US2401903A

US2401903A - Repeating firearm

Info

Publication number: US2401903A
Application number: US401602A
Authority: US
Inventors: Val A Browning
Original assignee: J M & M S Browning Co
Current assignee: J M & M S Browning Co
Priority date: 1941-07-09
Filing date: 1941-07-09
Publication date: 1946-06-11
Anticipated expiration: 1963-06-11
Also published as: US2363772A

Description

June 11,1946. v. A. BROWNING ,www

REPEATING FIREARM Filed July 9, 1941. 5 Sheets-Sheet l www June l, 1946. l v. A. BRowNlNG REPEATING FIREARM Filed July 9, 1941 5 Sheets-Sheetl 2 June El, i946. v. A. BROWNING REPEATING FIREARM Sheecs-Sheet 3 Filed July 9, 1941 y/llllllllllllll.

/042/3 Wma gwva/wbcw VAL A. 5R OWNJNG am il, g, V, A, BROWNlNG I ZLQS wREFFAILINGf FIREARM Filed July 9, 1941 5 Sheets-Sheet 4 Oia! T/f W 03 /9 40 43 7mm REPEATING FIREARM 5 sheets-sheets Filed July 9, 1941 Patented June 11, 1946 REPEATIN G FIREARM Val A. Browning, Ogden, Utah, assigner to J. M. &

M. S. Browning Company, Ogden, Utah, a corporation of Utah Application July 9, 1941, Serial No. 401,602

2 Claims.

This invention relates to repeating firearms and finds particular application in a iirearm of the blow-back type wherein the expanding power gases are utilized to automatically perform the functions of retracting the breech block and withdrawing the spent case, it being understood, however, that certain of the improvements may be used in other types of guns.

rlhe aim of the invention is to provide a repeating firearm which has various features of novelty and advantage and which is particularly characterized by its lightness in weight so that it may be easily carried and readily and quickly brought to ring position; which is very simple in construction and economical in manufacture, the various mechanisms and parts being of simplified construction conducive to low cost of manufacture and ready assembly and repair; which is very eiective, reliable, and smooth in operation in that it may be accurately aimed and fired, the arrangement being such that during firing the gun may be held on the target without appreciable tendency to jump or weave and the shock caused by recoil is distributed or smoothed out so as to relieve the shoulder of the shooter from excessive jars and relieve the ring and other mechanisms of the firearm from excessive strains or stresses, thus insuring to the gun a long and useful life; and which may be conveniently fired in either a semi-automatic or full automatic manner at the immediate selection f the shooter; in short, to provide a better firearm which is of minimum weight, more economical in construction and manufacture, more eiTective and convenient in operation, and which is particularly adaptable for military use.

A further aim of the invention is to providev certain improvements in the several mechanisms with which the gun is provided.

Other objects will be in part obvious and in part pointed out more in detail hereinafter.

The invention accordingly consists in the features of construction, combination of elements and arrangement of parts which will be exemplified in the construction hereafter set forth and the scope of the application of which will be indicated in the appended claims.

In the accompanying drawings:

Figure 1 is a side elevational view of my improved iirearm;

Fig. 2 is a sectional` view taken generally longitudinally and vertically through the receiver `of the rearmand showing the various parts in their normal or firing positions;

Fig. 2A is a detail View showing a portion of 2 the magazine box in horizontal section, the rear end of the follower in top elevation, and the arm of the stop-open latch in broken lines;

Fig. 3 is a sectional view taken generally longitudinally and vertically through the forward end of the stock and the tube or housing for the recoil spring, the rear end of the receiver being shown in elevation; f

Fig. 4 is a detail view, partly in section, of the means for locking the receiver to the tube which houses the recoil spring;

Fig. 5 is an elevational view of said locking means; l

Fig. 6 is a transverse sectional view through the stock, the rear sight being shown in front elevation, this view being taken on line 6 6 of Fig. 3 looking rearwardly in the direction of the arrows;

Fig. 7 is a transverse sectional view through the receiver and shows the magazine latch in front elevation, this view being taken substantially on line 1-`I of Fig. 2 looking rearwardly in the direction of the arrows, the magazine being omitted;

Fig. 8 is a transverse sectional View through the receiver in the plane which includes the pivot for the trigger, this view being taken substantially on line 8-8 of Fig. 2 looking rearwardly in the direction of the arrows;

Fig. 9 is a transverse section through the rear end of the receiver, this view being taken substantially on line 9-9 of Fig. 2 looking forwardly in the direction of the arrows, the sear 42 and the spring |25 being omitted in the interest of clarity;

Fig. l0 is a longitudinal vertical sectional View through the rearward end of the receiver looking towards the right hand side of the rearm with the parts of the firing mechanism shown in normal or firing position and with the screw |03 so adjusted that the gun can be fired in a semiautomatic manner only;

Fig. 11 is a View similar to Fig. 10 but showing the parts in red position, the trigger being shown as having been pulled and the breech block and firing pin being illustrated in substantially their rearmost positions;

Fig. 12 is a view similar to Figs. 10 and 11 but showing the parts in the positions which they have when the trigger is maintained in pulled position after ring and the breech block and firing pin have returned to their normal firing positions;

Fig. 13 is a view similar to Fig. 1.1, the screw |03 having been backed off and the trigger lbeing held in a position to effect full automatic firing;

Fig. 14 is a view similar to Fig. 13 and shows the manner in which the connector cams the sear to a release position when the recoil mass moves to its forward position while the trigger is maintained pulled to effect full automatic firing; Y

Fig, 15 is a side elevational View of the stock with its butt end in section in order to illustrate the manner in which the butt loop sling may be. adjusted; and

Fig. 16 is a View showing the breech block, the extension block and the trigger plate in perspective.

