Historical Document · 1906
Samuel McClean's gas-operated firearm patent, filed 5 April 1898 and granted 3 April 1906, assigned to the McClean Arms and Ordnance Company of Cleveland. The Lewis Gun dive uses it for the McClean design the Lewis grew out of.
No. 816,591. PATENTED APR. 3, 1906. S. N. MoCLEAN. AUTOMATIC GAS OPERATED FIREARM, APPLICATION FILED APR. 5, 19 8. 3 SHEETS-SHEET 1. |||| S Azézzesses yeaza 4-2 77zzozzoz. g a left No. 816,591. APPLICATION FILED APB.5, 1898. 3 SHEETS-SHEET 2. IN A /7 ZZvez (O7 k A A ?aleoAcadé64. No. 816,591. S. N. MoCLEAN. PATENTED APR, 3, 1906. . AUTOMATIC GAS OPERATED FIREARM, APPLICATION FILED APB. 5, 1898, 3 SHEETS-SET 3. si:-s a NsSs N SNNL a:s .235.RW as 3N W WW I W W A UNITED STATES PATENT OFFICE. SAMUEL N. McCLEAN, OF WASHINGTON, IOWA, ASSIGNOR TO THE McCLEAN ARMS AND ORDNANCE COMPANY, OF CLEVELAND, OHIO, A CORPORATION OF NEWJERSEY. AUTOMATIC GAs-OPERATED FIREARM. . . No. 816,591, Specification of Letters Patent. Patented April 8, 1906, Application filed April 5, 1898, serial No. 678,520, To all whom it may concern. action,areandthecombination of the operating Beit known that I, SAMUEL N. McCLEAN, parts, most direct, simple, and posi a citizen of the United States, residing at tive attainable. 55 . Washington, in the county of Washington further generic object of my invention is 5 and State of Iowa, have invented certain new to A control both the initial and terminal mo and useful Improvements in Breech-Loading tions of the - actuating force to and Discharge-Actuated Firearms; and I do either increasedischarge or diminish the actuating declare the following to be a full, clear, and force in such manner as the construction, ac exact description of the invention, \such as O will enable others skilled in the art to which tion, and safety of the operating parts shall require and to provide a system of compan it appertains to make and use the same, ref ion and coacting cams, and cam-guides to erence being had to the accompanying draw govern positivelyparts. the action and combination 65 ings, and to the letters of reference marked of the operating . thereon, which- form a part of this specifica Finally, there are certain details of im tion. in the operating parts of the in My invention relates to breech-loading and provement vention which more fully setspecification, forth in the discharge-actuated firearms or automatic and accompanying are drawings and 7o semi-automatic firearms. and inasmuch as the invention defined and The purpose of my invention is to produce set forth in the several improvements de a strong, light, cheap, simple, durable, ac scribed the specification and drawings is curate, and easily-manufactured discharge of such ainnature several modifications of actuated firearm embodying certain im the same may bethat made in the least 75 rovements in controlling and utilizing the departing from the spiritwithout of the invention I. orce of the discharge to operate the arm and do not limit myself to the precise form shown 25 certain details of improvement in connection and described. with the construction, operation, and combi 'In the accompanying drawings, which are nation of the operating parts of the arm. hereby made a part of this specification, Fig 80. Recognizing the fact that the frame of the ure a broken central longitudinal section un is E. basis of its accuracy, especially for of the1 isreceiver barrel, showing the right ong-range shooting, and that the manner in side wall of theand stock broken away and re which the frame sustains the strain of firing. moved, the operating parts shown in is 'intimately related to both the accuracy elevation in position for thebeing trigger to be and durability of the arm, I have devised in pulled to fire the gun. Fig. 2 is a transverse accordance with this principle a weapon in section on the line a. a, Fig. 1 the receiver, 35 which the strain of the discharge shall be re stock, and magazine of the of earm, showing ceived in the line of greateststrength, re an endview of the slide D. Fig. ... sisted by the shearing, crushing, and elastic end view of the breech-bolt. Fig.34isisaafront plan strength of the metal, distributed equally on of the breech-bolt looking every part of the arm and limited to the view its under side as shown in Fig. 1 SR least possible area, and in which the plan of the bolt-locking guide F. g. 5isustrating a broken the operating parts is not cut away or the detail of the handle P, showing the trigger strength and symmetry of the frame de lock detached and the means by 95 . stroyed. Recognizing also the fact that the whichinitsection is held in position. Fig. 6 is a bro merits of a mechanical construction reside ken section of the wall of the magazine, 45 primarily and largely in the 'hechanical taken on the linesside a ac, Fig. 1, showing the . movements of which it is composed and that J and detent or dog Min first and Sec-. few and simple movements are usually asso trigger pnd positions rest or positions respectively