US2499090A

US2499090A - Inertia operated pivoted bolt lock

Info

Publication number: US2499090A
Application number: US555949A
Authority: US
Inventors: Val A Browning
Original assignee: J M & M S Browning Co
Current assignee: J M & M S Browning Co
Priority date: 1944-09-27
Filing date: 1944-09-27
Publication date: 1950-02-28
Anticipated expiration: 1967-02-28
Also published as: BE466929A

Description

Feb. 28, E950 v. A. BROWNING INERTIA OPERATED vPIVOTED BOLT LOCK 5 sheets-sheet 1 Filed Sept. 27, 1944 INVENTogL 4 Z EmwIwZQ.

Feb. 28, 1950 v. A. BROWNING INERTIA OPERATED PIvoTED BOLT Loox 5 Sheeis-Sheet 3 Filed Sept. 27, 1944 Feb. 28, 1950 v. A. BRoWNlNG INERTIA OPERATED PIvoTED BOLT Loox 5 Sheets-Sheet 4 Filed Sept. 27, 1944 i. |||1vll-l:========= S mw Sw NN m S l o r n@ QS. um @A un INVENTQR. Vcd 25mn/fung.

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Feb. 28, 1950 V. A. BROWNING INERTIA OPERATED PIVOTED BOLT LOCK Filed Sept. 2'?, 1944 5 Shee'ts-Sheet 5 SS SESS@ a S SQ' ,l i :LI A.

l l gm Q 9 INVENTQIL y Valfowzzmg, Y

l @Y 5% d? Patented Feb. 28, 1950 INERTIA OPERATED PIV OTED BGLT LUCK l Val A. Browning, Ogden, Utah, assignor to J. M. & M. S. Browning Company, Ogden, Utah, a

corporation of Utah Application September 27, 1944, Serial No. 555,949

7 Claims. (Cl. 859-182) This invention relates to improvements in firearms, and particularly to self-loading, recoil-opf erated firearms.

It is an object of this invention to provide a self-loading, recoil-operated firearm which has a new and improved construction and a novel recoil self-loading operation and wherein the unlocking of the breech block from the 4barrel is caused to occur automatically during the recoil stroke of the barrel through the action of various forces at play with the result that the barrel and breech block are unlocked at a proper and safe moment irrespective of the character and intensity of the charge employed and promptly following the establishment of such proper and safe condition, and wherein such operation is eiected Without the use of abutments or stops for positively arresting the rearward movement of the barrel or the use of positively actuated means for disengaging the breech block from the barrel at a fixed point.

With my improved arrangement, some of the more severe shocks inherent in previous arms of this type are eliminated so that the kick on the operators shoulder and the shock to which the parts are subjected are greatly reduced, permitting of the use of lighter parts and a greater freedom in the selection of the materials of which the parts are made. Wear and tear on the firearm and its operating mechanism are greatly reduced. Furthermore, with my improved arrangement, the barrel recoil is materially shortened Which permits the use of a shorter receiver, a material improvement in the appearance of the firearm, and a, substantial reduction in weight.

A further aim of the invention is to provide in a firearm of this type a new and` improved'arrangement for transferring the successive cartridges from the magazine to the firing chamber and, particularly, to provide an arrangement wherein the magazine may be loaded at all times when the breech block is forward in closing position without the necessity of pushing a manual button or other instrumentality of the type usually employed on firearms of this character, and wherein the carrier is simplified and its operation is improved.

It is a further object of the invention to provide a new and improved firing mechanism for firearms which is simple in construction and highly efficient in operation.

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

The invention accordingly consists in the feaand 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.

The following description will be more readily understood by referring to the accompanying drawings, in which similar reference numerals refer to similar parts, and in which:

Figure 1 is a side elevational View of an automatic, recoil-operated firearm embodying the present invention;

Fig. 2 is an enlarged sectional view taken generally longitudinally and vertically through the firearm, with parts of the operating mechanism shown in side elevation;

Fig. 3 is a like sectional view, of a still greater enlargement, showing the operating mechanism of the rearm illustrated in Fig. 1 when the same is in firing position, the rear and forward ends of the firearm being omitted;

Fig. 4 is a view similar to Fig. 3, in which the parts are in a position which they occupy during an intermediate stage in the recoil stroke, and more particularly illustrating the barrel in the position which it occupies toward the end of its recoil stroke and the breech block in a position where it is unlocked from the barrel and is continuing its recoil movement;

Fig. 5 is a View similar to Fig. 3 but looking at the other side of the firearm and showing the relative positions of the parts when the breech block has almost reached the end of its recoil movement and at which time the carrier is in depressed position, as shown, to receive anew cartridge from the magazine;

