MACHINE-PISTOL FOR CARTRIDGES OF DIFFERENT TYPES

Abstract: The machine-pistol with an obturator (12) which extends longitudinally, so to surround with a cylindrical or semicylindrical portion, in its putforward shooting position, a longitudinal length of the barrel (13). The obturator is thus suitable both for the axial and for the radial or piezoelectric percussion. By optionally mounting in the weapon the obturator and the barrel of the desired configuration, the weapon is able to use different types of cartridges, both with case and caseless.

Description: MACHINE-PISTOL FOR CARTRIDGES OF DIFFERENT TYPES The present invention relates to an improved machine-pistol for cartr dges of different types. It is known that a portable weapon of the type defined as a "machine-pistol" is usually designed and manufactured on the basis of the characteristics of one, and only one, existing type of standard cartridge. The consequence of this custom if that the machine pistol has use characteristics rigidly tied to those of the only cartridge type it was manufactured for. The design efforts carried out to date in the field of the machine guns led to accomplishments all inspired to the principle of minimum weight and of minimum overall dimensions, but with all of them being only pivoted on nine-gauge Parabellum cartridge with case. This cartridge allows achieving an extremely si ple weapon, thanks to the adoption of the known system of mass shutting. However, also caseless cartridges exist, which, as compared to the cartridges of traditional Parabellum type with case, display the following basic advantages: - they are lighter (about 60%) and hence, with their weight being the same, the number of cartridges of the individual supply can be increased by about 67%; - they have an exit speed higher by about 20% than of the traditional cartridges, and thus they hit the target with a greater penetration energy at the useful shoot i ng distance; - they eliminate the bothersome need of recovering the cases at shooting end; - by being of one piece only, they are simpler; - they are cheaper; - they allow the shoot ng to be carried out in the absolute absence of the typical drawbacks caused by the ejection of the cases, and hence in full safety, also being on board of any civil and ilitary (terrestrial, maritime, air) transport means, and without damages, alfunctionings or the immobilization being caused of the transport means, in particular of the aircrafts, wherein it is a matter of flight safety: - they allow no traces to be left in the postings the shooting was carried out in. For these cartridges, to date no machine pistols have been developed, which are endowed with the c aracteristics of simpleness and of minimum weight and overall dimensions which are typical of the machine pistol for the above mentioned nine-gauge Parabellum cartridge. The purpose of the present invention is thus to provide a machine pistol which is easily convertible for the optional use of different cartridge types, with case and caseless, while maintaining c aracteristics of structural simpleness and of mini um weight and overall dimensions. Wit in the scope of this purpose, the invention wants furthermore prov de a machine-pistol convertible for the use both of axial-percussion and radial- percussion cartridges, besides of piezoelectric-priming cartridges. In view of these purposes, according to the invention an improved mac ine-pistol for different types of cartridges is proposed, which comprises a barrel provided with a cartridge c amber for housing a cartridge in its firing position, a magazine for feeding the cartridges, a percussion de ice for priming the firing, and an obturator movable relatively to the barrel for the actuation of said percussion device, characterized in that the obturator is provided ith a longitudinal portion defining an at least semicylindrical chamber, surrounding, for a certain longitudinal length, the barrel, with a small radial clearance, in the put-forward position for the actuation of the percussion device. Advantageously, such a type of configuration of the obturator and of the barrel allows the axial percussion or the radial percussion, as ell as the piezoelectric priming to be optionally achieved, in as much as the percussion device can be positioned in such a way that it can be optionally actuated by an axial portion of the obturator or by a portion able to surround, radially from the outside, the barrel. In other terms, the obturator and the barrel of a pistol according to the invention, even if they always show the same basic configuration, are different, from time to time, only as regards the percussion device, or the piezoelectric priming device mounted on them. By optionally mounting on the weapon the obturator and the barrel of the specific desired configura ion, the weapon is fitted to the use of several cartridge types. The general outer structure of the weapon remains the same for all of the various cartridge types. Further details and advantages of a machine pistol according to the invention result from the follo ing disclosure, made with reference to preferred forms of practical embodiment of the invention illustrated in the hereto attached drawings, wherein: Figure 1 is a partly cutaway view of a machine pistol according to the invention; Figure 2 is a partly cutaway axial view of the barrel and of the obturator in correspondence of the firing zone of a pistol according to the invention for case cartridges, for example of the nine-gauge Parabellum type, for axial percussion; Figures 3, 4 and 5 are sectional views, like that of Figure 2, of machine