US1293021A

US1293021A - Automatic machine-gun.

Info

Publication number: US1293021A
Application number: US12550416A
Authority: US
Inventors: John M Browning
Original assignee: Individual
Current assignee: Individual
Priority date: 1916-10-13
Filing date: 1916-10-13
Publication date: 1919-02-04
Anticipated expiration: 1936-02-04

Description

J. BROWNING. AUTOMATIC MACHINE GUN.

APPLICATION FILED OCT. 13. ISIS.

Patented Feb. 4, 1919. 4 SHEETS-SHEEP I Inventor.

J.- M. BROWNING. I AUTOMATIC MACHINE GUN. APPLICATION man ucr. I3. 1916.

Patented Fe b. 4, 1919.

1'. M. BROWNING.

AUTOMATIC MACHINE GUN.

APPLICATION FILED OCT. I3. I916.

Patented Feb. 4;, 1919.

4 snasrs-snszr 3 J. M. BROWNING.

AUTOMATIC MACHINE GUN.

APPLICATION FILED OCT. 13. l9l6.

Patented Feb. 4, 1919.

4 SHEETSSHEET 4- V R m E. b

Irgv E min r.

lllll I ail HEE M JOHN M. BROWNING, or OGDEN,

AUTOMATIC MAcHINE-GUN.

Specification of Letters Patent.

Patented Feb. 4, I919.

Application filed October 13, 1916. Serial No. 125,504.

To all whom it may concern:

Be it known that I, J OHN M. BROWNING, a citizen of the United States, residing in Ogden, in the county of Weber and State of Utah, have invented certain new and useful rel and recoiling members of the breech Improvements in Automatic Machine Guns,

of which the following is a specification,

reference being had to the accompanying drawings, forming a part hereof.

The invention relates generally to automatic machine guns of that description in which all operations of the mechanism are automatically effected by the energy of the recoil of the movable parts.

The invention particularly relates to novel improvements in recoil-operated machine guns in which the barrel and breech closing part recoil together while interlocked, a lim-- ited distance, are then unlocked, the movement of the barrel is arrested and the breech closing part alone continues its recoil, during which energy is stored in a reaction Y spring by which all parts are returned to the forward firing position.

The main object of the present invention is to produce an improved firearm of this class specially adapted for military service by being reliable, accurate, strong, and absolutely safe under all conditions, while very D light in weight, simple in construction, not

liable to get out of order, and inexpensive of manufacture. This object is attained by greatly simplifying the mechanism emplo ed in machine guns of this class, by provid ng a novel improved constructlon of certain members of the mechanism, thereby enabling these parts to perform several distinct functions, and thus reducing the number of the component parts, and bygiving to all parts 9 such'form that they may beplaced or removed and the entire arm may be assembled or dismounted without requiring the use of any tools.

.In the accompanying drawmgs:' s

5 Figure I, represents a right-hand side ele vation of the gun.

Fig. II, is a top view of the gun;

Fig. III, is a central longitudinal sect-ion through the gun showing the breech mechae o nism inits forward firing position.

lar to Fig. y

Ibolt, detached.

Fig. IV, is a sectional v1ew 81ml III, but with: the breech mechanism in its recoiled rearmost position. In these four figures a portion of the cooling jacket surrounding the barrel is represented as broken away.

Fig. V, is a left-hand side view of the barmechanism and of their guide, withdrawn from the breech casing.

Fig. VI, is a side view and a rear end VleWlOf the rear portion of the barrel extension- Fig. VII, is a rear end view of the barrel.

Fig. VIII, is a transverse section through the barrel extension in rear of the front wall in which the barrel is seated, looking forward.

Fig. IX, is a top view of the barrel ad justing pawl, detached.

' Fig. X, is a plan of the recoiling parts of the breechmechanism and their guide, similar to Fig. V, but seen from above.

Fig. XI, is a left-hand side view of the upper forward portions of the breech casing showing the cams inside of the casing in dotted lines.

Fig. 'XII, is a top view of a portion of the feed belt showing some cartridges in the pockets thereof and some pockets empty.

Fig. XIII, is'a transverse section through the gun at the feed channel above the barrel, showin same, ooking rearward.

Fig. XIV, is a transverse sectional view through the gun at a point in rear of the barrel, looking rearward, showing a front View of the breech bolt and of the feed extractor inits highest position.

Fig. -XV-, .is a sectional view, similar to Fig. XIV but showing the breech bolt its rear' position and the feed extractor in a lower position. 1 Fig. XVI, is a sectional view similar to- 1 s. XIV and XV, but showing the breech o t'ina position after it has returned partly forward and the feedextractor in its lowest position.

Fig. XVII, is a top view of the breech ,bolt, detached.

section through the breech olt, detached.

- ig. XIX, s a front end view of the breech a portion of the feed belt in the lever.

- Fig. XX, is a rear end view of the breech bolt, detached.

Fig. XXI, shows, on an increased scale, a side viewvand a rear view of the reaction spring guide rod, detached. Fig. XXII, is a transverse vertlcal section through a portion of the breech casing, top plate and breech bolt showing the cooking Fig. XXIII, represents the firing pin, detached, in a side view, bottom view, front view, and rear end view, and two transverse sections of the same.

Fig. XXIV, represents a vertical longitu dinal section.- of the upper rear portion 0 breech bolt with on an increased scale. Fig. XXV, represents a rear end view of a portion of the breech-bolt with the reaction spring guide rod in the released or unlocked position, on-an increased scale.

Fig. XXVI, represents a vlewsimilar to Fig. XX-V, but with the guide rod in its locked position, its lug's wedged in the eccen-.

- in a side view, detached and on an increased scale.

Fig. XXXI, represents a front end view of. the breech bolt with the feed extractor attached thereto, in its highest position, on an increased scale.

Fig. XXXII, represents a sectional view of t e head of the feed extractor, and the cam pin and shell ejector attached thereto, on an increased scale.

Fig. XXXIII, shows the rocking lever detached in several views. Similar letters refer to similar several views.

: The machine gun represented by the drawparts ings comprises the following main parts.

The breech casing A, containing the breech mechanism, is rectangular in form, having two side plates a,- a connected at the front by being firmly attached to the trunnion block D w ich closes the-casing and carries a circular flange d to which the rear end of j which are secured to the side the cylindrical barrel cooling jacket 6' is attached in the usual manner.

The rear portion of the breech casing A is closed at the bottom by the bottom' plate L and at the top by the top plate H bothof plates 0, 0:.

The forward portion of the breech casing A is open at the bottom, at the top it is the the reaction spring guide. rod locked therein,

opening the rear closed by the cover G which is hinged to tho trunnion block D, so that the cover G may be at will raised for uncovering the breech casin or closed down upon the same.