Fig. 6 is a View similar to Fig. 5 but showing the carrier latched in depressed position and the breech block locked in retracted position, a condition which takes place when the firearm has been red and the magazine is empty, or when the breech block is manually moved to its retracted position while there are no cartridges in the magazine;

Fig. 7 is a View similar to Fig. 3 but shows the positions which the parts assume while the breech block is moving rearwardly from the position shown in Fig. 5 to the extreme end of its recoil stroke;

Fig. 8 is a View similar to Fig. 7 illustrating the relative positions of the parts when the breech block is approaching the forward end of its return movement and just prior to the locking of the barrel 'and breech block;

.tures Aof construction, combination of .elements Fig. 9.is a plan. view/partlyin cross section,

taken on the line 9--9 of Fig. 5 and looking in the direction of the arrows;

Fig. yluis an elevational cross sectional view taken on the line lD-I of Fig. 3 and looking in v the direction of the arrows;

Fig. l1 isan elevational cross sectional view taken on the line li--ll of Fig. 3 and looking in thedirection of the arrows;

Fig. 12 is a perspective view showing the construction of the link;

Fig. 1B is a side View of the closure plate Il',` the right hand extractor 58 and the operating `handle i9 being shown in phantom; and

Fig. 14 is a top edge view of the closure plate i y and a portion of the breech block.

Before describing my improved iirearm in detail, a general statement as to its construction and mode of operation will first be given. My improved firearm has a frame here shown rin the form of a receiver, a barrel provided with a barrel extension mountedifor reoiprocation in the receiver, a breech block provided with means (such as va locking block) for locking the breech blockto the barrel extension, an inertia instru.-

mentality comprising an inertia member or block connected to the locking means and arranged to relduring the recoil stroke of the barrel and before the barrel reaches its rearmost point of recoil, and means comprising arecoilspring for resisting recoil movement of the barrel and exerting a resistance of sucient magnitude to yieldinglyv stopv the barrel in its rearward recoil movement and then return the barrel to its firing v position. When the firearm is red, the reari yward pressure of the gases resulting fromthe erating buttons or vthe like.

- into the :tiring chamber,

f By referring to the drawings, it will be noted that the present invention is illustrated as embodied in a firearm comprising a barrel Hl, a

frame orreceiver il, and a stock 12. is of usual construction and is provided at its rear end with a barrel extension i3 and a cartridge chamber !4. The 'barrel extensionextends into an opening 3B in the forward end of the receiver. The barrel is further equipped with a f barrelfguidering i5 which isslidably'mounted on the cylindrical magazine IB. rlhe receiver or frame y Il may be of any suitable construction automatically disengage the latter from the barhandle I9. The magazine I6 is permanently explosion forces `the barrel, the breech block in locked relation to the barrel extension, and the` inertia instrumentality rearwardlywith an accelerating movement through a very short distance and then the parts, due to the action of i y the recoil spring, undergo a decelerating recoil i movement during which time the breech block is automatically unlocked from the barrel extension due to the momentum of the inertia instrumentality. After the breech block is thus unlocked, the recoil resisting means will yeldingly stop rearward movement of the barrel in space (that is, Without the barrel Striking any ixed stops or abutments), and the recoil spring will then advance the barrel to its ring position while the breech block and the inertia block continue their recoil movement. An action spring then returns the breech block and inertia member to their` forward positions where the breech block is automatically locked to the barrel extension. The point at which the barrel is stopped in its recoil movement is variable (this being permissible as the barrel, in its rearward movement, is not brought against a xed abutment or the like) the extent to which the barrel moves rearwardly being largely dependable upon the character and intensity of the charge employed. Consequently, any standard shell may be employed in the firearm as variations in the explosive intensity of shells within the standard range are automatically provided for, and no manual Aadjustment of the rearm is necessary.

.stion so that it is out of the way which will and isk here illustrated as a one-piece member which is rounded 01T at its top rear surface to give the rearm an improved, streamlined ap-` vpearance. usual ejection opening il in one side face thereof The receiver is provided with the and a slot I8 extending from the rear edge of said opening vto accommodate the operating secured to the front end of the receiver as at 2B by screw threads :or other suitable attaching means.

, The rear of the receiver is preferably equipped with a threaded extension 2l which serves as a mounting for the inertia member tube 22, 'which fits within the bore 23 of the stock l2. The inertia member tube is closed at its rear end by a suitable plug 2e or the like, which is provided with an internally threaded opening 25 for accommodating the stool;v :bolt 26, preferably in the manner shown in Fig. 2. The stock bolt 26 extends through a smaller opening 21 in the stock and. has an enlarged head 28 abutting the inner end of a. larger opening 29 in the stock. Through the instrumentality of the stock bolt the stock is held in proper position on the receiver.

