GB2259972A - Gun using a liquid propulsive charge - Google Patents

Abstract

A gun using a liquid propellant comprises a barrel 1, a breech 2 movable relative to the barrel, a chamber 5 forming a reservoir for the liquid propellant annularly disposed around the barrel between the barrel and the breech 2, and means 8 for injecting the liquid propellant contained in the chamber 5 into the combustion chamber 7 of the gun during recoil of the breech. Specified injection means 8 are : a valve which is open during ejection of the projectile; a sleeve on the breech having an aperture which is freed during recoil; and one or more rods attached to the breech and freeing an aperture in the barrel during recoil. A projectile 3 includes an ignition cartridge 14 whose ignition builds up pressure in the combustion chamber 7 and consequently opens the injection means 8. <IMAGE>

Description

Gun using a liquid propulsive charge The present invention relates to a

gun using a liquid propulsive charge such as a liquid propellant.

The propulsive charge used in guns is conventionally in the form of a solid whose volume is set at the factory, taking into account the performance that the projectile must have. In general, this volume is modular so that it can be adjusted by the operator before firing depending on the range of the objective to be hit. This final adjustment step is carried out manually and consequently takes a certain time, which reduces the efficiency of the weapon system during combat.

An object of the present invention is con- sequently to avoid this disadvantage by using a liquid propulsive charge that can easily and rapidly be adjusted in an automatic manner.

According to the present invention there is provided a gun using a liquid propulsive charge, said gun comprising a barrel intended to receive a projectile, a breech closing said barrel at one of its ends. said breech being movable relativeto the barrel, a combustion chamber for said charge, delimited by said end of the barrel, the rear of said projectile and said breech, a chamber forming a reservoir for said liquid propulsive charge, said reservoir chamber being disposed between the outer surface of said barrel and the inner surface of said breech, and means for injecting said liquid charge into said combustion chamber during the recoil of said breech.

The invention will now be described by way of example only with particular reference to the accompanying drai..,,ings, in which C> - Figures la and 1b show a first embodiment of the gun of the present invention; - Figure 2 shows a second embodiment of the gun of the invention; - Figure 3 shows an element of the gun of the embodiment of Figure 2; - Figure 4 shows a third embodiment of the gun of the invention; - Figures 5a and 5b show a variant embodiment of the gun of the invention and - Figures 6a and 6b show an element of the gun of the invention.

In these Figures, like reference numerals denote like ele- ments.

Referring to Figures la and lb, Figure la shows the configuration of the gun during loading of the projectile, and Figure 1b its configuration after ejection of this projectile.

In thesefigures, there is shown a partial view of the barrel 1 of the gun, with the longitudinal axis XX, and its breech 2 which is movable relative to the barrel. Inside the barrel 1, there is shown (in Figure la) a projectile 3 intro duced into the gun 1 at the breech after removing a part 21 referred to as a chock. The space between the rear of the projectile 3 and the bottom of the breech 2 (constitu ted by the chock 21) forms a combustion chamber 7 (Figure 1b) in which the propulsive charge burns while producing gases causing the expulsion of the projectile.

Between the chock 21 and the projectile 3, there is disposed an igniter cartridge 14 (Figure la) whose role is described hereinafter.

The barrel 1 has, on the combustion chamber side, a peripheral bulge 11 forming one of the two bearings on which the breech 2 slides, the other bearing being the end 22 of the breech sliding on the outer surface of the barrel 1. The annu lar space 5 delimited by the outer surface of the barrel 1, its end 11, the interior of the breech 2 and its end 22 (Figure la) is used as a reservoir chamber for the liquid propulsive charge, for example a liquid propellant.

The barrel 1 is further connected to motion-restraining and positionrestoring means 15 schematically and partially shown, intended as is known to slow its motion and to bring it back to its initial position.

The gun of the present invention further inclu- des means 6 for injecting the liquid charge into the reservoir chamber 5. These means are, for example, a passage 61 in which a valve 62 has been disposed.

In the embodiment shown in Figures la, lb, the end 11 of the barrel 1 includes means 8 for injecting the liquid charge into the combustion chamber 7.

