US2590854A

US2590854A - Automatic hammer safety for automatic guns

Info

Publication number: US2590854A
Application number: US681281A
Authority: US
Inventors: Alonzo F Gaidos
Original assignee: Individual
Current assignee: Individual
Priority date: 1946-07-03
Filing date: 1946-07-03
Publication date: 1952-04-01
Anticipated expiration: 1969-04-01

Description

April 1, 1952 A. F. GAIDOS 2,590,854

- AUTOMATIC HAMMER SAFETY FOR AUTOMATIC GUNS Filed July 3, 1946 4 Sheets-Sheet l "Fig Alun zmFl E nidns April 1952 A. F. GAIDOS 2,590,854

AUTQMATIC HAMMER SAFETY FOR AUTOMATIC GUNS Filed July 5, 1946 4 Sheets-Sheet 2 .A III I.

I AlclnzhE Euillzs WMMWM April 1, 1952 A. F. GAIDOS 2,590,354

AUTOMATIC HAMMER SAFETY FOR AUTOMATIC GUNS Filed July 3, 1946 4 Sheets-Sheet 5 April 1, 1952 A. F. GAIDOS 2,590,854

AUTOMATIC HAMMER SAFETY FOR AUTOMATIC GUNS Filed July 3, 1946 4 Sheets-Sheet 4 55?; w 555E v iii; I\

525% E E! N Alonzo ET. Euidus Patented Apr. 1, 1952 AUTOMATIC HAMIVIER SAFETY FOR AUTOMATIC GUNS Alonzo F. Gaidos, Redwood City, Calif.

Application July 3, 1946, Serial No. 631,281

1 Claim.

trol mechanism for firearms of the semi-automatic type. There are many firearms of the semi-automatic type which have been converted to provide full automatic fire. However, such conversion usually necessitates alteration of existing major parts of the firearm as well as providing new additional parts. Further, known conversions are not entirely safe inasmuch as the hammer is not positively blocked in automatic fire during the intervals that the breech is unlocked. Thus it is possible for such hammer to prematurely fire the weapon before the bolt is fully locked due to failure to close.

Accordingly, it is an object of this invention to provide a simple fire control mechanism to convert a semi-automatic firearm to selectively obtain full automatic fire without the necessity of performing major machining operations on existing components.

Another object of this invention is to provide a fire control mechanism for a firearm that positively blocks the hammer until the bolt is fully locked for each round fired, thereby substantially eliminating any danger of premature discharge of the firearm.

A particular object of this invention is to provide a fire control mechanism for a firearm commonly known as the U. S. Carbine, Cal. .30, Ml, which as issued, affords only means to fire the Weapon semi-automatically.

Another object of this invention is to provide a fire control mechanism for a firearm which is controlled by the position of the operating slide of such firearm.

The specific nature of the invention as well as other objects and advantages thereof will clearly tracted position and the hammer latch is engaged by the hammer.

Fig. 2 is a fragmentary detail View showing the forward end of the actuating bar engaging the front end of the inertia member of the firearm.

Fig. 3 is a fragmentary detail top elevational (Granted under the act of March 3, 1883," as

amended April 30, 1928; 370 0. G. 757) most position.

view of the trigger guard shown with thhammer removed to illustrate the selector mechanism;

Fig. 4 is a fragmentary detail cross-sectional view taken along the line i-d of Fig. 1.

Fig. 5 is a fragmentary detail view shown partly in longitudinal section to illustrate the conventional sear mechanism of the firearm.

Fig. 6 is a detail fragmentary view of Fig. 1 showing the hammer latch released fromengagement with the hammer bythe actuating bar.-

Fig. '7 is a side elevational view of the firearm illustrating a modification of the embodiment shown in Fig. 1.

Fig. 8 is a perspective view of the hammer latch.

Fig. 9 is a cross sectional view taken along the line 9-9 of Fig. 3. g

Fig. 10 is a detail perspective View of the hammer latch stud of Fig. '7.

Fig. 11 is a sectional view taken along the line HH of Fig. 1. x .1,

Fig. 12 is a fragmentary detail View showing the hammer latch holding the hammerin the cooked position and the actuating bar in the rear- Fig. 13 illustrates a third modification of this invention and is shown in sideelevation mounted on the firearm with the hammer in the released position. 1

Fig. 14 is a top elevational View of thetactuating bar shown in Fig. 13.

