US1396832A - Gun - Google Patents

Description

O. B. GRAHAM.

GUN.

APPLICATION FILED JULY 2. 1919.

1,396,832. Patented Nov. 15, 1921.

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[mi/X7 013, 0//': e/ B. Graham.

O. B. GRAHAM.

GUN.

APPLICATION FILED JULY 2.1919.

Patented Nov. 15, 1921.

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I l g O. B; GRAHAM.

GUN.

APPLICATION FILED JULY 2.1919.

Patented Nov. 15, 1921.

5 SHEETSSHEE1 3.

7013 0/IV6/ZB. Gar/701m O. B. GRAHAM.

GUN.

APPLICATION FILED JULY 2,1919.

Patented Nov. 15, 1921;

5 SHEETSSHEEI 4-' li magi MN ww RN 0. B. GRAHAM. GUN.

APPLICATION FILED JULY 2,19l9- 1,396,832. Patented Nov. 15, 1921.

5 SHEETS-SHEEI 5.

I @17025; O/A er B 670/9011. J 6/7 m Jim T @111 T Q OLIVER B. GRAHAM, OF CLEVELAND, OHIO, ASSIGNOR TO AUTO-ORDNANCE CORPORA- TION, OF NEW YORK, N. Y., A CORPORATIO1\T OF NEW YORK.

GUN.

Application filed July 2,

To all whom it may concern:

Be it known that I, OLIVER B. GRAHAM, a citizen of the United States, and resident of Cleveland, in the county'of Cuyahoga and State of Ohio, have invented new and useful Improvements in Guns, of which the following is a specification.

This invention relates to firearms and more particularly to an army rifle operating semi-automatically according to the dis covery disclosed in the patent to Blish, No. 1,131,319, granted March 9, 1915. However, it is to be understood that the invention in certain of its aspects may be applied to guns of various types-manual, semi-automatic or automatic, but particularly automatic or semi-automaticas e. g. sporting rifles, shot guns, pistols, machine guns, and even heavy guns such as artillery pieces.

The principal objects of the invention are to provide a firearm in which the breech closure is automatically locked in closed position directly in response to the breech pressure acting on the closure while the breech pressure is at a high value and is automatically unlocked when the breech pressure has decreased to a relatively low value, in which the firing mechanism is automatically locked in safe condition until the breech closure is locked, in which the gun is cocked upon the rearward stroke of the breech closure directly by the force of the breech pressure. in which the breech closure is automatically held in retracted position after the last cartridge in the cartridge holder has been fired, in which the firing pin may be retracted only until its forward face is substantially flush with the forward face of the bolt so as to prevent the primer from blowing back into the firing pin opening. in which a striker having a long stroke is arranged to strike the firing pin to fire the gun, in which a safety catch is arranged to lock the striker out of contact with the firing pin. in which means is provided manually to unlock and retract the breech closure. and in which improved means is provided to lubricate the contacting surfaces between the. cartridge cases and the firing chamber, and if desired. also between the bullets and the bore of the barrel and between the sliding sur faces of the various parts of the breech action.

Other objects are to provide means where- Speciflcation of Letters Patent.

Patented Nov. 15, 1921.

1919. Serial No. 308,228.

by the cartridge magazine may be conveniently and quickly detached with one hand, to eliminate screws and other fastening means which are likely to Work loose and which render it slow and difiicult to assemble or disassemble the gun, and generally to simplify, lighten and perfect guns of the aforesaid character as will hereinafter appear.

In order to disclose the nature of the invention in its various aspects a specific embodiment thereof has been illustrated in the accompanying drawings in which Figure l is a top plan of the gun;

Fig. 2 is a side elevation of the gun;

Fig. 3 is a vertical central longitudinal section of the gun with the parts in position ready to fire, the barrel and stock being broken away;

Fig. 4 is a section on line 4-4 of Fig. 3;

Fig. 5 is a section on line 55 of Fig.

Fig. 6 is a section on line 66 of Fig.

Fig. 7 is a section on line 77 of Fig.

Fig. 8 is a section on line 88 of Fig. 3;

Fig. 9 is a side elevation of the portion of the gun shown in Fig. 3, showin the stock in central section and showing the receiver broken away above the broken line 70, the parts being in position ready to fire as in Fig. 10 is a horizontal section on line 1()-1() of Fig. 9;

Fig. 11 is a top plan of the portion of the gun shown in Figs. 9 and 10, showing parts in section and parts broken away on each side of the section;

Fig. 12 is a view similar to Fig. 3, showing the parts in the positions they occupy at the instant of firing;

Fig. 13 is a view similar to Figs. 3 and 12, showing the arts in the positions they 00- cupy after firing when the bolt is in fully retracted position, the cartridge lubricating and magazine catching means being omitted from this figure and also from Fig. 12;

Fig. 13 is a perspective view of the bearing plate for the bolt lock;

Fig. 14 is a perspective view of the bolt stop, ejector and interlocking washer slightly separated Fig. 15 is a perspective view of parts of the breech action slightly separated:

Fig. 16 is a perspective view of the bolt lock;

Fig. 17 is a perspective view of parts of the safety catch slightly separated;

gig. 18 is a side elevation of the bolt lock; an

Fig. 19 is a cross section of the magazine.