Referring more in detailv to the drawings, wherein I have shown, for illustrative purposes,

one embodiment which the present invention may take, A designates generally a receiver; B, a barrel secured in any suitable manner to the forward end of the receiver.; C, a stock which may bevof` the. usual construction; D, a tube or sleeve foi'housing 4the recoil spring E, this sleeve being mounted in the forward vend of the stock and having; its forward end demountably connected to the rrearend of the receiver;` F; the' breech blockI formingv a part of the multi-part recoil mass mounted in the receiver; G, a cartridgemaganine of the usual construction; and the trigger plate located. Vwithin the receiver and supporting' the trigger mechanism, the magazine latch, and the stop-open latch, as described more` in detail hereinafter, v

The receiver A is preferably in the form of a cylindrical` tube, this makinglfor Ylightness in weight: and cheapness in construction.. -As shown in Fig. 2;,the forward end of the cylindrical receiveris. internally threaded as at I- so as to receive the rear threaded end of the barrel B whichLmay be of the usualconstruction. The rear endf ofath'e. cylindrical receiver. is. externally threaded as. at il so as to be demountablly screwed into: the internally threaded Venlarged for-.ward end t2 of the recoil spring tube D. The receiver, adjacent its forward end and on, .its

under side, is longitudinally slotted as atl?. to f provide a. loading opening. which accommodates the upper .end of areplaceable magazine Gwhich may beof the usual sort. Secured tothe forward end of the receiver, as bymeans cfa screw. 1.4i, is afwooden, holder L of .generally U shape in cross section. so as to receivev the magazine. Secured to-theholder., as by means of a screw I6, is. a. rectangular shaped band or guide Il' into which the magazine isadapted to be slipped to the position shown in Figl 2. The receiver, adjacent its for.- Walid endend. on its right hand side, has; anrejection' opening I8 throught which the spent case. is thrown `upon recoil of the breechv block; in the usual` manner. The receiver at its rear end and on its underside has a slot l 9 for accommodating the trigger 4 I.

' The casing D for housing. the recoil spring E and for guiding parts of the recoil mass. on its recoil and forward movements is also preferably in thejformY of a `cylindrical tube in the interests of lightness in weight andfeconomy in manufacture. This tube'isin `axial alignment with the receiver and barrel and is mounted within a bore 24 in the forward end ofr the/stock C'. The bore may be 'ope-n at the upper side of the gun as at 25. The

stock k'may be provided at its forward end with a depending pistol grip 26. Screwed-into the rear endiof "thetube Dis a threaded-plug 21 (see Fig; 3). Within the tube and forwardly ofthe'plug isa buffer in the form of a fibre -disk 28 against which the rearward movement of the recoil mass plugv 2T; Therhead of the screw abuts against a rearwardly facing shoulder 33 on the stock. This screw 32 is in axial alignment with the tube D .A. rearwardly' of the loading opening I3.

and the receiver A and it is hollow or bored out so as to accommodate the rear end of the stem of the firing pin- 3ft'.

Thetriggerxplate H is secured as by means of a screw' 40 within thel cylindrical receiver Y This trigger plate supports the firing mechanism which includes a trigger4l, va sear 42, and a connector 43. at its forward end an ejector 44, a magazine latch I45, and a latch 46 (herein referred to as a stopopen latch) for automatically latching the breech block in its retracted position after the last shot in the magazine has been fired or for manually latchin'g the breech block in its retracted position at will. This trigger plate, as willV be seen from Fig. 8, is a parti-cylindrical member with its under surface conforming to and seating snugly against the internal periphery of the rel tension' block 29 of the recoil mass during the recoil andl forward movements of suchmass. The plate at its rear end is longitudinally slotted as at li'lv so as to accommodate the trigger mechanism, and the plate at its forward end is slotted as at l to accommodate'the latches 45 and 46. As stated, the trig-ger plate is secured against the bottom portion of the receiver by the screw 40 and this screw is also employed to hold a trigger guard 49 inplace. v positioning vthe trigger plate'in the receiver and holding it against movement relative thereto Athe trigger plate has two laterally spaced apart depending dowels'uwhich closely take into correspondingly positioned holes inthe receiver (see Figs. 'Zand 16).