11 its closed position the cover G is se cured by the spring-actuated cover latch I, which has a limited longitudinally sliding movement on the top plate H- where .a T.- shaped rib is provided to receive and guide the latch' I the front end of which overlaps the cover G, but may be at will pressed to the rear to release said cover for opening same. J

The rear of the breech casing is closed by the rear plate J which slidesvertically between the side plates a, a and is provided with a circular hub for receiving and carrying the handle K of the gun. The rear end of the cover latch I slightly projects over the top-of the rear plate J and normally the latch locks both the cover G and the rear plate J in position, but when the cover G is released and opened, the latch I may be pressed forward sufliciently to clear the plate J which may then be upwardly withdrawn,

See Figs. I, II, III, and IV.

The barrel B passes lengthwise through the cooling jacket 6 from the front of which its muzzle projects some distance; while the rear portion of the barrel is supported in a seat provided for it in the trunnion block D. The rear or breech end of the barrel carries an annular packing and the front end of the cooling jacket 6 is fitted with a stufling box, both of the usual construction,

so that the barrel may be firmly supported at both ends for longitudinal movement witlzuzut allowing the cooling fluid in the.

.jacke to escape therefrom.

The rear end of the barrel B is firmly attached by a screw thread to the barrel extension C, the rear portion of the barrel extension C having a downward projection, provided with internal grooves, -which fit and are guided upon corresponding ribs provided on. an upward projection Z on the bottom plate L, thus holding and guiding the rear of the barrel extension, which moves longitudinally with the barre Above the rear portion of thebarrel, ,the trunnion block D has a recess which forms the transverse feed ;channel for receiving and guiding the feed belt with the'cartridges inxits movements from the left to the right side of the gun. The top of the feed channel in the trunnion block is open so that the feed belt with the cartridges may be readily placed into thechannel from the top. The cover G of the breech casing is hinged in the trunnion block forward of the feed channel, so that the cover may be at' will raised and turnedupward and forward until it rests against the flange d of the trunnion block D, in'which position the cover does of the breech casing A.-

not close the feed channel and does not interfere with the placing of the feed belt cover and in the feed channel; and the downward projection or pawL carried by said feed slide 9 serves to engage the feed belt for moving it and the cartridges stepwise through the feed channel from the left a to the right side of the gun, in the well vents, in the usual manner, the feed belt known manner usual in guns of thisclass.

On the outer left side of the breech casing below the feed .channel a pawl M is pivotally attached so that its upper end is held by a spring yieldingly in the path of the feed belt in the feed channel. See Figs. I, II, *X, XI, and XIII. This pawl M prefrom moving in the wrong direction, from the right to the left side, but this pawl does not require the usual finger piece for .at will moving it out of the path of the feed belt in case of a stoppage of the same; because the feed belt may be, if necessary, instantly and readily removed, raised, or adjusted in the channel by simply opening the cover G, which gives the free access to the feed belt.

In rear of the barrel the breech bolt E is fitted to move in the barrel extension O andin the breech vcasing A in rear of the extension. The breech bolt having ribs in its sides which are guided in corresponding longitudinal grooves in the barrel extension and the rear end of the breech bolt in its rearmost position being guided upon the breech bolt guide F, located in the lower rear portion of the casing A.

In Fig. V these main parts of the gun mechanism, the barrel B, the barrel extension C, thebreechbolt E, and the guide F are shown in thelr relative proper positions but withdrawn from the breech casing.

This construction serves the important purpose of allowing the barrel and breech mechanism together to be at will removed from the breech casing after opening the rear of v the same by the removal of the rear plate handle 8.

Jwith the handle K upwardly, as hereinbefore described, and withdrawing the bolt Besides facilitating the assembling and dismount-mg of the barrel and breech mechanism, another important object is attained.

One of the most essential points in the oper-.

ation of machine guns is the proper adjustment between the'rear end of the barrel,

the forward end of the breech bolt, and-the locking device'by which the breech bolt is locked in its firing position, s9 as to securely the same into slots through both sides of the barrel extension C.

In Figs. III and V the locking block N is shown in its operative raised position in which its top has entered a corresponding locking recess 6 in the lower side of the breech bolt, clearly shown in Fig. XVIII. In Fig. IV the locking block N is shown in "its lowered position in which its top is withdrawn from the recess e in thebreech bolt and has allowed the bolt to move rearward over it.

The locking block N is positively forced into its upper locking position by an incline on the upward projection l on the forward portion of the bottom plate L which the lower end of the locking block encounters in the last of the joint forward movement of the barrel extension and' the breech bolt, so that on arriving at the forward firing position, the barrel extension -and.

breech bolt are positively interlocked. See Figs. III and V. The lowering of the locking block N to unlock the breech bolt from the barrel extension takes place during the joint rearward movement of the barrel, bar-l rel extension, and breech bolt under the en-'.

ergy of the'reeoil. For this purpose a forwardly projecting arm f is provided on each side vof the breech bolt guide F which fits into a horizontal groove in each outer side ofv the barrel extension. The forward ends of these arms f are inclined downward and rearward and these inclines act upon the transverse pin n of the locking block extending through the slots in the'barrel extension, so as to force the lockin block down and hold it there. See Fig. I

In assembling and adjusting the barrel and the breech mechanism before they are inserted into the breech casing, the barrel is first screwed into th barrel extension. A cartridge is then ins rted into the chamber of ,the barrel and the breech bolt is from the rear placed in the barrel extension Gand brought forward until it pushes the cartridge fully home in the barrel then the locking block N must be raised by exerting considerable force from below against it, so

as to firmly lock the breech bolt and sup-' port the cartridge. On the shoillder on the outside of the barrel just forward of the threaded portion of same, a series of partycircular recesses is cut and on the left side of the barrel extension C- a flat spring Eawl P is seated. The rear endof this pawl ts into a T-shaped slot provided for its reception in the barrel extension and the forward end of said pawl is bent inward and carries a party-circular point for engaging one of therecesses in the barrel; when T the barrel extension is in the breech casing,

. front end of the barrel extension C bears against the rear end of the trunnion block D. Then the breech bolt guide F is entered into the casing and the rear plate J replaced,

so that it looks in place the guide F, the rear .end of the guide bearing firml against the front face of the rear plate as shown in Fig. III. While these main parts are thus adjusted in their proper forward firing position, it is not unusual that by firing the gun the firmness of the adjustment may be affected, particularly if long serfis of shots, or volleys, are fired from the gun; because under the continuous strain exerted thereby the supporting parts may be forced into a slightly closer contact. In order to readjust the parts, the rear of the breech casing is opened and all the parts are drawn from the breech casing, and by simply attempting to screw the barrel farther into the barrel extension, with acartridge in the chamber and while the locking block locks the breech bolt in its forward position, the adjustment may be readily tested. If found necessary, the adjustment may be corrected by screwing the barrel farther into the barrel extension and by allowing the pawl P to take its bearing in one of the next succeeding recesses on the barrel.

