The present invention refers to an insert for cartridge .

As it is known, a generic cartridge of the type with shots is made up of a case that is closed below by a bottom bearing the primer and is capped above with a disc or with a star crimp obtained by bending the tube. The load of gun powder is housed inside the case and in contact with the primer, said gun powder having the wad and the shots in succession placed over it.

Such a wad, which acts as a damper element of the thrust that is generated when shooting, can be a simple element placed between the powder and the shots, typically made up of two plates that are interconnected by an element that can yield in an elasto-plastic manner. The plates shall be in the most suitable shape for sealing gas, for example with a peripheral lip seal. The yielding element can be in many forms, or structures, and can undergo deformation by squashing down in the moment of shooting, acting as a damper.

It has also been proposed to lengthen one of the plates of the wad with a cup which moves as a piston in the case and in which the shots are at least partially housed. This provision is considered advantageous due to the improved transfer of energy to the shots themselves, improving the dynamics of the expulsion of the load from the barrel of the weapon. The shots, indeed, travel at least most of the barrel inside the cup, which the wad is provided with, at least partially avoiding sliding against the barrel and their dispersion due to the gun gas. In such a last case, by wad it is meant both the tubular element for containing the shots, and the damper element formed below it.

One essential aspect that distinguishes in a clear manner the quality of the cartridge is that relative to the so-called "shot pattern", or rather to the distribution that the cluster of shots takes up in flight subsequent to being shot and coming out from the barrel .

It is indeed required for the shots to be distributed inside a predetermined area in the highest percentage possible defined as "density index".

Such a percentage can vary according to the amount of choke of the barrel and according to the shooting distance. A further important requirement is that inside of such an area the distribution of the shots is homogeneous without "empty" areas, said requirement being known as regular distribution.

Patent application FR2308901 describes the prior art that is closest to the present invention.

Such a document describes an insert for a cartridge of the type comprising a tubular container that is closed at one end and that is insertable in substantial wall contact in a cartridge.

Such an insert also comprises a separation element or wall that is arranged between the bottom of the insert and the open end.

The shots are arranged above such a separation element. By analysing the way such an insert operates, it can be seen that the separation element acts as an element that delays the passing of the impulse to the shots from the blast.

Indeed, there is a first shooting stage in which only the bottom of the insert is deformed without the deformation of the separation wall and only a second shooting stage, figure 11 of FR2308901, in which only then the bottom collides with the separation element transferring the impulse also to the shots.

The function of possible damping of the impulse is intended only for the air present between the bottom of the insert and the separation wall.

In other words in FR2308901 there is no elastic damping element which provides for transmitting the impulse to the shots in a gradual/damped manner right from the first stages of the blast, but only an element that is capable of delaying such a passage without any substantial damping.

Moreover, in FR2308901, precisely for the fact that such a separation element does not have to be involved in the shooting from the start, it does not rest on the bottom of the insert but rather weighs down upon the side walls thereof.

For such a purpose inclined abutment walls are provided formed both on the separation wall and in the insert. This fact, or rather the wall pushing sideways, can cause dangerous choking of the shooting stages slowing down the cartridge case inside the barrel.

The purpose of the present invention is that of making an insert for shot cartridges that is capable of solving the drawbacks of the prior art in an extremely simple, cost-effective and particularly functional manner .

Another purpose is that of making an insert for cartridges that is capable of ensuring that the shots in flight subsequently to the shooting and coming out from the barrel are homogeneously concentrated inside a reference area, in a percentage that is significantly higher with respect to the prior art, for the same shooting distance and choking level of the barrel .

These purposes according to the present invention are achieved by making an insert of the wad type for containing shots for cartridges as outlined in claim 1. Further characteristics of the invention are highlighted in the dependent claims.

The characteristics and the advantages of an insert for cartridges according to the present invention shall become clearer from the following description, given as an example and not for limiting purposes, with reference to the attached drawings, in which:

- figure 1 is a partially split schematic view of a cartridge provided with an insert according to the present invention;

- figure 2 is a partially split enlarged schematic view of the insert for cartridges shown in figure 1.

