Small-shot cartridges containing biodegradable separators

Abstract

The invention relates to small-shot cartridges containing biodegradable separators. Depending on the respective intended utilization, small-shot cartridges contain either scaling disks or cup-shaped wads that are referred to as separators and that separate the charge from the pellets. The cup-shaped wads usually consist of plastic, for example LDPE (low density polyethlene) or similar materials. The scaling disks may consist of plastic, but also of other materials, for example of cardboard, felt, fibers or combinations thereof. These materials may lead to sealing problems and may impair interior ballistics, the trajectory of the projectile in the barrel, and ignition and combustion processes. The separators are ejected from the barrel by the impact of the shot and are left behind during hunting in the countryside or during shooting in the shooting gallery, especially the non-biodegradable plastic materials constitute an environmental hazard. According to the invention, the separator (1) is therefore produced from a non-brittle, biodegradable material that is resistant to the temperatures of the propellants while it does not impair the function of the separator and that is completely biodegradable when stored under the conditions of comprising.

Description

[0001] The invention relates to a separating means between charge and shot in a small-shot cartridge.

[0002] Depending on the intended purpose, shot cartridges contain either sealing disks or cup-shaped wads, called separators, which separate the charge from the shot. The cup-shaped wads consist as a rule of plastic, e.g., LDPE (low-density polyethylene) or comparable materials. The sealing disks can also consist of materials other than plastic, for example cardboard, felt, fibers or combinations of same. Such materials can lead to sealing problems and thus to interference with the internal ballistics, the shot development in the barrel, and the ignition and combustion processes.

[0003] If these separators are ejected out of the barrel by firing and are left in the environment by the hunters, the rot-resistant plastics, especially, contaminate the environment.

[0004] The problem of the invention is to configure the separators such that they no longer pollute the environment and will at the same time improve the internal ballistics.

[0005] The solution of the problem is achieved by the fact that the separators, the sealing disk of the invention and the cup-shaped wads of the invention, are made from biodegradable, non-brittle materials which withstand the thermal stress of the propellant gases without any destruction to impair their function, and when left under composting conditions they are fully biodegradable, and furthermore are given a shape which results in an optimum seal against the hot gases of the propellent charge.

[0006] The biodegradable materials of the separators for example Bayer's plastic BAK * advantageously permit degradation in the earth by rotting in a reasonable time. When used in shooting galleries they can be eliminated with household wastes or by composting. The plastic can be strengthened, for example with biologically acceptable fibers such as natural fibers, carbon fibers, glass fibers or mineral fibers.

[0007] The configuration of the cup-shaped wads with reinforced disks permits optimum propulsion and clean guidance of the shot. The cushioning portion is so configured that a uniform transfer of the gas pressure to the shot packet and hence to the shot cluster is assured.

[0008] The novel shape and the new materials of the separators advantageously result in a uniform spread of the shot cluster.

[0009] The invention is further explained with the aid of examples.

[0010] FIG. 1 is a lateral elevation of an H-shaped disk in section,

[0011] FIG. 2 a longitudinal section of a cup-shaped wad of the invention, and

[0012] FIG. 3 a plan view thereof.

[0013] FIG. 1 shows an H-shaped separator 1 according to the invention, made of a biodegradable plastic. The outside diameter 2 and the diameter 3 of the reinforced middle section 4 as well as the thickness of the disk are related to one another such that the forces of the gas thrust are distributed over the entire disk surface against the shot. The good sealing of the disk 1 against the cartridge wall is achieved by the rims 7 on both sides which taper by the angle 6 to a thickness of about 0.4 to 0.5 mm, which thus act like sealing lips conforming to the shell wall. The angle 6 is approximately between 15 and 20 degrees. The central part 4 also tapers at the same angle 6. With an outside diameter 2 of about 18.6 mm according to the shotgun gauge, and an overall height 9 of 7.2 mm, the thickness 5 of the disk is 3 mm, and the diameter 3 of the middle section 4 is 7 mm at its surface. Since the sealing disk 1 is of symmetrical shape it is not necessary to perform its installation in one particular direction, which facilitates the assembly of the cartridge.

[0014] FIG. 2 shows a cupped wad 10 in longitudinal section. The diameter 11 is in conformity with the shotgun gauge and the overall height 12, 40 mm in the present embodiment, is divided into the height 13 of the cup 14 for the shot, here 23 mm, the height 15 of the cushioning part 16, here 9.5 mm, and the height 17 of the cup-shaped sealing part 18, here 7.5 mm, the annular wall of which conforms to the cartridge shell. The cushioning part 16 consists of two thin-walled V-shaped sections 19 whose apices are opposite one another, as can be seen in FIG. 3. The cup 14 has uniformly distributed over its circumference four slits 21 reaching to the bottom of the cup and running in the direction of the central axis 22. The individual wall segments act like flexible blades which facilitate the release of the shot charge when it leaves the cartridge. Here, too, the shape of the middle part permits a uniform transfer of the gas pressure to the shot and an optimum seal against the barrel.

Claims

1. Separator between charge and shot in a small-shot cartridge, characterized in that the separator (1, 10) consists of a non-brittle, biodegradable material which withstands the thermal stress of the propellent gases without destruction impairing its function and is completely biodegradable when exposed to composting conditions.

2. Separator according to claim 1, characterized in that the separator is in the form of a H-shaped, symmetrically configured sealing disk (1) which has a strengthened center portion (4), that the diameter (3) of the central portion (4) and the outside diameter (11) of the sealing disk (1) are so co-ordinated with one another that the forces of the gas pressure are distributed uniformly onto the shot charge over the entire disk surface.

3. Separator according to claim 1 or 2, characterized in that the ratio of the outside diameter (2) of the sealing disk (1) to the diameter (3) of the surface of the central portion (4) is approximately 2.3 to 2.8 to 1.

4. Separator according to claim 2 or 3, characterized in that on its top and bottom side the sealing disk (1) has symmetrically shaped upstanding portions (7) which taper toward their end and act as sealing lips.

5. Separator according to any one of claims 2 to 4, characterized in that the central portion (4) of the sealing disk (1) as well as the upstanding portions (7) taper at the same angle (6), and that the angle (6) is approximately between 15 and 20 degrees.

6. Separator according to claim 1, characterized in that the separator is in the form of a cupped wad (10), that the walls of the cup (14) for the shot are given a blade-like shape by slits reaching down to the cup bottom, that the cushioning part (16) consists of two thin-walled vshaped sections (19) whose apices (20) lie opposite one another, and that the sealing part (18) is cup-shaped.

7. Separator according to claim 6, characterized in that the walls of the cup (14) and of the sealing part (18) each taper toward their margin.

8. Separator according to any one of claims 1 to 7, characterized in that the material is reinforced by biologically unobjectionable fibers such as natural fibers, carbon fibers, glass fibers or mineral fibers.

9. Separator according to any one of claims 1 to 8, characterized in that the material is a plastic.