Fig. 15 is a fragmentary view of Fig. 13 showing the hammer in the cooked position and with the actuating bar in engagement therewith.

Fig. 16 is a side elevational view of the firearm embodying a fourth modification-of this invention, the hammer being in the released position.

Fig. 17 is a top ele'vational view of the actuating bar illustrated in Fig. 16.

Fig. 18 is a view similar to Fig. 16 showing the hammer in the cocked position and the latch in engagement with such hammer.

Fig. 19 is a perspective view of the selector.

While not limited thereto, the invention is particularly appli d to semi-automatic firearms of the type having a reciprocating operating slide which functions the boltbetween its locked, battery position, and an unlocked, recoiled position.

The invention to be described in more detail later essentially comprises an actuating bar mounted along one side of the firearm adjacent the receiver, one end of such bar being connected to the operating slide while the-other end is connected to a hammer latch. The hammer latch is pivotally mounted on the; trigger guard of such firearm. A cam is provided at the rear end of the actuating bar wherein an arm of the hammer latch is secured, such cam being provided to actuate the latch. A selector is provided to shift the position of the sear to selectively produce either semi-automatic or full automatic fire, as will be explained in more detail later. The hammer latch is utilized in automatic fire to block the hammer until such time as the bolt has been positioned in its locked position by the operating slide before release of such latch is effected by the actuating bar to prevent premature ignition of a cartridge.

In Fig. 1 there is shown in assembled relation 2. firearm of the semi-automatic type embodying this invention. The major elements of such firearm are substantially identical to the U. S. Carbine, Cal. .30, M1 which, as is commonly known, is constructed to fire semi-automatically. Such firearm comprises mainly a receiver I, a barrel 2, a bolt 3 and a. trigger guard 4. Barrel 2 is threadably secured to receiver I in a conventional manher and trigger guard 4 is mounted on the underside of receiver I. oppositely disposed ribs 5 (Fig. 4) provided on the rear end of receiver I engage corresponding ways 6 in trigger guard 4. The forward end of such trigger guard is secured to the receiver by a transverse headed pin 1 Bolt 3 is horizontally mounted within receiver I and reciprocates therein on suitable horizontal ways provided on the interior of such receiver. on the underside of barrel 2 there is slidably mounted an operating slide II and such slide is connected to bolt 3 by the rearwardly projecting offset handle portion I la of such slide. The elements thus far described are all conventional.

In the preferred modification of this invention, an actuating bar I4 is provided which is slidably mounted on the left side of receiver I as shown in Figs. 1 and 2. The forward end of bar I4 terminates in a hook I5 which is bent inwardly and engages the forward end of operating slide II. The rear end IB of bar I4 is of substantially greater width. A forwardly opening slot I1 is provided on the front end of enlarged portion I8 which is engaged by headed pin 1. The wood of the stock (not shown). prevents removal of the pin. A cam slot I8 is out in portion It. The forward end of cam slot I8 is enlarged to permit assembly of actuating bar I4 to a hammer latch I9.

A conventional trigger 2I and sear 22 as shown in Fig. 5 are pivotally mounted in trigger guard 4 on a novel selector 23. A sear spring 31 is mounted between sear 22 and trigger 2I urging sear 22 forwardly. Selector 23 comprises a shaft portion 24 and a knob portion 25, such knob portion being preferably formed integrally with shaft 24 and located exteriorly of the trigger guard to permit convenient manual rotation thereof. Shaft-24 is of enlarged diameter immediately adjacent a hub I2 provided on the inside face of knob 25 as shown at 26. A central portion 21 of shaft 24 is eccentrically formed with respect to the axis of shaft 24. The eccentric portion 21 passes through a slot-like hole 28 in sear 22. Two oppositely disposed notches 2-9 are provided on hub I2 each of which is selectively engaged by adetent 3| to be later described. Rotation of selector 23 between two 180 displaced positions indicated by notches 29 moves sear 22 longitudinally to selectively permit normal semi-automatic fire of the firearm or full automatic fire as will be later described.