loo ciated with few and simple parts, I have de for single firingofand single loading. Fig. 7 is . vised a weapon in which the movements in a longitudinal central section of the barrel So, volved in handling the ammunition form a and receiver, showing the parts in basis of the fvedsconstruction, and the move elevation in their second oroperating rear position arid ments invo in passing the ammunition the right-hand side of the stock-wall broken ros through the arm, and in the eonstruction, away and removed. Fig. sis a detail side. 2 816,591 1 view. and an end view of the shell-extractor from a round bar of metal and is provided and its spring tension. Fig. 9 is an end view with the usual bolt-chamber, having an of the breech-bolt. Fig. 10 is a bottom plan opening on its upper side to permit the in view of the breech-bolt, showing the bottom sertion and removal of the cartridges and an o side of the bolt as illustrated in Fig. 7. Fig. opening on its under side to permit the move 11 is a rear end view of the breech-bolt, show-ment and action of the operating device. The ing latch Fland a broken side yiewand of the part of theisbolt-chamber in front oforthefunnel lock bolt,theshowing the latch Finsection its ing-lugs internally beveled manner of engagement with the slide D. Fig. shaped to afford additional thickness and 12 is a transverse section of the tailpiece of strength of the receiver-walls at their point 75 the magazine H, showing the groove in which ofgreatest strain. Immediately at the end of the handle Pisguided and the cartridge-lifter the cartridge-chamber the receiver is formed . . O, pin O, groove Hin which it is guided, with a straight or shouldered part to afford a and the spring O. Fig. 18 shows a modified bearing for the extreme forward end of the form of the cartridge-lifter O in side eleva bolt, and it is also cut out to afford a path of 8o tion. Fig. 14 is a side, and end view of the movement for the extractor at the end of the cartridge feed and ejecting device R. Fig. bolt-chamber. The bolt-action in order to conform to this construction is formed with a 15 is a vertical cross-section of the trigger companion beveled or funnel-shaped forward and sear as shown in Fig.1 in its first posi end.. tion for single firing. Fig. 15 is a broken The forward end of the barrel is formed. 85 side elevation of the same parts in their third a funnel-shaped opening at the advan end of position for automatic firing. Fig. 16.is a with the bore of the barrel to afford certain plan view of the slide D and sear S. Fig. 17 is a broken central longitudinal section of the tages in utilizing the gases of discharge to op the arm. . 25 barrel, forestock, part of the magazine, tube E, erate weapon is formed to be actuated either and cylinder T, showing the right half of the .byThe hand or by the gases of discharge and is said parts removed and showing the operatin provided with a gas-actuating 'chamber (de-. parts in elevation.. Fig. 18 is a front en - the - - referencelE; ..). This cham view of the cylinder T with the drive-rod D. ber notedis by preferably at or near the for-95 in cross-section. Fig. 19 is a front end view ward end of thelocated It may be inte of the barrel. Fig.20 is a central longitudi grally formed with barrel. the barrel; but I prefer to . nal Section of the barrel, gas-chamber, gas cylinder, piston-head, and forestock. Fig. form the chamber Ex, and itonto is illus. as being screwed the . ..do 21 is a detail plan view of the sear M. Fig. forward trated inend Fig.20 of the barrel. This chamber. 35 22 is a top view of the rear end of the breech preferably extends from the front to one side bolt. of the bore of the barreland is constructed Similar letters of reference refer to similar afford a certain yielding and sufficient op parts throughout the specification, and for to convenience of description the different parts erating-pressureo he gases of discharge Ic5. of the same piece and of intimately-correlated within the chambe his result maybe at the. . . .end of the bore funnel pieces have been designated by the same ref- tained by forming . g the chamber of con- . erence-letter, the exponent above the letter shaped and by formit cross-sectional area from being changed to indicate the particular fea- stantly increasing end of the bore .. ture of the part to which the letter is applied the end ofth fannel-shaped that the passage for the gas IIo 45 The receiver may be of any desired form to from to thethe action, barrel to the action shall be of con adapt it to the bolt-action with which it is in size, so as to secure a re tended to be used; but for the purpose of at tantly-increasing in the pressure of the gases with taining certain manufacturing and military uction: the charnber. The anterior wall of the advantages I have invented a certain type of chamber is preferably formed on an arc. of a 115 receiverin which the barrel may beintegrally and contains an opening Cin line with formed with the receiver or fixedly