The particular embodiment of the invention chosen for the purpose of illustration, comprises in general a stock H, a receiver R, a. barrel A threaded into the forward end of the receiver, a breech bolt B, a trigger guard G, a clip C for securing the forward end of the stock H to the barrel A, and a rear sight mount w adapted to carry the rear sight u and also to cover the rear portion of the receiver R, the stock and receiver having alined openings on the lower side of the gun to receive a cartridge magazine CM. Mounted on the forward end of the barrel is a front sight 0, which may be of any suitable construction. The clip C is U-shaped and fits into a depression in the stock H, a screw 2 being provided to secure the two ends of the clip together beneath the stock. The clip C is provided on its upper side with a rearwardly extending shield 3, adapted to cover the opening in the upper side of the forward end of the receiver R, the shield 3 being formed integrally with the clip and being dovetailed into the receiver as shown in Fig. 4. A sleeve I of asbestos or other suitable insulating material is provided around the rear end of the barrel. this sleeve serving to protect the hand of the user from the hotbarrel and also serving to protect the stock from the heat of the barrel. The sight mount w slides into guides on the receiver from the rear as shown in Figs. 7 and 8 and is held in position by the upright portion of the trigger guard G which extends uplwardly through the stock and receiver as s own in Fig. A spring pressed plunger a; is provided in the rear end of the receiver to hold the trigger guard in position, a recess m being provided in the stock to give access to the plunger. The receiver is provided with a tongue 9 which extends rearwardly in a recess in the bottom of the stock to interlock the receiver and stock.

The cartridge magazine CM is of the flat elongate type and is formed of pressed metal. As shown in Fig. 19, the rear portion of the magazine is wider than the forward portion, the length of the wider portion being substantially equal to the length of the portions of the cartridges of maximum diameter. The bottom of the magazine is closed by a member 4 secured within the lower end of the magazine box in any suitable manner. The central portion of the rear wall of the magazine is pressed outwardly to form a longitudinal channel and the follower 5 is provided with a rear projection 6 extending into this longitudinal channel. Interposed between the bottom A and the follower 5 is a compression spring 7,

adapted to urge the follower 5 upwardly to feed cartridges to the top of the magazine to be picked up by the breech bolt in its forward strokes. Instead of extending the full length of the magazine, the spring 7 extends only the length of the wider portlon thereof and consequently engages the follower only throughout its rearward portion, thereby more certainly feeding the cartridges in the proper position to be engaged b the bolt inasmuch as the rearward end 0 the foremost cartridge otherwise might not be pressed upwardly into the path of the bolt. As shown in Fig. 4, the upper end of the magazine is provided with inturned lips adapted to engage the foremost cartridge and prevent it from being ejected from the magazine by spring 7, the lower side of the bolt being shaped to move between the inturned lips to pick up the foremost cartridge. A catch 8 is struck up from the left-hand side of the magazine, as shown in Fig. 4. to cooperate with a magazine catch 9 to hold the magazine in position. As shown in Fig. 5, the magazine is provided near the top with longitudinal slots extending substantially the full length of the thicker portion of the magazine to receive the cartridge lubricating rollers 10 and 10' hereinafter to be described.

The mechanism for detachably securin the magazine to the gun comprises a sha t 11 (Fig. 9) jourrialed in transverse portions 12 and 13 of the receiver, an operating handle 14 extending downwardly and to the right from the forward shaft 11 (Fig. 4). and a torsion spring 15 surrounding the shaft 11 between the bearing 12 and the catch 9, the spring 15 being anchored at the forward end to the bearing 12 and engaging the outer side of the catch 9 at its rearward end and being so twisted as to urge the catch 9 inwardly. The forward portion of the shaft is squared as shown in Figs. 4 and 9 and the catch 9 is provided with a square opening fitting over the square portion of the shaft, so that the shaft and catch are non-rotatably secured together. when the magazine is inserted, the catch 9 snaps beneath the struck-up lip 8 on the magazine and holds the magazine in place. In order to detach the magazine, the finger piece 14 is pressed upwardly thereby rotating the catch 9 out of engagement with the lip 8 on the magazine. By virtue of the unique disposition of the finger piece it may be engaged by the fore finger to unlatch the magazine in the upward motion of the hand in the act of grasping the magazine to remove same.

The oiling mechanism comprises the reservoir 16 disposed in the bottom of the receiver as shown in Figs. 3, 8 and 9. and oil ducts 17 leading from the forward end of the reservoir to the tubular shafts upon assesses which the lubricating rollers 10 and 10' are mounted, the tubular shafts being journaled at their opposite ends in brackets 18 and 18 mounted on the receiver. The brackets 18 and 18' are sufliciently elastic to permit the rollers to be forced outwardly when a magazine is inserted or removed and to hold the rollers in contact with the cartridges as the cartridges feed therebetween. The tubular shafts upon which the rollers 10 and 10 are mounted are provided with perforations through which the oil may flow to the rollers, the rollers being formed of felt or other suitable material through which the oil will permeate to the peripheral surface thereof.