Hammer latch I8 is a lever-like member (Fig. 8) 'pivotally mounted at "the rear end thereof on large diameter portion 26 of selector 23. A fixed headed stud 32 projects transversely from the forward end of latch I9. Such stud engages the cam slot I8 when actuating b'ar I4 is assembled to the gun by inserting the headed portion of stud 32 through the enlarged hole 26 in cam slot i8 and then sliding bar I4 forwardly to engage pin I in slot I1 and hook end I5 with slide II. An inwardly projecting lug or ear 33 is provided approximately in the center of latch I9 and is shaped to engage the hammer 34 of the firearm and prevent hammer 34 from rotating forwardly to fire the gun except when the bolt is in battery position, as will be presently described. Detent 3! is formed by bending one end of a torsion spring 35. Such spring ismounted on a pin 3; which is also utilized to pivotally mount hammer 34. The other end of torsion spring 35 is hooked about trigger guard 4 as shown in Fig. 3.

For semi-automatic fire, selector 23 is turned as shown in Fig. 6. In such position detent 3| engages one of the notches 29 thereby yieldingly securing selector 23 in the selected position. Eccentric portion 21 on such selector 23 is then in a forward position, and as such eccentric lies within slot-like hole 23 of sear 22, the sear is biased forwardly by sear spring 31. When hammer 34 is rotated rearwardly about pin 36 by recoil movement of the bolt 3, the forward end of sear 22 engages a sear notch 38 provided on the lower rear end of hammer 34. Sear 22 is forced rearwardly by the greater bias of hammer spring 46 and the rear end thereof then comes to rest on top of an upstanding projection 39 provided on trigger 2 I.

Vfhen such trigger is pulled rearwardly, the forward end of sear 22 is disengaged from sear notch 38 releasing hammer 34. As the load of hammer spring 4!] is removed from sear 22, the bias of sear spring 3'! urges sear 22 forwardly so that the rear end of sear 22 drops off projection 352. 0n the recoil stroke of bolt 3, the forward end of sear 22 again engages sear notch 38 of hammer 34 thereby holding such hammer in the cooked position irrespective of the fact that the trigger remains pulled. Hammer 34 cannot be released until the pressure of the finger is removed from trigger 2I because sear 22 is in the so-called disconnected position. That is, the rear end of sear 22 lies forward of and abutting trigger projection 39 and sear 22 cannot be disengaged from hammer 34 until trigger 2! is permitted to move forwardly sufficiently to permit the bias of hammer 3.4 to force the rear end of sear 22 rearwardly onto projection 39. Then sear 22 can be released and the gun fired by another pull on trigger 2 I.

To effect automatic fire, selector 23 is rotated in which position detent 3| then engages the other notch 22 on the selector. Such rotation moves eccentric portion 27 of selector shaft 24 rearwardly, hence limiting the forward movement of sear 22. In this position, when trigger M is pulled rearwardly and held there by pressure of the finger, the front end of sear 22 will disengage from sear notch 38. However sear '22 is prevented from moving forward to a cooking position relative to hammer 34 by eccentric 2'! and hence sear 22 does not re-engage hammer 24 until trigger '2I is again released. Thus it is apparent that changing the longitudinal position of sear 22 by rotation of selector 23 will provide semi-automatic or full automatic fire respectively. It is desired to point out that full automatic fire can be stopped at will by simply releasing the trigger which brings the front end of scar 22 into the path of notch 38 of the hammer and permits hammer 34 to force the rear end of sear 22 onto projection 39 thereby holding hammer 34 in the cooked position ready for release by the next pull of the trigger.

In full automatic fire, it is apparent to one skilled in the art that sear 22 is disengaged en- .tirely from hammer 34, and if no other means were provided, the hammer would follow the bolt, firing the gun when the forward movement of the bolt was arrested, independent of whether the bolt is fully rotated into its locked position. Hence it is highly desirable to momentarily delay the fall of hammer 34 until bolt 3 is fully locked, otherwise there would be danger of premature discharge of the cartridge with harmful results, or at any event, a lighter blow would be imparted by the hammer since it would follow the bolt forward.