attached circle to the same in the usual manner. : The re the bore of the barrel...This opening forms a continuation of the barrel, and its diameter is ceiver which I have invented is formed to such as to permit the Rege of the project-, i. have a certain specific. relation to the bolt ille, and it may have.any esired length to. '120 55 action and cartridge-feed device andisformed afford the required operating pressure of the to sustain the strain of the discharge. in the gases within the chamber. This chamber is. line of greatest strength to limit it to a small connected with the operating parts to actu. area immediately behind the barreland to ser late same, and, as illustrated in Fig. 20, I. cure the best relation of the bolt-action and havetheshown with it a cylinder or 1.25 receiver. I construct the walls of the re tube E, whichconnected in effect, thick said gas-chamber. ceiver with their greatest strength and la . . . constitutes a part of ness at the point of greatest strain without .. The weapon is automatically operated by. increasing the outside diameter of the receiver means of the discharge - actuated slide D. or materially decreasing EEE 65 breech-bolt. Such a receiver maybe turned This slide has at its forward end a piston 8 816,591. which is movable in the tube E, and the rear will be below the plane of the lower edge of ward end of the slide is connected with the the slide D and will engage the rear end of the bolt-action to control its reciprocating, lock cylinder T. When the forward end of the ing, and firing action. This operating-slide sear is thrown upward by the depression of is actuated by the gases of discharge in one its rear end, as hereinafter described, the direction and by the resistance of the coiled lug Swill enter the recess D in the slide D. spring E, preferably located in the tube E, and will no longer engage the rear end of the in the other direction. The piston-head on cylinder. T. The rod D will then move for a short distance through the cylinder the end of the slide D has preferably a mov ward able and an immovable part. The movable T, carrying the part S of the sear Snearly, 75 part of the head is formed with a chamber but not entirely, within the cylinder, the for D', in which the end of the slide D has a cer ward movement of the rod and sear being ar tain limited movement to afford an air-pres rested by the contact of the rear end of the sure for the purpose of preventing the escape rod D with the firing-pin when said pin is car I5 of the actuating-gas past the said piston ried by the breech-block, or if the pin is car head. This air-chamber D9 in the piston ried by the rod D, as in Fig. 16, then the for head is provided with openings D', which ward movement of the rod will be arrested communicate with an air-chamber surround by the contact of the firing-pin with the ing the piston-head. On the outer side of cartridge. Upon the rearward movement of the air-chamber the piston-head is formed the rod D under the influence of the gases of thin and yielding to afford an air-cushion in discharge the frictional contact between the S of the sear and the cylinder T due to checking the passage of the gas past the cyl part inder-head. This part of the piston-head is the spring T causes the cylinder to move preferably formed of a thin band of elastic rearward with the rod D till the dash-pot 25 material D, Fig. 20, on the outer side of E: is reached, when the cylinder's rearward 90 which is located a band of yielding material movement is gently arrested, and the slight D' Fig. 20, to afford a yielding pressure further rearward movement of the rod D and against the tube in which the pistonis recip sear S withdraws the part S from the cylin rocated. The air-chamber, D' in the piston der and permits it to fall behind the cylinder 95 the forward movement of the parts. is provided with a spring D9 to exert a yield upon ing pressure or tension between the end of the The tube E is provided on its under side slide D and the piston-head. The immov with an opening E", Fig. 20, to afford an exit. the gas at or near the terminal part of the able part D' of the piston-head has an open for ing D through its rear end leading from the movement of the E; The size of this ld O 35 chamber D', in which is located a valve D, opening may be adjusted by a slide E, at which is set to closé the chamber in an ad tached to and movable on the tube E and a thumb-piece E, -by which it may be vance movement of the slide D and to open haying it by a reverse movement of the slide, thus shifted. affording an air-pressure within the chamber The bolt-action may have any required of breech-bolt ios D' to operate as a gas-check. The operat form to adapt it to the type of ing-slide D is also provided at a point in rear locking action with which it is intended to be of the spring E with a cylinder T, slidably used. The preferred form of the bolt-action is that of a reciprocating and rotating breech mounted on and having close frictional