Historical Document · 1976
H&K's G11 rotating-breech patent, issued 21 December 1976. The Hyper-Burst Mechanisms dive cites it for the G11's swivelling chamber.
United States Patent [19] [11] " 3,997,994 Kastner et al. [45] Dec. 21, 1976 1541 SHOULDER ARM WITH SWIVEL BREECH FOREIGN PATENTS OR APPLICATIONS MEMBER 1751 Inventors: Giinter Kiistner; Dieter Ketterer; Tilo Moller, all of Obemdof; Ernst Wt'tissner, Sulz-Muhlheim, all of ‘Germany [521 [511 158] alignment with the barrel in is ?ring position and which Germany ........................ .. 2413615 is closed to the rear. The shoulder arm has an arrange ment for swivelling the breech member out of the ?ring position and into a loading position, in which said ?ring chamber is accessible for the introduction of a car tridge. The breech member is designed as a roller which can be swivelled about its longitudinal axis and which is arranged in a cylindrical hole in a member which is-?xedly attached to the barrel and whose wall directly closes the ?ring chamber when it is located in 42/60; 89/33 MC, 4 A, 13 R, 17, 126, 155, 156 38,772 39,232 1,294,636 2,976,770 References Cited UNITED STATES PATENTS Cook ..................................... .. 42/9 Underwood .................... .. 42/9 ABSTRACT pendicular to the axis of the barrel for loading the breech member contains a ?ring chamber which is in Int. (31.2 ....................................... .. F41C 11/00 2/1854 6/1863 7/1863 2/1919 3/1961 United Kingdom ................. .. 42/59 United Kingdom ................... .. 42/9 [5 7] Field of Search ................. .. 42/9, 15, 39.5, 59, 10,520 Czechoslovakia ..................... .. 42/9 12/1881 8/1884 A shoulder arm, such as a ri?e, having a breech mem ber which can be swivelled about an axis which is per US. Cl. ..................................... .. 42/9; 42/39.5 [56] 9/1944 5,564 10,944 Primary Examiner—Charles T. Jordan Attorney, Agent, or Firm—Spencer & Kaye - [73] Assignee: Heckler & Koch GmbH, Obemdorf, Germany Mar. 11, 1975 [221 Filed: [211 Appl. No.: 557,375 Foreign Application Priority Data 1301 Mar. 21, 1974 73,513 ' the ?ring position. The wall is retained in its respective position by means of the arrangement for swivelling the breech member. ' Howard .......................... .. 42/9 Dovell ................... .. 89/33 MC Fletcher ............................ .. 19 Claims, 2 Drawing Figures 89/155 A. 4111p "Egg-31%11 3,997,994 1 SHOULDER ARM WITH SWIVEL BREECH MEMBER ' ' The present invention relates to a shoulder arm, es pecially a ri?e, having a breech member which can be swivelled about an axis which is perpendicular to the axis of the barrel for loading and which contains a ?ring chamber which is in alignment with the barrel in its ?ring position and which is closed to the rear, further having an arrangement for swivelling the breech mem ber out of the ?ring position and into a loading posi tion, in which the ?ring chamber is accessible for the introduction of a cartridge. A shoulder arm of this type is known from Swiss Pat. No. 541,792. This is a shotgun, in which the barrel is 2 which is arranged in a cylindrical hole in a member which is ?xedly attached to the barrel and whose wall directly closes the ?ring chamber when it is located in the ?ring position, the wall being retained in its respec tive position by means of the arrangement for swivel ling the breech member. In the shoulder arm according. to the present inven tion, there is only one single moving part, i.e. the breech member itself, and this single moving part is designed as a simple, swivel roller, for which merely a cylindrical hole must be provided in the member which is ?xedly attached to the barrel. This makes the design of the shoulder arm according to the present invention extremely simple, while simultaneously achieving a high degree of dependability. In addition, it is also possible to keep the moving masses very small, so that no large forces are required for moving them, which means that no large forces must be exerted for loading the weapon. This is not only of signi?cance if the which is also slidable; and a crossbolt which can be 20 weapon is of the manually loaded type, but especially if followed by a breech member which contains the ?ring chamber, which can be shifted longitudinally relative to the barrel and which can be swivelled; a locking plate shifted and swivelled. With the weapon ready to ?re, a plane end surface of the breech member, which con tains the ?ring chamber, is in a contactin relationship with the rear end of the barrel and that portion of the the weapon is of the semiautomatic or fully automatic type. The arrangement according to the present inven tion is also suitable for weapons of this type. Especially in cases where the breech member must be moved very receiver containing the barrel; two engagement bolts 25 quickly in automatic weapons, it is of signi?cance for against the rear end of the breech member by the cross