Hammer latch I 9 therefore is arranged to hold hammer 34 in the cooked position until bolt 3 is fully locked before such hammer is released. This action is effective in both automatic and semiautomatic fire. When operating slide I I drives rearwardly upon discharge of a cartridge from force imparted by a piston (not shown), hammer 34 is rotated to its cocked position by bolt 3. If trigger ZI is not held rearwardly, sear 22 will engage sear notch 33 thereby hold ng hammer 34 in the cocked position until release of such is effected by pulling trigger 2i. hand, if trigger 2| is held rearwardly when bolt 3 recoils, hammer 34 will not be held cocked by sear 22.

However, as slide Ii is forced rearwardly, the

rear end of such slide strikes an integral lug 4i provided on the inside of bar I4 just slightly ahead of receiver I as shown in Fig. 11. Hence slide I I forces bar I4 rearwardly. A recess I5 provided on the left side of hammer 34 allows lug 33 of latch I9 to clear hammer 34 as such hammer is rotated rearwardly in a clockwise direction. As bolt 3 approaches the rear end of its recoil travel, cam slot I8 provided in the rear end I6 of actuating bar I4 forces latch I9 downwardly in a counterclockwise direction so that lug 33 of such latch engages hammer 34 slightly below recess I5. Thus hammer 34 is held in a cooked position until the face No of operating slide, returning to' the battery position, strikes hook I5 on the forward end of bar I4. Actuating bar I4 is then carried forwardly and cam slot I8 raises hammer latch I9 in a clockwise direction so that lug 33 will be raised out of engagement with hammer 34. Hence the bias of hammer spring 40 drives hammer 34 forwardly to strike a firing pin (not shown).

The cocking of the hammer is accomplished near the end of the recoil stroke as explained above and while the hammer 34 is rotating in a clockwise direction, the latch i9 is rotating counterclockwise whereby the lug 33 of latch I9 passes arcuately through recess I5 of hammer 34 and stops a short distance in front of the hammer below recess I5. Therefore when the bolt 2 starts forwardly into the battery position, the hammer also starts forwardly but after the hammer travels a short distance it is stopped and held by the lug 33 of latch I8 until the actuating bar I4 rotates latch I9 clockwise thereby disengaging such hammer.

It is desired to point out that in semi-automatic fire, lug 33 of latch I3 is similarly disengaged from hammer 34 but due to the high speed of the action, such takes place before trigger 2I can be released and pulled again, hence latch On the other 6 I9 is in effect inoperative in semiautomatic fire as far as the operator is concerned.

In Figs. 7 and 12 there is shown in assembled relation a modification of the arrangement above 5 described. In this modification substantially the same components are utilized as those described with the exception of the actuating bar. Selector 23 is again utilized to change sear 22 from automatic to semi-automatic fire positions. A hammer latch 43 (Fig. similar to hammer latch I9 is provided which, however, has a substantially different stud 44 secured to the forward end of such latch, such stud 44 being of greater length and diameter. An annular groove 45 is provided near the outer end of such stud and one end of a torsion spring 48 is mounted on hammer pin 33. Spring 46 extends rearwardly in a horizontal plane and terminates in a detent 41. Such detent engages selector 23 in a manner similar to detent 3I and serves to yieldingly retain selector 23 in one of two positions.

An actuating bar 48 is mounted underneath receiver I on the left of such receiver. Bar '48 is a narrow strip-like member and the forward end 49 thereof is of slightly reduced width and is preferably rounded. End 49 of bar 48 is pivotally secured to the rear of operating slide I I by a transverse pin 54.

Trigger guard 4 is normally cut away as shown at SI and the cut awayportion permits actuating bar 48 to lay snugly against the trigger guard. A substantial portion of the rear end of actuating bar 48 is of reduced width as shown at 52. A sloped cam surface 53 is provided on the extreme rear end of bar 48. The forward end of reduced width portion 52 is sloped upwardly as shown at 54. When the assembled action is placed within the stock of the firearm (not shown) such stock serves to hold actuating bar 48 in its proper place along the side of trigger guard 4.