en bolt. It has a body part, a bolt-head, and agement with the said slide, the cylinder 45 having its respective ends beveled to engage the usual locking-lugs. The bolt-head is cups or dash-pots E°and E, Fig. 17, located preferably formed integrally... with the body in the path of its terminal, forward, and rear part of the bolt and is provided with the , ward movements. The operating-slide is usual locking-lugs F, which are beveled or also provided with a sear Spivoted to the chamfered to fit the forward end of the bolt chamber, which is made of beveled shape to I 15 slide at S, which engages with the said move. afford additional thickness and stiffness of able cylinder T to prevent the slide from moving forward far enough to explode the the side walls of the receiver at the point of cartridge until the sear has its end S raised greatest strain. The locking-lugs A of the so as to partially enter the cylinder T, which receiver are formed with a double cam, the . . . 55 is accomplished by depressing the rear end of initial part of the cam-face of the lug on both 12o theThe searthrough the medium of the trigger. its front and rear sides having an increased slide D has on its under side a recess itch to afford an increased movement of the D', in which a lateral lug S on the forward olt to both seat and extract the cartridge. body part of the bolt is provided with a . . end of the sear S and below the line of the The carn-guide F, which partially encircles the 125 lower edge of the main portion of the sear is received. The upper e e of the end of the bolt and is preferably located on the inner sear' directly above the lug S is cut away, as side of the body part of the bolt. Referring shown in ig. 17. A spring T, carried by to E. 1, 4, 10, 11, and 22, it will be seen scam-guide is in the form of a slot F, the cylinder T, normally presses the forward that . 1. 65 end of the sear's downward, so that the lugs' | Figs, 1,7, and 22, in the body part of the boit 13o 4. - 818,591 extending longitudinally thereof at an acute breech-bolt. The groove F is formed with a angle to the bolt's axis with a substantially straight part at its forward end to permit the uniform pitch, except at its front and rear terminal firing movement of the slide D after ends. At its front end the walls of the slot the locking movement of the boltis complete. extend in a straight front and rear direction The cartridge-magazine is preferably formed substantially parallel with the bolt's axis, from a single piece of material and contains a while at the rear end the obliquity of the slot chamber for the reception, retention, and re to the axis of the bolt is increased, as will be lease of the cartridges. This chamber con understood by inspecting the part marked f forms in general to the shape of the cartridges Io in Fig. 22. Referring to Figs. 1 and 10, the and has on its upper side inwardly-turned breech-bolt is shown with an interior circum wings H, Figs. 1, 2, and 7. These magazine ferential gy formed around the upper wings project up.into the receiver, and their portion of its rear end, which groove has upper ends converge to exert a yielding and a beveled forward shoulder f'. A beveled retaining tension against the topmost car 15 shoulder F, substantially parallel with the tridge in the magazine. These wings are suf shoulder f', is formed in the lower rear end ficiently distant from each other to allow the wall of the bolt, as shown in Fig. 10. The under lug on the breech-bolt to be recipro combined effect of the beveled shoulder F. cated between them and rise up into the re and the increase fin the pitch of the cam F. ceiver far enough to allow the cartridge to be 2O is to shift the bolt and raise the rear part of readily pushed by the breech-bolt from the the slide D until it is to the rear of and in en magazine into the bore of the barrel. gagement with the shoulderf", thereby form For the purpose of attaining an advanta- ing a latching engagement between the bolt geous cartridge-feeding action in passing the and slide so long as the parts are retained in cartridges from the magazine into the barrel 25 this relation. The bolt is also provided with I have interposed between the magazine and 9o a latch F, which is preferably attached to the a cartridge-feeding slide R, Fig. rear end of the bolt, as illustrated in Fig. 11 bolt-action 14, which controls thearm. cartridge feeding and has a lug F, which projects into the path and ejecting actionboth of the This is of the operating-slide, and a companion lug reciprocated in guide-grooves H, Firs.slide 1 and 3O F.E.S. is located to be engaged by a lug 2, which are located in the sidewalls of the 95 H' on the upper side and rear end of the gun magazine. Its forward end R is formed to frame, Figs.1 and 7. The neck of the breech engage with the rearend of the cartridge, and bolt is provided with a groove or shouldered it has a projection or lug R, which en part Fto engage with the magazine-feed and and ages with the