PLASTIC CARTRIDGE CASE FOR ARTILLERY SHOT

Abstract

The invention relates to ammunition, in particular to the construction of composite artillery cartridge cases and can find wide application in the production of general cartridge cases with plastic main body for artillery shots with split-cartridges and unitary loading. The abovementioned cartridge case contain a metal bottom and a plastic body fixed to it, centrally in the metal bottom is made a cylindrically shaped protrusion in which a stepped hole is formed, in which a primer for artillery cartridges is mounted by means of a threaded connection, as at the metal bottom of a plastic main body is placed a mounting ring. In the metal bottom 1 at least two blind holes are formed, with a diameter equal to 0.1 to 0.25 of the diameter of the metal bottom 1 and a depth of 0.35 to 0.5 of the thickness of the bottom of the metal bottom 1, and in the bottom of the plastic main body 2 are formed at least two protruding, fixing elements 6.

Claims

1. The composite artillery cartridge case containing a metal bottom and a plastic body fixed to it, centrally in the metal bottom is made a cylindrically shaped protrusion in which a stepped hole is formed, in which a primer for artillery cartridges is mounted by means of a threaded connection, as at the metal bottom of a plastic main body is placed a mounting ring, and between the bottom of the main body and the lower surface of the mounting ring is placed a sealing pad, characterized in that in the metal bottom /1/ at least two blind holes are formed, with a diameter equal to 0.1 to 0.25 of the diameter of the metal bottom /1/ and a depth of 0.35 to 0.5 of the thickness of the bottom of the metal bottom /1/, and in the bottom of the plastic main body /2/ are formed at least two protruding, fixing elements /6/, with a diameter equal from 0.1 to 0.25 of the diameter of the metal bottom /1/, as the blind holes and the protruding fixing elements correspond in shape, size and location, whereby in the convex part of the metal bottom /1/ threaded sector is made, the maximum diameter of the thread in its protruding part D, the clamping fastening ring /4/ on the metal bottom /1/ is in the range of 0.3 to 0.42 of the minimum diameter D, and the diameter of the hole d for mounting the primer for artillery cartridges is made with a size in the range from 0.42 to 0.68 of the minimum diameter D of the protruding threaded part of the metal bottom /1/.

2. A composite artillery cartridge case according to claim 1, characterized in that the outer diameter of the clamping threaded ring (4) refers to the diameter of the metal bottom (1) under the flange and is from 0.66 to 0.87, and its thickness is determined from 0.35 to 0.7 of the thickness of its bottom.

3. A composite artillery cartridge case according to claim 1, characterized in that the clamping threaded ring /4/ has a central threaded hole with a size corresponding to the threaded sector made on the convex cylindrical surface of the metal bottom /1/ with diameter D, radially in the clamping threaded ring /4 at least two holes are made /5/.

4. A composite artillery cartridge case according to claim 1, characterized in that the outer radius R adjacent to the forming on the side surface of the plastic main body /2/ with its bottom is made with a radius of 0.6 to 1.3 of the inner radius of the metal bottom /1/.

5. A composite artillery cartridge case according to claim 1, characterized in that an antistatic graphite coating is applied to the inner surface of the plastic main body (2).

6. A composite artillery cartridge case according to claim 1, characterized in that the main body (2) of the cartridge case is made of plastic, which contains an antistatic substance.

7. A composite artillery cartridge case according to claim 1, characterized in that a protective zinc-phosphate or chromium coating with a thickness of not less than 7 m is applied to the metal parts of the cartridge case.

8. A composite artillery cartridge case according to claim 1, characterized in that the main body (2) of the cartridge case is made of low pressure polyethylene (high density), obtained by suspension and gas phase methods, by polymerization of ethylene at low pressure.

Description

DESCRIPTION OF THE DRAWINGS

[0045] An example of a composite cartridge case, object of the invention is presented in the drawings accompanying the description, where:

[0046] FIG. 1General view of a composite artillery cartridge case, object of the invention.

[0047] FIG. 2General view of a plastic main body of a composite artillery cartridge case in a particular embodiment, object of the invention.

EXAMPLE EMBODIMENT OF THE INVENTION

[0048] A composite cartridge case according to the invention consists of a metal bottom 1, with a centrally threaded socket with an internal thread, in which a primer for artillery cartridge is placed, in which a plastic main body 3 is fixedly mounted at the metal bottom, located at the bottom of the main body 3 elastic sealing pad 2 and compression ring 4.

