Patent Application
20230400270
The present invention relates to the field of shotguns, and more particularly to retainers for catching ejected cartridge cases.
Various shotguns eject the spent cartridge cases after firing. These spent cartridge cases are scattered on the ground, and the task to collect all the empty cartridges is a challenge to an individual, especially when the shooter does not have the fixed position of firing. The empty cartridges are often made from plastic that degrades very slowly in nature, if at all. When hunting at sea or on a lake, the empty plastic cartridges end up in the water.
Also, the cartridges are ejected at high speed and can strike and injure a nearby person, posing a hazard. Thus, there is a need to design a secure and safe system to automatically collect the spent cartridge cases, after the firing.
Hence, there is a need for a simple solution for collecting the ejected cartridges.
A first aspect relates to retainer adapted for catching ejected cartridge cases from shotguns, said retainer comprising:
wherein the elongate member comprises:
The inventor has found that the brass head of the cartridge cases is magnetic, and by using a magnet positioned close to the ejection port, the magnet is able to catch an ejected cartridge case. Preferably, the magnet is a rear earth magnet. The rear earth magnet may be a samarium- or neodymium-alloy magnet. Preferably, the magnet is neodymium-based as it is less brittle than samarium-based magnets. The neodymium magnet may comprise neodymium, iron and boron, e.g., but not limited to Nd2Fe14B. Nd2Fe14B exists in a tetragonal crystal structure. The tetragonal crystal structure can provide a high uniaxial magneto-crystalline anisotropy, which gives the magnet a very high coercivity or resistance to being demagnetized. The neodymium magnet may have a high magnetic dipole moment, which convers up to 18 times magnetic energy to the neodymium magnet as compared to ordinary iron-based magnets. Preferably, the neodymium magnet is coated with a polymeric material, such as plastic or rubber, to avoid oxidation. The samarium-based magnet may e.g., be a samarium-cobalt magnet. Both samarium-cobalt and neodymium magnet alloys are powdered metals, which are compacted in the presence of a strong magnetic field and are then sintered.
As the rear earth magnets create a very strong magnetic field, there is a risk that it interferes with the mechanics of the shotgun, thereby resulting in malfunction of the shotgun.
Hence, in one or more embodiments, the core comprises a plurality of magnets arranged to form a relatively weak magnetic field on one side of the elongate member, and a relatively strong magnetic field on the opposite side of the elongate member, and wherein the relatively strong magnetic field is facing away from the base. This configuration reduces the magnetic field's effect on the mechanics of the shotgun.
In one or more embodiments, the magnets are arranged as a Halbach array. A Halbach array is a special arrangement of permanent magnets that augments the magnetic field on one side of the array while cancelling the field to near zero on the other side. This is achieved by having a spatially rotating pattern of magnetization. The rotating pattern of permanent magnets (on the front face; on the left, up, right, down) can be continued indefinitely and have the same effect.
In one or more embodiments, the core is magnetically shielded with a shield at the side face facing towards the base. The design and material of the shield may be any suitable type well known in the field of magnetic shielding. An example of such a shield may be seen in
The shield may also e.g., be made from a material having a high magnetic permeability, such as mu-metal or permalloy. However, such a material is very expensive. In general, “mu metal” as discussed herein is a nickel-iron ferromagnetic alloy (e.g., 75% nickel, 15% iron, plus copper and molybdenum) that has very high magnetic permeability. The high magnetic permeability makes mu-metal very effective at screening static or low-frequency magnetic fields, which cannot be attenuated by other methods. Mu-metal can have relative magnetic permeabilities of 80,000-100,000 compared to a few thousand for ordinary steel. Other high permeability alloys, such as permalloy (nickel-iron magnetic alloy), have similar magnetic properties, and may also be used, although it is more difficult to shape. The term “permalloy” refers to a nickel iron magnetic alloy. Generically, it refers to an alloy with about 20% iron and 80% nickel content (i.e., Ni80Fe20). Permalloy has a high magnetic permeability, low coercivity, near zero magnetostriction, and significant anisotropic magnetoresistance.
To make sure that the caught cartridge case is moved as far as possible away from the ejection port, it may be an advantage to shape the cover to support such a movement of the cartridge case around the elongate member.
In one or more embodiments, the cover is configured with a rounded top face, and optionally a rounded side face facing towards the base. The rounded shape makes it difficult for the cartridge case to rest on these faces. In combination with the directed magnetic field this effect is strengthened. Preferably, the cover is configured with a straight side face facing away from the base, thereby allowing for an optimal resting place for the brass head of the cartridge case.
When mounted on a shotgun, the elongate member is preferably adapted for being positioned substantially parallel to the barrel of said shotgun.
The base may be fastened to the shotgun by any suitable means for fastening, such as gluing, welding, or fastening with screws or bolts.
The retainer may be adapted for being used with different types of shotguns.
In one or more embodiments, the cover comprises fastening means adapted for being releasably fastened to the base.
In one or more embodiments, the elongate member, when fastened to the base, is configured for being moved relative to the base, e.g., slidable attached to the base.
In one or more embodiments, the elongate member comprises one or more flexible elongated rods or bristles adapted for reducing the speed of an ejected cartridge case. In the present context, the term “flexible” means that the member can be flexed or bent. The elongated rods or bristles preferably extends upwards relative to the top face of the cover, preferably from said top face. The elongated rods or bristles may be positioned at the rear end (relative to the shot gun) of the elongated member and/or may be positioned in line along the length of the elongated member. The number of elongated rods or bristles may vary depending on the type of cartridge, such as the caliber, or the size of the cartridge case. In some embodiments, a single elongated rod or group of bristles may be used.
Another aspect relates to a shotgun comprising the retainer according to the present invention.
Yet another aspect relates to the use of the retainer the retainer according to the present invention for mounting to a shotgun.
It should be noted that embodiments and features described in the context of one of the aspects of the present invention also apply to the other aspects of the invention.
As used in the specification and the appended claims, the singular forms “a”, “an”, and “the” include plural referents unless the context clearly dictates otherwise. Ranges may be expressed herein as from “about” or “approximately” one particular value and/or to “about” or “approximately” another particular value. When such a range is expressed, another embodiment includes from the one particular value and/or to the other particular value. Similarly, when values are expressed as approximations, by use of the antecedent “about”, it will be understood that the particular value forms another embodiment.
The core may comprise different constructions, and two different examples are shown in
The first example (
The elongated rods or bristles 130 may be positioned at the rear end (relative to the shot gun) of the elongated member as shown in
Alternatively, or in combination, they may be positioned in line along the length of the elongated member as shown in
| Number | Date | Country | Kind |
|---|---|---|---|
| PA 2020 01200 | Oct 2020 | DK | national |
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/EP2021/079395 | 10/22/2021 | WO |