groove F of the breech-bolt, 35 ejecting device R, as hereinafter set forth. his lug carries a spring R, the ends of Ioo The forward end of the boltis-provided with which alsoRengage with the breech-bolt to ex an extractor-seat F, which has a beveled ert a yielding tension from the breech-bolt flange F to afford a latched relation of the 3. against the cartridge-feeding slido. The for breech-bolt and extractor, which flange is ward end of the cartridge-feed is beveled to : partly cut away to afford a convenient method a companion bevel with the forward 1 o5 of assembling and disassembling the extrac form end of the breech-bolt, and its under side is tor. The body part of the breech-bolt is cut beveled to cause the cartridge to be advanced out to permit the magazine to project up into up into a position in front of the cartridge the receiver (see Fig.2) and to allow the ro feeding slide when the slide is in its rearward 45 tating movement of the breech-bolt without position and when the cartridge rises to the IIo interfering with the magazine and to permit topmost part of the magazine. . . . the action of the operating-slide. . . . The cartridges are elevated in the maga The rear parts of the operating-slide Dis zine by the cartridge-levers O and O, Fig. 7. forked or double to permit its arms (illus levers are spring-actuated andThe are piv 5o trated in Fig.16) to be reciprocated on either These otally supported in the handle P., side of the cartridge-magazine. The rear end side of the magazine is slotted to permit rear. he D' of the slide D projects up into the breech lifting movement of the levers and to allow, bolt, Figs. 2 and 16, and has a cylindrical the rearward movement of the handle to de shape to conform to the shape of the cham press withdraw the levers after the mag 55 'berformed in the body part of the breech-bolt azine and is empty. in which the partlis reciprocated. The up formed in the gun perforward edge of this part D is chamfered portion of the receiveri or beveled to form a companion to the beyel of the rearward movem. fandon its under rear side is provided with cause these levers to be de 6o a beveledR to engage with its companion ward movement of the ha shoulder Fig. 11.withThe the sion of the levers O. part D isF, provided a pinE.of D , Figs..17; with shoulder Hiwhe R 22, which haspart a beveled side toFSE s the ends of the ever hem the diagonal of the E. and afford EE rel of the lowermost cartridge in thema, 65, a latched engagement of the slide D with the zirie, and die is slid forwardi EEE 816,591 5 ends of the levers pass under the lowermost In the side wall of this groove Hs guide cartridge and as soon as they are entirel grooves H are provided, which control the 65 freed from the restraining action of the shoul reciprocating movement of the handle by der H they tend to rise under the influence means of the lugs P and P. The body part of their spring and at the proper time act to P of the handle conforms to the shape of the elevate the cartridges into the receiver. The hand and forms a trigger-guard P and has a lever O' has the same general form as the forward-projecting arm which forms a maga lever O and has the E. on which it turns zine cover or door. arranged in the handle P to the rear of the The cartridge-lifting levers may be en d magazine. As shown in Fig. 7, both these gaged by and moved with the handle in its levers have the same pivot; but this is not backward and forward movements, whereby 75 essential. The lever O' is shorter than the the magazine is opened, the lifting-levers leven O and bears upon the body portion of withdrawn, and the magazine then closed, the lowermost cartridge, while the lever O and the lifting-levers again restored to opera L5 bears upon the E. By the action of tive position, or the handle may be operated the two levers the cartridges are maintained independently of the cartridge-lifting levers. 8o in parallel position as they are fed upward. For this purpose a spring-pressed dog L, hav Instead of the lever O', I may use, as shown ing a thumb-piece and an inwardly-project in 13, a lever O, pivoted to the forward ing lateral arm, is pivoted in the handle with 2o endFig. of the lever O and pressed upward by its spring acting to normally hold the lateral the spring O. The lever C is actuated by arm out of engagement with the lever O, but 85 the spring O, which is supported on the pivot upon pressing the thumb-piece of the dog L. O', and is adjusted to exert a yielding tension against the tension of its spring the lateral between the lever O and the track H of Fi's, arm-engages the lever O, and the latter will 12 and 7, in which the pivot O, on which the then partake of the movements of the handle. lever O is supported, is guided. The lever O The handle P is connected with the oper- go is provided on its upper side with an arm or ating-slide by an arm P', which projects into finger O', which as the lever O reaches the the path of and engages with the E. D to end of its