pistols according to the invention for caseless cartridges of advanced type, for radial percussi on; Figure 6 is a sectional view like that of Figures from 2 to 5, but relat ng to a machine pistol according to the invention for caseless cartridges, for axial percussion; Figure 7 is a transversal section according to path VII-VII of Figure 6; Figure 8 shows a detail of a variant. A machine-pistol 10 according to the invention appears, in its whole, as shown in Figure 1. In the cutaway portion, the magazine 11 is recognizable, and the particular shape is visible of the obturator 12, as well as of the barrel 13, which constitute a peculiarity of the invention, as it shall be esposed hereunder in greater detail. The obturator 12 is provided in fact with a longitudinal portion 12a which defines a cylindrical or semic lindrical chamber 14, which surrounds for a certain longi udinal length the barrel 13 with a small radial clearance 15, in the put-forward position for the actuation of the percussion device, to which position it is pushed by a recovery spring 16. The particular configuration of the barrel 13 and of the obturator 12 allo s various percussion devices to be installed, which may be of the axial type or of the radial type for the firing of case cartridges, or also of caseless cartridges. In Figure 2, the case is shown of axial percussion for a cartridge 17 with case, of Parabellu type, e.g., of 9-mm gauge, of known type. The firing of cartridge 17 takes place on percussion in the axial direction of the primer 18, mounted in the rear portion of case 19. The percussion takes place by means of the percussion pin 20, integral with the obturator 12 in the portion of this latter opoosite to the barrel 13. The percussion 20 is furthermore positioned lined-up with the axis of barrel 13. In the primer 18, the priming mixture 21 is housed, which causes the firing of the gun powder 22. The increase in pressure inside the case 19 causes the separation of the bullet 23 from the case 19. The bullet 23 continues then its run inside the barrel 13, unti l it is shot outside this latter. At the moment of the increase in pressure inside the case 19, this expands and is retained by friction inside the cartridge chamber 24 of the barrel 13, producing the ight sealing of the high-pressure gases. When the bullet 23 exits the barrel 13, the pressure decreases correspondingly and the residual pressure inside the barrel 13 pushes rearwards the case 19 and then the obturator mass 12, loading the recovery spring 16. In its rearwards run, ith the obturator 12, the case 19 is e ected from the weapon by the extractor 25. When the obturator 12 returns forward to ards the cartridge chamber 24 of the barrel 13, it draws from the magazine 11 a new cartridge 17 and the cycle can automatically continue, according to the position of a special shooting selector, for single shot or for burst shooting, of a ger_se known type. In Figure 3, the case is shown of radial percussion for a caseless cartridge 26 of advanced type, of known type. The firing of cartridge 26 takes place on percussion in the radial direction of a zone 27 of the side surface of bullet 28. The percussion occurs by means of a percussion pin 2o, radially guided inside the barrel 13 towards the interior of the cartridge chamber 24. Inside an inner chamber 30 of the side surface of the bullet 28, the priming mixture 31, which causes the firing of the gun powder 32, is housed along the whole circumference. The increase in pressure inside the bullet 28, in correspondence of the hollow wherein the gun powder 32 is contained, causes the bullet 28 to move inside the barrel 13, hile a cylindrical appendix 12b of the obturator 12, coaxial with the barrel 13, by penetrating, for a certain length, the cartridge chamber 24 of the barrel 13, produces the tight sealing of the high-pressure gases. The mass inertia of obturator 12 makes this latter move rearwards, under .the thrust applied by the high- pressure gases, with a certain time delay relatively to the motion of the bullet 28, so that the tight sealing of the gases in secured. When the bullet 28 exits the barrel 13, the obturator mass moves rearwards and loads the recovery spring 16. When the obturator 12 returns towards the cartridge chamber 24 of the barrel 13, is draws a further bullet 28 from the magazine 11 and the cycle can automa ically continue, according to the position of a suitable shooting selector, for single shot or for burst shooting, of a ger_se well-known type. In case of missed shot, due to any causes, the manual putting rearwards of obturator 12 causes the ejection of the unexploded cartridge, by means of the extractor 33 and of the spring ejector 34. The percussion pin 29 is housed in correspondence of the cartridge chamber 24 of the barrel 13 inside a seat 35 provided in the wall of barrel 13 and is provided with a retainer split ring 36 as well as with a collar 37 acting as a guide for it inside the seat 35. The percussion pin 29, which has the shape of a pin element, is subject to the action of a spring 38, e.g., a Bellevi lle spring, which tends to push the percussion pin 29 radially towards the outside, to keep its radially inner end out of the cartridge chamber 24, and which acts on collar 37. The percussion pin 29 has its radially outer end rounded, to faci litate the percussion motion by an actuator device, wh ch can be of various types, and which is integral with the obturator 12. In Figure 3, such a device is constituted by a longitudinal groove 39 in the portion 12a of the obturator 12, having an inclined length 40 which, owing to the forward