Between the barrel guide ring and the opposed face of the receiver a recoil spring 3D is provided, together with one or more friction rings 32-32 which serve to resist the recoil movement of the barrel and to restore the barrel to firing position following recoil. The friction rings 32-32 may be of any suitable construction and are here illustrated as comprising split collars 33--33 surrounded by suitable retainer springs 315-34.

In this particular invention the recoil spring 38 and the friction rings 32--32 are of such construction that they collectively provide suiicient resistance to the recoil movement of the barrel to stop its rear movement in space within the receiver, that is without the use of abutments or the like against which the barrel may strike. l

Within the magazine tube I6 a suitable magazine spring 35 is mounted for advancing the shells in the magazine rearwardly in the con-l ventional manner for automatic loading of the firearm. The forward end of the magazine tube i6 is threaded as at 36 for accommodating the magazine cap 31 which, with the usual fore-end 38, holds the barrel in mounted position with respect to the receiver.

In the opposite sidewalls of the receiver. at

The barrel an intermediate point in the height thereof, a pair of opposed grooves 4|l-40 are provided which constitute slide tracks for the barrel extension and breech block during their reciprocatory recoil and return movements. Laterally projecting anges ll-4|, formed on the lower forward portion of the barrel extension, are slidably mounted in the grooves 411-40. The breech block I 44 is provided with laterally extending flanges 45-45 which are likewise slidably mounted in I the grooves 40--40 in the receiver. The breech and lug in the present illustration is located outside of the body of the locking block and in such fu; position as to give the desired movement of the locking block relative to the breech block.

The forward portion of the breech block is provided with a central opening 49 for accommodating the iiring pin 50. The opening 49' is en- I larged, as at 5|, and constitutes a seat for the forward end of the iiring pin spring 52 which is preferably mounted as shown and which, at its opposite end, abuts the ilange 53 formed integrally with the firing pin. The intermediate portion of the firing pin is accommodated in the central slot 54 in the locking block 41, and its rear end is slidably mounted in a suitable opening therefor in the retaining plate 55. The breech block is further provided with suitable extractors 56-56 on the opposite sides thereof, of conventional construction.

The barrel extension 3 has a longitudinally extending groove therein in position to accommodate the extractor 56 located on the adjacent side of the breech block. At the rear of the barrel extension and at the end of the groove |30 is the ejector |3| which is of conventional construction and which serves in cooperation with the extractors to eject the spent cartridge. In addition, the barrel extension is provided with the locking opening |32 which is adapted to receive the projecting end of the locking block in such manner as to lock the breech block and the barrel extension in cooperative relationship. The locking opening |32 has its rearward lock-engaging face |33 formed on an arc which corresponds to the arc determining the shape of the face |34 on the locking edge of the locking block. This arc, however, is struck from a center somewhat above `the center of the arc determining the movement of the locking block 41, whereby a new and improved locking action results. This construction causes a smoother unlocking action be- The latch extends toward the rear of the firearm and has a locking end portion 63 adapted to engage the shoulder 64 of the locking block when the locking block is moved to unlocked position (seeFigure).

- The lowerrear corner 0f thelockingblock is pivoted at 65 to a link 66 which extends rearwardly and terminates in a suitable pivot member, such as 61, for pivotal connection to the inertia member 68. The particular pivot connection shown permits assembly and disassembly by merely sliding the link 66 laterally relative to the inertia member 68. As more particularly shown in Fig. 2, the inertia member 68 is slidably mounted in the inertia member tube 22 and also has abutting engagement with the action spring 69. The opposite end of the action spring is seated against the plug 24 which closes the rear end of the inertia member tube 22. The inertia member 68 is further equipped with the rearwardly projecting extension 98 which has sufcient length to abut the plug 24 in the extreme rearward position of the inertia member to form an ultimate stop for the recoil movement of the inertia member and breech block. A cushioning washer or disc |50 of felt, ber, rubber, or other suitable material is preferably placed on top of the plug 24.

The firing mechanism here illustrated comprises a trigger plate 10 having a central slot 12 therein and equipped with a suitable trigger guard 1| extending from the bottom thereof. The trigger 13 is pivoted on the pin 14 and has an upwardly extending end 15 pivoted at 16 to the counterbalancing link 11. The other end of the link 11 is pivoted as at 18 to the upper arm of the sear 19 which is mounted for oscillatory movement around the axis of a pin 80. The pin extends through an opening in the sear and projects on opposite sides thereof and is accommodated in the semi-circular bearings formed in the extensions 8|-8| on the upper face of the trigger plate.