upward movement is projected reciprocate it. This arm P' is preferably 30 into the path (if the detent R to en hinged to the handle P and has a lug P, gage the projectionMonsaid detent, to release which projects into the path of the lug D' of 95 the same from the trigger and permit it to the slide-D, preferably carried by the sear S. rise into engagement with the bolt after the This arm is provided with a pin or lug P, last cartridge has been fired, and thus leave which plays in the guide-groove H'. s 35 the breech open for the insertion of a single By pressure on thecontrols triggerthe J theaction person E. cartridge or to indicate that the magazine is crating the o the weapon of empty. whetherBy used for single firing or all While I do not contemplate the use of the weapon, tomatic firing. E;a the trigger handle Pfor the purpose of taking the place ficiently to move it thr portion onlysuf.of of the gas-operated piston for actuating the arc through which itough is capable of moving, the slide to throw back the breech-bolt after which movement for convenience I term its Ios the gun has been fired, the weapon to this ex “initial' movement, the firing mechanism tent being intended to be a gas-operated gun is released, causing the cartridge previously only, it is of importance that the be ca inserted in position to be exploded. The 45 pable of being hand-actuated for the purpose gases of discharge acting through the mech of withdrawing a cartridge which for any anism already explained will then cause the C reason has failed to be exploded, as well as breech-bolt to be thrown back, ejecting the when the weapon is used for single firing to empty shell to open the breech for the inser let down the breech-bolt onto a cartridge tion from the magazine of another cartridge. So without exploding it, and to subsequently The slide will then move forward, advancing draw back the firing devices into such posi the cartridge into the firing-chamber, closing II5 tion that the cartridge may be exploded by the breech, and holding the parts infiringpo pressing the trigger-inother words, forcock. ... 1 ing and uncocking the weapon. So, too, if sition. By pressing the trigger sufficiently to move 55 by any mischance the gas-chamber should it through a greater portion of the arc through be detached from the gun or be so injured as which it is capable of. moving, which move 2 to necessitate a hand operation, the fact that ment I term for convenience its “interme the weapon is capable of hand operation may diate' or “second’ movement, the firing be of importancé. The handle P is provided mechanism is released to explode the car to afford a means of operating the weapon by tridge already in position. RE the trig hand. This... handle has a reciprocatin ger has been given movement to this extent, I 25 movement on the under side of the stock and the gases of discharge acting through the is guided in a way, or groove H, Fig. 12, mechanism already explained will cause the which is formed in the tailpiece of the frame. breech-bolt to be thrown back, ejecting the as es 816,59i . . - empty shell, and holding the breech-bolt in of the lug Jon the lug S’. rear its rearmost position to permit a cartridge to end of the sears. When thedepress ES isthe moved be inserted by hand. . . . . . . through the full arc through which it is capa By pressing the trigger sufficiently to move ble of moving, the lug J will be brought into 5 it E.g. the full arc through which it is ca the path of the lug S', (see Fig. 15,) so that as the sear moves forward the lug Swill be de pable of moving, and this for convenience I pressed by the wedge shape of the lug J and term its “terminal' or 'final' movement, the cartridge already in the osition to be ex will pass forward between the lugs J and J. ploded will be exploded, and the gases of dis e trigger J is spring controlled and is O charge will cause the breech-bolt to be thrown provided with an arm J, which projects rear 75 back, ejecting the empty shell, another car wardly, into the path of the loosely-pivoted tridge to be fed up from the magazine, in or dog M. This arm J is provided serted in the firing-chamber, and exploded, detent with a lug J, which also engages with the this action continuing so If as the trigger pivoted detent or dog. The detent Mis piv 15 is kept in this position until the supply of otally supported against the side wall of the cartridges is exhausted. When the last car frame and is controlled by the spring M'. Its tridge has been fired, the finger O' on the le forward end M, Figs. 1 and 21, is offset from ver-O will be in position to cause, through the the main body, and is beveled or cam-shaped parts with which it coöperates, the breech on its forward end to allow the detent or dog bolt to be retained in open position to indi M to be disengaged from the trigger by the cate that the magazine is exhausted of ear: terminal movement of the cartridge-lifter. tridges or to permit the introduction by hand The trigger