciprocation in forward and rearward strokes between a forward loading position and a rearward battery position, means for delivering a cartridge with a case to a pickup station outside the receiver and-an extractor for removing the fired case of the cartridge from the barrel during the forward stroke thereof, a feed mechanism including a feed pawl device for transferring the cartridge from the pickup station to an indexed position in the receiver forward of the extractor and in axial alignment with the barrel, other pawl devices cooperating with said feed pawl device to releasably hold the cartridge in the indexed position for envelopment by the barrel during the recoil stroke thereof to the battery position, said other pawls including a holding pawl and a stop pawl arranged in cooperation with said feed pawl device for releasably holding the cartridge by three point contact in the indexed position, said stop pawl being pivotally mounted on apin and including a first arm on one side of said pin arranged for contact with the cartridge when in the indexed position and a second arm extending from said first arm on the opposite side of said pin, and cooperating means on said feed pawl device and said other pawl devices to effect displacement thereof out of interference with said barrel during envelopment of the cartridge thereby, said cooperating means including a ramp on the barrel contactable by said first arm to effect pivotal displacement thereof and a shaft on said feed pawl device contactable by said second arm for transferring displacement of said stop pawl to said feed pawl device.

3. In a machine gun having a receiver, a barrel supported by the receiver for reciprocation in forward and rearward strokes between a forward loading position and a rearward battery position, means for delivering a cartridge with a case to a pickup station outside the receiver and an extractor for removing the fired case of the cartridge from the barrel during the forward stroke thereof, a feed mechanism including a feed pawl device for transferring the cartridge from the pickup -station to an indexed position in the receiver forward of the extractor and in axial alignment with the barrel, other pawl devices cooperating with said feed pawl device to releasably hold the cartridge in the indexed position for envelopment by the barrel during the recoil stroke thereof to the battery position, said other pawl devices including a holding pawl and a stop pawl arranged in cooperation with said feed pawl device for releasably holding the cartridge by three point contact in the indexed position, cooperating means on said feed pawl device and said other pawl devices to effect displacement thereof out of interference with the barrel during envelopment of the cartridge thereby, an ejector device mounted in one side of the receiver for translational displacement toward and away from the indexed position, means for mounting said feed pawl device for translational displacement toward and away from the pickup station, a feed lever pivotally mounted to one side of the receiver, cooperating cam means on said barrel and in said feed lever for converting reciprocation of said barrel to pivotal movement of said feed lever, cooperating means on said ejector device, feed pawl device and feed lever for releasably transferring pivotal movement of said feed lever to said ejector device for displacement thereof toward the indexed position and to said feed pawl device for displacement towards the pickup station during forward stroke of the barrel.

4. The machine gun as defined in claim 3 wherein said holding pawl is mounted at one end to the receiver so as to extend thereinto for contact with the cartridge at the indexed position and so as to be pivoted out of interference with said barrel through contact thereby during the rearward stroke thereof to the battery position, and a spring disposed for biasing said holding pawl to the extended cartridge contacting position.

5. The machine gun as defined in claim 3 wherein said ejector device is provided with a carrier of T-configuration in cross-section mounted in a mating slot in one side of the receiver for translational reciprocation towards and away from the indexed position, and a spring-pressed ejector pawl pivotally mounted on said carrier and arranged to slip over the fired case held by the extractor during displacement of said carrier towards the indexed position and to drive against the fired case for ejection thereof from the receiver during displacement of said carrier away from the indexed position.

6. The machine gun as defined in claim 3 wherein said feed pawl device includes a slide of T-configuration in cross-section mounted in a mating slot in one side of the receiver for translational displacement towards and away from the pickup station, and a spring-pressed feed pawl mounted on said slide so as to slip over the cartridge in the pickup station during displacement of said slide thereto and to drive the cartridge to the indexed position during displacement of said slide away from the pickup station.

7. The machine gun as defined in claim 3 wherein said stop pawl is arranged to be spring-biased to a normal position clear of the fired case when ejected from the receiver by said ejector device, and including a cam surface on said feed pawl device disposed for engagement with a protuberance on said stop pawl for pivoting said stop pawl to a position for contacting the cartridge in the indexed position when said feed pawl device is actuated thereto from the pickup station.

8. The machine gun as defined in claim 3 wherein said cooperating means on said ejector device, feed pawl de vice and feed lever include a finger extending from said feed lever, a lip formed on a latch pivotally mounted on said ejector device so as to be contactable by said finger to actuate said ejector device towards the indexed position and into a driving engagement with the fired case held by the extractor, said lip and said finger being so related that said finger slips off said lip for releasing said ejector device from said feed lever after said ejector device has made driving engagement with the fired case, and a spring arranged for actuating said ejector device to eject the fired case when said ejector device is released from said feed lever.

9. The machine gun as defined in claim 4 wherein said cooperating means on said ejector device, feed pawl device and feed lever include a bearing surface extending from said feed lever, a release pawl pivotally mounted on said feed pawl device so as to be releasably contactable by said bearing surface to actuate said feed pawl device towards the pickup station and into driving engagement with the cartridge therein, means for pivoting said release pawl to release said feed pawl device from said feed lever when said feed pawl device makes driving engagement with the cartridge in the pickup station, and a spring arranged for actuating said feed pawl device when released from said feed lever to transfer the cartridge to the indexed position.

References Cited by the Examiner UNlTED STATES PATENTS SAMUEL FEINBERG, Primary Examiner.

S. C. BENTLEY, Assistant Examiner.

Claims

1. IN A MACHINE GUN HAVING A RECEIVER, A BARREL SUPPORTED BY THE RECEIVER FOR RECIPROCATION IN FORWARD AND REARWARD STROKES BETWEEN A FORWARD LOADING POSITION AND A REARWARD BATTERY POSITION, MEANS FOR DELIVERING A CARTRIDGE WITH A CASE TO A PICKUP STATION OUTSIDE THE RECEIVER AND AN EXTRACTOR FOR REMOVING THE FIRED CASE OF THE CARTRIDGE FROM THE BARREL DURING THE FORWARD STROKE THEREOF, A FEED MECHANISM INCLUDING A FEED PAWL DEVICE FOR TRANSFERRING THE CARTRIDGE FROM THE PICKUP STATION TO AN INDEXED POSITION IN THE RECEIVER FORWARD OF THE EXTRACTOR AND IN AXIAL ALIGNMENT WITH SAID BARREL, OTHER PAWL DEVICES COOPERATING WITH SAID FEED PAWL DEVICE TO RELESABLY HOLD THE CARTRIDGE IN THE INDEXED POSITION FOR ENVELOPEMENT BY THE BARREL DURING THE RECOIL STROKE THEREOF TO THE BATTERY POSITION, COOPERATING MEANS ON SAID FEED PAWL DEVICE AND SAID OTHER PAWL DEVICES TO EFFECT DISPLACEMENT THEREOF OUT OF INTERFERENCE WITH THE BARREL DURING ENVELOPMENT OF THE CARTRIDGE THEREBY, AN EJECTOR DEVICE ARRANGED TO EJECT THE FIRED CASE FROM THE RECEIVER, MEANS FOR SLIDINGLY MOUNTING SAID FEED PAWL DEVICE IN THE RECEIVER TO CONTACT THE CARTRIDGE AT THE CENTER OF GRAVITY THEREOF, AND MEANS FOR MOUNTING SAID EJECTOR DEVICE IN THE RECEIVER TO CONTACT THE FIRED CASE AT THE CENTER OF GRAVITY THEREOF.