Historical Document · 1915
Isaac N. Lewis's automatic firearm patent, filed 16 April 1912 and granted 15 June 1915, assigned to the Automatic Arms Company of Buffalo. The Lewis Gun dive cites it for the gun's mechanism as patented.
I, N, EWS, AUTOMATIC FREARM, 1,142,896. APPLICATION FED APR, 16, 912. Patented June 15, 1915. 2 SHEETS-SHEET 1. ???92.(X ??????? ???? ???????(e4=-4ttorney I, N, EWS, AUTOMATIC FREAR M, 1,142,896. APPLICATION FLED APR, 6, 192, Patented June 15, 1915, 2 SHEETS-SHEET 2. zzzz --ZT-Y-pºzzzzzzzzzzzz VAVI AEAV VOAR 6 As Cect C //, Zee 2s AY UNITED STATES PATENT OFFICE. ISAAC N. LEWIS, OF NEW YORK, N. Y., ASSIGNOR TO THE AUTOMATIC ARMIS COMPANY, OF BUFFALO, NEW YORK, A CORPORATION OF NEW YORK. AUTOMATIC FIREARNI, 1,142,896. Specification of Letters Patent. Patented June 15, 1915. Application filed April 16, 1912, serial No. 691,135. The present invention, however, is in no sense limited to association with these Be it known that I, ISAAC N. LEWIS, a specific features. It is intended for use citizen of the United States, and resident of in any gun a portion of the gases New York city, in the county of New of dischargewherein is diverted and used for effect 60 York and State of New York, have invented certain new and useful Improvements in ing automatic firing. In Fig. the gun barrel and gas cyl Automatic Firearms, of which the follow inder are within the cooling jacket 20. The ing is a specification. rotary cartridge magazine is represented at This invention relates to firearms and 21, the upper end of the tripod support 65 O particularly to automatic, gas-operated fire at 22, the stock at 23, the pistol grip at 24, arms wherein gases of one discharge store the trigger at 25. In the sectional view power in a spring for driving the feeding and Fig. 5 and in the details of the other and firing mechanism in the succeeding dis of figures the special features of the inven charge. 70 5 The chief object of the present invention tion appear. gas-operated guns heretofore designed is to provide a structure wherein said spring theIn mainSpring-the spring in which one may be located outside the heated zone, that is to say, beyond the reach of heat injurious discharge stores power for the next-has usually been located in the gas cylinder thereto. . 20 Other features of the invention will ap around the rod of the gas-driven piston. 75 To all whom it may concern, As such gas cylinder parallels the gun bar rel for the greater portion of the length The invention therefore consists in the structure of parts and in their coöperation of the barrel the spring is directly in the pear in the following description. and combination substantially as herein heated Zone and quickly deteriorates from 80 the effect of the heat. The present inven In the drawings which form a part of this tion replaces that sort of spring by a small specification, Figure 1 represents, in side convolute Spring located to the rear of the elevation, a gun in which the features of gun barrel entirely out of the heated zone. this invention are embodied; Fig. 2 is an The casing 26 contains the spring in ques 85 30 enlarged elevation of a portion of the gun; tion. The Spring itself is seen at 27 in 25 after set forth and claimed. 7 and 9. It is preferably so formed Fig. 3 is a transverse section on the line Figs.to6, give practically a constant pull 3-3 Fig. 2; Fig. 4 is a fragmentary trans as verse section in the plane indicated by the throughout each action thereof. This is line 4-4 Fig. 2; Fig. 5 is a longitudinal, best accomplished by gradually reducing its 35 axial, vertical section through the receiver cross-sectional area toward the Smallest con 90 and gas cylinder: Fig. 6 is a vertical, lon volution, as indicated in Fig. 7, preferably gradually narrowing the spring while gitudinal section, full size, through the by spring drum and casing and a portion of maintaining the same thickness. 5 illustrates the way in which the 95 the slide, sear and trigger: Fig. 7 is a Fig. has been applied in actual use. The transverse, vertical section on line 7-7 Fig. spring 6: Fig. 8 is a transverse section on line 8-8 casing 26 containing it is removably at Fig. 6: Fig. 9 is a sectional view, similar tached to the lower side of the receiver, to to that in Fig. 6, showing a modification in which also the grip 24 is removably at the connection between the spring and the tached. Within the receiver, as usual, are 100 piston rod; Fig. 10 is a plan of the spring the piston rod 28 and the breech bolt 29 casing and a portion of the slide carrying located in their respective cylinders, the the grip: Fig. 11 is a transverse section on breech bolt being reciprocated, locked and the line 11-11 Fig. 9; and Fig. 12 is an unlocked automatically by the firing-rn illustration of the form of gear teeth found post 80, carried by the piston rod and pro 50 necessary for the perfect operation of the iecting into the interior of the breech b olt, 105 as well understood in this art. mechanism illustrated in Fig. 5. The gun shown in the drawings is an air By reference to Figs. 6 and 7, it will be cooled gun and is provided with rotary Seen that the spring 27 has its inner end at magazine cartridge feed and is intended to tached to a hlub 31 on the ends of which the O 55 be supported upon a tripod when in use. Spring drum is journaled. This drum con ????? 