Historical Document · 1966
Theodor Koch's H&K breech-closure patent (German priority 30 October 1963; issued 8 November 1966) for the roller-delayed bolt. The HK PSG1 dive cites it for the G3-family bolt the PSG1 uses.
United States Patent 0 3,283,435 Patented Nov. 8, 1.966 2 1 FIG. 2 shows a breech system according to FIG. 1 with the breech being locked. 3,283,435 The drawing shows .a breech system of known con BREECH CLOSURE Theodor Koch, Oberndorf, Germany, assignor to Heckler & Koch G.m.b.H., Oberndorf, Germany Filed Oct. 27, 1964, Ser. No. 406,717 Claims priority, applicatiosi 6Germany, Oct. 30, 1963, 5 8 5 Claims. (hi. 42-16) struction which has been improved according to the in vention. The breech comprises a breech block 1, a con trol member 2 connected therewith and a breech head 4 which is mounted on the control member 2 of the breech to be displaceable in axial direction. The control mem ber 2 has two control surfaces 3 which cooperate with The invention relates to an automatic ?rearm compris 10 two interlocking rolls 5a and 5b which are disposed in openings 6a and 6b of the breech head 4 and displaceable ing a breech which is provided with a supplementary transversely to the direction of the movement. When the mass. Such supplementary masses are required in order breech is locked the rolls 5a and 5b enter the recesses to avoid troubles which are due to rebounding of the 7a and 7b of an interlocking piece 7 in which also the breech when running into its shooting position. In all known arrangements the supplementary mass consists 15 barrel 8 is anchored. When the breech runs forward a cartridge 9 is fed into the barrel 8 (FIG. 2). The of a movable piece mounted on the breech which exerts cartridge can be ?red by means of the striker pin 11, ‘an impact either directly or over a spring onto the breech which is displaceably disposed in the breech block 1 and to prevent a rebound of it. Since the elastic forces which in the control member 2 and is normally kept in a rest effect the rebound of the breech as well as the inert forces position by means of a coil spring 10. For ?ring the 20 of the supplementary mass depend on the speed of the cartridge 9 the striker pin in known manner is knocked breech, a satisfactory operation is guaranteed only for upon the bottom of the cartridge by means of a cock a rather small range of the ?ring rate. This is a con (not shown). siderable disadvantage of the breeches provided with a According to the invention the breech block 1 of the supplementary mass. The object of the invention is to avoid these defects 25 breech comprises two axial bores 12a and 1217 which are ?lled almost to the half with heavy metal granules 13 of the known systems. According to the invention this serving as supplementary mass, preferably with granules is achieved in that the supplementary mass is formed by of tungsten. The rear ends of the bores 12a and 12b a number of individual parts, which are movable relative are sealed by means of screwed plugs 14a and 14b. The to one another under friction. Such a construction of remaining hollow spaces 15a and 15b serve as working the supplementary mass has the advantage that a damp spaces for the supplementary mass 13. ing of the movement of the supplementary mass which is As known after ?ring a shot the breech is moved op high enough to prevent a rebound of the supplementary posite to the direction of fire, whereby it cocks the mass is obtained by the friction of the individual parts propelling spring until it is brought to rest by the thrust of the supplementary mass relative to one another and of the propelling spring or by the impact onto a buffer against the walls of guiding means. By dividing the arrangement (not shown). The supplementary mass 13 supplementary mass into many small individual parts according to the invention which is in the front part of the supplementary mass is losing its own elasticity, so the bores 12a and 1212 when the breech is locked as that the supplementary mass also for this reason has no tendency to rebound and does not exert a very short and 40 shown in FIG. 2 due to its inertia is thrown back when the backward movement of the breech is decelerated violent impact onto the breech but a lasting and effective and rests against the plugs 14a and 14b ‘as shown in thrust. Therefore a ?rearm according to the invention FIG. 1. Due to its inertia the supplementary mass has a less critical breech speed so that with such an arm remains in this position also during the forward mo ammunition of different kinds can be ?red, which can tion of the breech which is effected by the for much more be adapted to predetermined requirements ward motion of the breech which is eifected by the than up to now, since it is no more most important to relaxing propelling spring (not shown). observe a determined ?re speed. A further advantage of the invention is the extremely Simple construction and a high reliability. This is espe cially true when, according to a further feature of the invention, the parts of the mass are loosely ?lled into one or more chambers of the breech. In a preferred embodi ment of the invention the breech is provided with axially directed bores for lodging