The lower end of the Sear extends downwardly and presents a portion 82 in spaced and opposed relationship to a portion 83 of the trigger. These portions 82 and 83, respectively, are provided with recesses, as shown in Fig. 3, in which the opposite ends of a compression coil spring 64 are mounted. The lower arm of the sear is provided with a hammer-engaging tooth 85 which coacts with the hammer notch 86 on the hammer 81 for holding the hammer in cocked position. The hammer is pivotally mounted on a pin 88 carried by the lugs 89--89 extending upwardly from the forward portion of the trigger plate. The upper arm of the sear is provided with a tooth or hook 96 for engaging a cooperating tooth 9| on the hammer in the event that the trigger is held pulled after iiring a shot.

Extending through the hammer adjacent its pivot is a pin 92 equipped with parallel diametrically disposed holes 93 which accommodate the forward ends of the main spring guide rods 94-94. These rods are each provided with an integral flange 95 adjacent their forward ends to limit their forward movement with respect to the pin 92 and to provide abutments for the forward ends of the main springs 96-96. The pin 80, which extends through the intermediate portion of the sear 19, is likewise provided with parallel diametrically extending holes 91-91 which slidably accommodate the rear ends of the main spring guide rods Sli-94.

The trigger plate may be attached to the re-` ceiver by pins |36 located in longitudinally extending grooves |35 provided in the side faces of the trigger plate and which cooperate with complementary semi-circular grooves provided in the opposed faces of the receiver. When the firing' mechanism is in proper position, the co,-

7 operating grooves referred to are adaptedl to Yaccommodate retaining pins |-36| E26 which securely hold the parts in proper relationship. The retaining pins may be inserted from the rearV and held against accidental displacement by means' of the stock which covers the ends of the pin openings when the firearm is fully assembled.

A carrier portion of the receiver and preferably comprises a pair of spaced arms il--ll pivoted on the carrier pin H32 which has its opposite ends mounted in the spaced side walls of the receiver.A

guiding contact with the lugs 3S-8S on the forward end oi the 'trigger plate. These lugs guide the carrier in its vertical movements and prevent lateral movement thereof so that the pivot pin |02 is relieved of tortional strains.

Mounted on the rear pin ii, between the arms of the carrier, is a pair of looking pawls M35- m5 which are spaced apart to provide a central space for accommodating the carrier-depressing lever |06. The locking pawls iand the carrierdepressing lever i are all pivotally mounted on the pin Hifi, and the locking pawls are held in operative positions by means ci the ends lOl-|01 of the coil springs Hi8-H58, respectively. The ends itl extend into the slots H19 on the outer lateral faces of the pawls, whereby through the depressing action of the springs the pawls are held in operative position and at the same time a downward pressure is exerted on the pin lila. This downward pressure on the pin IM causes the opposite end of the lcarrier to be normally urged in an upward directIon. The carrier-depressing lever ii has its upper end extended suiiciently to occupy the space constituting the central slot im in the link 55, and for engagement, at the proper moment, with the shoulder or cam face located at the forward end of the slot i le.

The lower end of the carrier-depressing lever is formed to constitute a cam I il! which in certain positions is adapted to engage and bear upon the upper lace H3 of the bearing block ill-l slidably mounted in a groove H5 in the upper face of the trigger plate. Forward movement of the bearing block lill is limited by means of pin H6 and the block is normally urged in contact with the pin by means of the compression spring Ill.

As particularly illustrated in Figs. 5, 6- and 9, inclusive, the inner face ol one wall of the recever, at the location adjacent the exit of the magazine, is provided with a recess i2! in which is pivotally mounted the carrier lock and cartridge stop member |22. This member may be constructed in the mannerv illustrated in the drawings, and the pivot |23 therefor extends vertically as shown in Fig. 5. The outer face of the member H22 is provided with a recess |24 for accommodating the conical compression spring |25 which also bears on the face of the receiver recess and acts to urge the associated end of the carrier lock and cartridge stop member |22 outwardly into the space of the receiver. The forward end of the member |22 constitutes. a stop for the cartridges contained in the lmagazine-mid it!) is also mounted in the lowerthe'rear end ofthe member v|22co1ristitutes a lock for holding the carrier in depressed position under certain conditions. The arrangement, relation, and movements of the carrier and the carrier lock and cartridge stop member 22 are such that when, and only when, the carrier is in the depressed or cartridge receiving position shown in Figs. 5, 6 and 9 and the magazine is empty of cartridges, the. rear of the member |22 overlies the adjacent arm IUI of the carrier so that the carrier is locked down. In all other positions of the carrier, the arm thereof lies in the path of inward movement of the rear end of the member |22 so that that end will bear against the outer face of said arm and thus the member |22 is held in a position where the forward end thereof is in cartridge stop position. It is under stood, of course, that when a cartridge is delivered from the magazine onto the carrier, the flange on the rear end of the cartridge will force itself between the receiver wall and the member |22, and thus force the member to the full line position shown in Fig. 9. The forward end of the member |22 is resilient and yieldable whereby y it is free to move towards the wall of thereceiver during the insertion of cartridges into the magazine and to spring back to cartridge stop position after each cartridge has been so inserted. In order to manually disengage the member |22 from the carrier when the parts are in the position shown in Fig. 6, a button M0 is conveniently presented'on the outside of the receiver.

