Patent Application
20240128073
The invention relates to a lighting element for a firearm or sight with a gaseous tritium light source and with a—more particularly elongated—injection-molded plastic housing, wherein the plastic housing at least partially encloses the gaseous tritium light source.
To improve night vision for sights of firearms, it is known (WO2016/124686) to use a lighting element with a gaseous tritium light source. Such a use of lighting elements with radioluminescent light sources is subject to stringent requirements with regard to the mechanical ruggedness thereof. For example, for the USA, these lighting elements must pass a NUREG test (NUREG 1556, Vol. 8, Rev. 1, Appendix D) in order to insure that under various conditions, the gaseous tritium light source cannot come loose from the sight or get damaged. The gaseous tritium light source is therefore partially enclosed by a plastic housing to protect it. Plastic does in fact perform well for mechanically protecting the gaseous tritium light source, but in firearms, this plastic must also withstand comparatively high temperatures and a wide variety of cleaning chemicals such as gun cleaning oils—namely while retaining its mechanical resilience.
The object of the invention, therefore, is to modify a lighting element of the type explained at the beginning in such a way that while achieving a high degree of mechanical ruggedness, whereby it can also ensure a comparatively high temperature resistance and chemical resistance. The lighting element should also be easy to produce.
If the plastic housing at least partially consists of a polyamide 12 (PA12)-based or polycarbonate (PC)-based plastic, then a high mechanical resilience can be combined with a high thermal and chemical resistance—which makes the lighting element according to the invention particularly outstanding when used in a firearm or in a sight for this firearm. Preferably, the plastic housing consists entirely of a polyamide 12 (PA12)-based or polycarbonate (PC)-based plastic. It can also be sufficient, however, if the plastic housing consists of a polyamide 12 (PA12)-based or polycarbonate (PC)-based plastic in a see-through region of the plastic housing.
Because of its respective special chemical polymer structure, the PA12 or PC plastic of the plastic housing can ensure a high temperature resistance, for example up to 120° C. (degrees Celsius), and high chemical resistance, for example relative to solvents for gun cleaning oils, and thus can also successfully pass the NUREG test (NUREG 1556, Vol. 8, Rev. 1, Appendix D).
In addition, according to the invention, plastics used in the plastic housing can easily be used for an injection molding process even with thin wall thicknesses of the plastic housing, which promotes a simple and inexpensive production of the lighting elements.
Preferably, the polyamide 12 (PA12) base is selected from the group PA 12/MACMI, PA MACMI/MACMT/12, or PA12 GF30 as well as mixtures or blends of one or more of these plastics.
Alternatively, it is also conceivable for the polycarbonate (PC) base to be selected from the “PC-HT” group as well as mixtures or blends of one or more of these plastics.
Preferably, the plastic housing is embodied as at least partially transparent in order to thus enable a defined light emission.
The foregoing can be further improved if a first end of the plastic housing forms an optical lens. This also makes it possible to further simplify the design of the lighting element.
Alternatively to a one-piece embodiment of the plastic housing and lens, it is conceivable for a first end of the plastic housing to have an optical lens, wherein the lens is injection molded onto the plastic housing by means of a 2-component injection molding process. It is also conceivable for the plastic housing to be injection molded onto the lens by means of a 2-component injection molding process.
Through the selection of the plastic according to the invention, a 2-component injection molding process can also be particularly suitable as a production process for the plastic housing. With these plastics, it is also possible to use them in a transparent form or in a colored form, which can allow them to be used universally.
If the lens is embodied as plano-convex, convex-convex, or concave-convex, then the light emission of the gaseous tritium light source can be concentrated better, and the brightness of the lighting element can be further increased by means of this focusing.
Preferably, an inner radius (R2) of the lens and an outer radius (R1) of the lens are different from each other.
For this purpose, it can be advantageous if the inner radius and/or the outer radius is/are in a range from 1.25 to 4 times half of the diameter of the gaseous tritium light source.
Preferably, the plastic has pigments. For example, the pigments may be color pigments, luminous pigments, fluorescent pigments, phosphorescent pigments, or any combination thereof, in order to further increase the brightness and thus the improved visual recognition in low light conditions.