the axis of the ?ring chamber to intersect the axis of the roller forming the breech member, as it is then espe cially easy to ensure that the roller is at least approxi bolt, and its bevelled, projecting edges are in a support mately balanced in both the loaded and unloaded attached to the end surfaces engage corresponding aperturesin the receiver. A locking plate 40 is pressed ing relationship with corresponding bevelled surfaces 30 states, so that the bearing means do not have to be subjected to especially high forces. Moreover, when on the rear of the breech member. This locks the breech member in the ?ring position. To open the breech arrangement, the crossbolt is ?rst swivelled, the cartridge is ignited, the gas pressure does not result in any momentum which could have a tendency to swivel the roller out of place, so that the arrangement which eliminates the blocking condition of the locking plate; the crossbolt, the locking plate and the breech 35 for swivelling the breechmember is also not subjected to any large forces during operation either. member are then pushed rearwardly into‘ positions is arranged in the swivel crossbolt and a rear member is As already mentioned above, the weapon which is known from Swiss Pat. No. $41,792 is a shotgun. In this shotgun, the ?ring chamber is designed in such a man ner that, when the weapon is ?red, the front end of the cartridge case covers the gap between the ?ring cham ber and the section of the barrel located directly in arranged in a stationary portion of the receiver which is front thereof, thereby sealing it. However the arrange which permit the breech member to swivel freely. In the known weapon, the ?ring pin is arranged coaxially to the ?ring chamber in the ?ring position and com prises three members, of which a forward member is arranged in the slidable locking plate, a center member ment according to the present invention is intended for Although the arrangement of a swivel breech mem 45 use with any and all types of ammunition. It is therefore suf?cient for the breech member to be matched pre ber containing the ?ring chamber offers many advan , located directly behind the crossbolt. 1 tages over other loading‘ and breech mechanisms in shoulder arms, it can ‘be seen that, as a result of the cisely to the cylindrical hole and for the ?ring chamber to have a rear section of wider diameter, so that the powder gases act on a rearwardly extending shoulder in employment of a large number of moving parts and a divided ?ring pin, the design of the known arrangement 50 the ?ring chamber, thereby pressing the breech mem ber lightly against the rear end of the barrel. is relatively complicated, which results in considerable cost and can easily lead to malfunctions, with the result that the question arises of whether the advantages of a swivel breech member of this type are not outweighed The shoulder arm according to the present invention is especially well suited for ?ring caseless cartridges, which do not leave any remains, which would have to by its disadvantages, and whether the employment of a 55 be ejected, in the ?ring chamber after the cartridge is ?red. However if caseless cartridges are employed, breech member of this type does not, in the ?nal analy there is no cartridge case for sealing that end of the ?ring chamber facing the barrel. Iftlre ?ring chamber is It is therefore the object of the present invention to designed to receive caseless cartridges, it would thus design a shoulder arm, of the type described at the outset, having a swivel breech member, in such a man 60 also be necessary to provide sealing means at the rear end of the ?ring chamber as well. These sealing means ner as to achieve a very simple and dependable design, could be a lip seal limited by an annular groove, which which also results in a high degree of dependability, so forms a type of obturation and which is pressed gas that the advantages of the employment of a swivel sis, appear to have little sense. breech member can be utilized in full and are not out tight against the rear wall of the cylindrical hole by the weighed by the disadvantages of a complicated design. 65 pressure of the powder gases. In a preferred embodi ment of the invention, however, the area for receiving According to the present invention, this object is solved in that the breech member is designed as a roller which can be swivelled about its longitudinal axis and the propellant body of a caseless cartridge has a wider rear section, in which is inserted a sealing sleeve whose 3 3,997,994 4 inwardly extending ?ange is in a contacting relation gas pressure to be utilized for opening the breech ar ship with the wall of the member which is ?xedly at tached to the barrel. A sealing sleeve of this type en sures especially good sealing. The wider rear section of the area serving to receive thepropellant body can 5 loading position, and for simultaneously cocking the trigger mechanism. In both single-shot