On firing, the barrel and barrel extension,

and the breech bolt recoil together until the against the-barrel extension when the same is in the forward position. As the barrel 'extension moves from the position shown in Figs. III and V to-its rearmost position as A shown in Fig. IV, the rocking lever O is turned on its pivot and its upper end is thrown rearward with an lncreasing speed, until the lever O absorbs the energy of recoil and stops the barrel and barrel extension. At the same time the upper end of the rocking lever takes hold against the front of the downward extension of the breech bolt near its rear end and the rocking lever transmits its momentum to the breech bolt which is thereby thrown to its rearmost position as shown in Fig. IV. 7

On its'rear end, he barrel extension C carries a horizontal arm 0 which extends for some distance rearward and has a lateral projection oneach side at its rear end. The arm 0 also carries a pin p which projects some distance from the left side of said arm. See Fig. VI which shows the rear portion of the barrel extension C with the arm 0 and pin 2 .in a side view and rear view.

As shown in Figs. III, IV, V, and XXXIII, the upper portion of the rocking lever O occupies a position between the body of the barrel extension and the lateral projections on the rear end of the arm 0, the rocking lever. 0 having a central slot from the top downward to allow it to straddle the arm 0, and also the trigger W. Upon its concave rear'face the rocking lever 0 car ries a web or .rib 0 which is also slotted to.

admit the arm 0. In rear of the rocking lever O a iston Q is mounted, its rear en being i ed in a vertical central partition of the reech bolt guide F, andits front end forming a head which carries alate'rally extending guide pin 9 fitted to slide in a corresponding horizontal slot in the left side of the'guide F, and at a height which brings it in line with the projecting pin p on the arm 0. See Figs. III, IV, and V;

Between the head of the piston Q and the partition guiding its rear end, a spiral s ring is mounted by which the piston is yleldinglykept in its forward position. On its front face the head of the piston Q has a horizontal semi-circular recess which fits over the lateral pin 39 on the arm 0, so that the.tension of the spring on the piston Q is exerted to force this arm a and the barrel" extension-C forward, and so that the spring acts as a bufler to absorb any excess of recoil of the barrel extension.

In Fig. XXXIII, sheet 3, the rocking lever O is shown detached, in two left-hand side views and in a rear view. One of the side views shows the lever 0 turned forward and the web .0-on its rear face upward. And in the other side view the lever is turned rearward and the web 0 on its rear face downward, which two positions agree with those in which the rocking lever and its web are shown, respectively, in Figs. III

In Fig. IV the barrel exand V, and IV. tenslon is in its rearmost position in which the lever Ohas stopped it and in which thelateral projections of the arm a and the pin 2? on the same transmit thetension of the compressed spring on thepiston Q to the web on the lever O. *but'as. shown in Flgs. IV, VI, and XXXIII the lower front face of the lateral projections on the arm a is beveled downward and rearward and the rear face of the web on the lever 0, when the lever is in the position shown in Fig. IV, is correspondingly beveled downward and rearward so that while the tension of the spring on the piston Q is normally exerted to move the barrel extension forward, these beveled faces, in the position shown in Fi IV, serve to lock the rockingblever'O an the barrel extension C and arrel B in their rearmost positions as the lowest part of the web cannot move upward and forward unless the pistonQ. and the arm 0 are moved slightly rearward.

The reaction spring R is mounted in a longitudinal seat in the breech bolt E above and at the right of its axis, with its rear end against the rear plate J ofthe breech casing. When the breech bolt is in the rear most position as snown in Fig, IV, this spring is comgressed and almost entirely contalned in t e breech bolt, whereby its tension is exerted to force the breech bolt forward. After the breech bolt hasmoved forward some distance under the tension of this spring R, the downward projection on the breech bolt near its rear end strikes the end of the'rooking lever 0 thereby exerting suificient force to turn the lever forward from its rearmost position, compelling the spring and the piston Q to yield and to allow the lever to turn forward, as the re action spring R is stronger than the spring on the piston Q. This turning'forward of the lever 0 causes the same to force the bare rel extension and the barrel forward from their recoiled position, and the return movement of the barrel and barrel extension and breech bolt is thus accomplished under theand passing through a vertical slot in the firing pin. The forward portion of the firing pin S is bored out for receiving the mainsprin'g T which is inserted from the front, the rear end of the mainspring bearing against the-vertical locking pin 8 and the front end of the mainspring T bearing against a horizontal transverse pin inserteddinto the firing pin near its front. end. See Figs. .XVIII and XXIII. ,On the vlower edge of the front face, the firing point of the firing pin is located, extending therefrom throughthe corresponding small opening to the face of the breech bolt. In this location the firing point does notinterfere with the bore of the firing pin nor with the lower arm of the cocking leger extends into the slot in the firing pin, an the upper arm of the cooking lever extends upward from the breech bolt, so that by moving the upper arm of the lever U to the rear it leaves the firing pin free to move forward in the breech bolt until its firing point protrudes from transmit the igniting blow to the primer of the cartridge in front of'the breech bolt. By moving the upper arm of the cooking lever U forward, the lower arm of the lever takes hold against the firing pin at the rear end of the vertical slot therein and moves the firing pin rearward to its cocked position. The location and operation of the cooking lever U are clearly indicated in the detached views of the breech bolt in Figs. XVII and XVIII. a

In Fig. III where the breech bolt is in its forward firing position, the cocking lever U is shown as extending upward and rearward bolt E is moved rearward from the position shown in Fig. III to that shown in Fig. IV, the rear end of the slot in the top plate H causes the lever U to be turned upward and forward until the upper end of the lever U escapes from the slot in the top plate H and, during the last of the rearward movement of the breech bolt, the upper end of the lever U moves under the top plate H and is held in its forward position by the under side of the top plate, so that during the first of the rearwardrmovement the lower arm of the lever Uretracts the firing pin and during the re mainder of the rearward movement holds the firing pin positively in its retracted. position. The cooking lever U and the firing pin S remain in these relative positions during the first part of the forward return movement of the breech bolt until the upper end of the cocking lever U encounters the forward portion of the top plate H which projects downward so that the cooking lever V the face of the breech bolt sufiiciently' to will strike against it and will thereby be;

turned upward to reenter the slot in the top plate and be moved from its forward to its rearward position, or from the position shown in F1 IV to that shown in Fig. III; so that, as t e breech bolt reaches its firing; osition, the lower armof the cooking let er 5 is withdrawn out of the path of the firing pin leaving the same free to move forward,

igs. III and XVIII.

