United States Patent (19) (11 3,789,730 Hemes (45) Feb. 5, 1974

54) AUTOMATIC WEAPON WITH SELF 2,948,195 8/1960 Linder...... 89/190 LOCKING BOLT BREECH BELO-CEK 75) Inventor: Alfred Helmes, Willich, Germany FOREIGN PATENTS OR APPLICATIONS 73 Assignee: Rheinmetail GmbH, Dusseldorf, 617, 142 2/1949 Great Britain...... 42/25 Germany 12, 181 1891 Great Britain...... 42/25 22) Filed: Aug. 24, 1971 Primary Examiner-Stephen C. Bentley 21 ) Appl. No.: 174,369 Attorney, Agent, or Firm-Ernest G. Montague

30) Foreign Application Priority Data 57 ABSTRACT Sept. 1 1, 1970 Germany...... 2044964 An automatic weapon including a self locking bolt (52) U.S. C...... r 89/183,42/25, 89/33 SF, which comprises a weapon casing defining a loading 89/190 chamber. A breech block moves forwards and back (51) int. Cl...... F41d 3/00, F41d 9/02 and is adapted to insert a cartridge into the loading 58) Field of Search...... 42/25; 89/33 SF, 176, 182, chamber during the forward movement of the breech block. At least three laterally pivotable locking bolts 89/183, 190 are provided symmetrically to the longitudinal central 56 References Cited axis of the breech block, for complete locking of the UNITED STATES PATENTS breech block against the weapon casing. 2,861,374 l l (1958 Hampton...... 89/90 2 Claims, 3 Drawing Figures

