A break-action shotgun with a device for mass-production interchangeability of the barrels

ES 2 201 243 T3

DESCRIPTION

A detachable shotgun with a device for mass production interchangeability of the barrels.

The present invention refers to a shotgun with articulated barrels (also known as a "detachable" weapon), the barrels being articulated to the breech or rear portion of the weapon.

The invention relates more particularly, but not exclusively, to a detachable shotgun of the superimposed barrel type.

It is known that, in a detachable weapon, particular care must be taken in the formation of the aforementioned articulated connection between the barrels and the breech since the achievement of the desired smooth opening of the weapon that has to be guaranteed over time depends heavily on it.

Such a detachable shotgun is known from US-A-4964232.

For such an opening, it is necessary to achieve a correct calibrated friction between the components of the articulated connection with a continuous ability to accept both the play of the mount and the play that is inevitably created by the use of the weapon.

A rod-shaped tension member (called a stock member by those skilled in the art) is generally used for this purpose and is releasably applied to the gun barrel by means of a lever that engages a shaped hook projection. or attached to the barrel. The stability of the above application, and consequently the functional capacity of the stock member, is achieved with great difficulty by means of successive operations to correct the hook projection.

The tension or “tightness” between the barrel unit and the breech of the weapon and the amount of friction necessary for the stability of the weapon during opening depend on the dimensions of the rod-shaped element or stock element (its length and / or thickness). Satisfactory tension and stability can be achieved only by successive operations to correct and calibrate the rod-shaped element.

Precisely because the aforementioned multiple mechanical operations require expert intervention and successive adjustments carried out manually on an industrial level by skilled operators, the barrel / breech / stock assembly of a detachable weapon can be considered as a highly individualized single unit. . For this reason, in a detachable weapon, the interchangeability of the barrel unit produced specifically for that weapon with other barrel units of the same type is not possible unless all the above-mentioned mechanical operations and expert interventions are repeated.

The main object of the invention is to design a device that provides mass production interchangeability of the barrel unit of a detachable shotgun with other barrel units of the same type, overcoming the technical and economic problems currently involved by the manual and exclusive operations that have hitherto been necessary for the individualized adaptation of a gun unit to a respective chamber.

This and other objects that will become clearer from the following description are achieved by means of a device of the type mentioned above having the structural characteristics set forth in the following claims.

The characteristics and advantages of the invention will become clearer from the description of an embodiment of a detachable shotgun incorporating a device according to the invention given below with reference to the accompanying drawings, provided by way of non-limiting example, in the which:

Figure 1 is a side view with separate parts of a removable shotgun of the type with superimposed barrels, Figure 2 shows schematically and in partial section a detail of the weapon of Figure 1 incorporating a device according to the invention, Figure 3 is a perspective view of a detail of the device of figure 2 with parts separated and on an enlarged scale, Figures 4 and 5 show another detail of the device of Figure 2 in perspective and with parts separated, Figure 6 is a view of another detail of the device of Figure 2.

With reference to the drawings, a removable shotgun with superimposed barrels comprises a barrel unit 1 releasably articulated to the front end 2a of a chamber 2 which in turn is fixed to the stock 3 of the weapon. This joint is indicated in the drawings by the joint generally indicated 4.

A plate-shaped pin 5 of predetermined thickness, at the front end of which a hook projection 6 is formed, is fixed to the lower barrel 1a of the barrel unit 1, in known manner.

A device generally indicated as 7 provided for the so-called tensioning or "tensioning" function between the barrel 1 and the breech 2 of the weapon is applied in the projection 6 in the manner described below.

In accordance with the present invention, device 7 comprises a substantially rod-shaped element 8 (figure 3) called a "stock element" by those skilled in the art, and a unit 28 (figures 4 and 5) for applying the element 8 in the form of a stem on the pin 5 and consequently on the barrel unit 1.

The stem or stem element 8 comprises in turn a head 9 integrally formed or otherwise attached to the end of a short stem 10 (Figure 2), a straight stem 11 projecting from the stem 10, a slider 15 guided to slide on the stem 11, and a spring 16 positioned between the head 9 and the slider 15 in order to push it away from the head of the stock member.

According to a preferred but not exclusive embodiment, the stem 11 is constructed substantially as a rectangular frame comprising two identical parallel flat stems 12, 13 connected to one another and spaced apart by an intermediate plate-shaped spacer 14 and an end spacer 14a. plate-shaped. Respective flat straight guides 12a, 13a are formed on the flat rods 12, 13 (only the guide 12a is visible in figure 3), the slider 15 being engaged to slide over them.

The slider 15 is preferably constituted by a plate, the front end 15a of which is intended to bear against the pin 5. The plate also has a

ES 2 201 243 T3 stop 17 which extends at right angles and on which the spring 16 acts.

According to a characteristic of the present invention, the spring 16 is very strong, preferably exerting a load of approximately 200 kg. When the stock element 8 is positioned between the joint 4 and the pin 5, the spring 16 pushes the slider 15 (the movable part of the rod-shaped tensioning element 8) strongly against the pin 5, achieving at the same time the desired degree of "stretch" between the barrel unit 1 and the chamber 2, consistently and effectively accepting both play in mounting and play due to use of the weapon.

In fact, the use of an element 8 in the form of a rod formed by two parts (the rod 11 and the slider 15) of which a movable part (the slider 15) is subjected to the action of a strong spring 16 makes the element 8 in the form of a stem an element of "variable length". This feature enables the barrel unit 1 of the detachable weapon in question to be exchanged for another barrel unit of a similar type (mass production interchangeability) without the need for numerous operations to adjust and correct its parts. Due to the power of the spring 16 (which exerts a load of 200 Kg), to facilitate the positioning of the stock element 8, it is provided that the contact between the slider 15 and the pin 5 takes place in an inclined plane 7 ° -8 , 5 ° with respect to the longitudinal axis of the mounting element 8 or, in any case, at an angle α (figure 6) smaller than the steel / steel friction angle of the steel from which the slider and the pin are made.

With respect to the application unit 28 (figures and 5), it comprises a lever 18 rotatable on the opposite walls 19a, 19b of a support base 19.

The lever 18 has a pair of tabs 20, 21 on which a hook 22 is hinged to engage the projection 6 of the hook of the pin 5. The angular position of the hook 22 relative to the lever 18 is adjustable by means of two screws. 23, 24 without head, the use of which fixes the hook 22 to the above-mentioned lever 18.

The elongated base 19 has at its middle ends 25, 26 to fix it to the respective spacers 14 of the stem 11, 14a. It should be noted that the elongated base 19 is intended to be housed in the so-called front end of the shotgun in question from whose exterior the lever 18 is accessible, in a known manner, to apply the stock element 8 on the barrel 2a of the shotgun. .

The fact that the angular position of the hook 22 in relation to the lever 18 can be varied in an adjustable way allows the play in mounting or due to wear to be accepted between the hook 22 and the hook formed by the pin 5. This is , makes it possible for the gun unit 1 to be replaced (mass production interchangeability) by another of the same type.

With the device of the present invention, the tolerances of the stock / housing / wooden front end mounting are canceled within the unit itself without requiring manual adjustment operations and without interfering with the barrel; The device of the present invention therefore makes the front end / housing / stock element unit adaptable to all barrels provided they are identical; in addition, the weapon opens smoothly and with guaranteed precision.