in. See Figs. XVIII and As shown in Figs. I, (II, III, and IV, the a slot in the top plate of the breech casing, and

'the' cooking lever U extending into the same,

are covered over by the sliding spring latch I which prevents dust or dirt from entering into the gun casing through said slot. The' hollow inside of the spring latch carrles a flat ring secured by a rivet to the latch and the orward end of this spring rests in a recess in the top plate H which recess inclines upward and rearward at its rear end so that the tension of the spring is exerted to yieldingly hold the latch in its forward coverlocklng position. The front of this recess extends somewhat beyond the forward end of the spring, which allows the latch to be 'at will pushed forward sufficiently. to release the rear plate J which the rear end of the latch slightly overlaps, as hereinbefore described.

When the cocking lever has retracted the firing pin, the sear V takes hold of the firing pin and holds it in its cocked position until the sear is moved to release the same. The sear V is a narrow sliding plate fitted into a vertical T-shaped slot in the rear face,

of the breech. bolt so as to slide freely there- XX. The sear V has near its lower end a forwardly projecting arm in the upper surface of which a shoulder is formed by which the sear takes hold of the cocking shoulder on the under holds the firing pin in forwardly extending portion of the arm stroke of the firing pin when firing,

gives great strength to the sear shoulder, avoiding relatively thin or inclined cam surfaces forward of said shoulder, while insuring engagement of the searshoulder with the cocking shoulder of the firing pin at the proper time; for while this fiat top portion of the sear is depressed during the triggers action on the sear, entirely out of contact with the firing pin during the forward yet after the sear has been. released by the tri ger, during the recoil the flat portion 0 the sear arm will contact with the lower surface of the firin pin, thus keeping the sear depressedsu ciently so that its shoulder can snap over or in front of the cooking shoulder of the firing pin as soon as the two shoulders register. On top of the breech bolt, a flat sear spring '0 is located, its front end held down by the firing pin locking pin 8 to the top of which the forward end of the spring is riveted, the locking pin 8 itself being held in the breech bolt against moving upward by the tension of the mainspring T.

.XXVI, the rear The rear portion of the sear spring o, is divided by' a slot to allow the passage through it of the cocking lever U, and the ends of the spring 0 rest in a horizontal recess in the front face near the top .of the vertically sliding sear V, so that the tension of the' spring 41 holds the sear yieldingly in its operative upper position in which the shoulder on the arm of the sear holds the firing pin in its cocked position. The sear V is shown detached in Fig. XXVII, in a front view and in a side view.

The trigger W is shown detached in Fig. XXVIII in a top view and a side View. The trigger W is pivoted in the vertical central partition of the breech bolt guide F and extends from the same forward into a T-shaped slot in the lower end of the sear V below the forward extending arm .of the same, when the breech bolt is forward, the

- upper portion of the trigger beingrreduced in thickness to freely fit in the slot; the front end of the trigger W has two lateral projections which fit into the upper wider part of the T -shaped slot in the sear. The rear arm of the trigger extends from its pivot downward and rearward and carries at its rear end a finger piece by which the rear arm of the trigger may be raised and. therei by the front arm and with it the sear be lowered to release the firing pin. With the breech bolt in its forward position, the sear spring 0 also serves to hold the forward arm of the trigger W in raised position.

- When the breech bolt moves rearward, its

bottom sliding over the top of the trigger keeps the same in position.

As hereinbefore described, the forwaro portion of the reaction spring R is seated in the breech bolt while the rear end rests against the rear plate J of the breech casing; in order to keep the reaction spring R in this position when the breech bolt is forward, as seen in Fig. III, the guide rod 1* extends through the rear plate J and through the reaction spring R and for a short distance into the breech bolt in its forward position. 1 In Fig. XXI the ide rod 1' is shown detached on an increased scale. Therear end of the guide rod 1' which extends through and some distance beyond the rear plate J is of a larger diameter than the forward portion of the rod in the spring, and the spring pressing a ainst the shoulder on the rod yieldingly olds the rod in the rear,plate. The rear end of the rod is concave and has a slot, this construction allows the rod to be turned on its axis in the rear plate by using the head of a cartridge shell'in place of a screwdriver. In front of theirear plate and in line with the slot, the rod 1' carries two small lugs which'project from opposite sides of the rod. As shown in Fig. XX and on an increased scale in Figs. XXIV, XXV, and end of the breech bolt E, at

the end of the seat therein for the reaction spring R and the rod 1', is provided with a horizontal slot through which these lugs may be made to enter the breech bolt when the same is moved fully to the rear, see Fig. IV. Slightly in front of the rear face of the breech bolt two party-circular recesses are cut in the breech bolt into which the lugs of the rod may be made to enter bythe rotation of the rod. Figs. XXIV, XXV, and XXVI. The bottoms of these recesses are eccentric to the seat of the spring in the breech bolt, and when b the rotation of the rod the lugs are 'entere into these recesses, the outer ends of the lugs will come in contact with the eccentric bottoms of the recesses and-may be by forcible rotation caused to wedge therein so as to lock the rod in the breech bolt; in this condition the rod 7* with the breech bolt may be moved forward so as to withdraw the rear end of the rod from the 7 tion the rod may be unlocked for the removal August 1, 1917.

of spring and rod.

The, handle K of the gun is by a' screw thread fastened in the hub of the rear plate J and in the tubular horizontal portion of the handle a buffer plate is is seated, the re* duced front end of which projects through a corresponding hole in the rear plate, so as to stand in the path of the breech bolt; the rear I of this portion of the handle is closed by the screw plug and the space between the front of this plug and the rear of buffer plate is is filled with a number of washers of a resilient material, or with a spiral spring. By this means any excess of recoil ofthe breech bolt is absorbed by the buffer plate and the packing in the handle, the resiliency of which may be adjusted by screwing the rear plu more or less into the rear end of the ban le. I do not, however, claim in this application this buffer construction and adj ustment in the handle, reserving the right to claim this in a co-pending application filed by me, said application being Serial No. 188,841, for automatic machine rifles, filed With the trigger W pivoted in the vertical central partition of the barrel guide F, as. hereinbefore described and as shown in Figs. III and IV, the rear end of the trigger extends outside of the breech casing beyond the rear plate J and occupies a position in ing with the trigger. the left side of the trigger a small horizontal safety latch w is mounted in the rear plate J front of the handle K where it may be readily opera-ted 'with a finger of the hand grasping said handle. The rear plate J has a central vertical recess in its lower end through which the trigger passes so that .the plate may be raised and lowered without interfer- See Fig. XXIX. At

and provided on its rear with a thumb piece bywhich the safety latch may be at will pushed to the right when its end will enter a recess in the left side of thetrigger W and securely lock the trigger agalnst operation;

to yieldingly hold the safety latch w in either its locking or its releasing position v a small spring-actuated vertical piston is mounted in the rear plate J above the latch,

to enter one of two recesses cut in the upper edge of the latch. The top. of the locking recess in the trigger is open, so that on removal of the rear plate J the latch w may be withdrawn upwardly with the plate even if in its locking position, and in replacing the rear plate J the latch will readily reenter the recess in the trigger.