and autoloading simultaneously serve as a compensation area for pre rangement, i.e. for placing the breech member in the weapons, it is especially advantageous if the drive means operate conjointly with the trigger mechanism in venting an excessively fast increase in pressue when a the nature of an open-bolt weapon, i.e. for the breech cartridge of this type is ignited. lf caseless ammunition is employed, it is also possible mechanism to be caught in the loading position after bility of arranging a priming compound in a side sur every shot, so that the breech member is either pre pared for the manual introduction of a cartridge or, in automatic weapons, to prevent a cartridge from being introduced into the hot barrel after a burst and being ignited there unintentionally as a result of the high temperature. In a further development of the present face of the propellant body of the caseless cartridge in invention, in the loading position, the breech member a location in which the priming compound can still be can be swivelled at least almost 90° relative to the ?ring position, and there is a magazine in which the car for a ?ring pin, pointing at right angles to the axis of the ?ring chamber, to be arranged in the area serving to receive the propellant body in the breech member. The employment of a ?ring pin of this type offers the possi in a supporting relationship with that portion of the bullet which extends into the propellant body. This tridges are arranged perpendicular to the direction of ?re and in which the respective forwardmost cartridge 20 is located opposite the ?ring chamber when the breech which ensures proper ignition of the cartridge. member is located in the loading position. The car In a further development of the invention, in addition tridges can be introduced into the ?ring chamber from to the ?ring position and the loading position, the provides the priming compound ,with a solid support, a magazine of this type either individually by hand or breech member can also be swivelled into an ejection automatically by means of a simple slide or lever ar position, in which the rear end of the ?ring chamber is free and the front end faces a passage provided in the 25 rangement. In this connection, either box-type or drum magazines can be employed. However in either case it receiver of the shoulder arm for an ejector. An arrange is advantageous to be able to arrange magazines of this type ?atly on the weapon, as the stack of cartridges is located in a plane which is parallel to the barrel of the bility for ejecting jammed cartridge cases or unignited cartridges. In this connection, the ejector can be a 30 weapon. In an advantageous embodiment of the pre ment of this type is practical with both case-type car tridges and caseless cartridges in order to offer a possi separate rod which can be inserted into the passage or means which are arranged within the passage. sent invention, a box-type magazine is employed which is arranged above the barrel and parallel thereto. This The arrangement for swivelling the firing chamber permits magazines having a relatively high capacity to can comprise a slide which is arranged in the longitudi be arranged very compactly. In addition, attachment to nal direction of the weapon and which engages the 35 the barrel also makes it easily possible to mount the barrel with the breech mechanism in a receiver, as the breech member positively in each of the positions of magazine can readily move along with the barrel. the slide. For this purpose, in an especially simple man ner the breech member can have an eccentric stub In a preferred embodiment of the invention, to eject engaging a control slot in the slide. In order to ensure cartridges from the magazine and introduce them into that the breech member always assumes the desired 40 the breech member a loading lever is pivotally mounted about an axis which is parallel to the swivel axis of the loading or ?ring position precisely, without requiring the slide to also assume a precisely desired position, in breech member, a shoulder of the loading lever engag ing the respective forwardmost cartridge in the maga a preferred embodiment of the invention the control zine from behind in one position and pushing the car slot has two end sections extending parallel to its direc tion of movement, one of the end sections de?ning the 45 tridge out of the magazine and into the breech member, located in the loading position, by means of a swivel ?ring position and the other of the end sections de?n ing the loading position, each of the end sections being motion. In order to automate the loading operation, it ‘ connected one with the other by means of a transition which causes the breech member to rotate. In this con is advantageous for the loading lever to operate con jointly with a cam which is connected with the slide nection, again, it is especially advantageous if, in the 50 which causes the breech member to swivel. In