motion of the obturator, produces the radial percussion motion of the percussion pin 29 n the end step of the forwards motion of the obturator in its shooting position. In the example of Figure 4, the actuator device is constituted by a cylindrical roller 41, rotatably housed inside a hollow 42 of the portion 12a of the obturator 12 and is supported by a pivot 43 borne by the obturator 12, with its axis being perpendicular to the axis of the percussion pin. The mutual position is such that the engagement of the roller 41 with the end of the percussion pin 29 during the for ards motion of the obturator 12 involves the radial percussion motion of the percussion p n 29. In the embodiment of Figure 5, the actuator device is constituted by a bell crank 44, hinged onto the portion 12a of the obturator 12 and movable on a plane passing through the axis of the barrel 13 around a pivot 45 borne by the obturator 12. An arm of the bell crank 44 cooperates with a stop tooth 46, radially integral with the barrel 13, during the last length of the forwards motion of the obturator 12, in such a way that the other arm of the bell crank 44 performs the percussion movement of the percussion pin 29. This practical embodiment has the advantage that the wear of the guide surfaces of the percussion pin 29 and of the barrel 13 are eliminated, in as much as the direction of the actuation force results aligned with the axis of the percussion pin 29. Another advantage of this embodiment consists in that thanks to the shape of the bell crank 44, hinged in its central por ion, obtaining is possible different and suitable mutual ratios of the lengths of the two arms of the bell crank, it being possible to optimize the ratios for the highest functionality of the device according to the type of radial percussion cartridge used. In the embodiment of Figure 5, the vertical arm of the bell crank 44 is shorter than the horizontal arm. In such a way, the essential condition to the functional purposes is accomplished, that the necessary and sufficient vertical stroke of the percussion pin 29 is obtained by a very short horizontal stroke of the obturator 12. In as much as the actuation of the percussion pin 29 takes place during the end portion of the stroke of the obturator 12, also the shooting safety is accomplished: the f ring only takes place when the cartridge chamber 24 is completely obturated by the cylidrical appendi 12b of the obturator 12. In the forms of practical embodiment of Figures 3 to 5, when the obturator moves rearwards, the spring 38 faci litates the moving rearwards of the percussion pin 29. This movement can however take place without any spring aids, by the effect of the only gas pressure in the cartridge chamber 24, or because of the introduction of a new cartridge into the cartridge chamber 24. Another peculiarity of the percussion pin 29 is that of having at least three cylindrical elements, which act as a guide and as a "labyrinth" for the tight sealing of the gases evolved nside the cartridge chamber 24 of the barrel 13. Advantageously, the split elastic ring 36, once being mounted inside the special ring housing of the seat 35, accomplishes a reliable and easy fastening of the percussor pin 29 to the barrel 13. In Figure 6, the case is shown of the axial percussion of a caseless cartridge 46 of advanced type, of known type. The firing of the cartridge 46 occurs at the time of the percussion in the axial direction of the disk-shaped primer 47 of the cartridge by means of the percussion pin 48, integral with the appendix 12b of the obturator 12, and shaped as a protrusion of said appendix 12b, the axis of which is longitudinally lined up with the axis of the barrel 13. The primer 47 has its outer perimeter fastened inside the hollow of the bullet 49 which contains the gun powder 50. The primer 47 contains centrally in its inter or the pri ing mixture 51 which primes the firing of the gun powder 50. The sequence of t e motions of the bullet 49 and of the obturator 12 during the shooting takes place as previously described. In case of issed shooting, the ejection of the unexploded bullet 49 occurs again as previously disclosed. In the variant of igure 8, the cylindrical appendix 12b of the obturator 12 has a hollow configuration throughout its length. In this case, the extractor and the ejector shall be structurally arranged in a different way relatively to the previously disclosed forms of embodi ent . The hollow structure of the appendix 12b allows the effect of tight sealing of the gases at the firing time to be i proved, because the follow appendix 12b, by expanding due to the effect of the high gas pressu e at the firing time, comes in contact with the inner wall of the barrel 13. When the pressure decreases, during the motion of the bullet inside the barrel 13, the expansion of the hollow appendix 12b decreases and the contact with the barrel 13 ends, so that the obturator 12 can freely start its return stroke. It wi ll be understood from the foregoing how a machine pistol according to the invention is nurposely designed for the alternative use of at least two types of cartridges, having different use character stics, e.g.: - case cartridges, of traditional gauge n ne Parabellum type, with axial percussion; - caseless cartridge, of nine gauge special advanced type, ith a ial percussion, or radial percussion, or with piezoelectric pri ing. The subject machine pistol shows the advantage of being si ple, because uses, for both of the above-said cartridges, the mass-shutting system, as well as flexible, because it is in compliance with the modern Armies' trend