In this modification, as previously pointed out,

actuating bar 48 is connected to the operating slide II at all times and therefore moves with such slide. In automatic fire, lug 33 passes through recess I5 on the side of hammer 34 as bolt 3 recoils-to rotate hammer 34 to the cooked position. Cam 53 is disengaged from stud 44, hence the bias of spring 46 rotates hammer latch 43 in a counterclockwise direction as shown in Fig. 7. Thus lug 33 of such hammer latch engages hammer 34 to hold it in cocked position. On the counter-recoil stroke, slide II returns to its forward position carrying with it actuating 55 bar 48. As slide II nears the end of its stroke, after the bolt has been locked, cam 53 strikes stud 44 thereby rotating hammer latch 43 upwardly in a clockwise direction. Thus lug 33 is disengaged from hammer 34', permitting such hammer 0 to go forwardly to strike the firing pin (not shown) thereby effecting discharge of the cartridge only after bolt 3 has been fully locked. Operation of the sear by manipulation of selector 23 to selectively provide semi-automatic and full automatic fire is identical to that above described.

A third modification of a fire control mechanism embodying this invention is shown in assembled relation in Figs. 13 and 15. Such modi- 'fication essentially comprises an alternate form of actuating bar. The sear and trigger mechanism, including the selector, are identical to that used in the-two aforedescribed modifications.

In this modification an actuating bar 55 (Fig.

7 14) is provided which is mounted on the right hand side of trigger guard 4. Such bar is pivotally mounted to the trigger guard at the forward end thereof by transverse pin 1. An offset, vertically upstanding arm 56 of actuating bar 55 rests within a recess 51 provided in slide I I. The rear end 58 of bar 55 is substantially offset so that such rear portion will lie adjacent the right side of hammer 34. An arcuate cam surface 59 is provided on the bottom of the rear portion 58 of bar 55. On the extreme rear end of offset portion 58 a notch 60 is provided for a purpose to be presently described.

A headed stud GI is secured to the side of hammer 3t. Cam surface 59 rides on the top side of stud El. A torsion spring 62 is provided to bias actuating bar 55 downwardly as will-be presently described. One end of such spring rests on top of bar 55 while the other end is secured to the front end of trigger guard 4.

In the fired position as shown in Fig. 13, earn 59 overlies stud 6|. Upon rearward movement of the reciprocating bolt 3, hammer 3a is driven rearwardly by the bolt 3 to its cocked position. 'Cam 59 is held in contact with stud Si by the bias of torsion spring 52. During automatic fire, trigger H, of course, is held rearwardly, therefore sear 22 will not engage sear notch 38, hence hammer 34 will tend to follow bolt 3 forwardly, such hammer being urged in the forward direction by the hammer spring. When hammer 34 reaches its cocked position, stud 8! moves off cam surface 58 and into notch 6%) of bar 55. Bar 55 is held in this position by spring 62. Thus in effect, actuating bar 55 itself functions as a scar relative to the hammer. On the contourreooil stroke of slide H, therefore, hammer 3 3 will be held in the cocked position by the notch 69 provided at the rear end of bar 55. When. however, slide ll contacts the upper end of arm 56 provided on the forward end of bar 55, the rear end of bar 55 will be rotated about transverse pin 1 in a clockwise direction. This movement of bar 55 raises notch 58 out of engagement with stud fil thereby permitting hammer 34 to be driven forwardly, thus effecting discharge of the succeeding cartridge. As in the other modifications, when the sear '22 is in position for semi-automatic fire, bar 55 is inoperative except when the operating slide fails to return to battery. When the bolt and hence the operating slide fails to return to battery, bar 55 blocks hammer 34 thereby preventing premature discharge of the firearm.

A further modification of the fire control mechanism is shown in assembled relation in Figs. 16 and 18. Here again the identical sear release mechanism is utilized for semi and full automatic fire, including the eccentric means for efiecting such change. This particular modification utilizes a substantially diiferent hammer latch to restrain hammer 34 from following the bolt forwardly during automatic fire.