Referring now to the recoil mass, the same, as stated,'includes rtwo or more parts arranged in' successionV and mounted one behind the other, these parts hav-ing aL lim-itedA relative movement in the direction ofy the axis of the gun upon 4liringr in order: to disintegrate the shock of recoil as hereinafter described more in detail.` In the lpresent instance, this recoil mass comprises the breech block F, the extension block 29, and the follower block` 30. The' breech block consists of a,A parti-'cylindrical member slidably fitting within the receiver above the-trigger plate. The trigger plate and breech-block are complementary to one another, thatY is to say, in cross' section they form a cylinder which is divided along a common chord (see Figs.Y 2, -'7f a-nd l16). The under -side of the breech block is longitudinally grooved as at I55:. to each side of its center and' has laterally beyond these grooves flat surfaces Sli-,Which engage thelands 52'of the triggerplateQ Theupperwalll 69 of the left hand groove4 55 serves as aconnector holding surface. TheI breech block has a central or= vaxial bore 51' which slidably receives thev firing :pin Bil-which has on itsffor- The trigger plate further supports Also, for accurately ward` end a firing point 58. The bore 51 stops short of the forward end of the breech block so as to provide an end wall 51 which has a small opening 59 axially aligned with the bore for accommodating the firing point 58 when the firing pin is in forward position with respect to the breech block. The under -wall of the bore is longitudinally slotted as at 60 so as to accommodate the ejector 44 which may be vof the usual construction and which, as previously stated, is carried by the forward end of the trigger plate Mounted in the forward end of the breech block is an extractor 6l for withdrawing the spent case from the firing chamber of the barrel upon recoil of the breech block when the gun is fired. This extractor may be of any ordinary kind, the same being diagrammatically shown in the drawings.

The extension block 29 comprises a generally 'cylindrical piece (see Figs. 2 and 16), the body portion of which is of the same general radius as the internal radius of the tube D so that it may slidably t in said tube. The forward end of the extension block has an enlarged head B2 of substantially the same radius as the breech block and this head slidably fits within the cylindrical bore of the receiver. The under side of Athe extension block up to just short of its rear end is slabbed off so as to provide surfaces 63 which ride upon the lands 52 provided on the upper surface of the trigger plate. The rear end of the extension block is in the form of a substantially complete cylinder which lits in and is always engaged within the tube D. This extension 4block has an axial bore 64 aligned with the bore 51 of the breech block for accommodating the firing pin. This bore is open at its under side, as shown most clearly in Figs. 8 and 9, so as to accommodate the rear end of the sear during longitudinal movement of the extension block and to permit the Sear to engage in the notch B5 `of the ring pin for holding the firing pin in cocked position. It may be stated here that this notch at its rear end has a shoulder 56 against which the rear end of the sear is adapted to engage. The notch at its forward end is tapered as at 51. The extension block has on its under side and to the left hand side ofthe bore 64 a connector holding surface 68 which is above the plane of the surfaces 63. This surface 68 is in the same plane as and, in effect, forms a continuation of the surface 69 which defines the upper wall of the left hand groove 55 in the under side of the breech block F. At

, the rear end of this connector holding surface 68 is a notch 10 which opens into the left hand side of the extension block. The rear wall 1I of this notch is abrupt or perpendicular and its front wall 12 is forwardly and downwardly inclined for a purpose to be later described.

The follower block 30, which is located within the tube D, is in the form of a piston having its forward end of such diameter as to slide within and be guided by the tube. The rear end of this block is of somewhat reduced diameter so that the forward end of the recoil spring E may surround the same and abut against the shoulder provided by the rear end of the forward enlarged portion.` This block alsohas an axial bore 14 in line with the central boresbf the breech block and extension block so that these several bores may accommodate the firing pin.

In the present illustrative disclosure, the breech block F and extension block 29 are confnected together so that the relative movement therebetween in an axial direction is somewhat limited, one lpurpose of this arrangement being to prevent such separation of the blocks on firing of the gun as would rpermit the connector 43 from being caught or jammed in the gap between the extension block and the breech block during movements of those blocks. This connection between the blocks may in some instances not b e required. In the present instance, the connection, as will be seen from Figs. 2 and 1l, is in the form of a pin and slot arrangement comprising a transverse pin 15 carried by the rear end of the breech block and bridging a notch therein and a slot 16 provided in a tongue 11 projecting from the forward end of the extension block into said notch. For a purpose to be later described, I provide between the breech block F and the extension block 29 means which normally tends to urge these two blocks apart. In the present instance, this means includes -a coiled compression spring 18 located in a longitudinally extending hole in the rear end of the breech block and bearing at its rear end against the forward end of the tongue 11.

The firing pin 34 is provided with a rearwardly extending rod or stem 98 for supporting a ring pin spring 9i coiled thereabout (see Fig. 3). This spring, at its forward end, abuts against the rear end of the body portion of the firing pin and at its rear end abuts against a disk 92 through which the rear end of the stem 99 slidably extends. The rear end of the stem is headed or peened over as at 93 so that the disk cannot come loose from the stem. This disk abuts against the forward end of the hollow screw 32. It is clear that the rear end of the firing pin extends into the screw when the firing -pin is in other than full advanced or flred position.

By providing a multi-part recoil mass of the character just described, the shock caused by recoil to the shoulder of the shooter and to the firing and other mechanisms of the firearm is reduced or disintegrated, as will be clearly understood from the following explanation When the parts are in their forward firing positions shown in Fig. 2, the breech block F is forced against they rear end of the barrel, and the breech block, extension block 29 and follower block 39 are forced together by the recoil spring E so that the three blocks act as an integral mass to close the breech. As a result, at the instant a cartridge in the firing chamber is fired, the power gases generated act upon the various blocks as though they were one integral mass, the recoil mass being driven violently to the rear causing compression of the recoil spring. However, upon such rearward movement, the breech block lags behind the follower block so that the blocks separate slightly with the result that the recoil movements of the follower block, the extension block, and the breech block are successively stopped in that order at very slight intervals apart so that the shock of stopping such rearward movements is disintegrated or smoothed out. More particularly, it will be seen that lagging of the breech block upon recoil with respect to they extension block is due to the spring lpressure of the firing pin spring 9| (the forward end of the firing pin being against the end wall 51 of the breech block) and also due to the friction of the uppermost cartridge in the magazine against the botto-m of the breech block. As the breech blocks rearward velocity is thus retarded, the breech block and extension block separate slightly, the extent of separation being limited by the pin and slot connection 15 and 10. This. separation is further aided by the spring 18 whichl is interposed betweenthe extension block and the breech block. After a separation between the breech block and the extension block to theextent allowed by the pin and slot connection, the extension block will move rearwardly at the same rate as the breech block and thus the rearward movement of the extension block will lag with respect to the follower block, thus permitting the follower block to separate slightly from the extension block. Rearward travel of the follower block is limited by the impingement ef that block against the buffer 28 located in the rear end of the recoil spring tube D; the extension block then stops against the forward end of the follower block, and then vthe breech block stops against the forward end of the'follower block. Thus the several blocks oi the recoil mass are separately and sucvcessively stopped in their rearward movements,

these stoppages being effected in an almost imperceptible period of time but they being spaced apart sufficiently in time to permit of a smoothing out or distribution oi the shock of recoil over that which would result should such movement between the several parts not be permitted. Thus the jars to which the shoulder of the shooter is subjected are somewhat relieved, and the strains and stresses caused by shock upon recoil upon the various parts and mechanisms of tl `e 'gun are reduced. The spring '81 also serves the purpose of aiding in disintegrating or distributing the shock incident to stopping the forward movement of the reco-ily mass. It is understood that the recoil spring is compressed during recoil and then that spring forces the recoil mass forwardly into the firing positions shown in Fig. 2. During such forward movement, the spring 'I8 accelerates the forward speed of the breech block relative to the other blocks so that the breech block stops against the rear end of the barrel and then the extension block will stop against the rear end of the previously stopped breech n block.

It will further be observed, particularly from Figs. l, 2, and 3, that the barrel, tubular receiver, and the recoil spring tube are in a straight' line alignment, that is to say, their axes coincide; and that the buffer 28 in the rear: end of the recoil spring tube D against which the recoil mass impinges on ring of the gun is positioned an appreciable distance rearwardly from the forward end of the stock and more closely t0 the shoulder of the shooter than has heretofore been the case, and thus, upon recoil, the shock of the recoiling parts is in the line of fire and is closely adjacent to the butt end of the stock which engages the shoulder of the Sshooter. This is all of advantage in that tendencyY for the gun to jump or weave upon firing is greatly reduced and the firearm may be more readily aimed and more readily held on the target. It will further be observed that the receiver and the recoil spring tube are cylindrical members so that' they can be readily and economically manufactured either by simple drawing or turning operations and that these parts are of relatively light weight while at the same time they have vsuiicient strength to adequately perform their functions.

The firing mechanism, which includes the trigger 4|, the sear 42, and the connector 43 will now be described. The trigger is pivoted on a pin |00 located adjacent thefforward end of the-slot 41 in the trigger plate. Also -pivoted on this pin and between the ears on'the forward Yend of 8 thetrigger is a pressure lever |01 theunderside of theforward end of which. is'adaptedtozabut against a shoulder |02 onthe trig'genpl'ate forthe purpose of limiting the extent of upward' pull` on the Ltrigger..` Preferably, in orderr tov prevent cramping between the trigger and the' pressure lever, a bearing sleeve 99 (see` Fig, 8) islinter-v posed Ybetween the pin` |00 and the trigger; and the'pressure lever is journalled on this'sleeve. This lever |0|', as hereinafter describedmore in detail,A is held against pivotal movement relative tothe trigger when'the'gun is to be fired `only `in a semi-automatic manner by a screw |03 mounted'for :axial adjustment in athreaded` opening in the body of the trigger. AboutY this. screw and between the tail end of the lever andthe vtrigger is a coiled'spring 104th@ purpose of *whichV will be hereinafter described more in detail. Downward ,movement of the trigger is limited by the engagement of Ya small rearwardly extending. .lug

V|05 against the -bottom portion of thereceiver,

asshown most clearly in Fig, 2.