[0049] On the inner surface of the bottom of the metal bottom 1 are formed at least two, preferably four blind holes, with a diameter equal to 0.18 of the diameter of the metal bottom, the depth of the holes is 0.42 of the thickness of the bottom of the metal bottom 1.

[0050] The maximum diameter R of the thread in the convex part of the metal bottom 1, shaped for the purpose of mounting the compression ring 4 in the metal bottom 1 is 0.35 of the minimum diameter d of the thread for winding the explosive device, in this case-a primer for artillery cartridges, and the diameter of the screw hole of the primer for artillery cartridges is within 0.55 of the minimum diameter D of the convex threaded part of the metal bottom 1.

[0051] At least two, preferably four convex cylindrical surfaces 6, with a diameter equal to 0.18 of the diameter of the metal bottom 1, are made on the bottom of the plastic main body 3. The protrusions corresponding in shape, size and location of the blind holes formed on the inner profile of the metal bottom 1.

[0052] According to a preferred embodiment, the plastic main body 3 of the cartridge case is made of plastic, which contains an antistatic substance, ensuring the prevention of electric shock from static electricity when rubbing the elements inside the cartridge case (bags with discharging charge) in the walls of the cartridge case.

[0053] Preferably, the main body of the cartridge case 3 is made of high density polyethylene, obtained by suspension and gas phase methods, by polymerization of ethylene at low pressure.

[0054] It is appropriate to specify that the added antistatic additive to the plastic of the main body 3 migrates to the surface of the main body, due to the relative incompatibility with the polymer, creating a conductive layer by absorbing atmospheric moisture.

[0055] The antistatic additive can be used in the production of the main body 3 by various manufacturing methods, such as injection molding or casting, and its application has an instantaneous and long-lasting effect, long-term antistatic properties, low humidity efficiency, but also more pronounced low resistance obtained through the use of amine-based substances.

[0056] During designing process of the main body 3 with antistatic additive, the process temperature should not exceed 250 C. in order to avoid degradation or deterioration of the properties of the antistatic layers, which may be affected by other components in the layer, for example other migrating additives, such as glidants, leading to greasy surfaces and altering the antistatic effect.

[0057] In one embodiment of the cartridge case, the clamping thread ring 4 according to its outer diameter towards the diameter of the metal bottom 1, in particular below the flange, is equal to 0.77 and the thickness equal to 0.55 from the thickness of its bottom, and these parameters provide the necessary hardness of the compression ring 4, respectively provides hardness and integrity of the compound of the plastic main body 3 of the cartridge case with the metal bottom 1. Such hardness is especially necessary in the conditions of vigorous extraction of the fired cartridge case at small angles of elevations on the barrel, when the energy of the recoil devices of the gun is significant, and as a consequencethe extraction speed of the fired cartridge case reaches its maximum value.

[0058] The compression ring 4 is made with a central threaded hole, with a diameter D, defined so that the compression ring 4 is screwed to the convex cylindrical surface with a diameter D of the metal bottom 1.

[0059] At least two, preferably four technological openings 5 are formed radially on the clamping ring 4, intended for clamping the plastic main body 3 to the metal bottom 1.

[0060] It is suitable the radius of connection of the forming on the outer cylindrical surface R of the compression ring 4 with its bottom surface is equal to 0.9 of the inner radius of the metal bottom 1.

[0061] The embodiment of the outer adjacent radius of the forming on the side surface of the plastic main body 3 with its bottom surface is equal to 1.2 of the inner radius of the metal bottom 1.

[0062] It is appropriate to pay attention to the fact that when performing the adjacent radius of the outer forming surface of the plastic main body 3 with the bottom, i.e. with a radius of less than 0.6 of the inner radius of the metal bottom 1, in this embodiment the contact area of the adjacent surfaces of the plastic main body 3 and the metal bottom 1 with the sealing rubber pad 2 is sharply reduced, as a result of which it cannot be secured the required tightness of the connection between the metal bottom 1 and the plastic main body 3.

[0063] In the embodiment of the adjacent radius R of the outer forming surface of the main body 3 with the bottom, i.e. with a radius greater than 1.8 of the inner radius of the metal bottom 1, the contact area of the adjacent surfaces between the plastic main body 3 and the metal bottom 1 and the sealing pad 2 is significantly increased. In this embodiment, uniform deformation of the metal bottom 1 with the rubber sealing pad 2 is not ensured, as a result of which the guaranteed tightness of the joint between the metal bottom 1 and the main body 3 cannot be achieved again.