In Figs. XVII, XVIII and XIX the breech bolt E is shown to be provided at its front end with a vertical flangeway which consists of a central T-shaped slot adapted to receive from above and guide downward the rear ends of the cartridges. The two laterally overhanging front edges of the slot are fitted to enter the annular groove in the ca'i'tridges near their rear end, thereby firmly holding the cartridges against lengthwise movement. In Fig. XXXI a front view of the breech bolt E is represented on an increased scale clearly showing the flangeway on the face of the breech bolt, one side of said flangeway extending vertically from the top to the bottom of the breech bolt while the other side extends only partly upward from the bottom, leaving a space at-the top of that side for the rear end of a cartridge inthe feed belt to be moved through it laterally until it is stopped by the other side of the flangeway in a central position in front of the breech bolt.

In the same figure, the breech bolt is show n' provided with the combined cartridge feed extractor X and shell ejector 'w. The cartridge feed extractor X 1S IIlO11I1t8Cl by a strong pivot 9 on that side of the breech .bolt-towhich the flangeway is open for the reception from the side of a cartrldge. On

the other side of the flangeway the shell ejector m is pivotally mounted in the feed extractor X. f i

As hereinbefore described, cartridges are supplied in a feed. belt fed through the feed channel from the left side to the right, as

shown. in Figs. 1, II, III, IV, x11, and

XIII, by the transverse movement of the feed slide g, in the usual manner. The feed slide 9 in its movements is actuated by a two-armed lever Y which is mounted on the the top of the cover and through the hub of the lever into the supporting arm; a flat spring. attached to the top of the pivot pin y and resting upon the top of the cover plate locks the pivot pin against accidental removal. The forward arm of the feed lever Y extends into a recess in the rear face of the feed slide '9 so as to communicate its movements to the same in the usual manner, see Fig. II; the rear arm of the feed leverY carries a depending circular stud .2 which extends into a cam groove Z cut in the uppersurface .of the breech bolt E. By this construction the reciprocating movement of the breech bolt causes the stepwise movement of the feed belt and cartridges through the feed channel as usual, so that when the breech bolt arrives at its forward position a cartridge is moved to the front of the vertical center line .of the breech bolt, having been carried over the top of the shorter side of the flangeway on the left side of the breech bolt.-

In this position, see Figs. III and V, the

'feed extractor X is in its raised position so that a downward projecting lip Z (nthe under side of the feed extractor X, centrally above the flangeway, stands above the oove in the cartridge in front of the breech bolt and, on the first rearward movement of the breech bolt this lip Z descending into the groove in the cartridge, grasps the same and draws the cartridge rearward out of the feed belt. As the breech bolt moves farther rearward, the feed extractor X is lowered and forces the cartridge held in its grasp to enter into the flangeway, where it is held in 7 a horizontal position as the breech bolt is moved fully to the .rear. During the return or forward movement of the breech bolt, the feed extractor X is farther forced down so thatthe cartridge is lowered until it is in line with the chamber in the barrel, which it will enter during the remainder of the forward movement of the breech bolt until the cartridge is fully inserted into the barrel, and barrel and breech bolt returned tov the firing position. After firing the cartridge in the barrel, these movements are repeated, and during the next rearward movement of the breech bolt another] cartridge is..withdrawn from the feed belt, drawn fully to the rear, and by the return movement entered into the chamber of the barrel.

In addition to this, the second rearward movement of the breech bolt not only withejector is forced inward, as it descends, when lower end strikes the upper edge of the barrel extension below it, see Figs. XIV, XV, and XVI, the upper inner corner of the extension being inclined inward and downward and the shell ejector being correspondingly beveled so that it is forced inward and kept in its vertical position until it reaches I its downmost position.

In Figs. XIV, XV, and XVI are represented transverse sections through the breech casing A and barrel extension 0 in rear of the barrel, looking rearward, and showing 'a front view of the breech bolt, and of the feed extractor respectively in its highest position, in a lower position, and in the lowest position. InFig, XXX the feed extractor X is shown on an increased scale and in its highest position in which the lip Z takes hold in the groove of the cartridge shown in dotted lines below the head of the feed extractor. In Fig. XXXI the front of the breech bolt is shown on an increased scale and the feed extractor X-and shell ejector w are shown in their raised position. In Fig. XXXII a vertical transverse section through thehead of the feed extractor is represented, showing the shell ejector m pivoted in a vertical slot in the right side of the feed extractor X and yieldinglyheld in its vertical position by a spiral spring pressing against the upper arm of the shell ejectorw. The other end of this spring rests against a horizontal cam pin 7 which is inserted into the left side of feed extractor X and fixed therein for a limited movement by a small transverse stop pin, so that the 1 spring yieldingly keeps the pin 7 projecting from the left side of the feed extractor. These views being seen from the front, the left and right sides appear reversed, as normally their location is determined from a position in rear of the gun looking forward.