the parts of the mass and the bores are sealed preferably at their rear ends. The parts of the mass are thereby formed by gran ules of a heavy metal, especially of tungsten. The use of granules of a heavy metal according to the invention has the advantage that such a granulated material has During the forward motion the breech head 4 removes a cartridge from a magazine or a belt in the usual manner and feeds it into the cartridge chamber in the barrel 8 of the arm. After the breech head 4 has fed the cartridge 9 into the barrel of the arm and has come to rest the inter locking rolls 5a ‘and 5b are pushed into the recesses 7a and 7b by means of the control surface 3 of the follow ing control member 2. This proceeds under the develop 55 ment of considerable forces resulting from the kinetic energy of the control member 2 and the breech block 1, which are both brought to rest. The interlocking piece 7 at ?rst yields to the impact of parts 1 .and‘2 of the a high speci?c density and that the required supplemen 60 = reech exerted over the interlocking rolls 5a and 5b, however it then rebounds and presses the interlocking tary mass can be accommodated in a small space. Fur ther the inner friction of such a granulated material is very high so that an excellent damping is obtained. Beyond that such a granulated material is also mechanical ly very stable so that an abrasion does not occur. Further objects, details and advantages of the inven tion are apparent from the following description in which the invention is explained in detail with reference to the embodiment shown in the drawing. rolls 5a and 5b against the control surfaces 3 of the con trol member 2, which in connection with the elasticity of the control member 2 would result in ‘a rebound of breech parts 1 and 2 if no countermeasure were taken. In the 65 moment of rebound the individual parts of the supplemen tary mass 13‘ strike the front surface of the bores 12a and 1217, these parts are thrown forward from their posi tion near the plugs 14a ‘and 1417 due to their inertia and thus exert a thrust onto the breech which acts against FIG. 1 shows a longitudinal section through a breech 70 the forces which would cause a rebound of the breech. system with the breech running into the shooting posi tion, and The impact of the granulated supplementary mass to 3,283,435 3 the front surfaces of the bores 12a and 1212, however, does not, ‘as in known breeches with a one-piece supple By the proper selection of these values the time slope and the value of the thrust of the supplementary mass can mentary mass, take place as an elastic shock, which could :be adapted to an optimum to the given conditions. What I claim is: be avoided, but as an essentially inelastic shock, since UK 1. Automatic ?rearm comprising a breech provided the supplementary mass consisting of individual parts with a supplementary mass, characterized in that said which are movable relative to one another has a high in supplementary mass is formed by a number of individual ner friction by which elastic vibrations of this mass are parts in mutual frictional contact, said parts being mova again give rise to rebound effects, which, however, should entirely prevented. The inelastic impact of the supple mentary mass effects a lasting and effective counter thrust which de?nitely prevents a rebound of the breech and guarantees a perfect interlocking of the breech in a very extensive range of breech speeds. It is to be understood that the invention is not limited to the embodiment described. The invention is quite independent from the speci?c construction of the breech and can be applied on principle in all known breeches. Especially the supplementary mass according to the in vention may be used not only in a two~part breech as used in the embodiment described, but also in a one-part or mass breech. Further modi?cations of the speci?c embodiment described may be devised in that certain of the features characterized by the claims may be used in other embodiments of the invention either individually or in an arbitrary combination. The elfect of the divided ble relative to one another. 10 2. Firearm according to claim 1, characterized in that the parts of the supplementary mass are loosely disposed in one or more chambers of said breech. 3. Firearm according to claim 1, characterized in that said breech is provided with axially directed bores for lodging said parts of said supplementary mass and that said bores are sealed preferably at their rear ends. 4. Firearm according to claim 1, characterized in that the supplementary mass is formed by granules. 5. Firearm according to claim 4, characterized in that said granules consist of a heavy metal, especially of tungsten. References Cited by the Examiner UNITED STATES PATENTS 2,495,460 1/1950 Koucky ____________ __ 42—l6 supplementary mass is not only in?uenced by the total mass of the individual parts used but considerably also BENJAMIN A. BORCHELT, Primary Examiner. by the relation of their total volume to the volume of FRED C. MATTERN, JR., Examiner. the chamber and beyond that also by the shape of the chamber in which the individual parts are assembled. 30 S. C. BENTLEY, Assistant Examiner.