GB2522784A - Cartridge for small arms - Google Patents

Abstract

A cartridge for small arms contains a cartridge case 1 with a body 4, head part 5 and cap seat 6. A damper is provided in the form of internal or external recess 7 in the head part 5 of the case near the cap seat 6.

Description

CARTRIDGE FOR SMALL ARMS

This invention relates to ammunition, in particular it relates to the design of small arms cartridges, and may be used while producing cartridges of various caliber and application.

We know of steel cartridge cases containing case head and body, its internal surface being conjugated to the case head along the radius and is made in a form of conical sections, total height of which is 21.2 to 23.4 times the of radius of case head conjugation with internal surface of a body [RU N2 2179701 Cl, F42B5/26, 2002].

Disadvantages of the said cartridge case may include inadequate strength and io plasticity caused by inhomogeneity of material used for cartridge body walls resulting in periodic and unforeseen fracture of the cartridge case when using cartridges in small arms.

We know of cartridge cases used for small arms cartridges, containing a body with case head, case shoulder and mouth. The internal surface of case head is conjugated to the body along the radius and is made in a form of conical sections, providing that wall thickness is at height h=0.30-0.53H from the line of radius conjugation to the internal surface of a body corresponds to t=0.08-0.2T, where t -is a body wall thickness in weakest section, H -is general height of conical sections, T -is cartridge case head thickness [RU N2 2267078 Cl, F42B5/28, 2005].

Disadvantages of the said cartridge case may include a combination of low strength and plasticity of the cartridge walls with manufacturing faults connected with increase of cartridge thickness and subsequent heavier jamming of cartridge walls in cartridge chamber when firing at high pressure of powder gases (over 3000 kg-f/cm2 (300 MPa)), causing random rupture of cartridge walls when extracting it from the small arms.

We know cartridges for small arms containing cartridge case with body, case head and case mouth, powder charge, cap and bullet. It is also known to include a recess or flat, which width is from about 0.2 to 0.5 times the caliber and is made on external surface of cartridge case body at a distance from about 1.2 to 1.3 times the caliber from cartridge case head end towards the mouth of the case from a cross-section formed through connection of radius part of internal cavity of cartridge case bottom with internal surface of cartridge case body [RU N92309369 C2, F42B5/00, 2007].

Disadvantages of the said cartridge may include occasional fracture of cartridge body along its length initiating from the made recess or flat towards the cartridge shoulder.

Occurrence of such fractures can be explained by the fact that recess or flat made on the cartridge case is a concentrator of the cartridge case material fracture stress. Moreover, making of recesses and flats on the cartridge case body is quite a labor-intensive process.

The most similar to the present invention is a cartridge case of small arms including an encapsulated cartridge case, missile charge and bullet. The cartridge case body has a case head part, groove, as well as cone-shaped body, shoulder and mouth. Compensator of deformation is made on the external surface of a cartridge case body at area of its probable fracture or jamming in a cartridge chamber. Generating line of deformation compensator is made in a form of combination of straight palallel or inclines from about 0.00 to 3.00 angle towards the cartridge case longitudinal axis and radius concave or convex lines. Generating line will create a gap between conditional line and compensator edge. At its length the compensator is made equal from about 0.2 to 0.9 of the cartridge case body. [RU NQ 2470254 Cl, F42B5/00, 2012].

Disadvantages of the said cartridge may include excessive wear of cartridge chamber and jamming of used case as a result of regular impacts of the case walls against walls of the chamber at each shot. Besides, such design is admissible only for bottle-shaped cases, which limits the functional capabilities of the cartridge case.

is The task of improving the cartridge case design of small arms to provide their reliable operation, functional enhancement and simplification of their manufacturing process are assumed as a basis of invention.

Assigned task shall be achieved, when, according to the invention, a damper in a form of internal or external recess is made in a case head part close to cap seat at a cartridge case containing case with body, case head part, cap seat, powder charge and bullet.

Internal or external recess are made in the form of solid ring of round, triangle, trapezoid or spherical cross sectional shape or separate recesses of round, triangle, trapezoid or spherical cross sectional shape.

Recess in a form of solid ring is made with a width of about 0.001 to about 1.2 times and a depth of about 0.001 to about 1.3 times the case caliber.

Where the recesses are separate recesses, the number of separate recesses in the case head shall be at least three providing recess with a width of about 0.001 to about 1.5 times the case caliber and a depth of about 0.001 to about 1.6 times the case caliber.

Execution of internal or external damper recesses or damper recesses at case head part of a cartridge body nearby cap seat shall create air cavity between breeching face and case head, as well as increasing the net volume of the case. This minimizes negative deformation changes of a case configuration during shot at high pressures (above 3800 kg-f/cm2 (380 MPa)), preventing ruptures and jamming of cases and providing for reliable operation of small arms cartridges.

In terms of manufacturing, the damper recess or recesses shall be executed by one, maximum two, operations, which allows production of cases without application of high-value equipment and complex tools.

Design of the assigned cartridge is acceptable for both bottle-shaped and non-bottle-shaped cases which extends its functional capabilities.

The invention is explained graphically.