Referring to the breech action, which embodies the more important aspects of the invention, the movable parts of the breech closure comprise a bolt B which reciprocates longitudinally-in the receiver, a lock L movable obliquely with respect to the bolt to lock the bolt in firing position and movable longitudinally with the bolt when unlocked, an extractor E mounted on the upper side of the belt at its forward end, a firing pin F, slidable along the axis of the bolt, a firing pin spring a for yieldingly holding the firing pin in retracted position, a firing pin stop 6 for limiting the rearward movement of the firing pin, a striker Z slidable along the axis of the bolt for striking the firing pin to fire the gun, a cocking sleeve 0 adapted to retain the striker in cocked position, and a striker spring (Z for plunging the striker forwardly against the firing pin when the striker is released from the cooking sleeve.

The bolt B comprises a forward head 27,

a rear body portion 28, and a neck 29 of reduced width joining the head and body together (Figs. 5, 10 and 15). The opposite sides of the body 28 are provided with longitudinal grooves 30 and 30 (Figs. 6, 9., 10 and 15) adapted to receive the inturned flanges 20 and 20' (Fig. 6) on the receiver, these flanges serving as supports and guides for the bolt in its reciprocatory movements. The forward face of the head 27 is provided with a cartridge seat 31 adapted to receive the head of a cartridge. The rear end of the extractor is cylindrical and slides into a socket 33 in the projection 32 on top of the neck 29 (Fig. 15) and the forward end of the extractor hooks over the cartridge seat to prevent the extractor from being dislodged (Figs. 3, 12 and 13). Extending the full length of the bottom of the bolt is a slot 34 adapted to receive the ejector.

The rear faces 21 and 21' of the lateral portions of the head 27 are inclined at angles of 41 to the vertical and straddling the neck 29 is a U-shaped lock L having lateral portions 22 and 22 whose forward faces are also inclined at angles of 41 to the vertical. The two lateral portions of the lock are integrally joined together at the top by means of a transverse portion 23. Extending outwardly from opposite sides of the lock L are lugs 24 and 24 whose forward and rearward faces are inclined at angles of 45 to the vertical. The oblique rearward faces of the lateral portions 22 and 22 of the lock L are inclined to the vertical at the same angle as the lugs, viz., 45. The lateral portions 22 and 22 are provided at their lower end with rearwardly extendlng projections whose upper faces are concave and whose rear faces are vertical, as shown in Figs. 9, 15, 16 and 18. In cooperative relationship with the lugs 24 and 24 on the lock, channels are provided in the inner faces of the opposite sides of the receiver. These channels comprise forward oblique portions 25 and 25 and rearward longitudinal portions 26 and 26, the oblique portions 25 and 25' being inclined to the vertical at the same angle as the lugs 24 and 24, viz., 45. Mounted over the rear faces of the oblique channels 25 and 25' of the receiver is a bearing p-late P of hardened steel or other material adapted to withstand high'pressure, this plate comprising two legs 34 and 34 and a transverse portion 35. (Fig. 13.) The plate P is dovetailed into the receiver and slides into place from the top. (Fig. 11.) The plate is provided at the top with a rearwardly extending flange which engages a beveled edge of the receiver to limit the downward movement of the plate (Figs. 13 and 13 The plate is held in place by the" shield 3 (Fig. 13).

As shown in Figs. 3, 10, etc., the firing mechanism is constructed as follows: The firing pin F is disposed in an axial chamber in 105 the bolt which is of somewhat larger diameter than the shank of the pin. The rear end of the pin is provided with a head which slidingly fits in the chamber'and the forward end of the pin slidingly fits in an opening 110 of smaller diameter. The compression spring d surrounds the shank of the pin and presses rearwardly against the head thereof.

A firing pin stop I) is slidingly fitted into a transverse opening in the bolt immediately 115 in the rear of the firing pin, to limit the rearward movement of the firing pin, the stop b having an axial opening to permit the forward end of the striker to pass therethrough into engagement with the firing pin. The 120 length of the firing pin is such that when the rear end thereof abuts against the stop I) the forward end thereof is flush with the forward face of the bolt, whereby the portion of the cartridge primer fitting over the fir- 125 ing pin opening can never blow back and lodge in the firing pin opening. The lefthand end of the stop 6 is beveled as shown in F i 10 for a purpose hereinafter to be described. The striker Z comprises a tubular 130 portion closed at its forward end and having pins 36 and 37 res ectively extendin forwardly and rearwar 1y from the close end of the tubular portion (Fig. 3). The forward pin 36 is adapted to engage the firing pin when the striker is plunged forwardly and the rearward pin 37 extends beyond the open end of the tubular portion of the striker and thence through an axial opening in the cocking sleeve 0. The rear end of pin 37 is provided with a hook adapted to hook over the cocking sleeve and the pin 37 is sufficiently flexible to be sprung downwardly to disengage it from the cocking sleeve. The striker spring 15 surrounds the pin 37 within the tubular portions of the striker and cocking sleeve. A tripper T slides in a vertical channel in the rear face of the bolt (Figs. 3 and 10) and is yieldingly held up by tripper spring 6. The rear end of spring 6 is tightly fitted into an opening in the under side of hood 38, which extends rearwardly from the bolt B, and the forward end of the spring 6 extends into an opening in the upper end of the tripper T (Figs. 3 and 7). The lower end of the tripper is provided with. a hook by which the tripper may be pulled downwardly against the action of spring 6 when the trigger is pulled. The tripper is provided with a central opening adapted to receive the head of pin 37 so that the in is unhooked from the cocking sleeve w en the tripper is pulled downwardly.