The Sear IlzA is pivoted between its ends on a pin |06 carried by the trigger plate rearwardly ofthe p-in |00. VThe rearV end of this -sear :has a shoulderv` |01 adapted to engage the `shoulder 66 of the firing pin for holding thatpin inthe firing position shown in Figs. 2 and 10. The ,forwardl end of the-scar has a downwardly facing connector engaging face ,|08 which terminates at its rear end in a connector locking-abutment |09 disposed` generally at right angles toY they face |08. The sear further has, rearwardly ofthe abutment |09 and meeting the upper end of 'that abutment at an obtuse angle, a camsunfacal I0.

.The extreme forward end of the sear also'has a rearwardly facing depending hook which is adapted to interlock withy the connector 43 in order toV preventthe sear from being jarred from firing pin holding position.

The'connector 43 is pivoted. to the trigger as at H5. This' connector has a sear engagingpor- -tion located beneath and in the vertical plane of theforward end of the sear, and this portion has a normally upwardly facing sear actuating surface I6 which is positioned beneath and in opposition to the connector engaging surface A|08 vofv the sear when the ringrmechanism is in the normal or firing position shown in Figs. v2. and

vl0.,` At the forward end of thel surface `H6 is a ,forwardly extending lug which is adapted to takel into the hook (see Figs. 2 and 10) The forward end of` this lug constitutes an abutment at theforward end of the surface |6 and this abutment isY adapted to engage the connector locking abutment |09 of the sear as-shown in Fig.A 12 for 'the' purpose of preventing the connector fromv swinging. forwardlyto a position where the surfaces |08 and |-B are opposed until .sear fromthe ring pin when the firearm is being fired in a full automatic manner.

Extending upwardly from the sear engaging -portion of the connector and` located to one side of the sear is a nger ||8 which extends into the notch 70 of the rextension block when the recoil mass is in itsforward position (see Figs. 9,'and 10). VThe 'upper end of the nger is in engagement with vthe -

connector engaging surfaces

68 and 69 of the extension block and follower block during the rearward and forward movements of such blocks (see Figs. 11 and 13).

The sear is normally urged into its firing pin holding position, the trigger is normally urged towards its unpulled position, and the connector is normally urged forwardly into a scar actuate ing position by a very economical, simple, and effective spring arrangement which may be easily and quickly installed. These functions are obtained by a single spring |25 which is preferably in the form of a round spring wire bent generally into S form. The sear is longitudinally grooved on its under side so as to provide a kerf which accommodates the upper arm of the spring.. with the upper bend or crook of the spring in partial encircling relation to the pin |06 on which the sear is pivoted. The forward end of the lower arm of the spring is received by a hole in a projection |25 extending forwardly from the base of the nger ||8 of the connector. Extending through the bottom crook or bend of the spring is a transverse pin |21 removably carried by the trigger plate. To install the spring, it is merely necessary to slip the upper arm thereof into the sear, slip the forward end of the lower arm into the hole in the projection |26, and then slip the pin |21 into the bottom crook of the spring.

As previously stated, when the screw |03 carried by the trigger is screwed home so that the pressure lever I! can have no relative movement with respect to the trigger, the gun can be fired only in a semi-automatic manner. Assuming, for the present, that that condition exists, the functioning of the mechanism is briey as follows. Figs. 2 and 10 shows the firing mechanism in its normal position, that is, the breech is closed and the gun is ready for firing. It will be observed that the sear is in cocked position, the trigger is down in unpulled position, and the connector is in its forward position with its sear engaging surface ||6 opposed to the downwardly facing surface |08 on the forward end of the sear and with its ringer extending into the notch 10 of the extension block. Upon pulling of the trigger, the connector is raised resulting in actuation of the sear and release of the firing pin. The ring pin, under the comp-ression of the ring pin spring 9|, moves sharply forward so that this pin strikes the primer of the cartridge located within the firing chamber of the barrel. On the resulting explosion, the power gases drive the recoil mass backwardly, as previously described, and as this mass starts backwardly, the inclined camming surface 12 on the extension block engages the finger H8 of the connector and cams the connector to the position shown in Fig. 11 and in which position it is thereafter held by the

connector engaging surfaces

68 and 69 of the extension block and breech block during the rearward and forward movements of those bloclm providing that the trigger is held in the pulled position shown in Fig. 1l. Upon the return of the recoil mass to its forward position, the trigger still being maintained in pulled position, the'connector and slear assume the positions shown in Fig. 12.

the sear. f This means that in order to again fire the gun, the trigger must be released and again pulled between which movements thel connector would be released from the sear bringing' the face ||6 of the connector beneath the face |03 of the scar. Of course, if, during the movement ofthe recoil mass, the trigger is released, theparts-auto-` matically assume the positions shown in Fig.-10 when the recoil mass reaches to its forward or normal breech closing position. `vIt will be ob, served that when the gun is set to Qperatein a semi-automatic manner, the extent to which the trigger can be raised is limited to the position shownl in Figs. 11 and 12 and in whichposition the camming corner ||9ion theconnector lisnot high enough to engage the camming surface VI-lill of the sear. i