If the gaseous tritium light source is integrally bonded to the plastic housing by means of a—more particularly white—adhesive, then this can further increase the ruggedness relative to mechanical stresses. In addition, a white adhesive can have an advantageous effect on the brightness of the lighting element.
The design of the lighting element can be further simplified if the gaseous tritium light source has a hermetically sealed, more particularly round, glass tube, more particularly made of borosilicate glass, as its outer shell.
A sight can have the lighting element according to the invention in order to further improve the visibility of the sight in low light conditions.
In addition, a firearm can have this sight or also the lighting element according to the invention in order to further improve the visibility of the firearm, a marking thereon, a part thereof, etc. in low light conditions.
The subject matter of the invention is shown by way of example in the figures based on multiple embodiment variants. In the drawings:
The lighting elements 1, 2, 3, 13 shown in
The first plastic housing 5 of the lighting element 1 according to
By means of the PA 12/MACMI plastic, the first plastic housing 5 can advantageously also integrally form a concave-convex optical lens 8, which significantly reduces the design complexity of the lighting element 1. The plastic can be PC-based.
The lens 8 adjoins a casing 5a of the first plastic housing 5 that is annular cross-section and in this example, forms the first end 5b of the plastic housing 5.
The integration of the optical lens 8 with freely selectable lens shapes into the first plastic housing 5, however, does not incur added costs of any consequence, for example, if this is carried by means of an injection-molded shaping. It is therefore possible to omit a cost-intensive, specially produced, shaped lens or sapphire used as an insert in the plastic housing.
As is clear from
In addition, the gaseous tritium light source 4 is integrally bonded to the first plastic housing 5 by means of a—more particularly white—adhesive 9 in order to thus increase the brightness of the lighting element 1 at the end 5b through reflection.
According to
In comparison to this, the third plastic housing 7 according to
The third plastic housing 5, which is another component in the 2-component injection molding process, is made of a transparent plastic based on polyamide 12 (PA12), namely PA 12/MACMI. It is also conceivable for a transparent PC-based plastic to be injection molded.
The sight 100 according to
Here, too, the fourth plastic housing 15 of the lighting element 13 also partially encloses the gaseous tritium light source 4, which is glued in a recess 16 on the circumference surface 15a of the plastic housing 15 with the aid of an additional adhesive 110. At the end 15b of the plastic housing 15, this forms a see-through region 17 for providing a view of the gaseous tritium light source 4. The fourth plastic housing 15 is made of a transparent plastic based on polyamide 12 (PA12), namely PA 12/MACMI. It is also conceivable for a transparent PC-based plastic to be injection molded.
The sight 100 is provided on a barrel 104 of the firearm 101, as schematically depicted in
The selection of the polyamide 12 (PA12)-based or PC-based plastic for the various plastic housings 5, 6, 7, 15 yields a high mechanical ruggedness, high temperature resistance of up to 120° C. (degrees Celsius), and a chemical resistance.
The plastic housing 5, 6, 7, 15 according to the invention also passes the environmental test according to NUREG (NUREG 1556, Vol. 8, Rev. 1, Appendix D). This NUREG test tests the environmental conditions of the lighting elements 1, 2, 3, 13 during its use for sights 100 and in so doing, subjects the plastic housing 5, 6, 7, 15 to tests of resistance to dry heat at 120° C., moist heat at 42° C. with 100% humidity, cold at −46° C., temperature shock cycles (−46° C. to 80° C.), vibrations, pressure, mechanical shock (drop test), firing test with 5000 rounds, and penetration. In addition, tests for leaks and chemical resistance (e.g.: to gun cleaning compound) were performed.
The testing of the lighting elements 1, 2, 3, 13 with the plastic housings 5, 6, 7, 15 according to the invention was thus carried out in relation to cleaning compounds according to the specification MIL-C-372B of (NUREG 1556, Vol. 8, Rev. 1, Appendix D, 3.3.2.1 Chemical). This requirement was adapted to current practice, i.e. the carcinogenic and thus prohibited agent chloroform was replaced with the conventional substances listed below. The resistance of the lighting element 1, 2, 3, 13 was tested by immersing it for forty-eight hours at room temperature in each of the following substances: Cleaning compounds, gun oils, and products containing combinations thereof:
The illuminants 1, 2, 3, 13 with the plastic housings 5, 6, 7, 15 according to the invention passed all of these tests.