The neck 29 of the bolt B is provided with a transverse slot 39 extending from the slot for the firing pin stop I) rearwardly to the plane of the forwardend of the bolt body 28. A pair of transmitters T and T" are disposed on opposite sides of the neck (of the bolt with arms projecting into the slot. 5, 10 and 15.) The inner ends of the inwardly projecting arms are spaced apart so as to permit the pin 36 of the striker to pass therebetween but so as to extend into the path of the forward end of the tubular body of the striker. When the transmitters are at the forward end of the slot 39 the striker can strike the firing pin but when the transmitters are moved rearwa-rdly in the slot 39 the tubular portion of the striker will strike the inner ends of the transmitters and prevent the striker from striking the firing pin. Extending rearwardly from the outer ends of the transmitters are cylindrical lugs over which fit the recoil springs Q and Q. These lugs are of sufiicient length to hold the transmitters in proper angular position transversely of the bolt. The forward faces of the transmitters bear against the rear vertical faces of the lock L and transmit the forces of the recoil springs to the lock and thence to the bolt. When the lock is in uppermost locked position the inner ends of.

the transmitters are at the forward end of the slot 39 in the bolt and when the lock is in lowermost unlocked position the inner ends of the transmitters are at the rear end of the slot 39. The left-hand transmitter T is provided with a forwardly projecting lug 40 whose beveled inner face engages the beveled end of the firing pin stop 6, whereby if the gun is assembled without the lock L the firing pin stop b will be pushed to the right until the striker opening therein is out of alinement with the striker and the gun cannot be discharged as will hereinafter be described more fully.

The recoil springs Q and Q, are disposed in cylindrical channels in the opposite sides of the receiver, as shown in Figs. 6 and 8, and the upper walls of these channels overhang the springs to such extent as to hold the springs snugly in the channels throughout their entire length. The spring channels extend to the rear end of the receiver so that the springs may be inserted thereinto from the rear.

Fitting in the rear end of the receiver is a buffer mount M which has lateral lugs extending into the spring channels in the receiver to form abutments for the rear ends of the recoil springs. The buffer plunger N has a rod extending axially through the buffer and thence through, an opening in the rear end of the buffer mount, the rear end of this rod being notched on the u r side as shown in Fig. 3. A buffer key is disposed behind the buffer mount-to form a back stop for the buffer mount, the key fitting into vertical recesses in the opposite sides of the receiver both above and below the recoil spring channels as shown in Figs. 3, 7 and 10. The buffer ,key is provided with a slotted opening to receive the hooked rearward end of the buffer plunger so that the key also serves to prevent the plunger from being accidentally displaced from the buffer. The buffer key is held down by the sight mount to as shown in Fig. 7. The space within the buffer is filled with rawhide or other suitable shock absorbing material. Extending forwardly from the buffer plunger is an integral tube which serves to recock the gun when the breech closure recoils as will hereinafter be do scribed more fully.

The trigger mechanism comprises a trigger U hooked over a pin in the receiver at its upper end (Figs. 3, etc.), a trigger bar V hooked over a pin in the receiver in its central region, a trigger bar spring m, and a tripper pawl X mounted on the forward end of the trigger bar. The upper end of the trigger is bifurcated to receive the rear end of the trigger bar as shown in Fig. 7. The bar V is provided with :1 lug 12 which projects into an opening in the bottom of the receiver to prevent the bar from accidentally becoming unhooked from its wardly beneath the tripper hook.

The ejector J and bolt-stop Y are mounted in the bottom of the receiver interlocked relationship as shown In Figs. 3, 6,

' 12, 13, etc., these parts being shown in perspective in Fig. 14. The bolt-stop slides down into a vertical opening in the bottom ofthe receiver and the ejector also slides down into position immediately in the rear of the bolt-stop with the forward portion 41 extending downwardly through the opening 42 in the bolt-stop. (Figs. 3, 14, etc.).

The ejector has a rear flange 43 overhang ing a transverse portion of the receiver to limit the downward movement of the ejector. The bolt-stop has a downwardly projecting shank surrounded by a coiled compression spring 11,. The bifurcated washer V slides forwardly through the slot 44 in the bottom of the ejector and straddles the shank of the bolt-stop. The margin of the washer bears against the bottom of the receiver so as to lock the ejector in position. The spring 92 bears against the lower face of washer W which is provided with a pair of depending lugs arranged to prevent the washer from being Withdrawn from the bolt-stop and ejector until the upper end of the spring 1?. has been pressed downwardly below the level of the lugs. 45 of the bolt-stop slides vertically in the space 46 in the ejector, the vertical dimension of the cross-bar being less than that of the space 46 so that the bolt-stop has a lim ited range of vertical movement. The upper hooked end 47 of the bolt-stop has a vertical rear face adapted to engage the forward end of the bolt when the stop is in uppermost position and hold the bolt retracted, and the hooked end has a horizontal under face overhanging the vertical channel in the rear wall of the magazine which is adapted to be engaged by the rear end 6 of the follower 5 when the magazine becomes empty. The bolt-stop is normally held down by spring n out of the path of the bolt but when the magazine becomes empty the stop is lifted by the follower into the path of the bolt, whereby the bolt is automatically held in retracted position after the last cartridge is fired. The lower end of through an opening in the stock so that the The cross-bar stop may be manually lifted into position to stop the bolt by pressing upwardly on the projecting end of the shank.