When it is desired to `it may be selectively` operated in either a semi automatic manner or a full automaticmanner by varying the pull of the operators finger on the trigger, the screw |03 is backed on", as shown in Figs. 13 and 14, to permit of a pivotal movement of the trigger with respect to the pressure lever |0|. This allows the trigger tobe selective.- ly moved to the position shown in Figs,4 1-1 and 12 in which semi-automatic firing is obtained,-or to the higher position (by exerting a greater pull on thev trigger) shown in Figs. 13 and 14 vin which full automatic firing is obtained so long as the trigger is maintained in its fully pulled` or highest position; yAssuming that the'screw;v |03 has been backed off, the operation of the firing mechanism is now briefly as follows. Starting with the parts in their normal firing positions shown in Fig. 2, if it is desired to re thefrearm in a semi-automatic manner, the trigger is pulled to the intermediate position-shown in Figs.' 11 and 12 and in which position, it being assumed that the screw |03 has been backed off, the coiled spring |04 is not compressed or atleast is not compressed to any appreciable extent.` 'Ihe op.- eration will now be the'same as that previously described in connection with vthe"semi-automatic firing. If it is desired to ire in'afull yautomatic manner, it is merely necessary to .exert a harder pull on the trigger thus raising the trigger to its upper limit of movement lshown in Figs. 13ancl 14,*it being observed that, due to this harder pull, the spring |04 'is compressed. Upon upward movement of the trigger from-its unpulledposition shown in Fig. 2, the connector will release the sear from the firing pin in the same manner as heretofore described, resulting in' the '.rstring of the gun. Upon recoil of 'the recoil'mass, the cam surface 12 of the extension block will cam the connector backwardly to the position shown in Fig. 13 in which position it will be held by the

connector engaging surfaces

68 and 69 of the extension block and breech block during the rearward and forward movements of those blocks. It will be observed that the connector has a more rearward position than that shown in Fig. 11 because the pivot ||5 for the connector .is in a higher position during full automatic ring than it has during semi-automatic ring. i During forward movement of the recoil mass, the' rear end |01 of the sear will automatically engage the shoulder of the advancing firing pin and thereby lhold the firing pin rin cocked position until the recoil mass reaches its breech closing position. 'As the recoil mass approaches such position, the vertical wall 1| of the notch 10 will engage the finger H8 and positively swing Vthe connector forwardly'so that Vthe corner ||9 von the body portion rof the connector will engage andvride along the cam surface |10 of the sear, thus camming the forward end of the sear upwardly and the rear end downwardly with the `result that when the recoil mass has fully reached its breech closing position the firing pin is automatically released and the firearm is fired a second time. The Vfirearm will continue to re 'in a lfull automatic manner so long as the trigger is held in its fully raised position and so long as cartridges are supplied to the gun. As long as the 'trigger lremains in full pulled positiony the upwardly facing shoulder ||6 on the connector cannot come below the connector engaging surface |08 Vof the sear for each time that the vconnector is swung forwardly 'by the extension block, i

the forward face of the lug I |1 forms a stopface for engagement with the rearwardly facing abutment |09 ofthe scar. The -perpendicular shoulderv or wall 1| of the -notch 10 of the `extensi'on block .pushes the connector substantially to the last mentioned position but not beyond it. When it is desired to cease full automatic firing, it is merely Anecessary to release the trigger in which case the parts again assume the position shown in Fig. "2. It is thus noted that the operator'may very quickly and readily' change from firing 'in a semi-automatic manner to a full automatic `manner andl vice versa by merely changing, at'any time he may desire, the amount :of pressurey which he exerts on the' trigger.

It may kie-desirable. at times to selectively render the rearm operablel for 'eithernsemi-automatic 'firing or for' full automatic firing without employing the selective arrangement just. .described, and to this endlI provide a .manually adjustable sectorA whichalso serves the purpose of locking the trigger of the iiring mechanism in safety or unpulled position. This manually :ad-` justable selector comprises a split metal bandv :|35 mounted for angular adjustment in a groove4 pro'- vided' in the outside of the receiver adjacent lthe rear-end thereof. The trigger, adjacent its V'rear end fand' behind `the connector, is provided at opposlte'sides with'r two upwardly facing .shoulders 1|36and |31, theleft vhand shoulder being lower than the right hand one. The endsl |38r and |39 of thev band are spaced apart at the slot |'9 in the receiver :through :which-the ltrigger extends. f The bandi's adjustably adjusted :to three positions, it being resiliently'held in each of these positions by .the selective engagement of a small nib |40 .carried bythe band in notches |4| provided in the external periphery of the receiver'fsee Fig. 9). The band is provided with finger pieces '|42 sothatA it `may be more easily adjustedv to its several. positions. With'this arrangement, when it is desired to iire the gun in a full automatic manner, `the band is adjusted to the-mid-position shown in Fig. 9, in which case both ends of the bandiareout of the path' of 'movement ofzthe trigger so thatl the trigger may be raised to the Y fulliautomatic .firing Vposition shown in Figs. 13

Vbeen previously pointed `out that:y the searV 'has -a rearwardly facing depending hook |.l l, andthe connector has a forwardly extending lug H1 adapted to engage in the hook when the trigger mechanism is in normal condition. The purpose of this interlocking arrangement is to prevent the sear from being jarred outof its cocked position resulting in an accidental discharge of the rearm in the event the Vsame were droppedor jarred. Thus, when the trigger is locked in safety position by the band |35, the sear is locked by the hook l against accidental movement. -However, the gun may be cocked while the safety is in .the ,on position without doing any damage to the parts because, upon the rst opening movement of the .breech block, the inclined surface 12 on the extension .block will swing the connector out of locking engagement with the sear.