1,142,896 sists of the gear section 32 comprising an Through the side of the receiver is formed outer cup into which the cup 33 is slipped a slot 42 and in the piston rod is formed a laterally before the drum is inserted in its shorter slot 43. In the slot 43 there is in casing 26. The inner cup is held against serted a knob 44, Fig. 3. By this knob the rotation in the outer cup by the radial pro piston may be manually operated, the shank jection 34 which fits a corresponding recess of the knob traversing the slot 42. This in the outer cup. The outer end of the knob is preferably readily removable from spring is preferably riveted to this thickened the piston rod. For this reason its shank is pórtion of said inner cup. After the drum split and the end of each fork is exteriorly is inserted in the casing the squared pin 85 ribbed to spring into a recess at its respec 75 is inserted through one side of the casing and tive side of the slot 43 on the farther side of the piston rod. There are similar ribs the head of the pin, the other end of the pin also formed on the shank near the knob and being inserted in a squared opening in the these lie in recesses in the piston rod at 5 opposite side of the casing. By rotating the either side of the slot 43. They also slide drum in one direction, the spring will be behind the edges of slot 42 which is nar 80 wound upon the hub, then by releasing the rower throughout the greater portion of its drum it will be rotated in the opposite direc length than at the rear end where the shank tion by the spring. Therefore by applying of the knob is to be passed through for in 20 the force of a portion of the gases of explo sertion in the piston rod. 85 sion to the rotation of the drum for winding To close the slot 42 a cover 45 is provided up the spring, the spring in unwinding, may , ?. ??? 36 screwed into the opening against ends slide in ways formed in the wall be made to drive the feeding and firing whose of the receiver just below the ends of said mechanism of the This has been ac slot 42. This cover 45 is slid up over the 25 complished in the present instance by form slot when the gun is not in use, to keep out 90 ing a rack on the piston rod to mesh with It also serves as a safety check, since the teeth formed on the geared section 32 of itdirt. is when the gun is cocked that the cover is the spring drum as seen in Fig. 5. As here used. It is therefore notched at 46 to span tofore in this class of guns, the gases of dis the shank of the knob 44. Should the trig 30 charge entering the gas cylinder through ger be accidentally pressed when the cover the port 37 act upon the piston 38 to drive is over the slot, the cover will prevent the 95 it and the piston rod 28 rearwardly thereby advance of the firing pin. The notch 46 is winding up the spring which on unwinding also undercut at its forward end furnishes alone the full power for operating so thatpreferably should such accidental pressure of the 35 the firing mechanism; driving the piston for trigger occur the shank of the knob will ward to effect the advance of the breech bolt, enter saidi undercut, thereby preventing the 00 the insertion of a cartridge, the locking of withdrawal of said cover until the piston rod the breech bolt and the firing of the cart has been drawn back to cocked position. ridge, in the manner usual in the automatic To hold the cover in withdrawn position or 40 firing of guns of this class. If the piston in place over the slot, a short rib 47 is rod is to he halted before firing, the sear 39 formed on the back thereof (Fig. 4) to rest 05 is released by the trigger and enters its notch in a depression in the side of the receiver or in the piston rod as seen in Fig. 6. The sear over the lower edge of slot 42 respectively. may then be withdrawn by the trigger As above outlined, the slide 40 is remov 45 whereupon the spring will complete is work. able by sliding it longitudinally rearward, After the first round, the gun will continue the trigger being pressed and the stock hav 10 to fire automatically so long as the trigger is ing been removed from the receiver. The pressed. The first charge is fed in by hand removal of the slide releases the spring cas manipulation of the piston rod as is usual ing which is pivoted by lug 48 upon a pin 49 50 in this class of guns. The means for oper a recess in the underside of the 15 ating the piston rod by hand will be ex traversing receiver. The lug 4S is rounded on its upper plained farther on. surface enough to permit the gear casing io This invention provides for the employ Swing down till the teeth on the spring drum ment of the simplest sort of trigger and sear 55 mechanism. They are mounted in the slide are disengaged from the rack on the piston rod. As the spring 27 should have a little 40 to which the grip 24 is attached. This initial tension, means are provided for pre slide is fitted to a longitudinal guideway venting its running down when the casing is formed in the underside of the receiver. so swung down or removed altogether as it This guideway is seen in cross-section at 40 80 in Fig. 3. The sear 39 is a cupped cylinder may be by pushing out pin 49. A detent 50 is provided in the casing 26 for engaging the spring-seated in a socket in said slide 40, gear teeth on the drum. This is preferably as seen in Fig. 6. In the side of the sear is a a spring detent, the integral plate spring 51 notch and into this projects the end of the serving to hold the toe in mesh with the bell-crank trigger 25 which is located in a teeth. Since this detent must be held out of recess in slide 40 and pivoted on pin 41. engagement with the teeth when the gear is 30 1,142,896 in operative position it is provided with a piece rests in the notches 58. Before putting heel 52 with which the locking projection 53 the casingin place on the receiver, the desired on slide 40 may engage when all parts are initial tension may be given to the spring by assembled. As projection 53 is inserted in carrying the crosspiece 57 over into vertical the recess of the spring casing under the notches 59 at the other end of the casing. 