US2857814A - Feeding mechanism for a firearm - Google Patents

Description

, c. H. TAYLOR 2,857,8145

FEEDING MECHANISM FOR A FIREARM 4 Sheets-Sheet 1 Oct. 28, 1958 Filed April 4, 1956 INVENTOR.

- 41 5. iQJd-M Oct. 28, 1958 c. H. TAYLOR FEEDING MECHANISM FOR A FIREARM 4 Sheets-Sheet 2 Filed April 4, 1956 INVENTOR. BY Basil 111 1371131 Oct. 28,1958 c. i-I; TAYLOR 2,857,814

FEEDING MECHANISM FOR A FIREARM Filed April 4, 1956 4 Sheets-Sheet 3 INVENTOR.

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5m Q I vlw vw mo. W w om v mm mm mm mfimmn United States Patent Oil-ice 2,857,8l4 Patented Oct. 28, 1958 FEEDING MECHANISM FOR A FIREARM Cecil H. Taylor, New Milford, Conn., assignor to the United States of America as represented by the Seeretary of the Army Application April 4, 1956, Serial No. 576,223

6 Claims. (CI. 89-33) This invention relates to feeding mechanisms for automatic firearms and more particularly to feeding mechanisms for firearms which are fed by a belt of linked cartridges.

Heretofore, with those firearms of automatic type wherein the feeding mechanism is operated directly by the firearm to feed a linked belt of cartridges to the receiver, considerable trouble has been experienced due to the excessive stress placed upon the belt while being drawn to the receiver by the.feeding mechanism. The reason for this strain is that the feeding mechanism is operated, whether by recoil forces or by gases bled from the barrel, during only a portion of the operating cycle. The action on the belt, therefore, is intermittent and is subject to rapid acceleration, especially with rapid fire .guns.

It is an object of this invention to provide a feeding mechanism which isolates the linked belt from the excessive acceleration to which the mechanism is subjected by the rapid and intermittent requirements of the gun.

It is another object ofthis invention to provide a feeding mechanism which handles the cartridge belt and strips the cartridges positively therefrom without the use of pawls or springs. v g

It is still another object of this invention to provide such a feeding mechanism which is entirely gun operated and controlled.

It is another and still further object of this invention to provide such a feeding mechanism which is compact and rugged in construction and which permits ready accessibility, without the use of tools, to the pathway of the cartridges to correct any malfunctions of the feeder.

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 shownin the accompanying drawings in which:

Fig. 1 is a partially cross-sectioned top view of the feeding mechanism;

Fig. 2 is a view taken along line 22 of Fig. 1 and shows the crane mechanism in normal position;

Fig. 3 is a view similar to Fig. 2 but shows the sprocket mechanism moved away from normal position by the inertia of the sprocket belt;

Fig. 4 is a view taken along line 4-4 of Fig. l with the crane mechanism in the normal position shown in Fig. 2;

Fig. 5 is a view similar to Fig. 4 but with the crane mechanism moved to the position shown in Fig. 3; and

Fig. 6 is a longitudinal cross-sectioned side view of the feeding mechanism. f

Shown in the figures is a feeding mechanism 12 which is adapted to feed a supply of cartridges 14 to a revolvertype firearm 16 having a rotatable drum 18 with five equally-spaced chambers 20 therein to receive thecartridges. Cartridges 14 are carried to firearm 16 by means of a belt 22 comprised by a plurality of articulately joined cartridge gripping links 24 from which the cartridges may he pried sideways. Drum 18 is mounted on a drum shaft 26 which is rotated by a gun actuated gas system (not shown) during the firing portion of the cyclic operation of firearm .16.

Feeding mechanism 12 is contained within a case 28 mounted on the firearm receiver 30 which extends as a platform rearwardly and below drum 18. The rear end of drum shaft 26 is provided with a splined axial bore 32 which slidingly receives the front end of a matingly splined axle 34. Axle 34 is longitudinally aligned with drum shaft 26, and the rear end is rotatably supported by a bearing 36 which is flanged and bolted to the rear end of case 28. Fixedly mounted on axle 34 is a feeder sprocket 38 provided with five channels 40 which are longitudinally aligned with chambers 20 in drum 18. Whereby, the cartridges 14 carried in channels 40 are slidable into chambers 20 by means of a two-step rammer mechanism 41.