'I'he magazine latch and the stop-open latch will now be described. The magazine, as is usual, has a box or body portion |5 within which is a follower spring |5| bearing at its upper end against a follower |52 (see Fig. 2). The follower at its rear end, has a rearward extension |54 which extends into a slot in the ller piece |53 secured to the wall of the magazine box (see Fig. 2A). The magazine latch 45 and the stopopen latch 46 are pivoted at their upper ends on a pin |51 carried by the forward kend ofthe trig'- ger plate and bridging the slot 4'8 thereof.' This pin also supports the ejector which', as shownV in Figs. 2 and '7, is interposed between :the upper ends of the two

latches

45 and 46. The rear end of the ejector is engaged with the trigger plate as at |58 and with a stop pin |59 so thatit is maintained against turning. The magazine latch has, fat its lower end, a hook |63 which is adapted to engage a shoulder |61 provided in the rear wall -of the magazine body whereby to hold the magazine in place.. Extending rearwardly from the lower `end of the magazine latch is a finger piece |62 whereby the latch may be manually withdrawn from Amagazine holding position. The stop-open latch is mounted for Vswinging movement with, and also for up and downmovement relative to, themag-azine latch. To these. ends,

the .stop-open latch, vadjacent its upper end, has

an elongated slot- |53 which receives the pivot pin |521, and the stopeopen latch intermediate its ends carries a screw |64 provided with a reduced end wh'ichvengages in an elongated verticalslot |65.

in themagazine latch. The stop-open latch 'has at its upper end a forwardly extending a-rm |66, the `under surface of which is adapted to be `engaged by the .rearward extension |54 of the follower when the last cartridge in the .magazine has been removed therefrom. This arm, at its upper side, has a rearwardly facing stop or shoulder |61 located beneath the surface 69 which constitutes the upper Wall of the left hand groove 55 in the breech' block.v When the stop-open latch' isin its @operative holdingposition, the forward end of the breech block engages this stop |61. The stop-open latch 46 at its lower `end has a finger piece |68.; The magazine latch is forced into the latching position shown in Fig. 2 by a ystrong helical spring |68 and a plunger |10 posif .tioned in a bore in the forward `end of the trigcase .the right hand end (referring to Fig. 9) Vof i the `band lies immediately overV the right hand shoulder |31 of the trigger. The trigger cannot nowbe lifted fromiits unpulled position. It has mama iger plate. When the magazinewith cartridges therein is inserted in the firearm, they cartridges4 block to the firing chamber, the rearward extension |54 of the follower |52 engages the under side of the arm |65 of the stop-'open latch so that the follower spring urges the stop 31 against the surface 63 of the breech block. Upon firing of the last cartridge, the breech block will recoil and th'e follower spring |5| will raise the stopopen latch 46 so as to position the stop |61 thereof in front of the forward end of the breech block. As the breech block strikes the stop-open latch, the latter swings slightly on its pivot and as themagazine latch is connected to the stop open latch by the screw |64, the latter latch swings rearwardly out of engagement with the magazine. Thus, after the last cartridge is fired, the breech block is automatically stopped in its open position and the empty magazine is automatically released from the rearm. it will be noted that when the breech block thus strikes the stop |51 of the stop-open latch, the comparatively stiff helica1 spring |53 is compressed and thus the stopping of theV forward movement of the breech block is cushioned. To reload the firearm, a full magazine is placed in position and the stop open latch is manually moved downwardly whereupon the breech block moves forwardly taking the uppermost cartridge out of the magazine and moving it into the ring chamber ready for firing.

If it is desired t0 manually move the breech block to retracted position and lock the same in that position for the purpose of cleaning or examining the inside of the receiver or for any other reason, this may be done by manually retracting the breech block by means'of a handle |15 and then manually raising the stop-open latch. The handle projects from the right hand side of the breech block, as shown in Fig. 7. It will be observed that the magazine latch and stop-open latch are relatively simple in construction and the parts may be economically manufactured and assembled. Each of the latches comprises but one part. These two parts are pivoted on the Same pin and are so connected that cushioning of the force of the recoil mass when stopped in open position is effected through the magazine latch bearing against the plunger |10 behind which is the spring |69.