The operation of the illustrated embodiment of the invention will now be described and, as a starting point, it will be assumed that the firearm is in the firing condition shown in Fig. 3, a shell is in the ring chamber, and shells are in the magazine. When the parts are in these positions, the action spring 69, through its forward pressure on the inertia block 68, forces the inertia block, the link 66, and, through the locking block al, the breech block 44 together so that these parts act as an integral mass to close the breech and maintain the firearm in locked condition when the same is fired. The distribution of the engaging faces |34 and |33 of the locking block and barrel extension I3, respectively, is such as to bring about a wedging action tending to press the breech block against the head of the cartridge in the ring chamber and, in addition, to take up wear which might develop between the parts and which otherwise would cause'undesirable head space. Upon pulling the trigger, the hammer 8'! is released from the sear 'I8 so that the hammer is free to swing (under the inuence of the main springs 96) from the full line position to the dotted line position shown in Fig. 3 thus striking the ring pin 50 and causing explosion of the shell within the ring chamber.` As a result of the explosion, the power gases generated act against the forward. face of the breech block and cause thebarrel, the vbreech block, the link, and the inertia member to move rapidly rearwardly7 in recoil. At the instant of firing, the pressure of the gases builds up very rapidly so that the barrel and the breech block in locked condition' are driven backwardly through an eX- tremely small distance with an accelerating movement and then, as the pressure of the gases decreases, and because of the resistance offered by the recoil spring 30 and associated parts, continued recoil movement of the barrel is progressively retarded and decelerated. During said relatively short accelerating portion of the recoil movemenufthedink 6B and-'the'inertia member B8, due to their mass and tendency to remain in a state of rest, will move rearwardly with the breech block acting in the nature of an integral mass so that, during such portion of the recoil movement, the locking block 41 will be securely retained in locked relation tothe barrel.

The recoil movement of the barrel causes a corresponding rearward movement of the barrel guide ring i as well as the friction rings 32 and also a compression of the recoil spring 30. The resistance of the recoil resistance means, including the spring and the friction rings, is such, as previously indicated, that the recoil movement of the barrel will be rapidly decelerated after it has reached its highest recoil velocity and rearward movement of the barrel is yieldingly terminated in space at a variable point depending upon the character and intensity of the charge and then the recoil spring will return the barrel to its forward or normal position.

During the initial portion of the decelerating recoil movement of the barrel, the breech block, being connected to the barrel, tends to decelerate therewith while the inertia member tends to continue at its then attained velocity so that the inertia member will exert a rearward pull on the locking block and draw it downwardly out of locking engagement withthe barrel extension. Unlocking of the locking block from the barrel starts as soon as the recoil movement of the barrel begins to decelerate, and the unlocking is entirely effected before the barrel has reached its rearmost position. During downward unlocking movement of the locking block, the angular locking faces |33 and |34 slide on one another so that the disengagement takes place gradually. This permits the breech block, due to its momentum, to move faster than the decelerating barrel so that the breech block may be gradually picked up by the inertia member resulting a smooth and effective action. Furthermore, during the unlocking period, the breech is being gradually opened, that is, the breech block is moving gradually away from the firing chamber and it is at this time that the extractors 5B pick up the empty shell, this being of advantage in that this primary extraction of the empty shell is gradual as distinguished from an extremely violent initial extraction which would be apt to rupture or deforrn the shell.

It is understood that the resistance of the recoil resistance means is of such magnitude as to progressively retard the recoil movement of the barrel after it has reached its highest velocity and then yieldingly bring the barrel to rest, and the inertia instrumentality is of such mass that its momentum, during the decelerating movement of the barrel, is sufficient to unlock the locking block from the barrel extension and, while the point at which the unlocking action takes place will vary somewhat dependingupon the intensity of the charge, the relation of the operating parts is such that such unlocking cannot occur until after deceleration of the barrel starts whereby the unlocking of the breech block from the barrel occurs only at a time when it is entirely safe to unlock.