Pivotally mounted to axle 34, as hereinafter described, is a crane 42 which includes a pair of substantially similar supporting triangular end plates 44. Each one of the end plates 44 is rotatably mounted at corresponding apexes on hearing portions provided on axle 34 adjacent the opposite ends thereof. Mounted between corresponding ones of the remaining apexes of the end plates 44 are a tubular support 50, which is fixed thereto as by welding so that such end plates are parallelly aligned, and a cylindrical shaft 52, which is rotatably mounted to said end plates 44 by means of bushings 54 fixed to the remaining ones of the apexes.

A pin 56 is mounted, longitudinally to firearm 16, in the upper left-hand corner of the rear end of case 28 by means of a pair of spaced lugs 58 integral with such case, and pivotally mounted on such pin to transverse such case is an air spring device 60 having a cylinder 62 and a piston 64. Another longitudinally disposed pin 66 is mounted between a pair of spaced lugs 68, provided on the right side of case 28 below and rearwardly of pin 56. Fixedly mounted on pin 66 in alignment with piston 64 is an arm 70, the free end of which is received by a slot 72 in piston 64 and is pivotally mounted thereto by means of a pin 74. Fixedly mounted on pin 66 in alignment with the rear one of the end-plates 44 is an arm 76 which is connected by a link 78 to such rear end plate between axle 34 and shaft 52. Link 78 is of such length that shaft 52 is positioned thereby above axle .34.

Air spring 60 is-arranged to resiliently force arm 70 into contact with a stop 80, fixed to the insideof case 28, and against the drag of cartridge belt 22 as hereinafter noted. Arms 70 and 76 are so fixed to pin 66 that when arm 70 is in contact with stop 80 and is in a vertical position, arm 76 is related thereto at an oblique angle so as to extend from such pin downwardly inward into case 28. Whereby, crane 42 is pivotable in a clockwise rotation against the resiliency of air spring 60 by the inertia of cartridge belt 22 as hereinafter noted. Fixedly mounted to shaft 52 above feeder sprocket 38 is a pair of fourchanneled stripper sprockets 82 which are formed and spaced so as to grippingly receive opposite ends of the larger diameter portion of cartridges 14. Fixed to the rear end of axle 34 is a gear 84 which meshingly engages a gear 86 fixed to shaft 52 and which has a five-tofour ratio with such gear. Whereby, when axle 34 is rotated by drum shaft 26, the four channels of. stripper sprockets 82 align during rotation with the five channels of feeder sprocket 38.

A feedway 87 for cartridge belt 22 is formed by a tray 88, which sets down in the top of case 28 to rest on ledges 90 formed therein with a pair of dowels 89 extending upwardly from such ledges releasably holding such tray, and a cover 92, which incloses the top of such case above the stripper sprockets 82. Cover 92 is hinged at the forward end and suitable pawl means (not shown) releasably holds such cover in closedposition and permits easy access to cartridges 14 in feeding mechanism 12 in event of malfunction. Suitable openings 93 in the sides of case 28permit entry of cartridge belt 22 through the right side off-the case and ejection'of-the empty 'links 24; from the left side. A suitable opening-98 is provided in tray 8 8. to permit projection of stripper Sprockets 82. upwardly therethrough and the passage of cartridges 14 after being stripped from links 24fas hereinafter'described.

To prevent fouling of cartridge belt; 2 2 with tray88, a

-T-rail 180 depends'from'the inside of cover- 92 and, eX-

tends between openings--98. -T-rail-100 is slidingly engaged byapair of oppositely disposed 11138102 provided in the top sidesof links 24 so that suchlinks are slidable alongsuch-T-rail as'cartridge belt-'22 is ,Pulled through the feedway by stripper sprockets 82. "To increase the time of engagement-between cartridges'l tand stripper sprockets- 82, tray-88 and covey-9 2 are transversally arched, as noted at-104.

Fixedly mounted to support -50-is a pair of strippers 106which are longitudinally aligned with stripper sprockets 8 2 and extend upwardly into feedway 87 through openingx98. Strippers 106 are arcuately formed so as to' encircle stripper sprockets 82 and are terminated by prong portions 108 which are insertable between links 24, being carried by the stripper sprockets, and cartridges 14 engaged thereby to pry such cartridges loose. The inside curves of strippers 106 are shaped to hold stripped cartridges'14 in stripper sprockets 82 until transferred therefrom to feeder sprocket 38.