With reference to the figures, an embodiment of an insert for cartridges according to the invention is shown with reference numeral 10 and a cartridge provided with such an insert 10 is shown with reference numeral 100.

As visible, the insert 10 comprises a tubular container 11, provided with a closed end 12 and insertable in substantial wall contact in a cartridge case 101 of a cartridge 100, and a damper element 14 realizing a wad associated with the tubular container 11 for damping the pushing of the gun gas.

In particular, according to the invention, the damper element 14 is inserted in the tubular container 11 leaning on the closed end 12 so as to occupy part of the height thereof.

The upper part of the container 11 that is not occupied by the damper element 14 constitutes the housing for a charge of shot .

Therefore, according to the present invention, the damper element 14 is arranged inside the tubular container 11 which houses the shots 13.

In such a way, as visible in figure 2, the damper element 14, on one side, leans on the closed end 12 of the container 11, and on the opposite side, it is in direct contact with the shots 13.

As shown in the figures, the tubular container element 11 is without notches and outside it is equipped with a plurality of circumferential rings 15 for guiding the insert 10 inside the cartridge case 101 and the barrel. The fact that there are no notches on the tubular container element 11 prevents contact between the shots 13 and the barrel during their translation in it.

It should be highlighted that the present invention sets the condition that the majority or the entire load of shots is contained inside the tubular container, precisely to avoid deformation thereof by sliding friction during translation inside the barrel.

The tubular container element 11 consists, from its closed end 12, of two tubular portions 16, 17 that are arranged in succession respectively with greater external diameter and smaller between them.

The reduction of the diameter of the tubular portion 17 that is distal from the closed end 12 leads to numerous advantages, including making it possible to reduce on one hand the radial pressure on the mass of shots when passing in the choke and on the other hand the possible deformation of the shots and the compression of the central cluster of shots preventing that, once in flight, it acquires greater speed with relative lengthening.

The second tubular portion 17 with smaller diameter also has a tapered internal wall 18 towards the inside of the tubular container 11.

The first tubular portion 16 with greater diameter of the tubular container 11 has a development that is substantially equal to the height of the damper element 14 and has inner walls that are substantially vertical. In the example shown, the damper element 14 comprises a tubular structure 21 whose axis is orthogonal to the axis of the tubular container 11, two buffer elements 22, 22' placed laterally on opposite parts of the tubular structure 21, and two disc-shaped portions 23, 23' placed respectively above and below the tubular structure 21 laterally in contact with the internal wall of the first tubular portion 16 of the tubular container 11.

In particular, also the buffer elements 22, 22' are in contact with the internal wall of the first tubular portion 16 of the tubular container 11, so as to avoid asymmetrical deformations of the damper element 14 during the blast stage.

The two disc-shaped portions 23, 23' are externally provided with lip seals acting against the internal wall of the first tubular portion 16 of the tubular container 11.

Finally, the insert 10 comprises an inverted-cup shaped portion 19 that is associated with the closed end 12 of the tubular container 11 on the opposite side with respect to the damper element 14 for containing powder 102 inside the case 101, arranged above the primer 103, and for the sealing of the blast gas .

Such an inverted-cup shaped portion 19 is moreover externally provided with a scraping-powder ring 20.

Advantageously, and in a completely unexpected manner, the Applicant has found that an insert 10, as previously described, where in particular the damper element 14, which acts as a wad is arranged inside a tubular container 11 which houses the shots 13 to be in turn inserted in the case 101, obtains a shot pattern that is considerably better than those obtained with cartridges known today.

Indeed it has been found that thanks to such an insert 10 the shots, in flight subsequently to the shooting and the coming out from the barrel, for the same shooting distance and choking level of the barrel, are concentrated in a percentage that is considerably higher and in a homogeneous manner without "spaces" inside a reference area.

The insert for cartridges of the present invention thus conceived can undergo numerous modifications and variants, all covered by the same inventive concept; moreover, all the details can be replaced with technically equivalent elements. In practice, the materials used, as well as their dimensions, may be of any type according to the technical requirements .