this loading and ?ring positions, the stub of the breech connection, the loading lever can be designed in sucha member assumes one respective position of two prefer manner that it retains the second forwardmost car tridge in its original position while the forwardmost cartridge is being inserted into the breech member and dicular extending through the swivel axis of the roller, 55 until the loading lever has returned to its initial posi ably symmetrically located positions in the direction of travel of the slide, located on both sides of the perpen and the transition between the two end sections is de tion, so that the retained cartridge can only then ad signed as a vee. With an arrangement of this type, the direction of movement of the stub of the breech mem vance to the forward most position. In a preferred em ber in its two end positions forms the largest angle with the direction of movement of the slide, which results in the highest possible degree of accuracy in positioning bodiment of the invention, however, the loading lever is slidably arranged in its longitudinal direction and is subjected to the force of an elbow spring, which retains it in a position of rest, in which the shoulder is posi tioned both beside and behind the forwardmost car tridge in the magazine. In this connection, the cam on the breech member. In single-shot weapons, the slide can be actuated the slide pushes the loading lever out of the position of manually. However it is preferable if the slide is con nected with drive means which are actuated by gas 65 rest, against the force of the elbow spring, and ?rst into that position in which the shoulder engages the for pressure. An arrangement‘ of this type is not only of wardmost cartridge from behind before the cam swivels interest for automatic shoulder arms, but even for sin the loading lever to push the cartridge into the breech gle-shot weapons, as in this manner it is possible for the 5 3,997,994 member and then releases the loading lever directly thereafter, permitting it to return to its position of rest, so that the shoulder of the loading lever passes by the forwardmost cartridge in the magazine as the loading ' lever swivels back into its position of rest. This arrange 6 In order to produce a gas-tight transition between front section 6 of the ?ring chamber and bore 5 of the barrel as well, the con?guration of breech member 4 is matched precisely to that of hole 3 in member 2. The pressure of the powder gases, acting on the shoulders ment provides the advantage that there is more time between section 6 and area 9, as well as between area available for moving the stack of cartridges and placing 9 and rear section 10 of the ?ring chamber, then presses that section of breech member 4 surrounding the outer end of front section 6 of the ?ring chamber the forwardmost cartridge in a position which is suit able for its introduction into the breech member. Since the stack of cartridges has a relatively high mass and ' the generally employed follower springs cannot be designed too strongly, a relatively long period of time is required for advancing the cartridges, so that the above described measure permits the rate of ?re of a weapon of this type to be increased or, with a high rate of ?re, ?rmly against that section of member 2 surrounding bore 5 of the barrel, thereby providing a gas-tight tran sition from the ?ring chamber to bore 5 of the barrel. It would be readily possible to employ a known ?ring pin arrangement, in which the firing pin strikes the rear end surface of the cartridge in the conventional man the dependability to be improved. ner, in a shoulder arm designed in accordance with the The ejection position of the breech member is advan present invention. An arrangement of this type would tageously located between the loading and the ?ring also be necessary with casetype cartridges. Cartridges positions, and, when the breech member is located in of this type would also be readily employable, as a the ejection position, the loading lever assumes an 20 deformation of the case head, caused by the cylindrical intermediate position, in which the shoulder thereof is wall of member 2, which could occur under the effect located outside of the path of a portion of the cartridge of the powder gases,-can be accepted. However in the which is to be ejected. illustrated practical example, which is equipped for The above discussed and other objects, features, caseless cartridges, a ?ring pin 21 is arranged in a hole advantages and embodiments of the present invention 25 22, extending perpendicular to the ?ring chamber, in will become more apparent from the following descrip breech member 4, so that ?ring pin 21 is aligned at tion thereof, when taken in connection with the practi right angles to the axis of the ?ring chamber. The tip of cal example shown in the accompanying drawings. The ?ring pin 21 is located opposite a side surface of pro features contained in ‘the