In order to prolong the engagement between cartridges 14 and their respective links 24, and thereby assure proper engagement between the following cartridge and the channels of feeder sprocket 38, there is provided a guide member 110 whichis pivotally mounted, as hereinafter described, between stripper sprockets 82 on shaft 52. Guide 110 is an arcuately formed shell having a rectangular cross-section and has one end which is elliptically formed, as noted at 112, so as to encircle shaft 52 passing therethrough. Guide 110 is mounted for pivotal movement on shaft 52 by means of a bearing 114 fixedly mounted, as by welding means, in elliptical portion 112. A pin 116 extends longitudinally, respective to firearm 16, through the opposite end of guide 110, and rotatably mounted on the front end of such pin is a roller 118 which is slidingly received by a rail 120 having the same radius as such guide and is bolted to the front end of case 28 so as to guide the tail end of guide 110 when crane 42-oscillates.

The arcuate contour of guide 110 is such-that the outside surface thereof, noted at 122, acts as a ramp to prolong the engagement between cartridges 14 and the associated links 24 while being carried by stripper sprockets 82 and pried apart by strippers 106. The inside curves of strippers 106 are shaped to conform to the path imposed upon cartridges 14 by guide 110. The contour of the inside surface of guide 110, noted at 124, is shaped to retain cartridges 14 in feeder sprocket 38 after being passed thereto by stripper sprockets 82 and beforebeing rammed into chambers by rammer mechanism 41.

' When firearm 16 is operated, rotating drum 18 causes a counterrotation of stripper sprockets 82 by means of axle 34, whichis splined to drum shaft 26 andrneshing gears 84 and ,86. As stripper sprockets 82rotate, they successively engage cartridges 14 in cartridge belt 22 to draw such cartridgebelt into feedway 87 where strippers 106 separate the cartridges from the engaging links while being carried by stripper sprockets 82. After heing separated, links 24 continue along T-rail 100 to the outside of firearm 16, and cartridges 14 are carried around by stripper sprockets 82 with the inside curve of strippers 106 retainingthe cartridges in engagement with the stripper sprockets until transferred therefrom to feeder sprocket 3 8; Theinsidecontour, 124 of. guide 110 retains cartridges ;14 in engagernentwith feeder :sprocket 38 until rammed into chambers 20 of drum 18 by rammer mechanism 41.

As cartridge belt 22 is accelerated by the intermittent rapid rotation of stripper sprockets 82 during the power portion of the operating cycle of feeding mechanism 12, the inetria of the belt plus the tooth pressure of gears 84 and 86 exert a force which swings crane 42 away from stop 80, thus, energizing air spring 60 which returns crane 42 to normal position, when the acceleration stops, to draw cartridge belt 22 engaged by the stripper sprockets into feedway 87.

The accelerative force applied against cartridgebelt 22 is, thus, cushioned and the intermittent rotation of drum 18 converted to substantially continuous linear movement of the cartridge belt through the oscillation of crane 42. In effect, there is formed between the limits of the oscillating movement of crane 42 and the associated stripper 186 and stripper sprockets 82,.mounted thereto, a bank of cartridges 14 from which cartridges may be withdrawn without substantially moving cartridge belt 22 and without starving firearm 16. Thus, cartridge belt 22 is isolated from the acceleration forces produced by the intermittent rotation of drum shaft 26. The arch in cover 92, the arcuate contours of the outer surface 122, the inner surface 124 of guide 110, and the contour of the inner curve of strippers 106 assure control of cartridges 14 during travel within feedway 87 while crane 42 oscillates. Further, as gears 84,and 86 have a fiveto-four ratio, the spaces between the channels of feeder sprocket38 and stripper sprockets 82 positively register for every-position of crane42 for transferring cartridges 14 therebetween.

From the foregoing it is clearly apparent that there is herein provided a novel feeding mechanism which isolates the cartridge belt from excessiveaccelerationfand strain, which handles the cartridge belt and strips the cartridges positively therefrom without the use of pawls or mechanical springs, which is entirely gun operated and controlled and which is compact, rugged in construction, and readily accessible in event ofmalfunction.