As previously stated, the rear end of the receiver is adapted to be screwed into the forward end of the tube D. For the purpose of locking these parts against relative rotary movement, an improved take-down latch is provided. This latch, as shown most clearly in Figs. 4 and 5 comprises a slide having a stem |80 provided at its inner end with a locking head |8| and at its outer end with an elongated finger piece |82. The stern |80 extends through and is slidably mounted in an elongated slot |83 in the enlarged forward end l2 of rthe tube D. The rear end of the receiver is provided with a notch |84 which is adapted to receive the head |8| when the latch is in locking position. The latch is held in its two positions of adjustment by a leaf spring |85 positioned between the finger piece |82 and the head |2 of the tube D. This spring normally has a longitudinal curvature so that when it is positioned in place it will bear at its central portion against the under side of the nger piece |82 and at its ends against the periphery of the head |2. In order to permit the parts to be assembled, the spring has a transverse elongated opening |86 through which the finge-r piece may be inserted when the spring is in a position at 90 to that shown in Fig, 5. After the spring is thus slipped overl the finger piece, the spring is turned to the position shown in that gure. In order to prevent the spring fro-m turning out of the position shown in Fig. 5, the forward end of the spring has a finger |81 engaging in a groove |88 in the head i2. It will be seen that this take-down latch is very simple in construction and that the parts thereof maybe readily assembled. The latch maybe easily operated by sliding the finger piece from one position to another. The spring, in addition to serving to hold the latch in place, covers the slot |83 so as to prevent dirt or the weather gaining access to the interior of the receiver.

In order that ,the gun may be conveniently carried and quickly brought to shoulder position for firing, there is provided at the rear end of the stock C a butt-loop sling |80 see Figs. 1 and l5). This sling is in the form of a strap, the respective ends of which are threaded through vertical slots i9! in the upper Aand lower walls of the stock adjacent its butt end. The ends of the strap within the stock may be adjustably secured togetherby a suitable buckle |92 located within a cavity in fthe stock. When carrying the rearm, the sling goes over the shoulder of the shooter with the gun depending along the side of the body and the leg of the shooter. When it is desired to re the gun, all that is necessary is for the operator to grasp the handles thereof and swing the gun to lfiring position. During such movement, the sling slips about the shoulder of the shooter as a pivot.

Also, in accordance with the present invention, I provide an improved rear sight which is shown most clearly in Figs. 3 and 6. This sight includes a base block |95 located at the rear end of the slotl 25 of the stock and secured, as by means of a screw |96, to the tube D adjacent the rear end thereof. The block has a forwardly facing shoulder |91 at each side, and forwardly or' these shoulders is a transverse hole in which is located a pivot pin |98. On the opposite projecting ends of this pin are posts |99, The openings in the posts which receive the pin |98 are of larger diameter than the pin so that the posts may have a limited transverse movement. The posts support a sightpiece 200 which has a central circular portion 20| provided witha sight aperture 262. The central portion 20| is carried by side portions or arms 203 which are grooved on their opposing faces so as` to provide guideways which accommodate the posts |99. One of the posts may be provided along its outer edge with notches 204 and one of the arms 203 may have a lug 285 adapted to selectively engage in these notches in order to hold the sightpiece in its several positions of adjustment depending upon the range at which the firearm is to be fired. For the purposes of urging the posts apart so that they will frictionally engage in the opposed surfaces provided by the guideways of the arms 203 and for resiliently holding the sight in the elevated position shown in-Figs. 3 and 6 or in a down position Where the sight lies horizontally within the groove 25, catches 206 and a spring 201 therebetween are provided. These catches and this spring are located in a transverse opening 208 in the base block |35 positioned upon and slightly forwardly of the pivot pin |98. The catches are preferably in the form of hollow caps having outer rounded ends so located that when the sight is in raised position the spring 201, acting through the caps, urges the posts |93 against the shoulders of the base block. When the sight is swung to folded or down position, the` .catchesengage the then .upper Y edges of the posts so as to hold the sight in that position. In all positions of the sight, the posts are urged outwardly into frictional engagement With the sightpieCe, and the sight-piece, acting through the posts, hold the catches Within the transverse opening 208, `It will be observed that, due to the loose mounting of the posts on their pivot |98, and due to the fact that the spring 261, acting through the catches 206, tends to urge the posts apart, the sightpiece may be adjusted on the posts bypressing the free ends of the posts towards each other, Virtually adjusting the sightpiece to the desired position and then releasing the pressure on the posts; and the sightpiece is maintained in its adjusted position by theexpanding apart of the posts.

As many changes could be made in the above construction and many apparently widely different embodiments of this invention could `be made without departing from the scope thereof, it is intended that all matter contained in the above description or shown in the accompanying drawings shall be interpreted as illustrative and not ina .Iimitingsensa It is also to be understood that the language 1.6 used in the following claims is intended to cover all of the generic and specific features of the invention herein described and all statements of the scope of the invention Which,`as a matter of language, might be said to fall therebetween.

I claim as my invention:

1. In a. rearm, a tubular receiver having a tubularv bore, a parti-cylindrical trigger platein the receiver having a flat upper surface and having its under surface curved correspondingly to and seating against the bottom of the receiver, a recoil mass having aparti-cylindrieal breech block fitting within the bore of the receiver and having on its under side flat surfaces engaging the flat uppersurface ofr said trigger plate, a spring behind said bloc-k and trigger mechanismrcarried by said trigger plate.

2. In a rearm, a tubular receiver of circular cross-section, a parti-cylindrical breech block guide xedly mounted in said receiver, and a parti-cylindrical breech block arranged to rest and reciprocate on said guide, said breech block and guide fitting closely and complementarily into said tubular receiver.

VAL A. BROWNI'NG.