70 heel 52, the toe is withdrawn from the drum Under the crosspiece when thus located is gear. The gear of the drum is however then the end of a spring arm 60 which arm is in mesh with the rack on the piston rod pivoted in the casing similarly to the detent which in turn is held in place by the sear 39. 50. When the casing has been put into With the spring drum and casing con place, the application of slide 40 will, by the 75 O structed as described, it is an easy matter, action of its locking lug, thrust the arm 60 should a spring break, to insert a new one. upward and press up the crosspiece 57 into With the new spring inserted and the casing anotch 61 in the underside of the piston rod. in hand, the initial tension is readily given There the crosspiece stays and as the piston 5 to the spring by rolling the drum with the is driven backward the tape rotates the drum 80 thumbs, the detent 50 holding the tension so 56 and winds up the spring. As the spring given until the casing is in place on the re unwinds the tape is wound up and the pis ceiver as above described. ton returned, performing the functions at The adoption of rack and pinion gearing tending its return as already described. A 85 20 for the joint operation of the spring and the groove as indicated at 62 may be formed in piston rod necessitated the development of the underside of the piston rod for the tape a special form of gear teeth. Such teeth are 55. In removing the casing 26, the cross illustrated in Fig. 12. In the attempt to piece 57 must first be pushed back into use the ordinary involute teeth the upward notches 59. After slide 40 has been removed, thrust on the piston rod, due to the line of this may be done by reaching in through the 90 pressure incident to such teeth, created so aperture 63 in the end of the casing 26. much friction as to render the mechanism Many modifications in the general struc inoperative. The involute teeth were there ture and in the details above described may fore cut on the inner half of the engaging be made within the spirit of this invention. 95 30 face (as at 54) in epicycloidal form, the The invention claimed is:other three-fourths of each tooth remaining 1.In a gas operated gun, the combina of involute form. Therefore the engaging tion of the gun barrel, a cylinder parallel or driving faces of the teeth of the rack and ing it, a rotary, reciproc?ting breech bolt, pinion are half involute and half epicycloi a gas-driven piston in said cylinder whose 35 dal. It will be seen that in the action of rod carries the firing pin the post of which 100 rack and pinion in the present instance, the operatively engages the breech bolt, and a rack is the driving element in one direction single spring mounted at the rear of the gas while the pinion is the driving element in the cylinder and gun barrel and connected to the other direction. With the teeth cut as above piston rod for driving the entire mechanism. 40 described the line of pressure upon the rack 2. In a gas operated gun, the combination 05 has been reduced from an angle of 14, that of a rotary reciprocating breech bolt, a gas of involute gearing, practically to Zero or to driven piston whose rod carries the firing parallelism with the direction of reciproca pin the post of which operatively engages tion of the rack. the breech bolt, and a convolute spring oper 45 The rack and pinion connection between atively connected to said piston for driving 10 the spring drum and the piston rod, con all said parts and located in a readily re structed as above described, works perfectly movable manner at the rear of the gun..bar yet it is possible to connect these parts other rel for the purpose set forth. wise, therefore the features of this invention 3. In a gas-operated gun, the combina 50 relating to the adoption of a convolute tion of a receiver and a gas-driven piston, a 15 spring are not to be limited by the use cylinder for said piston paralleling the gun therewith of rack and pinion gearing. An barrel, a readily detachable convolute spring other form of connection between the con mounted on said receiver, an operating con volute spring and the piston rod is illus nection between the piston and spring 55 trated in Figs. 9, 10 and 11. Therein the whereby the spring may be put under ten 12 casing 26, the spring and the spring drum, sion, a casing located at the rear of Said cyl and barrel out of the Zone of damag with the exception of the teeth on its pe inder riphery, and the manner of mounting the ing heat and containing said spring and de drum in the casing are the same as already tachably connected to the receiver for ready 25 60 removal, and feeding and firing mechanism described. of the gear tape is usedInstead for connecting theteeth, springa metal drum driven by said spring. to the piston rod. This tape 55 is connected 4. In a gas-operated gun, the combina at its inner end to the drum 56 and has a tion of the receiver and the gas-driven pis crosspiece 57 secured to its outer end. When ton, a cylinder for said piston paralleling 65 the drum is inserted in the casing this cross the gunbarrel, a convolute spring detach 3. 