Fig.1 shows graphically a cartridge of small arms with bottle-shaped case, on which external or internal surface damper recess is made in a form of solid ring; Fig.2 -cartridge of small arms with bottle-shaped case, on which external or internal io surface damper recesses is made in a form of separate recesses; Fig.3 -cartridge of small arms with non-bottle-shaped case, on which external or internal surface damper recesses are made in a form of solid ring; Fig.4 -cartridge of small arms with non-bottle-shaped case, on which external or internal surface damper recesses are made in a form of separate recesses.

is Cartridge of small arms contains a case 1, powder charge 2 and bullet 3. Case 1 contains a body 4 and case head part 5, in which nearby a cap seat 6 a damper is made in a form of solid internal ring recess 7, or solid external ring recess 8, or at least three separate internal recesses 9, or at least three separate external recesses 10. Recesses can be of round, triangle, trapezoid or spherical cross sectional shape and depend on tool wear resistance in course of cartridge manufacture.

Recesses 7 and 8 in a form of a solid ring are made with a width (a) of 0.001 to 1.2 times the cartridge caliber and depth (B) of 0.001 to 1.3 times the cartridge caliber. Separate recesses 9 and 10 in case head parts of case 1 have a width (a1) of 0.001 to 1.5 times the cartridge caliber and a depth (Bi) of 0.001 to 1.6 times the cartridge caliber.

The assigned cartridge of small arms operates as follows.

When shooting powder gases actuate the bullet 3, forcing its motion along the barrel bore, and the internal part of a case 1, pressing the side walls of the case 1 against the cartridge chamber walls, and case head partS of the case 1 -to breeching face. In so doing plastic and elastic deformation (strain) of case 1 body 4 takes place. Following this the case head part 5 of case 1 is shifted and rests against breeching face and compresses damper recesses 7, 8, 9 and 10, having decreased air cavity between case head part 5 of case 1 and breeching face. Case 1 is stretched, its inner volume, peening of walls of body 4 of the case 1 and the period of powder gases exposure through case head part 5 onto breeching face is increased.

The internal volume gain of the case 1 favorably affects the combustion performance of powder charge 2, diminishing peak pressure bumps, smoothing the general combustion diagram of powder charge 2, preventing both longitudinal and transverse fractures of the case 1 and diminishing arms vibration during shooting.

Enlarged peening of walls of the body 4 of case 1 improves material elastic characteristics of the case 1. After the shot when pressure is decreased in the barrel, the case 1 is compressed more intensively, having returned to ingoing or close to ingoing geometrical dimensions, creating uniform circular air clearance between side walls of the body 4 of the case 1 and walls of the cartridge chamber, as well as between head part 5 of the case 1 and breeching face, thereby preventing jamming of the case 1 while being extracted.

Increase of powder gases pressure effect period through the head part 5 of the case upon breeching face shall favorably affect ergonomic rating of shooting. At the same shooting pulse a rifleman experiences higher comfort when pressure effect of powder gases are most spread out in time, which creates illusions of recoil reduction.

Claims (11)

1. CLAIMS1. Cartridge for small arms comprising a case with body, head part and cap seat, powder charge and bullet, in which there is a damper at the head part of the case nearby the cap s seat in a form of either internal or external recess.
2. 2. Cartridge according to claim 1, in which internal or external recess is made as the solid ring of round, triangle, trapezoid or spherical cross sectional shape or separate recesses of round, triangle, trapezoid or spherical shape.
3. 3. Cartridge according to claim 2, in which the recess in a form of solid ring is made with io width from 0.001 to 1.2 and depth from 0.001 to 1.3 of the case caliber.
4. 4. Cartridge according to claim 2, in which the number of separate recesses at the head part of the case is a least three providing recess width from 0.001 to 1.5 and depth from 0.001 to 1.6 times the case caliber.
5. 5. A munitions cartridge comprising a head part wherein there is a recess on either the is interior or exterior of the head part.
6. 6. A munitions cartridge according to claim 5 wherein the recess is a recessed ring.
7. 7. A munitions cartridge according to claim 6 wherein the recess is round, triangular, trapezoidal or spherical in cross sectional shape.
8. 8. A munitions cartridge according to claim 6 or 7 wherein the recess has a width from 0.001 to 1.2 times the caliber of the case and a depth from 0.001 to 1.3 times the caliber of the case.
9. 9. A munitions cartridge according to claim 5 that has not less than three separate recesses.
10. 10. A munitions cartridge according to claim 9 wherein the recesses are round, triangular, trapezoidal or spherical in cross sectional shape.
11. 11. A munitions cartridge according to claim 9 or 10 wherein there are separate recesses, each with a width from 0.001 to 1.5 times the caliber of the case and a depth from 0.001 to 1.6 times the caliber of the case.Amendments to the claims have been made as follows:CLAIMS1. A cartridge for small arms containing a case with body and damper, head part and cap seat, powder charge and bullet, wherein there is provided a damper at the head part of the case nearby the cap seat, which damper being in a form of internal recess.2. A cartridge according to claim 1, wherein the internal recess is made in the form of separate recesses of cylindrical, triangle, trapezoid or spherical shape.3. A cartridge according to claim 2, wherein the number of separate recesses at the head part of the case is at least three providing each recess width from 0.001 to 1.5 and depth from 0.001 to 1.6 times the cartridge caliber. * ** * . * ** * * **.. * . * .. * * * * ***. *.** * * * * *