Such hammer latch is shown at 63 and compises a lever-like member, the rear end 64 of which is oifset as shown in Fig. 17 so that such end will lie against the right face of hammer 3%. The top surface of the rear end portion 65 of latch 63 is rounded as shown at 55. Such surface is rounded to permit a transverse stud 6! on the hammer to ride along such curved surface. The extreme rear end of latch 63 is squared as shown at 66. The forward end of latch 63 is rounded and is pivotally mounted to trigger guard d by transverse pin l. A short distance to the rear of pin 1 a stud 61 is suitably and rigidly secured 8 to latch 53. Latch 63 is raised upwardly'by a torsion spring 30 secured to pin '1 to engage stud st to hold hammer 3a in the cooked position. A cam bar 59 comprising a forward portion 68 and a rearwardly extending spring-like arm portion it is provided to actuate latch 63. On the forward end of cam bar Gdan upstanding lug H is provided, the top of which is bent inwardly as shown at E2 ,to engage the top of operating slide H. The rear end of lug H is likewise bent inwardly to'engage the front surface of slide I thereby providing means for attaching bar 69 to slide I i. Somewhat to the rear of lug H there is provided an inwardly projecting lug M. Such lug engages a recess iii normally provided at the rear portion of slide ii, thus securing cam bar 38 against longitudinal movement relative to slide H.

The extreme, rear end of arm 79 is sloped downwardly as shown at 73. Such sloped surface acts as a earn as will be presently described. The sloped end it of cam bar 69 is located to the rear of stud 6"! on hammer latch 53 so that such sloped end contacts stud 63 only when slide H is practically at its extreme forward position.

As previously mentioned, the hammer latch is provided to restrain the hammer from following the bolt forwardly to the closed position until the bolt is locked, thus preventing premature discharge of the cartridge in full automatic fire. Cam bar 69 reciprocates with slide Ii. On the recoil stroke of slide i i and hence bolt 3, hammer 3 2 is of course rotated to the cooked position. While hammer Sfiiis rotated to such position, stud E l passes over the arcuate surface on the rear end 56 of latch 63 and engages squared end 66 of such latch. Assuming trigger 21 is held rearwardly and selector 23 is in its automatic fire position, sear :22 cannot engage sear notch 38 of hammer t l, as previously explained, therefore hammer 3d starts to rotate forwardly due to the bias of hammer spring to. However, stud 6| contacts the end as of latch 83 and the hammer is held in the cocked position shown in Fig. 18.

Latch 63 is restrained from rotating in a clockwise direction by the underside of the receiver. As slide H moves forwardly, locking the bolt, the sloped canr-lilce surface E3 of arm l'il strikes stud s? and latch 63 is forced downwardly. This forces the end 66 of the latch to disengage from stud SI of the hammer. When such disengagement is effected, slide i i has reached the limit of its forward movement, hence bolt 3 is securely locked, and hammer 3 3 is then free to effect discharge of the cartridge without danger of premature ignition.

From the foregoing description it is readily apparent to one skilled in the art that a simple, effective fire control mechanism to permit full automatic fire or semi-automatic fire is hereby provided. Further, such mechanism can be readily adapted to firearms arranged to fire only semi-automatically or such mechanism can be readily adapted to any new design of firearm requiring selective full or semi-automatic fire control. It is also apparent that a positive hammer latch is provided which insures that the hammer of the firearm is safely blocked at all times until the bolt of such firearm is securely locked in battery position. Thus premature discharge of the firearm in an unsafe position of the bolt is eliminated.

I claim:

In an automatic firearm having a receiver, a bolt reciprocable therein forwardly to and rear- 9 wardly from a battery position, a reciprocable operating member for the bolt and a spring biased hammer pivoted in said receiver and movable by the bolt to its cocked position, the improvement comprising, an actuating bar slidably mounted on the receiver adjacent the operating member, a

pair of projections on said actuating bar respectively disposed in the path of rearward and forward movement of the operating member Whereby said actuating bar is moved rearwardly as the operating member moves to counter-battery position and forwardly as the operating member moves to battery position, a hammer latch pivotally mounted on the receiver adjacent said hammer, a latching projection on said hammer latch engageable with said hammer in its cocked position, said actuating bar having a cam slot therein adjacent said hammer latch, a projecting stud on said hammer latch engageable in said cam slot, said cam slot being constructed and arranged to pivot said hammer latch to engage said i V w latching projection with said hammer as the operating member moves into counter-battery position and to release said hammer as the operating membermoves into battery position.

ALONZO F. GAIDOS.

" REFERENCES CITED The following references are of record in the file of this patent: