The present invention relates to the field of firearms, more specifically to the characteristics and details of the barrels thereof.
The present invention provides a barrel of a pre-strained rifled gunbore for a weapon which considerably reduces the loss of shot precision resulting from the progressive heating up of the barrel in a long succession of discharges.
The problem with most barrels is the progressive heating-up thereof during a long succession of discharges. This increase in temperature results in expansion which releases strains accumulated in the material of the barrel during the fabrication process. When a critical temperature is reached, this all results in the inevitable loss of precision. In the barrels of a rifled gunbore, the barrel exhibits during the discharges a simple harmonic movement similar to that experienced by a cord when shaken by one of its extremes while the other end is free. According to the intensity of the same, the muzzle of the barrel describes an oval of greater or lesser amplitude. The precision is most compromised when said amplitude is greatest.
Attempts to alleviate this effect by providing the walls of the barrel with a greater thickness with the object of achieving greater rigidity are equivalent to simply making the cord thicker. This achieves nothing more than delaying the so feared loss of precision, given that the expansions which eventually appear are more permanent in nature as a result of the greater quantity of heat stored therein. It is also necessary to keep in mind, at the same time, the massive increase in the weight of the arm, making it very heavy and difficult to manage.
The present invention resolves the above-mentioned inconveniences by providing a barrel of a pre-strained rifled gunbore which considerably reduces the undesired defective movement of the piece at the moment of discharge, thus optimizing the precision of the discharge and which is also adapted to reduce the noise arising from the discharges.
Said barrel of a pre-strained rifled gunbore which is the object of the present invention comprises at least:
Said rifled gunbore preferably disposes of at least two holes disposed in the proximity of the extremes which are suited to the disposition of the screwed union and are disposed preferably diametrically opposed to each other. An annular air-filled chamber is defined by the components described above which is hermetically sealed from the exterior. Said holes traverse the wall of said rifled gunbore, in a manner such that the interior of said gunbore is connectively communicated with the air-filled chamber.
With this disposition, during the discharge phase, the hot gases produced in the interior of the rifled gunbore pass to the air-filed chamber, heating the outer sleeve until the temperature thereof reaches proximal to that of said rifled gunbore, in a manner to maintain the difference in strains existing between the rifled gunbore and the outer sleeve.
In accordance with the preferred embodiment of the invention in which there are various holes enabled in the rifled gunbore, said holes are maintained separated by means of transverse partitions disposed between the rifled gunbore and the outer sleeve, defining small independent chambers. Said partitions may form part of the casing which is mounted between the rifled gunbore and the outer sleeve, whose base disposes an aperture which may be fitted to the periphery of the rifled gunbore.
In addition, it is envisaged that the outer sleeve disposes an attachment for gases adapted to the function of a repeal mechanism or such like. On pressurizing the air-filled chamber via the screw-holes, the attachment for gases enabled in the outer sleeve enables the coupling of the barrel configuration to any weapon with a system of repetition for the outlet of gases.
All that is required is to calculate the diameter of the holes required to assure the volume of flow of gases to enable the desired system. In the same manner, the points of disposition of the holes may be varied such that their disposition are in the zone where the pressures of the gases are most appropriate to assure the adequate function and correct automation of the sequence of discharges.
Preferably, the air filled chamber(s) which remain between the rifled gunbore and the outer sleeve may be filled with a low density material which has a high capacity for thermal conduction, as a means of facilitating a better thermal equilibrium between these two pieces.
In accordance with another objective of the invention, a manufacture procedure of the barrel of a pre-strained gunbore described above is disclosed which comprises the following stages:
On returning the rifled gunbore to the initial its temperature, it attempts to recover its initial position. When this is not possible, since this is impeded by the outer sleeve, the gunbore remains in a state similar to a cord in strain between two extremes. In this state, the intensity of the simple harmonic effect is eliminated, since it is almost impossible for this phenomenon to be manifest because the entire gunbore is strained.
In this manner, the oval defined by the muzzle of the barrel is observed to be reduced to minute proportions, if not eliminated entirely.
In accordance with the second objective of the invention, the manufacture procedure of the barrel of a pre-strained gunbore described is carried-out at room temperature and comprises the following stages:
In this manner, on removing the conjoined configuration from the traction machine, the rifled gunbore remains permanently pre-strained because the outer sleeve impedes the recuperation of the initial disposition.
As a result, the barrel of a pre-strained gunbore of the present invention enables an assured simultaneous warming of the different pieces which comprise said barrel, in such a manner that the reduced defective movement of the muzzle of said barrel optimizes the precision of the discharge. At the same time, a somewhat silencing effect on the noise of the discharge is enabled.
In order to complement the enabling description and with the object of facilitating a better comprehension of the characteristics of the invention and in accordance with a preferred example of a practical embodiment of the same, a set of drawings is provided below as an integral part of said description for the purposes of illustration and not limiting in any way:
A barrel of a pre-strained gunbore is shown in
As can be seen in
Said holes (5, 6), shown in
Moreover,
Number | Date | Country | Kind |
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P200802840 | Oct 2008 | ES | national |
P200900357 | Feb 2009 | ES | national |
Filing Document | Filing Date | Country | Kind | 371c Date |
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PCT/ES2009/070424 | 10/7/2009 | WO | 00 | 6/24/2011 |