The means for giving to the feed extractor X the vertical movements at the proper times will now be ex lained. On the under side of the cover Gr and near the left edge of the same, so as not to interfere with the feedlever Y there are mounted a fiat spring 2 and a longitudinal rib 3, the under edge of the rib 3 having the form of a cam. The 8 ring 2 and the rib 3 are represented in gs. III and IV. in dotted lines for the reason that these views are central vertical sections showing the interior of the right hand half of the breech casing and the cover, while the spring and the rib are located in the left half of the breech casing. In Fig. II, the top view of the gun, the position of the rib 3' is indicated as just inside of the left side plate a of the breech casing. When the breech bolt is in its forward position, Fig. III, the flat spring 2 rests upon the head of the feed extractor X and holds the same yieldingly down upon the rear end of the cartridge with the lip l in the annular groove of the cartridge. During the first of the rearward movement of the breech bolt and feed extractor, the highest portion of the head of the feedextractor, which is near its moved rearward beyond the rear end of said rib 3. In Fig. XI an outside view of a por-- tion of the left side plate a and a section of the cover G are shown. The lower edge of the rib 3 depending from the cover is rep resented in dotted lines being loeated near the inner side of said side plate. Underneath the rib 3 and fastened by rivets to the inside of the left side plate are shown two cams, 4 and 5, their location in the vertical plane with the rib 3 being also indicated in the top view represented in Fig. X. The forward portion of the cam 4 is less high than the rear portion, a shoulder 6 being formed on the top edge of the cam 4, which shoulder 6 is laterally inclined rearward and inward, and as the breech bolt and feed extractor X pass rearward under the rib 3, this incline forces the cam pin 7 into its seat in the head of the feed extractor where it is held by the inner face of the cam 4 until the breech bolt and feed extractor reachtheir rearmost position; there the head of the feed extractor haspassed beyond the rear end of the rib 3 and the cam pin 7 beyond the rear end of the cam 4 and, there fore, thepin 7 is by its s ring forced outward again and projects rom the left side of the feed extractor X. In the first of the forward return movement ofthe breech bolt and feed extractor, the cam pin 7 encounters the rear end of the cam 4 fastened to the left side plate, and this rear end being inclined downward and forward, the cam pin and the feed extractor are positively forced down to the lowest position shown in Fig. and held there by the under edge of cam 4 until the pin arrives at the forward end of the cam 4 which is inclined upward and forward. Then the cam pin 7 encounters the rear edge'of the cam 5, which inclines forward and upward, and this forces the feed extractor to again rise to its highest po-.

sition when the breech bolt arrives at its forward closed position.

As shown in Figs. I and II, for at will moving the breech bolt rearward and forward by hand, a handle 8 is inserted into the right side of the breech bolt near its front end and inoves in a slot in the right sideplate of the breech casing; a collar on the handle 8 of a larger diameter than the width of the slot and located inside of the side plate, serves to lock the handle in its seat in the breech bolt.

As seen in Fig. I, the slot ends at the rear in a larger circular opening through which le 8 with its collar may be inserted the han or removed, when the rear plate J is removed for entering or withdrawing the breech bolt from the casing. This enlarged opening being in rear of the rearward limit of the normal movement of the breech bolt during the operation of the gun, the handle cannot accidentally escape from the breech bolt.

With the foregoing description ofits construction, the operation of the breech mechanism may be readily understood. After a feed belt with cartridges in the pocketsthereof, see Fig. XII, has been inserted into the feed channel from'the-left side to the right, Figs, I, II, and XIII, the breech bolt is once moved by hand to the rear. By this motion, the first cartridge is withdrawn out of the feed belt and as the handle is released the breech bolt is returned forward by the tension of the reaction spring R,- and the cartridge, properly lowered'by the feed extractor,is inserted into the barrel while the next step of the feed belt brings another cartrid e above the barrel within the reach of, the eed extractor. On pulling the trig I ger and releasing the same, the first cartridge is fired and the operation of the breech bait is automatically repeated, and the next cartridge is seated'in the barrel ready for firing. l

In this manner single shots may be at wi fired, the pulling of the trigger lowering the sear each time and allowing it to return upward for holding the firing pin' again in the cooked position.

If it is desired to fire a succession of shots, or-a volley, the tri ger is pulled and retained in its raised position, when the lateral pro ections on the front ,end of the forward arm of the trigger, which projections are inclined rearward and upward on their under sides, will automatically cause the sear to release the firing pin each time when the breech bolt reaches its forward locked position and thereby release the firing pin automatically for firing each succeeding shot-,3 v

until the trigger isreleased.

If it becomes necessary a t to ob-- i tain access to the breech mechanisngfor to the feed belt or the mechanism moving the l' can not enter the cam groove in the top of the breech bolt, but descends to rest upon the top surfacepf the bolt sidewlse ,of the groovethe cover may nevertheless be readily pressed down and be locked by the latch I,

'asthe rear arm of the. feed lever Y, being thin and of a spring temper and havinga a space between its upper surface and the under side of the cover, will yield bybending upward; then on the first rearward movement of the breech-bolt the cam groove will be brought beneath the stud e which will automatically find its place in the groove,

'the tension of the lever arm forcing the stud down into-the groove.

It is evident that various changes in form.

and arrangement of the parts may be made without departing from the spirit-{of the invention. I v

What I claim and desire to secure by Letters Patent is:

1. In a machine gun, the combination of a breech casing, a barrel and barrel extension supported and guided for lon 'tudinal movement in the casing, a breech lt supported and guided for longitudinal movement in they-barrel extension, a removable g ide for'said breech-bolt inserted in the casing, and a removable rear plate for closing the casing and locking said movable members and said guide therein, and for opening the casing to allow the movable members and the guide in their relative positions to be withdrawn from said casing.

2. In a machine gun, the comb nation of a breechcasing, a barrel and barrel extension supported and guided for longitudinal movement in the casing, means located ena tirely .within the breech casing, and not extending through or into the side walls thereof,,for supporting, guiding .and securingin position said barrel and barrel extension, a

breech-bolt supported and guided for longitudinal movement in the barrel extension,

and means located entirely within thebreech .casing, and not extending through, or into the side walls thereof, for guiding and supporting the rear end of the breech-bolt, and

I a removable rear plate for closing the easing and locking said movable members in place therein, and fol-opening the casing to allow the movable members in their'relative positions to withdrawn from said casing, whereby said members of the breechv I mechanism may be readily inserted in-the breech casing or removed therefrom; "3. In a machine gun, the cdmbination of a breech casing, a barrel and barrel extension supported and guided for longitudinal movement in the casing, means located entirely within the breech casin and not extending through or into the si e lwalls thereof, for

within the breech casing,

a removable rear plate for closing the casing and locking the barrel, barrel extension and breech-bolt within the casing and for opening the casin to allow said parts in their relative positions to be withdrawn therefrom.

bolt supported and guided for longitudinal movement to open and-close the breech of the barrel, feed mechanism for successively feeding cartridges to a position above and in line with the barrel, a feed extractor pivoted to thebreech-boltand having an integral cartridge-engaging projection near its free end an means for causing said feed extractor to engage the cartridge, whereby upon rearward movement of the breech-bolt a cartridge is withdrawn from the .feed

mechanism.

5. In a machine gun, a barrel, a breechbolt supported and guided for longitudinal movement to open and close the breech of. the barrel, feed mechanism for successively feeding, cartridges to a position above and in line with the barrel, a feed extractor pivoted to the breech-bolt and having a cartridge-engaging projection near its free end 4. In a machine gun, a barrel, a breech-i and means for cau'smg said feed extractor toengage the cartridge, whereby upon rear ward movement of the breech-bolt a, car- .tridge is withdrawn from the feed mechanism, and. means for depressing the free end of said feed extractor and keeping it in engagement-with thecartridge until the cartridge is fully depressed and in line with the bore of the barrel.