cut-off Kisformed on an arc of of another cartridge. a circle which corresponds to the shape of the In using the WE for single firing or for trigger guard or handle. It is controlled. . .by. 25 firing and loading by hand the trigger after a. SEg: which is fixedly attached to the '90. being pressed to the required position should handle P and is movable in a chamber also be released, while for automatic firingit should formed on an arc of a circle in the cut-off K. . be pressed to the full limit of its movements This cut-off Kis provided with a lug K, and and there held as long as it is desired that the the handle Pisprovided with a series of com automatic action shall continue. . . . panion notches KKKK to lock the trig. 95 - In order to stop the movement of the trig ger against action and stop it in any one of ger at the desired point, I provide the trigger the three parts of its movement, as herein cut-off K, as hereinafter described. The set forth. . . . .. . -weapon is discharged by the force of the ter after The extractor Gis movably retained in en Ioo 35 minal movement of the actuating-spring E, gagement with the breech-bolt and does not exerted through the slide D, E; E. firing partake of the rotation of the bolt. It en action is accomplished by the engagement of ters into a semilatched relation with the the trigger with the sear S to release it from breech-bolt and cartridge when advancing the cylinder T, and thus permit the terminal the same and a locked relation with the same movement of rod D. The trigger J is pivot: parts when withdrawing the cartridge. It is Io5 ally supported at Jagainst the side walls of spring-actuated and in its preferred form is the gun-frame and in its preferred form does illustrated in Figs. 17, and 8. The extrac not partake of the movement of the handle. toris preferably carried by the breech-bolt in It has an arm J, Figs. 1, 7, and 15. This advance of the locking-liigs of the bolt, al 45 arm is provided with cam-lugs J. and J, though it may be carried behind the locking O which are located in the path of the terminal lugs of the bolt. The extractor-seat in the . . forward movement of the lug S on the sear bolt, as before stated, is formed with a bev S. The rear end of the sear Sextends down eled flange to permit a limited latching move ward, and the lower end of the downward ex ment of the extractor, and the extractor has tension projects a short distance forward in a latching end to engage with the flange or I5 . . the form of a lugS, having its inner face bey groove of the cartridge and is preferably in eled, said lugbeing in the longitudinal verti; tegrally formed with a collar part, which has call plane of the lugs J and J. This lug S' a companion bevel to engage with the car has a flat upper face and is preferably trian tridge-seatin the bolt-head. This collar part 55 glar in cross-section, as shown in Fig. 15. of the extractor partially encircles the bolt to The upper-lug J is wedge-shaped, with the cause the extractor to pull from the center. thin edge of the wedge to the rear, as shown. line of the bolt and to permit the rotating. The lugs J and J are spaced a sufficient dis movement of the bolt. The rear side of the tance to permit the lug S' to pass be collar part is cut out to permit the latching. tween them. When the gun is cocked and movement of the extractor, and the spring by I 25 ES to be fired by pulling the trigger, the which the extractor is actuated is preferably: - .lug rests with its upper face in contact carried by the extractor and formed to exert with the lowerface of the lug J, so that pres: a yielding tension between the extractor and sure on the Er sufficient to depress the ; the bolt-head, and the bolt-head is wided 65 forward end of the arm J will, by the action with a notch or depression to afford semi- i3o . . .'; if 818,591. 7. latched engagement of the extractor with the bér to start the ES; of the bolt-head. . . . . . . . . armby means of a gradually increasing pres The firing-pin D (illustrated in Figs. 4 and sure. By vari the length of the el 7) is preferably a plunger which is retracted shaped end of the bore the pressure of the op by the spring D. It has a lug integrally erating-gases within the actuating-chamber 70 formed with it, against which the force of the may be varied as may be necessary to afford spring is exerted to\withdraw its striking any required intensity of the gas-pressure. point from the cartridge, and the chamber in As the forward end of the projectile passes. the bolt-head is cut out to permit the firing into the opening C in the gas-chamber it d pin to be assembled at a point beyond its will partially or entirely close this opening 75 working path of movement. It is obvious, and will prevent the escape of the gas from however, that the firing-pin may be either a . the case to an extent depending upon the loose plunger or it may be integrally formed size of the opening and caise any required on the front side of the part D'of the operat increase in the operating-pressure of the . . 