The breech block, link, and inertia member continue their movement to the rear under the influence of their own momentum and against the action of the action spring. Such recoil movement of the breech block will be terminated when the extension 98 of the inertia member engages the cushioning disk |50 on the closing plug 24, whereupon the action spring (the barrel in l0 the meantime having been returned to'ring position) will advance the inertia block and breech block to their forward position so that the firearm is again in the condition shown in Fig. 3 ready to be fired.

It will thus be seen that, with my improved construction, cartridges having charges of various character and intensity may be fired in the firearm, as previously stated, without making any adjustments. As the recoil movement of the barrel is yieldingly terminated in space, and in the absence of any abutments or stops therefor, the extent of the kick on the shoulder o the operator is reduced and the operating parts are relieved of excessive shocks and strains. lt is clear, without further explanations, that trie advantages and objects recited in the opening paragraphs of the specification are accomplished with the structure, the operation of which has just been described.

The rearward movement of the breech block and the simultaneous forward movement of the barrel extension cause an extraction of the spent shell from the ring chamber by virtue of the fact that the ange of the cartridge is engaged by the extractors 5S, 56 mounted on the breech block. When the relative movement between the breech block and the barrel extension has progressed to the point where the flange ofthe cartridge is brought into engagement with the ejector |3| carried on the barrel extension, the spent cartridge is ejected laterally through' the ejection opening During the rearward movement of the link 66, the shoulder thereof engages the hammer 81 and pivots the hammer backwardly to its cocked position.

Continuing the description of the operation of the rearm, particularly in connection with the carrier, as previously stated, when the rearm is in ring condition, as shown in Fig. 3, the forward end of the carrier lll is in an elevated position so that cartridges may be inserted in the magazine. In this position, the springs |03 resiliently maintain the forward portion of the carrier up against the bottom of the breech block. Furthermore, in this position of the carrier and, in fact, in all other positions thereof (except when the carrier is in depressed or cartridge receiving position shown in Fig. 6) and during the movement of the carrier up and down, the rear end of the carrier lock and cartridge stop member |22 bears against the outside face of the right hand arm |0| of the carrier Hill so that the member |22 is held in cartridge stop position. Upon firing the rearm, the link 68 and associated recoil parts recoil rearwardly as previously described and as the link (it approaches its rearmost recoil position, the shoulder on the link will engage the upper end of the carrier-depressing lever ||JS (see Fig. 5) and rock the same rearwardly so as to cause the cam extension ||2 on the opposite end thereof to move downwardly in engagement with the upper face I3 of the bearing block H4. In view of the fact that the cam extension has greater height than the distance between the upper face of the bearing block and the pivot pin |94 when the carrier is in the intermediate position shown in Fig. 4, the continued movement of the carrier-depressing lever will cause the pivot pin ill to be raised and, consequently, the opposite end of the car rier to be depressed to a position where it may receive a new cartridge from the magazine, as shown in Fig. 5. On continued rearward movement of the link (from the position shown in Fig;

il 5 to that shown in Fig. 7), the cam extension rides off of the bearing block 11d whereupon the springs Hi8 are free to raise the forward end of the carrier to the position shown in Fig. 7. In this position, the cartridge just received from the magazine is held in elevated position by the carrier in alignment with the firing chamber. When the carrier is cammed down, as just described, to the cartridge receiving position shown in Fig. 5, the right hand arm moved below the rear end of the member 122 so that that end may snap over the arm (see the dotted line position of the member 122 in Fig. 9). In the event that the magazine is empty, the

member 122 will lock the carrier in the depressed position shown in Fig. 6. In the event, however, that the magazineis not empty, the rearmost cartridge therein, as soon as the carrier is moved to depressed position, will be snapped back onto the carrier by the magazine spring 35, and the head of this cartridge will bear against the rear portion of the member 122 thereby camming the member 22 to the full line position shown in Fig. 9, so that the carrier is free to be raised by the springs 108. In this latter operation, there may be, in some instances, a short period during which the carrier is latched down by the member 122, depending upon the speed with which the cartridge is fed onto the carrier and other factors. During the return for ward movement of the breech block, the carrier is cammed downwardly by the breech block from the full elevated position in Fig. 7 to the intermediate position shown in Fig. 3. Also, as the breech block is approaching its normal forward position, the shoulder provided by the rear end of the slot 1111 in the link 65 will engage the upper endof the carrier-depressing lever me and move the same forwardly and thereby swing the extension 112 to the position shown in Fig. 8. During such movement of the cam extension, it

will engage and move the bearing block i 14 backwardly until it clears the same and then the block is snapped forwardly by the spring 11'1.