description and drawings may pellant body 8 of a cartridge, having a rectangular cross be employed in other embodiments individually or in 30 section, located in breech member 4 in such a location any desired combination. In the drawings, that it is also located opposite that section of bullet 7 FIG. 1 shows the parts of an automatic ri?e of signi? which extends into propellant body 8. Embedded in cance for the invention, partially as a side view and propellant body 8 at this point is a priming compound partially as a section; and 23. This priming compound extends to the bullet, FIG. 2 shows a longitudinal section through the thereby being in a sort of supporting relationship with breech member, and the components adjacent thereto, the bullet, so that when struck by ?ring pin 21 the force of the ri?e shown in FIG. 1, in a larger scale. of ?ring pin 21 is fully utilized and ensures dependable Referring now to the drawings, wherein like refer ignition. With a rectangular cross section of propellant ence numerals designate like parts throughout the sev body 8, there is a second priming compound 23°on the eral views, the practical example shown therein is an automatic ri?e equipped for ?ring caseless cartridges. 40 side of propellant body 8 facing away from the ?ring pin, so that the cartridge can be inserted into the ?ring Located in a member 2 which is ?xedly attached to the chamber in each of the two attitudes possible with a barrel 1 is a cylindrical hole 3, whose axis extends rectangular cross section of the propellant body and perpendicular to the axis of the barrel and intersects ignition is always ensured. Firing pin 21 has a wider said axis of the barrel. Mounted in this hole in a roller head 24, which has a rearward tapered surface which is shaped breech member 4, which can be pivoted about in a contacting relationship with a corresponding mat the axis of hole 3. This breech member is illustrated in ing surface in hole 22 of breech member 4 under the the ?ring position in the drawing. In this ?ring position, force of ?ring pin spring 25 in the position of rest of the a ?ring chamber arranged in the breech member is in ?ring pin, thereby sealing the ?ring chamber. Firing pin alignment with the bore 5 of barrel 1. The ?ring cham 21 is struck out of this position of rest to ignite a car ber has a front section 6 for receiving the tip of the bullet 7, which projects from the propellant body 8 of a caseless cartridge inserted in the ?ring chamber. Propellant body 8 is located in an area 9 of the ?ring chamber which has a larger diameter than section 6, tridge by a hammer 26, which operates conjointly with members of a trigger mechanism 27 (FIG. 1) in the conventional manner, whereby the members of trigger mechansim 27 are, themselves, in an unillustrated op which serves to receive the bullet. The front end sur 55 erative connection with the trigger 28. face of propellant body 8 is in a contacting relationship with the shoulder formed by the transition between ‘ For loading the weapon, breech member 4 can be swivelled 90°into a loading position, in which the firing chamber in FIG. 2 is vertical and its rear end, contain area 9 and section 6 of the ?ring chamber. Area 9 for ing area 9 for receiving propellant body 8 of a car receiving propellant body 8 has a wider rear section 10, in which a cylindrical sealing sleeve 11 is inserted. The 60 tridge, faces upward toward a magazine 31, which is arranged above barrel 1 of the weapon and extends rear end of this sealing sleeve has an inwardly extend ing ?ange 12, which is in a contacting relationship with parallel to said barrel. Magazine 31 is a box-type maga the wall of member 2, which is ?xedly attached to the zine in which cartridges 32 are arranged in such a man ner that they are perpendicular to the direction of ?re, barrel, in the ?ring position. When a cartridge is ig nited, ?ange 12 is pressed ?rmly against the wall of 65 with the bullet tips 33 pointing toward the axis of the barrel. With breech member 4 in the loading position, member 2, which is ?xedly attached to the barrel, by the respective forwardmost cartridge 34 is aligned with the gases produced, thereby providing secure sealing of the ?ring chamber to the rear. the firing chamber in the breech member. 