1,142,896 ably connected to said piston, a casing con tion with the gas-driven piston having a taining said spring and detachably connect gear rack upon the piston rod, of a rotary 65 ed to the exterior of the receiver at the rear spring drum having a pinion thereon adapt of said cylinder and barrel whereby the to mesh with said rack, a removable cas spring may be out of the Zone of damaging ed ing in which said drum is mounted, a detent heat and whereby a new spring may be in said casing for engaging the teeth of the readily substituted for a defective one, and pinion, and means for automatically with 70 firing mechanism driven by said spring. said detent from said teeth in as 5. In a gas-operated gun, the combination drawing Sembling the parts of the gun. 1) with the receiver and gas-operated piston, of In a gas-operated gun, the combina a removable spring casing, a spring-contain tion11.with a gas-driven piston having a gear ing drum within said casing for operating rack upon the piston rod, of a rotary spring 75 the firing mechanism, and an interengaging drum having a pinion thereon adapted to driving connection between said drum and mesh with said rack whereby the piston may 5 piston said interengagement being automati Wind up the spring and the spring in un cally effected in the act of attaching the said winding may operate the firing mechanism, casing to the receiver. . engaging faces of the gear teeth having 80 6. In a gas-operated gun, the combination the their outer halves in involute form and with the receiver and gas-operated piston, inner halves in epicycloidal form for 20 of a removable spring casing adapted to be their the purpose specified. locked to said receiver, a spring-containing 12. The combination with the spring cas drum within said casing for operating the ing, of a squared pin located transversely 85 firing mechanism, a driving connection be in said casing, a hub traversed thereby, a tween said drum and piston, and automati 25 tally acting means for effecting said connec ospring drum mounted for rotation upon said hub and consisting of an inner cup inserted tion in the act of locking said casing upon within an outer one and connected thereto, a said receiver. spring connected to said hub and to said 90 7. In a gas-operated gun, the combination inner cup, and driving means provided on with the receiver, of a gas-driven piston the the periphery of said drum. 30 rod of which reciprocates in said receiver, 13. In a gas-operated gun, the combina firing mechanism driven by said rod, a coll tion with the gas-operated piston and spring volute spring for driving said rod, a casing for returning the piston, of the piston rod 95 containing said spring arid removably at provided with a notch in its underside, a tached to the receiver, means for holding vertically reciprocating sear for engaging 35 said spring under tension when said casing in said notch consisting of a cupped cylinder is removed, and a connection between said a notch in its side, a spiral spring seat spring and the piston rod whereby the with ed in the cupped cylinder, and a bell-crank 00 spring may be wound up by the rearward trigger for depressing said sear by its toe movement of the piston and in unwinding engaging the notch in the side of said cyl 40 may operate the firing mechanism. inder. 8. In a gas-operated gun, the combination 14. In a gas-operated gun, the combina of the receiver, the gas-operated piston, a tion with the gas-driven piston and spring convolute spring adapted to be connected to for returning the piston, of the piston rod 105 said piston for operating the firing mecha provided with a slot therethrough, and a 45 nism, a casing for holding said spring re knob adapted to be removably located in movably attached to the receiver, a device for manual operation of the piston. holding the Spring under tension when the said15.slot In a gas-operated gun, the combina 10 casing is removed from the receiver, and a tion with the gas-driven piston, of the re slide carrying the grip and trigger mecha ceiver provided with a cylinder for the pis 50 nism and provided with means for releasing rodthrough and witha side a slotwall extending longitudi said tension holding device when said slide ton nally of said cylinder, is put in place on the receiver. an operating knob attached to the piston rod 5 9. In a gas-operated gun, the combination and adapted to reciprocate in said slot, and with the gas-driven piston having a gear a cover for said slot notched to embrace the rack upon the piston rod, of a rotary spring shank of said knob. N drum, a pinion driven thereby and adapted Signed at New York city in the county of to mesh with said rack whereby the piston New York and State of New York this 9' 20 may wind up the spring and the spring in unwinding may operate the firing mecha day of April A. D. 1912. 60 nism, a removable casing in which said drum SAAC. N. LEWS. is mounted, and a detent, for engagement. Witnesses: with the pinion when the casing is removed. D. P. Rupp, 10. In a gas-operated gun, the combina W. L. WESE.