As previously indicated, when the last cartridge is fired, there being no more in the magazine, the breech block will be automatically locked in its recoiled position as shown in Fig. 6. ln this position of the parts, the member 122 locks the carrier in depressed position and the locking pawls carried on the pin Ill at the rear end of the carrier are disposed in a position where they engage the shoulder 160 on the underside and adjacent the forward end of the link G6. The locking pawls engage in the notch Hit) upon initial forward movement of the breech block and the link. When it is desired to close the firearm. that may be accomplished by manually pushing the button lili) inwardly so as to move the forward end of the member 122 into cartridge stop position and the rear end of the member 122 out of locking relation with the carrier. When the carrier is thus unlocked, the forward end thereof will move upwardly under the influence of the springs 108, thereby disengaging the pawls 165 from the notch its of the link 66 whereupon the breech block is free to be moved forwardly by the action spring 159. The action spring, acting through the link 66 and the pawls |05, assists the carrier springs 108 in raising the forward end of the carrier, and this may also occur when there is a cartridge in the magazine and the cartridge, when expelled therefrom, moves the rear end of the member 122 out of locking relation to the carrier.

101 thereof is Itis noted that with the construction described. the barrel has a relatively short recoil stroke and this, together with the relatively short breech block, permits the use of a receiver of minimum length with a consequent reduction in size and weiglitof the firearm. rThis reduction in length also permits the upper rear portion of the receiver to be rounded off to give a new streamlined appearance to the firearm. The breech block, however, is not of suncient length to provide a complete closure for the ejection opening 1T. In order that the ejection opening may be closed when the breech block is in forward position, a closure plate 1'10 is slidably mounted on the breech block. As shown in Figs. 1l, 13 and 14, the breech block, in its right hand side face, 'has a longitudinally extending dove-tailed groove 168 in which is slidably mounted a correspondingly shaped rib lll provided on the closure plate. The groove is open at its rear end so that the rib may be inserted thereinto. The groove 168 has a shoulder 16S at its forward end so as to limit forward movement of the plate with respect to the breech block. The forward end 112 of the plate i'l is bent inwardly so as to engage the forward end of the breech block and thereby limit` the extentto which the plate may move rearwardly with respect to the breech block. The plate is made of thin spring metal so that this forwardr end may be sprung outwardly a sunlcient distance to permit the rib 1'11 to be slippedy into the groove 161% and the plate moved forwardly f until its end H2 snaps over the forward end of the breech block. The plate is of sufficient length to provide a full length closure for the ejection opening and, at the same time, by virtue of its sliding relationship to the breech block, it may move forwardly and rearwardly by engagement with ythe receiver and the barrel extension, respectively, during the recoil and return movements of the breech block.

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 in a limitingsense.

It is also to be understood that the language used in the following claims is intended to cover all of the generic and specic features of the in vention 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:

1. In a recoil operated firearm of the character described, a receiver, a barrel carried by and mounted for reciprocation relative to said receiver, a breech block carried by the receiver for reciprocation, locking means carried by the breeech block for locking the breech block in operative relation to the barrel, recoil resistance means for progressively retarding the recoil movement of the barrel and yieldingly stopping recoil movement of the barrel in space and then restoring the barrel to its firing position during the interval when said breech block is undergoing its nal recoil movement, and an inertia instrumentality associated with the locking means and effective solely by its inertia to completely release the breech block from the barrel with a continuous action during the recoil movement of the latter and before the barrel reaches the rear end of its recoil stroke. said breech block, locking 13 means, and inertia means being capable of continuing the recoil stroke after the barrel and breech block have been unlocked and while the barrel is being restored to its ring position.

2. In a recoil operated iirearm of the character described, a receiver, a barrel carriedby and mounted for reciprocation relative to said receiver, a breech block carried by' the receiver for reciprocation, locking means carried by the breech block for locking the breech block in operative relation to the barrel, recoil resistance means for progressively retarding the recoil movement of the barrel and yieldingly stopping recoil movement of the barrel in space and then restoring the barrel to its ring position during the interval when said breech block is undergoing its iinal recoil movement, an inertia instrumentality associated with the locking means for completely releasing the breech block from the barrel with a continuous uninterrupted movement during the recoil movement of the latter and before the barrel reaches the rear end of its recoil stroke, said breech block, locking means, and inertia means being capable of continuing the recoil stroke after the barrel and breech block have been unlocked and while the barrel is being restored to its iring position, and means for restoring said breech block in cooperative locked relation with the barrel after the barrel has been restored to ring position.

3. In a recoil operated iirearm of the character described, a receiver, a barrel carried by the receiver for reciprocation, a breech block mounted for reciprocation in the receiver, locking means carried by the breech block for locking said breech block in cooperative relationship with the barrel, recoil resistance means comprising a spring for progressively retarding the recoil movement of the barrel and yieldingly bringing the barrel to rest in space and then restoring the barrel forwardly to ring position, an inertia instrumentality connected with the locking means and operative solely by inertia to completely unlock the breech block from the barrel with a continuous uninterrupted action after the barrel has reached its highest rearward velocity and during the decelerating recoil movement of the barrel, and an action spring behind said inertia instrumentality and normally urging the same forwardly and urging said breech block into locking engagement with the barrel when the latter is in ring position, said inertia instrumentality having such mass that it assists in maintaining the barrel and breech block in locked condition upon firing and during the initial recoil movement of the barrel, and due to its momentum willy draw the locking means out of locking engagement with the barrel during the decelerating movement of the latter whereupon' the locking means and inertia instrumentality will continue their recoil stroke while the barrel is being restored to ring position.

4. In a recoil operated firearm of the character described, a receiver, a barrel carried by the receiver and mounted for reciprocating movement relative thereto, a breech block carried by the receiver and mounted for reciprocation relative thereto, locking means carried by and movable relative to the breech block for locking the same to the barrel, recoil resistance means for retarding the recoil movement of the barrel and yieldingly terminating the recoil movement thereof in space and then restoring said barrel to its firing position during the interval when the breech block is undergoing its nal recoil movement, a

rearwardly extending link connected to said lock ing means, an inertia member connectedto the rear end of said link, and an action spring behind said inertia member, said link andinertia member being of such mass as to completely unlock the breech block from the barrel during the recoil movement of the barrell whereupon the breech block, link and inertia member continue their recoil strokefand while the barrel is being restored tofits firing position.

5. In a recoil operated rearm of the character described, a receiver, a barrel carried by the receiver and mounted for reciprocation relative thereto, a breech block mounted for reciprocation in the receiver, locking means carried by and movable relative to the breech block, interengaging shoulders on the locking `means and barrel for locking said breech block in operative relation with the barrel, recoil resistance means comprising a spring for progressively retarding the recoil movement of the barrel and yieldingly bringing the barrel to rest in space and then restoring the barrel forwardly to firing position during the interval when the breech block is undergoing its nal recoil movement, and an inertia instrumentality connected with said locking means and operative by its inertia to completely unlock the breech block from the barrel after the barrel has reached its highest rearward velocity, said interengaging shoulders being so arranged that during the unlocking operation the breech block may move rearwardly with respect to the barrel. l

6. In a recoil operated rearm of the character described, a receiver, a barrel having a barrel extension mounted for reciprocation in the receiver, a breech block carried by the receiver and mounted for reciprocation therein, a generally forwardly facing locking shoulder on said barrel extension, a locking member carried by said breech block for radial movement relative thereto and having a generally rearwardly facing shoulder arranged to engage with said first-mentioned shoulder when the breech block is locked to the barrel extension, recoil resistance means for retarding recoil movement of the barrel and yieldingly terminating the recoil movement thereof in space and then restoring said barrel to its ring position during the interval when said breech block is undergoing its iinal recoil movement, and an inertia instrumentality associated with the locking member for moving continuously the same to completely unlocked position during the recoil movement of the barrel, said shoulders being inclined rearwardly of the rearm whereby during the operation of unlocking the breech block from the barrel extension, the former will move rearwardly with respect to the latter.

7. In a recoil operated firearm of the character described, a receiver, a barrel, a breech block, locking means for locking said breech block in cooperative relationship with the barrel, said barrel and breech block being mounted for reciprocatory motion relative to the receiver and said breech block having a recoil stroke of predetermined length, said barrel and breech block being arranged to undergo recoil movement while in locked cooperative relationship, means for progressively retarding the recoil movement of said barrel, bringing the same to rest in space before said breech block has completed its recoil stroke, and then restoring said barrel to its firing position during the interval when said breech block is undergoing its iinal recoil movement, inertia means eiectve solely by its inertia for actuating said looking means for completely unlocking said barrel and breech block with a continuous action during the recoil movement of the barrel and before said barrel has comu pleted its recoil stroke, and means for restoring said breech block in cooperative locked relationship with the barrel after the barrel. has been restored to ring position.

VAL A. BROWNING.

REFERENCES CITED The following references are of record in the 111e of this patent:

Number UNITED STATES PATENTS Name Date Darche May 1, 1894 Johnson Apr. 26, 1904 Febiger Aug. 15, 1905 Johnson Aug. 29, 1905 Post Feb. 7, 1911 Chronis V Nov. 5, 1912 Pesek 1 ---1 1 Nov. 5, 1912 Henry Apr. 5, 1932 Browning Aug. 17, 1937 Browning Oct. 22, 1946