The mechanism for manually retracting the bolt comprises a retractor '1' pivotally mounted on top of the bolt by a retractor pin f, a catch j and spring I: being associated with the retractor )in yieldingly to hold the retractor in normal position. The retractor r and pin 7' are shown in perspective in Fig. 15 and the catch j and spring is are shown in perspective in Fig. 17. The forward end of the retractor is bifurcated and straddles the projection 32 extending upwardly from the neck of the bolt. The handle of the retractor is provided on its under side with a longitudinal recess adapted to receive parts of the safety catch to be described hereinafter. The bifurcated ends of the retractor are provided with a pair of cam faces 48 and 48' adapted to engage the concave faces 49 and 49' of the lock to move the lock downwardly from locked to unlocked position when the retractor is swung upwardly on the pin f (Figs. 9 and 15). The bifurcated ends of the retractor are also provided with a pair of cam faces 50 and 50' adapted to engage the faces 51 and 51' of the receiver (Figs. 9 and 15) to retract the bolt slightly after the lock has reached unlocked posltion. The bolt may then be fully retracted by pulling rearwardly on the retractor.

The retractor pin f is provided with a square head adapted to fit into a square portion of the opening in the bifurcated ends of the retractor (Fig. 10) so that the pin rotates with the retractor. In its center the pin f is provided with a peripheral groove (Figs. 3, 10 and 15) into which the bead 52 (Fig. 17) on the retractor pin catch j is adapted to extend, the groove being provided with a depression adapted to receive the head 52 when the retractor is in normal position. The catch y' is slidingly fitted in a longitudinal socket in the bolt, the upstanding end of the catch projecting through a slot 53 (Fig. 15) in the top of the bolt, and the catch is urged forwardly by spring is. The catch holds the retractor pin in place by virtue of the head 52 extending into the peripheral groove in the pin and the catch also holds the retractor in normal position by virtue of the bead 52 extending into the depression in the peripheral groove.

The mechanism for rendering the gun safe after being cocked com rises a safety catch 8, a safety catch detent B, and a safety catch pivot Z, all shown in perspective in Fig. 17. The detent D is slidingly fitted into the rear end of the same socket as retractor catch j above described, the detent having a lu extending upwardly into the slot 53 (Fig. 15) to prevent it from rotating in the socket. The detent has a pivot pin extending into in the forward end of the safety catch to hold the safety catch in normal position, the detent bein yieldingly urged against the end of the sa ety catch by spring 7:: which also actuates the retractor catch as above described. The safety catch is pivotally supported at its rearward end by the pivot pin Z extending forwardl through the vertical portion 54 of the b0 t and thence into an axial socket in the rear end of the safety catch, the gin I being held in position by the tripper above described. The forward end of the safety catch is provided with an eccentric head 55 which projects into the path of the striker when the catch is rotated in a clockwise direction (Fig. 3) and the rearward end of the safety catch is provided with a finger-piece for rotating the catch.

If the gun is uncooked the eccentric head 55 engages the periphery of the striker when it is attempted to rotate the catch into safety position thereby indicating that the gun is uncocked'. The rear face of the eccentric head 55 is slightly cammed so as to retract the striker until the hooked end of the striker pin 37 disengages the cocking sleeve, whereby if the tripper T is depressed by pulling the trigger while the safety catch is in safe position there will be no danger of the hook on pin 37 catching in the axial opening in the cocking sleeve and failing to return to the position wherein it will hook over the cocking sleeve when the tripper returns to normal position. The hollow handle of the retractor 1' when in normal position covers all of the safety catch mechanism except the finger-piece 56.

In order more clearly to disclose the con- .struction of the firearm illustrated in the accompanying drawings the method of disassembling the parts will now be described. The catch a: is driven inwardly until it clears the trigger guard G and the trigger guard may then be slipped downwardly out of the gun. The sight mount u; may then be slipped to the rear off the receiver. After the sight mount w has been removed the buffer key K is raised until the. buffer plunger N may he slipped forwardly out of the plunger mount M. The key K may then be slipped upwardly out of the receiver. The buffer mount M is then slipped rearwardly out of the receiver. The recoil springs Q may then he slipped rearwardly out of the receiver. v After first moving the lock L downwardly into unlocked position,

the bolt and all the parts carried thereby may then be slipped rearwardly out of the receiver, the transmitter T and T" falling latterly from the bolt.