of being equipped, as far as possible, with weapons endowed with multi -use characteristics. Some examples have been supplied of configuration of the percussion device, installed on the barrel and/or on the obturator, but it should be understood that the installing percussion devices of any different types is possible, the type known as the device for piezoelectric priming being included, for cartridges ith case, as well as for caseless cartridges. By the machine pistol of the present invention it is possible to be equipped, in the first place, with a bimodal weapon in terms of multi-use, and in the second place, with an extremely cheap weapon, quite as a function of these character stics, in addition to all of the advantageous consequences due to the minimum number of spare parts to be kept in store. It should be observed that the configuration of the obturator and of the barrel according to the invention produces also a considerable effect of dampening of the motion of the obturator mass, and of cooling of the parts of the weapon undergoing heat stress, during the shooting, by the effect of the closeness of the parts and of the forced air motion produced by the reciprocating motion of the obturator. Furthermore, the structure according to the invention ad antageously constitutes a closed and tightly sealed system for the protection of the percussion devices and of the piezoelectric-priming devices. The accomplishment of the above said tightly sealed protection system is of basic importance to the purpose of the reliability of the weapon, the use of which is foreseen to take place both under normal conditions and, and above all, under the extreme conditions as pro ded by the N.A.T.O. for a war weapon: life, precision, falls, barrel obstruction, prolonged immersion in water, in mud, exposure to rain, sand and in moist high-temperature and low-temperature environments.

Claims: C __l. _ a _2__.E_ s 1. Improved machine-pistol for cartridges of different types, which comprises a barrel provided with a cartridge chamber for housing a cartridge in its firing position, a magazine fo feeding the cartridges, a percussion device for priming the firing, and an obturator movable relatively to the barrel for the actuation of said percussion device, characterized in that the obturator is provided with a longitudinal portion defining a.i at least semicylindrical chamber, surrounding, for a certain longitudinal length, the barrel, with a small radial clearance, in the put-forward position for the actuation of the percussion device. 2. achine pistol according to claim 1, characterized in that the obturator is provided with a cylindrical appendix suitable to penetrate the barrel under gas-tight conditions. 3. Machine pistol according to claim 1 or 2, cha acterized in that the percussor pin is integral with the said appendix. 4. Machine pistol according to claim 1 or 2, characterized in that the percussion pin is positioned inside the wall of the barrel and is radially movable relatively to it, under the action by an actuator device integral with the obturator. 5. Machine pistol according to claim 4, characterized in that the actuator device is constituted by an inclined plane of a longitudinal groove of the obturator cooperating with the percussion pin during the end phase of the forward motion of the obturator in the shooting position. 6. Machine p stol according to claim 4, characterized in that the actuator device is constituted by a cylindrical roller rotatably supported by the obturator inside a hollow thereof, with its axis being perpendicular to the axis of the percussion pin. 7. Machine pistol according to claim 4, chaτ-a-c-teπ * zed in that the actuator device is constituted by a bell crank hinged onto the obturator and movable on a plane passing through the axis of the barrel, as ell as by a stop tooth for said bell chank integral with the barrel, in such a position as to engage the bell crank in correspondence of the end length of the forward stroke of the obturator. 8. Machine pistol according to claim 7, character zed in that the bell crank has arms of different lengths, with preferabl the shorter arm being that cooperating with said stop tooth. 9. Machine pistol according to one of claims from 4 to 8, characterized in that the percussion pin comprises a pin element radially movable relatively to the barrel inside a seat provided inside said barrel, and provided with a retainer split ring as well as with a a collar acting as a guide for it inside the seat. 10. Machine pistol according to claim 9, characterized in that inside said seat a spring is provided, which acts in the sense of radially pushing the percussion pin towards the outside. 11. Machine pistol according to claim 9, characterized in that the collar is movable inside said seat under gas-tight conditions. 12. Machine pistol according to claim 1, characterized in that it comprises a piezoelectric priming device. 13. Machine pistol according to claim 2 or 3, charac erized in that said appendix is provided with an extractor, as well as with a spring ejector. 14. Machine pistol according to one of claims 2, 3 or 13, characterized in that said cylindrical append x is hollo throughout its length. 15. Improved machine pistol according to the preced-ing claims, and according to as disclosed and i llustrated, for the alternative use with cartridges with case, and with caseless cartridges.

Inventors: MARZOCCO ALESSANDRO, MARZOCCO, ALESSANDRO
Applicants: SOCIMI, SO.C.I.MI. SOCIETA COSTRUZIONI INDUSTRIALI MILANO
Application year: 1987
Main classification: F41C11
IPC codes: F41A3, F41A15, F41A19