PATENTEDFEB 5197, 3.789.730

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zaevaez, 3,789,730 2 AUTOMATIC WEAPON WITH SELF LOCKENG breech block and the gun can be kept small. In this BOLT BREECH BLOCK way, the requirements for a further advantageous em The present invention relates to an automatic bodiment of the invention are simultaneously provided, weapon with self locking bolt breech block. in that two cartridge magazine devices can be brought close to the gun and to the breech block by which Breech blocks for automatic weapons, in which the means a rapid change from one type of ammunition to breech block is locked to the breech housing by means another is possible. For this purpose two apertures for of pivotable locking bolts, are generally referred to as the cartridge magazine are provided in the gun casing self locking bolt breech blocks. In this case the locking which - seen in cross section - are located respec bolts are pivotally mounted at both sides in the breech O block. After the completed countercoil of the breech tively between two adjacent locking bolts. . block, after it has inserted a cartridge in the loading It is still another object of the present invention to chamber of the gun barrel, the locking bolts pivot out provide an automatic weapon with self locking bolt wardly and engage in appropriate recesses provided in breech block, wherein in order to achieve a good cen the breech housing, in which case the forces acting on 15 tering of the breech block and for the transmission of the breech block of the breech at the time of firing are the supporting forces to the gun casing, it is also of ad transmitted by the locking bolts to the weapon or vantage, if the breech block is guided in the breech breech housing. Thus considerable surface pressure is housing by means of guide faces located around a applied to the support faces at the breech block and the closed sector and if these guide faces are located radi breech housing. ally relative to the locking bolts. 20 It is a further object of the present invention to pro In an effort to increase the efficiency of the guns and vide an automatic weapon with self locking bolt breech the ammunition, and in order to obtain as high as possi block, wherein in a further advantageous embodiment, ble rate of fire, a comparatively short recoil path for the - seen in cross section - the breech block has chord breech block and a comparatively small recoil force of like truncations between the guide faces. Due to this the breech block are desired. The breech block should 25 the magazines for supplying cartridges can be brought thus, on the one hand, be as short as possible and, on still nearer to the loading chamber, which, in accor the other hand, should be kept as small as possible in dance with the objects of the present invention, has a lateral dimension. Further, a short recoil path for the favorable effect on the dimensions of the breech block breech block is very desirable, so that despite the de and on the breech block recoil path length. sired high rate of fire - the velocity of the breech 30 block can be kept comparatively low, which, together It is still a further object of the present invention to with a short breech block enable a favorably low recoil provide an automatic weapon with self locking bolt force to be obtained. In addition, the recoil path of the breech block, wherein in addition, a further feature of breech block is dependent both on the cartridge length the present invention contributes to keeping the length and on the distance between the cartridge magazine 35 of the breech block as short as possible, in that the and loading chamber. Thus, attempts are made to keep spring-loading of the ejector claw consists in known this distance as small as possible, in order to facilitate manner of a closed spring ring, which is inserted in an a rapid insertion of the cartridges, into the loading annular groove provided in the ejector claw and near chamber. the front face of the breech block. Due to this further cross sectional weakenings of the breech block head It is thus, one object of the present invention to pro 40 are avoided, which weakenings are present in many vide an automatic weapon with a self locking bolt other arrangements extractor claws and their spring breech block which with the same or smaller dimen loading arrangements. sions relative to known breech blocks of this type, pro vides an increase in efficiency of the gun; in particular With these and other objects in view, which will be with comparatively small dimensions and low weight 45 come apparent in the following detailed description, relative to customary locking bolt breech blocks, the the present invention, which is shown by example only, breech block should facilitate a greater rate of fire and will be clearly understood in connection with the ac provide a capacity to withstand greater supporting companying drawing in which: forces. FIG. 1 is a partial longitudinal section through the 50 casing of an automatic weapon and the breech block; It is another object of the present invention to pro FIG. 2 is a cross-section along the lines II - II of FIG. vide an automatic weapon with self locking bolt breech 1; and block, wherein three locking bolts are provided sym FIG. 3 is a cross-section along the lines III - III of metrically with respect to the longitudinal central axis FIG. I. of the breech block. Firstly, this has the advantage that, with the same or even smaller width relative to the cus 55 Referring now to the drawing, the weapon casing 1 tomary arrangement, the breech block can support is located a multi-part breech block 2, which moves greater forces and secondly, the centering of the back and forwards, and which for each forward move breech block is improved. Therefore, without any dan ment inserts a cartridge into a loading chamber 3 of the ger of tilting, the breech block can be kept shorter, gun. The breech block is self locking and consists es 60 sentially of a breech head 4, a breech block body 5 and which in addition helps towards the desired reduction support flaps 6 and 6'. ficiency.of the breech block weight - despite an increase in ef In the breech head there are provided three locking It is yet another object of the present invention to bolts - symmetrical to the longitudinal central axis of provide an automatic weapon with self locking bolt the breech block - which are mounted to pivot radi 65 ally in the breech head by means or semi-cylindrical breech block, wherein one of the locking bolts is ad support faces 7. The breech block body 5 is connected vantageously located in the vertical, longitudinal cen to the breech head 4 to slide by the lengths. During the tral plane of the gun, due to which the width of the forward movement of the breech block the locking 3,789,730 3 4. breech block body lags behind the breech block head a weapon casing defining a loading chamber, by the length s, the locking bolt 6 being pivoted, as a breech block moving forwards and back and shown in dot-dash lines in FIG. 1. After the insertion of adapted to insert a cartridge into said loading a cartridge 8 into the loading chamber and as soon as chamber during the forward movement of said the breech block head, has reached its forward posi breech block, tion, the locking bolts are pressed outwards by means at least three laterally pivotable locking bolt means of the inclined faces 9 provided on the following lock provided symmetrically to the longitudinal central ing breech block body, by which means they enter the axis of said breech block, for complete locking of recesses 10 provided in the weapon casing and the said breechblock against said weapon casing, breech block assumes the locked position according to O FIG. 1. one of said locking bolts is arranged in the vertical As can be seen from FIGS. 2 and 3, the breech block longitudinal central plane of said weapon casing, 2 is guided in the weapon casing by means of guide cartridge magazines, faces 11 and 11" arranged in a circular arc, these guide said weapon casing has two apertures for receiving faces being located radially to the locking bolts 6 and one end of each of said cartridge magazines, 6". Symmetrical to the vertical longitudinal central 15 the latter are arranged, in cross-section symmetrical plane there are provided in the weapon casing - in the with respect to the vertical longitudinal central region between two adjacent guide faces - supply plane of said weapon casing, and openings 12, 12 cartridges, in which the bodies 13, 13' each of said cartridge magazines is disposed between of cartridge supply magazines engage. In order to be two adjacent locking bolt means. able to supply the cartridges as near as possible to the 2. An automatic weapon including a self locking bolt breech block 2, the latter has chord-like truncations comprising 14, 14' in the peripheral region between the guide a weapon casing defining a loading chamber, haces 11 and 11". In the plane of the drawing the car a breech block moving forwards and back and tridge supply magazines are pivotally connected to 25 adapted to insert a cartridge into said loading each other by a small amount, so that either a cartridge chamber during the forward movement of said from the case 13 or the case 13' is gripped at will by the breech block, forward face of the counterrecoiling breech block head at least three laterally pivotable locking bolt means and is inserted into the loading chamber 3. In the for provided symmetrically to the longitudinal central ward face of the breech head 4 an extractor claw 15 is axis of said breechblock, for complete locking of guided to move radially against the force of a spring 16. said breech block against said weapon casing, The spring 16 consists of a closed spring ring (FIG. 2), said weapon casing includes guide faces constituting which is arranged in a groove 16' located near the for arcs of a circle in cross-section arranged around a ward face of the breech head 4. closed sector thereof for guidance of said breech While I have disclosed one embodiment of the pres 35 block during its forward and backward movement, ent invention, it is to be understood, that this embodi and ment is given by example only and not in a limiting said guide faces are provided radially to said locking ScSe. bolt means, and I claim: said breech block, in cross section, has chord-like 1. An automatic weapon including a self locking bolt 40 truncations between said guide faces. comprising ck k . k >k sk

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