To disassemble the bolt unit, the tripper spring e is withdrawn rearwardly through the slot in the bolt-hood 38 in which the spring is mounted. The trip r T is slipped downwardly out of the slot in the rear end of the bolt. The cocking sleeve a, striker Z, and striker spring d are then permitted to slide out of the rear end of the bolt. The

firing pin stop I) is slipped out of the bolt pivot l is withdrawn from the rear of the bolt and the safety catch detent D is pressed forwardl against the action of the spring k until it disengages the safety catch a, whereupon the safety catch may be removed from the bolt. The safety catch detent D, spring K and retractor pin catch j may then be slipped rearwardly from the bolt. The extractor E is detached from the bolt by springing the forward end upwardly until it clears the portion of the bolt which extends into the transverse slot in its lower face and then pulling the extractor forwardly until itsrear cylindrical portion is withdrawn from the socket 33 in the bolt.

To remove the stock from the receiver and barrel, the clip C is loosened and slipped forwardly off the forward end of the stock, the shield 3 slipping out of the dove-tailed guides in the top of the receiver as the clip is slipped forwardly. Thev cartridge magazine CM having been detached from the gun as hereinbefore described, the stock The rear end of the trigger bar is then I pressed downwardly and the spring m is removed. The trigger bar is then unhooked from its pivot pin. The tripper pawl may then be slipped forwardly ofi the trigger bar after first springing the hooked rearward end thereof downwardly until it clears the shoulder on the bottom of the trigger bar. To remove the bolt-stop Y and the ejector J, the upper .end of the bolt-stop spring 7). is pressed downwardly below the level of the depending lugs on washer W and the washer is then slipped rearwardly from the slot 44 in the bottom of the ejector. The ejector and bolt-stop may then be slipped upwardly out of the receiver as a unit or the ejector may first be removed and then the bolt-stop. After the stock has been removed the magazine catch shaft 11, to gether with the finger-piece 14 fast thereon, may be slipped out of the bearings 12 and 13, thereby permitting the catch 9 and spring 15 to drop out. To remove the lubricating mechanism the brackets 18 and 18' are dctached from the receiver and the entire 111- bricating mechanism may then be removed.

The operation of the gun is as follows: \Vhen the gun is ready to fire the parts are in the positions illustrated in Figs. 3 and 10. \Vhen the trigger is pulled the tripper T is moved downwardly until it engages the hook of striker pin 37 and unhooks the striker from the cocking sleeve 0.. The striker Z is then plunged forwardly by the spring (1 until the forward end 36 strikes the firing "pin F and drives the firing pin forwardly against the primer of the cartridge in the firing chamber. At the instant offiring the parts occupy the positions shown in 12; i Vhen the cartridge is fired the breech pressure is transmitted to the receiver through the bolt head 27, thence to lock L, and thence .to the bearing plate P which is mounted on the oblique face of the receiver immediately in the rear of the lock L.

Referring .now to Fig. 18 the lateral portions 22 and 22' of the lock L bear against the plate P throughout the surfaces extending from the transverse line 60 downwardly to the transverse line 61, the central trans verse portion 35 of the bearing plate (Fig. 13) extending downwardly only to the line 61. The lateral lugs 24: and 24' of the lock L bear against the legs 34: and 34' (Fig. 13*) of the bearing plate from the transverse line 62 downwardly to the transverse line 63. The oblique surfaces 21 and 21 on the bolthead bear against the oblique forward -face of the portions 22 and 22 of the lock L from a transverse line 64 downwardly to the trans verse line 65. The lock is so designed that the bearing surfaces of its opposite sides are symmetrically disposed with respect to the plane 6667, which plane extends transversely of the path of movement of the lock and makes equal angles a, a and b, b with said bearing surfaces and which plane is perpendicular to the bisector of the angle between the forward and rearward faces of the lock and intersects the forward faces in the horizontal axial plane of the firing chamber, this plane being midway between the lines 64 and 65. With the bearing surfaces thus arranged the breech pressure is-distributed uniformly over the bearing surfaces between bearing plate over the surfaces extending between lines 60 and 61 and half of the pressure being transmitted to the bearing plate over the surfaces of the lugs 24 and 24' extending between the lines 62 and 63. Owing to the wedge action of the lock L the pressure between the lock and the bearing plate will be greater than the pressure between the lock and the bolt-head, and the bearing surfaces at the rear of the bolt are therefore preferably made larger in area so that the pressure per unlit of area is the same on both sides of the b0 t.

Owing to the fact that the forward and rearward faces of the lock are inclined at angles to the vertical differing from each other only approximately four degrees, the rear face being inclined at the greater angle, there is a tendency for the lock to be forced downwardly by the breech pressure to unlock the bolt. However, this angle of four degrees is so small that the lock will not move downwardly while the breech pressure remains at a high value, but when the breech pressure has decreased to a relatively low value the lock is forced downwardly directly in response to the breech pressure, thereby unlocking the bolt from the receiver according to the discovery disclosed in the aforesaid patent to Blish. In this connection it is to be noted that the effective angle of the lock is determined largely by the magnitude of the breech pressure. The example chosen forthe purpose of illustration is an army rifle firing standard cartridges which develop a breech pressure of approximately 52,000 pounds per square inch. In guns developing a lower breech pressure the effective angle wouldthe proper effective angle (four degrees in.

the present example).

After the breech pressure has dropped to a relatively low value and the lock is automatically moved downwardly until it clears the bearing plate P, the bolt and lock and other parts carried by the bolt are retracted by the breech pressure against the action of the recoil springs Q and Q until the vertical portions of the rear face of the bolt strike the flange on the buffer plunger N, whereupon the excess momentum of the bolt is absorbed by the buffer. During the brief interval of time required for the lock L to move down into unlocked position the transmitters T and T" are moved from the forward to the rearward end of slot 39, thereby pushing the striker Z back out of contact with the firing pin. The striker is thus prevented from contacting with the firing pin until the lock is returned to locked position. During the recoil of the bolt the ejector J, which extends upwardly into the slot in the bottom of the bolt, ejects the cartridge case from its seat on the bolt at the instant the forward face of the bolt passes the forward edge of the ejector. During the recoil of the bolt the tubular portion of the buffer plunger N engages the rear face of the cooking sleeve 0 and compresses the striker spring (1 until the hooked end of the striker pin 37 has passed through the axial opening of the cocking sleeve and hooked over the rear face of the sleeve, the forward end of the tubular portion of the striker abutting against the rear faces of the inwardly pro- 'ecting fingers of the transmitters T and Afte(r1.the bol;. hals1 reached its rearmoa.

'tion i '13 t e recoil springs 5123 Q returi the bolt to closed position.

.During the forward movement of the bolt it feeds a cartridge from the magazine to the firing chamber in the usual manner. Also during the forward movement of the bolt, the ejector J engages the cocking sleeve 0 and stops the forward movement of the striker and cocking sleeve, which were interlocked together on the recoil, before the bolt reaches closed position, so that when Inasmuch as the recoil springs act on the bolt through the transmitters T and T" and thence through the lock L, the'lock is automatically moved into locked position by the pressure of the recoil springs during the last interval of the forward stroke of the bolt, the forward obli ue faces of the lock engaging the oblique aces of the bolt and receiver respectively. The inner ends of the transmitters T and T" which I roject into the slot 39 in the neck of the olt move forwardly from the rearward to the forward end of this slot while the lock is moving into locked position and it is not until the lock has reached a'safe locking position that the inner endsof the transmitters have advanced sufliciently to permit the striker to engage the firing pin. Thus it is impossible prematurely to fire the gun before the bolt 1s safely locked.

When the magazine becomes empty the rear end 6 of the follower 5 lifts the boltstop into the path of the bolt so that the bolt aaeaesa before described. The bolt may then be manually retracted by pulling rearwardly on the retractor.

If it is desired to render the gun safe after it has been loaded and cocked, the safety catch 8 is rotated in a clockwise direction until the eccentric head 36 has moved downwardly into the path of the striker and forced the striker slightly to the rear as hereinbefore described.

What I claim is:

1. A gun comprising a frame, a breech block and a lock for locking said block in closed position, said lock being longitudinally movable in said frame, and having opposite faces abutting faces of said frame and block respectively, and said block and frame faces being substantially symmetrically disposed relatively to a lane. extending transversely of the path 0 movement of the lock and making equal angles with said faces.

2. A gun comprising a frame, a breech block, and'a lock for locking said block in closed position, said lock b'ei longitudinally movable in said frame, and hav1n opposite faces abuttin faces of said ame and block respective y, certain of said faces being so inclined to the line of breech pressure, and said block and frame faces being substantially symmetrically disposed relatively to a plane extendin transversely of the path of movement of t e lock and making elual angles with said faces.

3. gun comprisin a frame, a breech block, and a lock for focking said block' in closed position, said lock having opposite faces abutting faces of said franie and block respectively, the frame-lock and lock-block surfaces respectively making different angles with the line of breech pressure, and said block and frame faces being substantially symmetrically disposed relatively to a plane extending transversely of the path of movement of the lock and making equal angles with said faces.

4. A gun comprisin a frame, a breech block, and a lock for ocking said blockin closed position, said lock having opposite faces abutting faces ofsaid frame and lock respectively, the frame-lock and lock-block faces making an angle with each other, and said faces being disposed s mmetrically to a plane which is substantial y perpendicular to the bisector of said angle an sects said block-lock surfaces substantially in line with the axis of the breech pressure.

5. A gun comprising a breech closure, a lock for locking the breech closure in closed position, said a lock being movable transversely of the line of breech pressure into and out of locking position, a firing pin, a striker, and means interposed between the lock and striker to obstructthe movement of the striker toward the firing pin when the lock is out of locked position thereby to prevent the gun from being fired except when the lock is in locked position.

6. A gun comprising a frame, a breech block, and a lock for locking said block in closed position, said lock having opposite faces abutting 'faces of said frame and lock respectively, the frame-lock and lock-block faces making an angle with each other, and said faces being disposed symmetrically to a plane which is substantially perpendicular to the bisector of said angle.

1 '7. A gun comprising a breech block, a

lock for locking said breech block in closed position, said lock being movable transversely of said block into and out of locked position and when in unlocked position being movable withthe block, recoil springs on opposite sides of the block respectively,

transmitters interposed between said lock and said springs respectively, the parts being arranged so that the force of the recoil springs is transmitted to the block through the medium of the transmitters and the lock to move the block from open to closed position.

