The present invention refers to a casing for firearms (in particular for a semi-automatic rifle).
A casing for a firearm constitutes the front structure to which a metal barrel and auxiliary devices are fixed.
During firing steps, the casing undergoes substantial thermal stresses, following the transfer of heat from the barrel, and mechanical stresses, due to the fast dynamic of the firearm and the consequent knocks due to the breechblock.
Currently, casings for firearms are made from metal or in any case comprise a high number of metal components, suitable for ensuring the necessary resistance to thermal and mechanical stresses.
This solution implies the realisation of an expensive firearm of substantial weight.
Greater use of polymeric materials for the realisation of the casing would undoubtedly allow costs and weight to be substantially reduced, but it poses problems of thermal and mechanical resistance, in particular in the area which the barrel is fixed.
The purpose of the present invention is that of realising a casing for firearms of reduced weight.
Another purpose of the present invention is that of realising a casing which is resistant and reliable in particular in the area which the barrel is fixed.
Another purpose of the present invention is that of realising a casing for firearms which is particularly simple and functional, with contained costs.
These purposes according to the present invention are accomplished by realising a casing for firearms as outlined in claim 1.
Further characteristics are foreseen in the dependent claims.
The characteristics and advantages of a casing for firearms according to the present invention shall become clearer from the following description, given as an example and not for limiting purposes, referring to the attached schematic drawings, in which:
Hereafter, specific reference shall be made to a rifle, although that which is object of the invention can generally be applied to other firearms, including side-by-side, semi-automatic, rifled and military ones, etc. Moreover, given that the invention is intended for experts in the field of firearms, it is omitted the detailed description of the structure and operation of a firearm, in particular of a rifle like the one described. Reference is made only to the functions of the firearm parts involved in the technical problem forming the basis of the invention.
With reference to the figures, a casing for firearms is shown, wholly indicated with 10, to which a metal barrel 12 is fixed.
The casing comprises an outer shell 13 substantially shaped according to the final shape of the casing 10 and shown in the figures only in its front part. The casing also comprises an inner element 14, made from polymeric material with high thermal and structural resistance, as well as a sleeve 15, for example made from aluminium suitable for establishing the attachment with the barrel 12.
As shown in the exploded view of
The ring nut 19 is equipped with an entry portion 20 with a frusto-conical inner surface for the positioning on a rear end 21 of the sleeve 15, tapered externally with a matching frusto-conical generatrix, according to that which is shown in the sections of
The entry portion of the sleeve 22 is also equipped with a centring cut or milling 23, which defines the correct rotational positioning of the barrel on the sleeve, when coupling is carried out with a flattened portion 24 formed in the abutment ring 16 of the barrel 12 (FIGS. 5 and 6).
The sleeve also has side elements 25 protruding to form a bridge, and an upper projection 26, equipped with holes 27, for example threaded, which when the casing is mounted are situated at openings 28 of the inner element 14 and of the shell 13 and to which auxiliary devices (not shown) are applied, such as small metal plates or a support for the aiming device.
The production method of the casing for firearms 10, object of the present invention, foresees the execution of successive overmouldings in sequence starting from the sleeve 15 shown in FIG. 2.
By overmoulding it is meant the moulding, according to the prior art, of structures made from polymeric material between two moulding shells in which the element is suitably positioned about which the overmoulding must be carried out.
On the sleeve 15 the inner element 14 is firstly moulded made from polymeric material equipped with excellent thermal and structural behaviour, for example a polymeric material loaded with glass fibres, in such a way forming the sleeve—inner element group 11 shown in FIG. 3.
The outer casing 13 made from polymeric material with lower density and worse thermal behaviour is then overmoulded on the group 11, to form the casing 10 (FIG. 4).
Finally, the barrel 12 is stably fixed to the casing 10, in a removable manner, through the threaded ring nut 19.
Indeed, the barrel 12 is inserted into the rear of the sleeve 15 until the correct axial and rotational positioning is reached in abutment against the ring 16. The locking of the threaded ring nut 19 on the frusto-conical tapered portion of the sleeve 21 ensures the stable self-centring locking of the barrel 12 to the sleeve 15 and therefore to the casing 10.
The inner element 14 is equipped, on side walls, with engagement elements, for example consisting of a plurality of ridges and throats 29, which when the outer shell 13 is overmoulded give rise to matching engagement elements of the shell 13, for example matching ridges and throats 29′. The provision of matching engagement elements offers a better anchoring surface with regard to roto-translational movements and ensures better heat dispersion between the inner element 14 and the shell 13.
Other anchoring points of the inner element 14 to the sleeve 15 consist of the upper projection 26, as well as the side bridge elements 25 of the sleeve 15, which enclose portions of material 30 of the inner element 14.
In the casing 10, according to the invention, the inner element 14 and the locking sleeve 15 of the barrel 12 constitute a single piece with the shell 13, being embedded into each other, and therefore cannot be dismounted.
The final shape of the inner element 14 substantially reproduces that of the shell 13, to avoid overmoulding portions of shell 13 of substantial thickness to realise the final shape of the casing 10.
Finally, the casing 10 according to the invention can, for example, have applied to it support and protection elements for auxiliary devices, such as the aiming shaft of the sight, engaged in an upper hole 31, and an attachment for a possible belt-carrying mesh in a lower hole 32.
The casing for firearms, object of the present invention, has the advantage of ensuring excellent thermal and mechanical resistance and of being shaped according to ergonomic shapes which may even be complicated.
The casing according to the invention is also advantageously equipped with extremely low weight.
The realisation of the casing through two successive overmoulding operations advantageously allows different materials to be used according to the specific requirements of resistance or of lightness.
Moreover, through the double overmoulding of structures which have a complex shape it is advantageously possible to avoid different shrinking of the material in areas of different thickness, which would determine substantial states of stress upon the material.
The casing for firearms thus conceived is susceptible to numerous modifications and variants, all of which are covered by the invention. Moreover, all of the details can be replaced with technically equivalent elements. In practice, the materials used, as well as the sizes, can be whatever according to the technical requirements.
Number | Date | Country | Kind |
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MI2002A0856 | Apr 2002 | IT | national |
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