[0064] The implementation of the maximum diameter of the hole for the primer for artillery cartridges less than 0.22 of the minimum diameter of the protruding part of the inner surface of the metal bottom, makes it difficult to spread the forcing of the fire from the primer for artillery cartridges to the discharging charge, which causes unevenness of its ignition, accompanied by a high pressure of gunpowder gases beyond the permissible limit. This phenomenon leads to an increase in the radial deformation of the walls of the metal bottom and the chamber of the cannon, the formation of significant radial contractions between the walls of the metal bottom and the chamber of the cannon and the impossibility of extraction of the shot cartridge case.

[0065] The implementation of the maximum diameter of the opening of the primer for artillery cartridge, more than 0.93 from the minimum diameter of the protruding part of the inner surface of the metal bottom, causes at the time of operation of the ignition parts, destruction of the protruding part of the metal bottom, which excludes multiple usage of the fired cartridge case, due to the uneven distribution of the pressure gradient in the inner surface of the cartridge case and reducing the wall thickness of the upper end of the protruding part of the metal bottom.

[0066] In one embodiment of the cartridge case according to the invention, the cartridge case comprises a second compression ring 4, ensuring the reliability of the connection of the plastic main body 3 with the metal bottom 1. This embodiment is suitable for cartridge cases used under operating conditions at fast rate guns and automatic system for nudging the cartridge case with the charge in the chamber of the cannon.

[0067] The main body of the cartridge case 3 could be made from plastic, in the composition of which is added from 3 to 5% antistatic substance. Such an additive prevents the occurrence of an electric discharge of static electricity, which usually occurs when the elements (bags with discharging charge) rub inside the cartridge case, more precisely in the walls of the cartridge case.

[0068] The above-described composite artillery cartridge case works as follows: The convex cylindrical parts 6 of the main body 3 are fixed in the blind holes of the metal bottom 1, the rubber sealing pad 2 is placed between them and in the case of such an assembly, the clamping ring 4 is mounted, which is screwed by means of the radial technological openings 5 by means of a special wrench, with a certain tightening force, to the convex part of the inner cylindrical surface D of the metal bottom 1.

[0069] The cartridge case with the ejection of the powder charge is placed in the chamber of the cannon. After activation of the primer for artillery cartridges, begin ignition and complete combustion of the discharging charge. The pressure of the gunpowder gases acts on the walls of the plastic main body 3, causing radial deformations of the walls of the metal bottom 1. In this case, there is a simultaneous deformation of the cut of the metal bottom 1, while creating favorable conditions for interaction of the bottom 1 and the plastic main body 3 with providing transverse strength of the plastic main body.

[0070] The walls of the convex inner part of the metal bottom 1 with diameter D are deformed elastically, preserving its strength and preventing the deformation of the means for igniting gunpowder gases and excluding the possibility of leakage (breakthrough) of gunpowder gases in the chamber of the cannon.

[0071] This ensures guaranteed extraction of the cartridge case after the shot, as well as the possibility of multiple usage of the fired cartridge cases.

[0072] In the process of producing the shot, the bottom part of the metal bottom 1 undergoes radial elastic-plastic deformations without forming significant end wedges between the outer surface of the metal bottom 1 and the chamber of the cannon, which provides the necessary reliability at extraction of the fired cartridge case.

[0073] The plastic main body 3 is deformed in the process of firing, without the formation of cracks, thanks to the optimal degree of deformation of the walls, which ensures the integrity of the structure.

[0074] The design of the cartridge according to the invention increases the reliability of its operation in the composition of the artillery shot and, as a consequence, the efficiency of firing in general.

[0075] The invention can be used in the development of various types of artillery cartridge cases.

LEGEND

[0076] 1. bottom; [0077] 2. rubber sealing pad; [0078] 3. plastic main body; [0079] 4. clamping threaded ring; [0080] 5. radial technological holes for tightening the threaded ring; [0081] 6. convex cylindrical surfaces from 2 to 4 pcs. at the bottom of the cartridge case; [0082] Ddiameter of the cylindrical part of the inner surface of the bottom; [0083] ddiameter of the socket for screwing the primer for artillery cartridges; [0084] Rtransition radius between the outer and bottom surface of the plastic main body;