6. Ina machine gun, abarrel, a breechbolt supported and gpided for longitudinal movement to open and close the breech of the, barrel, feed mechanism for successively feeding cartridges to a position above and in line with the. barrel, a feed extractor pivoted to the breech-bolt and having a cartridgeengaging projection near its freeend and means for causing said feed extractor to engage the cartridge whereby upon rearward movement of the breech-bolt a cartridge iswithdrawn from the feed mechanism, face of the breech-bolt integrally therewith,

a vertical flange-way formed on the.

and means for vertically moving the free end of said feed extractor to lower the cartridge and force its head into said flangeway.

7. In a machine gun, a barrel, a breechbolt supported and guided for longitudinal movement to open and close the breech of the barrel, feed mechanism for successively feeding cartridges to a position above and in line with the barrel, a feed extractorpivoted to the breech-bolt and having a in line with the barrel, a feed extractor pivoted to the breech-bolt and having a cartridge-engaging projection near its free end, means for causingsaid feed extractor to engage the cartridge, a vertical flange- Way formed on the face of the breech-bolt integrally therewith, a shell ejector carried by the free end of said feed extractor, and means for vertically moving the free end of said feed extractor to lower the cartridge and force its head into said flange-way and to cause said ejector to eject the empty shell from the flange-way.

9. In a machine gun, a barrel, a breechbolt supported and guided for longitudinal movement to open and close the breech of the barrel, feed mechanism for successively feeding cartridges to a position above and in line with the barrel, a feed extractor pivoted to the breech-bolt and having a cartridge-engaging projection near its free end, and means for causing said feed extractor to engage the cartridge, whereby upon rearward movement of the breech-bolt a cartridge is withdrawn from the feed mechanism, and a shell ejector carried by the free end of said feed extractor, means for depressing the free .end of said feed ex-r tractor to lower thedeartridge' during the rearward movem'ent of the breech-bolt, and

means for further depressing said free end h ldulring the returnmovement of said breecho t.

10. In a machine gun, a barreLfa. breechbolt supported and guided for longitudinal movement to open and close the breech of the barrel, feed mechanism forsuccessively feeding cartridges to a position above and in line with the barrel, a feed extractor pivoted to the breech-bolt and having a "cartridge-engaging projection near its free end, and means for causing said feed ex supported and, guided for longit',

tractor to engage the cartridge, whereby upon rearward movement of. the breech-bolt a cartridge is withdrawn from the feed mechanism, a shell ejector carried by the free end of said feed extractor, means for depressing the free end of said feed extractor to lower the cartridge during the rearward movement of the breech-bolt,

means for further depressing saidfree end I during the return movement of said breechbolt, and means for raising the free end of said feed extractor near the end of the return movement of the breech-bolt;

11. In a machine gun, a barrel, a breech-V extractor, a spring and a cam rib located.v

above the free end of the feed extractor for engaging sameand depressing said free end.

12. In a machine gun, a barrel, a breechbolt supported and'guided for longitudinal movement to open and close the breech of the barrel, feed mechanism for successively feeding cartridges to a position above and in line with the barrel, a feed extractor pivoted to the breech-bolt and having a cartridge-engaging projection near its free end, means for causing said feed extractor to engage, the cartridge, whereby upon rearward movement of the breech-bolt a cartridge is withdrawn from the feed mechanism, ashell ejector carried by the free end. of said feed extractor, a pin extending from the feed extractor and yieldingly mounted therein, and cams for engaging said pin and forcing it into the feed extractor and forthereafter releasing same during the rearward-movement of the breech-bolt, and earns for engaging said pin andthereby depressing and later raising the free end of said feed extractor during the return movement of the breech- -bolt.

the breech casing, a" arrel and barrel ex- ;te'nsion supported and guided for longfitggdlr nal movement in the casing, a breecj movement in the barrel extensioi-i, a pivoted rocking lever, a rib on the rear'1face thereof, a locking face .on said ribgian arm on the barrel extension, a locking face on said arm for engaging the locking face on said rib, and a bufferspring and piston for engaging said arm, whereby at the end of the rearward movement of the barrel extension said rocking lever and barrel extension are locked against return movement;

14. In a machine gun, the combination of a breech casing having a removable rear plate, a barrel and barrel extension adjustably secured together by screw threads and supported and guided for longitudinal movement in the casing, a breech-bolt supported and guided for longitudinal movement in the barrel extension, a series of recesses around the circumference of the barrel forward of the barrel extension, a spring pawl secured in said barrel extension for engaging one of said recesses and in position to be engaged by the breech casing, whereby the barrel is positively locked against rotation when in place in the breech casin but whereby the barrel may readily be adJuSted in the barrel extension relatively to the breech-bolt when the parts are rearwardly withdrawn from the breech casing.

15. In a machine gun, the combination of a casing, a barrel and barrel extension, a breech-bolt movable lengthwise in the barrel extension, a-lockingiblock mounted in the.

- closing and guiding the breech mechanism and having an open transverse feedwa'y for receiving and guiding a cartridge feed'belt, a top cover attached to the casing by a ivot 'or' hinge pin near the forward end 0 the casing, a transversely moving cartridge feed slide provided with a feed pawl mounted upon the under side of said cover, a feed lever pivotally mounted upon the under side of said top cover and adapted to move said feed slide through the feedway, and a breechbolt having a cam groove in its top surface adapted to actuate said feed lever.

17 In a machine gun, a breech casing inclosing and guiding the breech mechanism 1 and having an open transverse feedway for receiving and guiding a feed belt, a, top cover attached to the breech casing, a feed slide anda feed pawl mounted upon the under side of said cover, a' two-armed feed lever pivoted upon the underside of said cover and having a depending stud on the rear arm, and a breech-bolt having a cam groove in its top for receiving said stud, the rear.

arm of" said feed lever being vertically resilient, whereb saidcover may beclosed without said stu entering said cam groove, and said stud-will automatically spring into rear plate on being movedin opposite direction. v

19. In a machine gun, a breech casing having a pivotally attached top coverand a removable rear plate, and provided with a longitudinally sliding spring-actuated latch for normally locking both said top cover and said rear plate in place, but releasin said top cover on being pressed rearwar and releasing said rear plate on being pressed forward.