5 ing-slide D, as illustrated in the broken sec gases within the chamber. The length of 8o tion of the same parts in Fig.2 and in Figs. 16 time the pressure of the gasywithin the cham- . and 17. . . . . . . ber is continued will depend upon the length For the purpose of affording a convenient of part C. of the gas-chamber. The gas ic and rapid method of disassembling the breech tuating-chamber itselfmay be of any required bolt I have devised a hinged and locked rela size to catch either a larger or smaller quan-85. . . tion of the receiver and frame, in which one tity of the gas. It is thus apparent that the. member of the hinge is either fixedly or inte E.g., E. of the gases within the grally formed with the frame, and when piv chamber E. be controlled to start the pres otally connected they permit, a sufficient sure gradually, to continue it for any re 25 movement to allow the operating-slide to be quired length of time, and to cause the pres- 9o depressed out of the path of the bolt and the sure within the chamber to have any re bolt-action either withdrawn or inserted. quired amount of operating force and to The receiver and frame. are locked together either accelerate or diminish this force. The . by means of a rotating lock or latch N, Figs. 1 pressure of the gas in the chamber against and 7, which is preferably located in the the operating parts may be controlled by 95 frame-wall in front of the rear end of the re means of the slide or valve E° of Fig. 20, ceiver and engages with the receiver to lock which, as above described, may be operated and release it. It has a thumb-piece and a by hand to either partially or entirely open latching end which projects into the receiver. or close the opening E into the cylinder E, 35 The hinged connection of the frame and re thus permitting the gas to Spe freely from Od ceiver is illustrated in Fig. 1 and denoted by the cylinder near the terminal part of the the reference-letter H. . . . . rearward movement of the actuating-slide. The operation is as follows: Supposing the The piston-head or end of the slide D being parts to be in position. (illustrated in Fig. in the forward end of the gas-tube E, as illus 1)--that is to say, with a cartridge in position trated in Fig. 20, the force of the gas operat Ios to be fired-with the breech-bolt locked in ing against the end of the piston or slide position closing the breech and with the firing causes it to traverse the tube E and its rear . mechanism in position on being released to end D° to traverse the cam-track F in the cause the cartridge to be fired, the weapon is breech-bolt, bringing the pin D into the rear 45 discharged by a pull of the trigger, which ef part of the cam-groove F, causing its beveled . . O fects the release of the operating-slide and side to engage with the beveled side at the . discharges the weapon by the force of the ter rear end of the groove F and bringing the minal movement of the operating-slide ef rear end of the slide D into engagement with . fected by means of the actuating-spring. the cam-shoulder F on the rear end wall, of . weapon will be then operated to be re the breech-bolt, the cam action of which II5 so The charged by the force of the actuating-gas. shoulder causes the art D' to rise into en- . . . The operation of the gas actuatingW. device is. gagement with the eveled facef' and de-, . as follows: When the bullet has traversed presses the latch Fandallows it to reengage the bore of the barreland passes into the fun with the part D', as illustrated in Fig. 11, 55 nel-shaped opening at the end of the barrel, thus causing the operating-slide to assume 2O the actuating-gas escapes past the end and a locked or latched engagement with the sides of the projectile intoV the actuating breech-bolt by means of the cam-lug F and chamber gradually and in a small quantity the cam-shoulder f', also the diagonal rela into the gas actuating-chamber. The fun tion of the pins D with the track in which it . 6o nel-shaped end of the barrel and the gradu is reciprocated. The initial part of the rear- 125 ally-increasing diameter of the chamber per ward movement of the operating-slide causes. mit a constantly-increasing SES gas. the breech-bolt to rotate and brings its lock to escape around the projecti e into the gas ing-lugs into the space between the locking-. actuating-chamber, thus causing a constant lugs A of the receiver, and the locking-lug 65 increase of the gas-pressure within the cham on the under side of the bolt is at this time 13o 816,591 brought into its path of movement between charge of the arm is effected by the pull of the Wings H of the magazine. The farther movement of the slide this trigger, the arm J', through its lug.J. de pressing the rear end of the sear S, causing . bolt back in the receiver to a point suffi the forward end of the sear to rise against the ciently distant from the end of the barrel to of the spring T, raising the lug S. permit the