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

I claim:

1. In a firearm, a mechanism actuated by the firearm during a portion of the cyclic'operation thereof for-feeding the firearm with a supply of cartridges carried by-a belt of joined cartridge engaging links, said mechanism including a stripper device intermittently actuated by the firearm for moving the belt into the firearm and stripping the cartridges from the links during actuation ofs aid stripper device, crane means for pivotally mounting said stripper device so as to be movable against the direction of movement of the belt by the greater inertia of the belt when said stripper device is actuated, and resilient means for pivoting said crane means in an opposite direction between actuations of said stripper device to continue drawing the belt towards the firearm.

2. In a firearm having a drumintermittently rotated by the firearm on an axle rotatable therewith and provided with a plurality of chambers for receiving" cartridges carried to the firearm by a belt of cartridge engaginglinks, a feeding mechanism including a feeder sprocket synchronized with the drum, channels in;s aid feeder sprocket aligned with the chambers, a feedway, a crane mounted for pivotal movement about the axle, a shaft rotatably mounted to said crane for oscillation therewith, a pair of meshed gears mounted to said shaft and the axle for transmitting the intermittent rotation' of the drum to said shaft, a pair of spaced stripper sprockets mounted on said shaft for rotation thereby, channels in said stripper sprockets for successively engaging the cartridges in the belt to draw the belt along said feedway and carry the cartridges to said feeder sprocket for passage to the chambers, stripper means mounted to said crane for stripping the cartridges from the links and for retaining the cartridges in said stripper sprockets until transferred to said feeder sprocket, an arcuately formed guide mounted on said shaft between said stripper sprockets for arcuate oscillation therewith, an-inside surface on said guide for retaining the cartridges in said feeder sprocket until rammed into the chamber, and an outside surface on said guide extending into said feedway for prolonging engagement between the cartridges and the links engaging the cartridges while being separated by said stripper means until the following one of the cartridges in the belt is engaged by said stripper sprockets.

3. In a firearm supplied with cartridges from a linked belt, a feeding mechanism including a movable crane device, sprocket means rotatably mounted to said crane for oscillation thereby and engaged with the belt, said sprocket means being disposed for intermittent rotation by operation of the firearm for engageably drawing the belt thereinto, and resilient means cooperating with said crane device and subject to the inertia of the belt by the intermittent rotation of said sprocket means for converting the intermittent actuation thereof to continuous movement of the belt towards the firearm.

4. In a firearm supplied with cartridges from a linked belt, a feeding mechanism including sprocket means engaged with the belt for actuation thereof toward the firearm, means actuated by the operation of the firearm for intermittently rotating said sprocket means during a portion of the operation cycle of the firearm to draw the belt into the firearm, a crane device for mounting said sprocket means so as to be oscillatable in line with the belt and actuatable against the direction of movement of the belt by the inertia of the belt when said sprocket means is rotated, and resilient means engageable with said crane device to be energized by said crane device when actuated against the direction of movement of the belt for moving said sprocket means to advance the belt toward the firearm between the periods of rotation of said sprocket means.

5. In an automatic firearm having a drum rotated during a portion of an operating cycle thereof, the combination of a belt for releasably joining a plurality of car tridges, a sprocket engaged with said belt for advancing the cartridges therein into the firearm, means for operationally connecting said sprocket means to said drum for rotation therewith whereby said sprocket is intermittently energized to overcome the inertia of said belt for the advancement thereof into the firearm, a crane for mounting said sprocket for oscilalting movement in the plane of the movement of said belt, a pivotal linkage con nected to said crane, a stop member engageable by said linkage when said sprocket is positioned for movement against the direction of movement of said belt through the resistance of. said belt to the rotation of said sprocket, and a resilient member engaged with said linkage for the biasing thereof against said stop and said crane in a direction to move said sprocket for continuing the advance ment of said belt into the firearm between the intermit tent rotations of said sprocket.

6. The combination as recited in claim 5 wherein said means for operationally connecting said sprocket to the drum includes an axle connected to the drum for rotatation therewith, a shaft for rotatably mounting said sprocket to said crane, and a pair of meshed gears respectively mounted to said axle and shaft for transferring the rotation of the drum to said sprocket, and said pir of gears being disposed to aid the inertia of said belt in moving said sprocket against the direction of movement of said belt when rotated by the drum.

References Cited in the file of this patent UNITED STATES PATENTS 2,396,136 Trotter Mar. 5, 1946 2,644,365 Maillard July 7, 1953 2,803,169 Linke Aug. 20, 1957 FOREIGN PATENTS 558,950 Great Britain Jan. 28, 1944

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