8. A gun comprising a breech block, a lock for locking said breech block in closed position, said lock being movable obliquely forwardly into locked position and when in unlocked position being movable with the block, a recoil spring, a transmitter interposed between said lock and said spring, and firing mchanism on said block, said transmitter being movable longitudinally of said block as the lock moves obliquely into and out of locking position and said transmitter being associated with said firing mechanism so as to prevent the gun from being fired except when the lock is in locked position.

9. A gun comprising a breech block, a lock.

for locking said breech block in closed position, said lock being movable obliquely forwardly into locked position and when in unlocked position being movable with the block, recoil springs on opposite sides of the block respectively, a transmitter interposed between said lock and said springs, and firing mechanism in said block, said transmitter being movable longitudinally of said block as the lock moves obliquely into and out of locking position and said transmitter having a portion extending into a longitudinal slot in the block in operative relationship to said said block as the lock moves obliquely into and out of locking position and said transmitter being associated with said striker so as to prevent it from actuating the firing pin when the lock is in unlocked position.

11; A.- gun comprising a breech block, a lock for locking said breech block in closed position, said lock being movable obliquely forwardly into locked position and when in unlocked position being movable with the block, recoil springs on opposite sides of the block respectively, a transmitter interposed between said lock and springs, a firing pin in said block, a striker arranged to strike said firing pin to fire the gun, said transmitter being movable longitudinally of said block as the lock moves obliquely into and out of locking position and said transmitter having a portion extending into a longitudinal slot in the block in advance of a shoulder on the striker so as to prevent the striker from actuating the firing pin when the lock is unlocked. v

12. A gun comprising a breech block, a lock for locking the breech block in closed position, a firing pin in the breech block, a striker for actuating the firing pin, means for actuating the block and lock, and a stop movable into the path of the striker by said means to prevent the striker from actuating the firing pin when the lock is removed from the gun.

13. A gun comprising a breech block, a lock for locking the breech block in closed position, a firing pin in the breech block, a.

stop transversely of t e block until the open-' ing therein is out of alinement with the striker when the lock is removed from the gun so as to prevent the gun from being fired.

14. A gun comprising a semi-automatic breech block arranged to be retracted automatically, a bufi'er disposed behind the breech block to absorb the excess recoil force mounted on the breech bl mechanism and means associated with said buffer for cooking said firing mechanism upon therecoil of the b f rising b hbl k 15. com a reec oc movable forw rl dly aiid rearwardl into and out of breech clos' position, afiring member movably moun on said block to move forwardly and rearwardly between cocked and firing positions, a cocking member for latching the firing member in cocked position, said member also being movably mounted on said block so as to be latched to said firing member, a spring inte between said members for forcing t e firing member from cocked to firing position when unlatched from the member, and means for restraining the rearward movement of the cocking member duri the rearward movement of said block to ri said members into latched relationship, an means for restraining the forward movement of the latched members du the forward movement of said block to r' the said latched members into cocked position.

16. A gun comprising a breech closure, firing mechanism asociated therewith, and means for automatically recocking the firin mechanism during the periods the breec closure is opened and closed, said means inof the breech block fi' 'cludinigman ejector for ejecting cartridge cases m the gun. 17. A gun comprising a semi-automatic breech closure, firing mechanism associated therewith and means for automatically recocking t e firing mechanism during the opening and closing of the breech closure,

said coc member also bei movably mounted on said block so as to latched to said firing member, a ring inte d between saidmembers for orcing the ring member from cocked to firing position when unlatched from the cocking member, means for, moving said cocking member relatively to said block into latchedrelationship wit said firing member during the opening movement of the block, an ejector associated with the breech block for ejecting cartridge cases,

said ejector being arranged to restrain movement of said members in latched relationship relatively to said block during the closing movement of the block. 7

19. A gun com rising a' frame, a breech bolt movable in t e frame, a lock movable on said bolt, and a lever pivotally mounted on the bolt so as normally to lie alongthe bolt and so as to be swung out from the bolt, said lever havin cams adapted to engage said frame and ock respectively when the lever is swung out to move the lock out of lockin position and to retract the bolt.

20. gun comprising a breech block, a firi member movably mounted on the breec block, means movably mounted on the block for' manually retracting the block, means movably'mounted on the block for preventing said firi into firing position, etents for respectively holding said two means in ino rative position,'an d a single spring yiel ingly holdand a key slidingly fitted into transverse ides in the rear of said buffer to hold it in position.

22. A gun comprising a frame, an automatic breech closure movable in said frame,

a bufier in the rear of the breech closurefor abmrbing the recoil of said closure, said bufier including a mount and a plunger fitted into said mount from the front and extending therethrough to the rear, and a key interlocking with said plunger to hold the mount and plunger in position.

23. A gun comprising a frame, a cover over the rear end of said frame, a breech closure movable in said frame and cover, and a trigger guard arranged to lock said cover in position on the frame.

24. A gun comprising a frame, an automatic breech bolt, a bolt-sto means for antomatically moving said bol t-stop into position to hold said bolt in retracted position after the last cartridge is fired, and an ejector for ejecting cartridge cases from the gun, said stop and ejector being interlocked in said frame.

Signed by me at Cleveland, Ohio, this twenty-fourth da of June 1919.

. IVER B. GRAHAM.

member from moving

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