7 3,997,994 Breech member 4 is swivelled by means of a slide 41, which is slidably mounted in the longitudinal direction of the weapon and which is connected with unillus trated drive means, actuated by means of the gas pres sure by means of a rod 42. Slide 41 has a control slot 43, in which an eccentric stub 44, attached to the end surface of breech member 4, engages positively. Con trol slot 43 comprises two end sections 45 and 46, which extend parallel to its direction of travel and 8 tacting relationship with the rear end of slot 52, facing away from the direction of ?re. Loading lever 51 is arranged next to magazine 31, and one end of the load ing lever has a lateral shoulder 55 which is located in front of forwardmost cartridge 34 of magazine 31 in the above-described position, illustrated in FIG. 1. When speaking of the magazine and the cartridges contained therein, the expression “forward” refers to the direc tion of feed of the cartridges in the magazine, which is which are connected one with the other by means of a opposed to the direction of ?re. The forwardmost car V-shaped transition 47. As can be seen, stub 44, and tridge is thus that cartridge which is ready to be intro thus breech member 4, is retained in a de?ned position duced into the ?ring chamber. independently of the position of slide 41 as long as stub The end of loading lever 51 opposed to shoulder 55 44 is located in the area of one of end sections 45 or 46 has an arm 56, which operates conjointly with a cam 57 of control slot 43. Consequently, the breech member is 15 on slide 41, which serves to swivel breech member 4. positioned precisely, without slide 41 having to assume Cam 57 has a straight section 58, upon which arm 56 of precisely de?ned end positions. This characteristic of loading lever 51 rests in the indicated position and the above-described arrangement is of signi?cance which extends parallel to the direction of travel of slide especially if the loading operation is controlled by the 41. Arranged on the front end of straight section 58 is gas pressure, as the forces occurring, and consequently a nose 59 having a ?ank 60 which rises from straight the movements caused by these forces, can be subject section 58 and a forward end surface 61 which is per to considerable variations, which must not affect the pendicular to the direction of movement. operation of the weapon. As long as arm 56 of loading lever 51 rests on straight In the arrangement according to FIG. 1, stub 44 of section 58 of control cam 57, it is retained in a center breech member 4 is located in rear end section 45, with 25 position of rest, which is illustrated in FIG. 1. As men the breech member being retained in the ?ring posi tioned above, this is the position in which a shot can be tion. When slide 41 is now moved rearwardly by the gas ?red. When a shot is‘ ?red, slide 41 is moved rearwardly pressure after a shot is ?red, projection 48 on the upper under the in?uence of the powder gases which develop edge of control slot 43, which belongs to V-shaped therefrom. In this connection, nose 59 of cam 57 passes transition 47, strikes stub 44 and drives it along rear 30 by arm 56 of loading lever 51, causing loading lever 51 wardly. Consequently, breech member 4 performs a to ?rst perform a brief clockwise swivel motion before counterclockwise rotation, during which stub 44 trav it is released by nose 59 of cam 57 and can then be els through the V-shaped transition until the stub enters swivelled counterclockwise by elbow spring 62 without front end section 46 of control slot 43. Breech member hindrance. This lifts shoulder 55 on loading lever 51 so 4 has then performed a 90°rotation and has been 35 far that is positioned behind the end of forwardmost placed in the above-mentioned loading position. When cartridge 34. If slide 41 is then moved back into the the slide travels forward, the rotation is performed in initial position shown in FIG. 1 by means of a spring the opposite sense. Since both end sections 45 and 46 which is tensioned by its return movement, for exam of control slot 43 are aligned one with the other, stub ple, end surface 61 first comes into a contacting rela 44 of breech member 4 assumes two end positions, 40 tionship with arm 56 of loading lever 51. The arrange located symmetrically to a plane extending through the ment is designed in such a manner and elbow spring 62 pivot axis of the roller and perpendicular to the direc is dimensioned in such a manner that loading lever 51 tion of travel of the slide and the direction of end sec is ?rst pushed into slot 52 without being swivelled. This tions 45 and 46. As can further be seen, the motion of guides shoulder 55 from its lateral position next to breech member 4 is caused exclusively by control slot 45 forwardmost cartridge 34 into a position in which it 43, and the breech member is retained in its end posi engages said forwardmost cartridge from behind. When tions exclusively by the positive engagement of stub 44 journal stud 54 has come into a contacting relationship - in control slot 43. Since the axis of the ?ring chamber intersects the axis of the roller forming the breech with the front end, in the direction of ?re, of slot 52, the end surface causes loading lever 51 to swivel clock member, the forces occurring as a result of the gas 50 wise, thereby moving shoulder 55 of the loading lelvel pressure when a cartridge is ?red act symmetrically toward breech member 4. During this sequence, shoul upon the breech member, so that there are no torques der 55 drives forwardmost cartridge 34 out of the mag whatsoever and no signi?cant forces are required