20. In a" machine gun, a breech-bolt, a slotted firing pin carried thereby, a mainspring within the firing pin, a, vertical pin confining the firing pin in the breech-bolt and also confining the rear end of the mainspring in the firing pin, and a horizontal transverse pin for confinin the front end of said mainspring in the ing-pin.

21. In a machine gun, a breech-bolt, a firing pin carried thereby, having a tubular portion open at the front end, a main spring within said tubular portion, a transverse pin for confining the front end of said main spring within the firin pin, and means carried by the breech-b0 t for engaging and supporting the rear'end of said spring.

22. In a machine gun, a breech-bolt, a firing pin carried thereby having'atubular portlon open at the front end, a main'spring within said'tubularfportion, a transverse pin for confining the.

ont end of said main spring within the firing pin, means carriedv by the breech bolt for engaging andsup V porting the rear end of said spring, and a firing point on the lower edge'ofthe front face of said tubular-portion.

23. In a machine gun, a breech casing, a breech-bolt, a firing pin carried thereby hav ing a tubular portlon open at the front end, a main spring withinsaid tubular portion a transverse pin for confining the front end of said main springwithin the firing pin, means carried by the breech bolt for engaging and-supporting the rear end of said "sprlng, saidfiring pin also having a slot in rear "of said tubular portion, and a cooking lever pivoted in the breech bolt and enter-- ing said slot in the firing pin.

24. In 'amachine gun, a breech casing having a fixed top plate; .a breech=bolt a firing pin and a mamspring. carried thereby, a cooking lever also'carri breech-bolt, combined with afslo' plate of the breech casing,sai a rear wall for engaging sai and moving it into position to hold the firing pin retracted, and also having a downwardly projecting front wall for engaging said cocking lever during the last of the forward movement of said breech bolt and positively moving said cockinglever into engagement with said rear wall again:

25. In a machine gun, a breech casing having a fixed top plate, a breech-bolt, a firing pin and a mainspring carried thereby, a cocking lever-also carried thereby, a slot in the top plate of the breech casin having a rear wall for engaging said 000 'ng lever and moving it into position to hold the firing pin retracted, and having a downwardly projecting front wall for engaging said cocking lever during the last of the forward movement of said breech bolt, and positively moving said cocking: lever to initial position out of reach of said firing pin.

26. In a machine gun, a breech-bolt, a firing pin and amainspring carried thereby, a vertically sliding sear also carried thereby, and a searsprin for holding Esaid sear 1n the path of the firmg pin, said s'ear provided with an arm having a shoulder for engaging and holding said firing pin in cocked posltion, said arm also havin forward of said shoulder a surface extendmg parallel to the axis of the firing pin and of suflicient length to underlie the firing pin when in its forward or firing position.

27. In a machine a breech casing, a breech-bolt, a breec -bolt guide, a sear mounted in the breech-bolt, a trigger pivoted in the breech-bolt guide having a finger piece extending at the rear beyond said guide and beyond 'the breech casing, said trigger also having a forward extension to engage the sear for at will causing it to release the firing pin.

28. In a machine gun, a breech casing, a breech-bolt, a breech-bolt guide, a sear mounted in the breech-bolt, a trigger pivoted in' the breech-bolt uide having a finger piece extending at t erear beyond said guide and beyond the breech casing, said trigger also having a forward extension with inclines on its front end to engage and lower said sear in its forward movement.

29.'In a machine gun, a breech casing, a breech-bolt carrying the forward portion of a reaction spring on a guide rod, a rear plate for the breech easin for supporting the rear end of said guide rod, cooperating means for enteringv and engaging b rotation said rod with the breech boIt, and means for positively preventing further rotation of said rod in the same direction while frictionally locking it against reverse rotation.

30. In a machine gun,-abreech-bolt, a reaction spring and a guide rod with their forward portions extending into the breechbolt, and codperating means upon said guide "breech-bolt, a breec rod and breech-bolt whereby upon the rotation of said guide rod it may be positively prevented from further rotation in the same irection and frictionally locked against reverse rotation.

pivoted in the breech-bolt guide having a finger piece extending at the rear beyond the guide and beyond the breech casing, a removable rear .plate closing the breech casing at the rear, said plate having in its lower edge a slot for the passage through it of the rearward extension of the trigger, whereby said rear plate is adapted to be removed or to be replaced without afiecting the tri ger.

33. n a machine 1gun, a breech casing, a

pivoted in the breech-bolt guide and havin a finger piece extending at the rear beyon the guide and beyond the breech casing, a removable rear plate closing the breech casing at the rear, said plate having in its lower edge a slot for the passage through it of the rearward extension of the trigger, and a safety slide movably mounted in the lower ortion of said rear plate, and a cooperatlng recess in the side of said trigger whereby said trigger may be at will secured against operation or released for operation. 34:. In a machine gun, a breech casing, a breech-bolt, a breech-bolt guide, a trigger pivoted in the breech-bolt guide and having a finger piece extending at the rear beyond the guide and beyond the breech casing, a removable rear plate closing the breech casing at the rear, said plate having in its lower edge a slot for the passage through it of the rearward extension of the tri ger, and a safety slide movably mounted in the lower portion of said rear plate, and a cobperating recess in the side of said trigger, said recess being open at the top, whereby said trigger may be at will secured against operation or released for operation, and whereby said rear plate is adapted to be removed or to be replaced without affecting the trigger or the Safetyslide.

35. In a machine gun, a breech casing having a fixed top plate, a breech-bolt, a firing pin and a mainspring carried thereby, a cocking lever also carried thereby, a slot in the top plate of the breech casing having a rear wall for engaging said cockinghlever and moving it into position to hold t e fir- -bolt guide, a trigger of the breech-bolt, and a' downwardly ing pin retracted, and a surface upon the under side of said top plate for thereafter engaging said cocking lever and holding it in said position during the rearward and greater portion of the forward movements projecting front wall of said slot for e said cocking lever during the last of the for- .ward movement of said breech bolt and positively .moving said cocking lever to initial position but of reach of said firing pin.

36. In a machine gun, a breech casing in closing and guiding the-breech mechanism and having an open transverse feed way for receiving and guiding a feed belt, means for moving said feed belt stepwise through said feed way, a top cover attached to the breech casing, a movable feed lever-mounted upon naoaoa 1 the under side of said cover and having a ceiving said stud, whereby said cover be closedwithout said stud en said cam groove and whereby said stud W111 automatically spring into said cam groove when the motion of the breech bolt carries thegroove to the properv position for receiving said stud.

This specification signed and witnessed this third'day of October, A. D. 1916. V

' 1 'JOHN'M. BROWNING. In the presence of.

ARTHUR L.- Unnrcn, KATHERINE A. Pownns.