for azine and inserts it into the ?ring chamber in the retaining the breech member. Consequently, no com breech member, which is placed in the loading position plicated locking means are required for the breech 55 during the rearward movement of slide 41. The height member either. of nose 59 is dimensioned in such a manner as to ensure A loading lever 51, which is mounted slidably in the complete insertion of the cartridge. When arm 56 of longitudinal direction of magazine 31 in a slot 52, which is parallel to magazine 31, in a stationary bearing loading lever ‘51 has reached the crown of nose 59, it is released longitudinally and can therefore be moved member 53 and which is mounted pivotally about an axis which is parallel to the axis of breech member 4, serves to introduce cartridges 32 from magazine 31 into the ?ring chamber of breech member 4, which is 62. However during this sequence the loading lever still remains swivelled clockwise relative to the position located in the loading position. An elbow spring acting rearwardly to its initial position again by elbow spring illustrated in FIG. 1. However lateral shoulder 55 as sumes the attitude illustrated in FIG. 1 relative to mag on loading lever 51 and on bearing member 53 at 65 azine 31, thereby permitting unimpeded advance of the tempts to swivel the loading lever counterclockwise and retain it in the position illustrated in FIG. 1, in which journal stud 54 of the loading lever is in a con next cartridge into the forwardmost position at this time. Moreover, it can swivel into the position of rest illustrated in FIG. 1 without hindrance through the 9 3,997,994 magazine and the forwardmost cartridge when arm 56 10 slides along inclined ?ank 60 of cam 57 as slide 41 member 4 has been swivelled 45°into the above described ejection position, so that shoulder 55 of the continues moving forward. The above described cycle is repeated with every shot. loading lever does not cover the rear end of the ?ring chamber in the breech member when the breech mem In the illustrated weapon, the movement of slide 41 is ber is in the ejection position and, consequently, does further utilized to actuate a shot counter 71, which not prevent the ejection of a cartridge, as would be the case if it were left in that position which it assumes operates conjointly with the trigger mechanism in an unillustrated manner. For this purpose, the slide has an arm 72, which comes into engagement with a switching member of the shot counter every time the slide moves ‘ back and forth. Moreover, the slide can also serve to cock hammer 26 of the trigger mechanism in an unil lustrated manner. It is practical to design the trigger immediately after the introduction of a cartridge, i.e. in which shoulder 55 is located directly adjacent to the periphery of breech member 4. The purpose of straight section 58 of cam 57 is thus to temporarily bring load ing lever 51 into an intermediate position, in which it does not hinder the ejection of a cartridge from the ?ring chamber. Nevertheless, care has been taken to catches slide 41 in a rearward position, in which ham ensure that loading lever 51 does not have to travel mer 26 is cocked, breech member 4 is in the loading excessive distances and complicated switching means position and loading lever 51 is positioned to the side of do not have to be provided in order to move the loading and behind forwardmost cartridge 34. When trigger 28 lever differently when slide 41 moves forward or back is pulled, slide 41 is then released, permitting it to move ward. It is obvious that an intermediate position of the to its forwardmost position, whereby it ?rst shifts load 20 breech member would also have to be provided if the ing lever 51 forwardly in the above-described manner, arrangement according to the present invention were then swivels it for the introduction of a cartridge into to be employed with autoloading weapons utilizing breech member 4, then swivels the breech member into case-type cartridges, in order to permit ejection of the mechanism in such a manner that after every shot it the ?ring position, and ?nally releases the hammer for empty cartridge cases. ignition of the cartridge. After ignition, the above-men 25 Obviously, many modi?cations and variations of the tioned parts are then returned to the initial position in present invention are possible in the light of the above teachings. It should therefore be understood that within sponds to that of an open-bolt weapon, and offers the the scope of the appended claims, the invention may be advantage that there is no cartridge in the closed ?ring practiced otherwise than a speci?cally described. chamber with the weapon in a state of rest. Especially 30 Having thus fully disclosed our invention, what we the above-described manner. This behaviour corre with caseless cartridges, it would otherwise be quite claim is: ' possible for a weapon that has been heated up from 1. A shoulder arm having a rigidly attached barrel ?ring to result in spontaneous ignition of a cartridge and capable of ?ring a'cartridge having a primer, espe located in the ?ring chamber if, as is common in the cially a ri?e, the shoulder arm having a breech member case of closed-bolt weapons, the cartridge has been 35 which can be swivelled about an axis which is perpen ready to ?re in the closed ?ring chamber for an ex dicular to the axis of the barrel for loading and which tended period of time. contains a ?ring chamber which is in alignment with When stub 44 on the end surface of breech member said barrel in its ?ring position in which it is fully closed 4 travels through V-shaped transition 47 of control slot to the rear, further having a ?ring pin which upon trig 43 in slide 41, the breech member brie?y assumes a 40 gering hits the primer of the cartridge to be ?red by the de?ned position located between the ?ring position and the loading position. In the illustrated practical ?re arm, further having an, arrangement for swivellin g said breech member out of said ?ring position and into example, this intermediate position is employed as an , a loading position, in which said ?ring chamber is ac~ ejection position, which can be required, for example, cessible for the introduction of the cartridge, in which for ejecting cartridges which fail to ?re as a result of an 45 said breech member is designed as a roller which can ammunition defect. In this intermediate position, in be swivelled about its longitudinal axis and which is arranged in a cylindrical hole in a member which is which breech member 4 is swivelled 45° relative to the ?ring position illustrated in FIGS. 1 and 2, the ?ring ?xedly attached to said barrel and whose wall directly closes said ?ring-chamber when it is located in the chamber is in alignment with a passage 81 in member 2; passage 81 is then adjacent to front section 6 of the 50 ?ring position, said roller being retained in its respec tive position by means of the arrangement for swivel ?ring chamber. This passage serves as a guide foran ling'said breech member. ejector which, in the simplest manner, can be a rod which is attached to the ri?e in such a manner that it 2. The shoulder arm set forth in claim 1, in which the can be removed and inserted into this passage. ‘In the axis of said ?ring chamber intersects the axis of said illustrated practical example the tube 82 which follows 55 roller which forms said breech member. passage 81 contains a ram 83 which is attached to the 3. The shoulder arm set forth in claim 1, in which said front end of a spiral hose 84 guided in said tube. Spiral ?ring chamber is designed for receiving caseless car tridges and the area for receiving the propellant body hose 84 can be slid within tube 82 together with ram 83 through unillustrated means and, with the breech mem has a wider rear section, in which is inserted a sealing ber in the ejection position, can be pushed through the 60 sleeve whose inwardly extending ?ange is in a contact ?ring chamber. That side of member 2 facing away ing relationship with the wall of said member which is ?xedly attached to said barrel. from passage 81 has a recess 85 into whose area the rear end of the ?ring chamber in breech member 4 4. The shoulder arm set forth in claim 3,,in which a ?ring pin, pointing at right angles to the axis of said free for the ejection of a cartridge. Magazine 31 with 65 ?ring chamber, is arranged in said area of said breech cartridges 32 and shoulder 55 of loading lever 51 also member which serves to receive said propellant body. 5. The shoulder arm set forth in claim 1, in which said engage this recess. The loading lever has already reached the position illustrated in FIG. 1 when breech breech member can be swivelled into an ejection posi opens, so that the rear end of the ?ring chamber is also 11 3,997,994 tion, in which the rear end of said ?ring chamber is free and the front end is opposite a passage for an ejector, said passage being located in said member which is ?xedly attached to said barrel. 6. The shoulder arm set forth in claim 1, in which said arrangement for swivelling said breech member com 12 respective forwardmost cartridge is located opposite said ?ring chamber when said breech member is lo cated in the loading position; and in which a loading lever is pivotally mounted about an axis which is paral lel to the swivel axis of said breech member, a shoulder of said loading lever engaging said respective forward prises a slide capable of occupying a plurality of posi tions which is arranged in the longitudinal direction of most cartridge in said magazine from behind in one the weapon and which engages said breech member positively in each of the positions of said slide. 7. The shoulder arm set forth in claim 6, in which said zine and into said breech member, located in the load ing position, by means of a swivel motion. 16. The shoulder arm set forth in claim 15, in which said l