These means 8 are, for example, one or more passages 81 in which one or more valves 82 are disposed.

The injection means can be, for example, of the type of those described in the published French patent application nO 2,604,247.

They can also be implemented as shown in Figures 6a and 6b.

These means 82 are of the valve type. They essentially comprise a moving part 83 closing the passage 81 under the action of a spring 84 as shown in Figure 6a.

When the pressure builds up in the combustion chamber 7, it drives the part 83 back (Figure 6b) and thus frees the passage 81 and allows the liquid charge to flow to the com bustion chamber 7 through apertures 85 provided in the body of the part 83.

Finally, the barrel 1 and the breech 2 include sealing devices 12 and 13, respectively.

The operation of the gun of the present invention is as follows:

In a preliminary step, the projectile 3 is introduced into the barrel 1. The projectile includes the igniter cartridge 14 that is detached from the latter during its introduction in.to the breech and retained by the latter. Ignition of the cartridge 14 results in a pressure build-up in the combustion chamber 7 and, consequently, in the introduction into this chamber of the liquid propellant contained in the reservoir chamber 5 (by opening of the valve or valves 82) and displa cement (arrow 24) of the breech 2 toward the rear. The combus tion of the liquid propellant thus introduced causes the ejec tion of the projectile 3 and recoil of the breech 2 until it is stopped by the end 11 of the barrel 1.

It thus appears that the breech 2 can freely move back, without driving the barrel 1 to the rear so long as it does not stop against the barrel, thus playing the role of a pro pellant injection differential piston.

As said above, the breech 2 stops against the end 11 of the barrel at the end of propellant injection. In a particu lar embodiment shown in Figure lb, the shape of the mating surfaces is not arbitrary, but instead is designed to cause a restraining action on the breech before its stopping against the end 11 of the barrel 1. The flow of the liquid propellant toward the valve 82 takes place through a baffle 18 whose cross section decreases, forming a damper with the liquid.

This arrangement substantially reduces the stresses produced by stopping the breech.

Figure 2 shows a second embodiment of the gun of the invention, in which the propellant injection cross section is variable.

In this Figure, the various elements described above can be seen, except the sealing means 12 between the portion 11 of the barrel and the breech 2.

There is further shown between the reservoir chamber 5 and the breech 2, attached thereto, a sleeve 4 that includes one or more apertures 41 gradually freed during the recoil of the breech 2 (arrow 24), thus permitting the injection of the liquid propellant into the combustion chamber 7.

An embodiment of such an aperture 41 is shown in Figure 3.

In this latter Figure, there is shown a partial view of the developed surface of the sleeve 4 at the place where it includes an aperture 41. This aperture has substantially the shape of a slot, increasing toward the muzzle of the barrel 1 There is shown an aperture 41 made up of three sections 42, 431 44, resepectively, whose widths are increasing.

During the combustion that takes place in the combustion r 7 with the barrel 1 remaining fixed, the breech 2 and consequently the sleeve 4 attached to it move back, thus freeing successively the sections 42, 43 and 44. The increasing widths of these sections thus allow a more and more significant injection of liquid. This allows the time dependent variation of the Dressure in the combustion chamber to be controlled, taking into account the fact that the volume of this chamber increases due to the forward motion of the projectile 3.

The shape of the aperture shown in Figure 3 is, of course, only an example, and any other shape may be used to give the desired trend to the pressure variation curve.

Figure 4 shows a third embodiment of the gun of the present invention.

chambe In this Figure, the-same elements as in Figure 1 can be seen, with the exception of the means 8 for injecting the liquid charge into the combustion chamber that are here a set of adjusting rods fixed in the breech 2 and with variable lengths, passing through the end 11 of the barrel 1. As an example, two such rods 81 and 82, respectively, of different lengths, are shown.

During the motion of the breech 2 toward the rear of the gun, the rods 81 and 82 attached to the breech are freed from the end 11 of the tube 1, and this occurs at times that depend, of course, on their length. Through the variation of the length of the various rods being used. it is thus possible to vary the flow rate of the liquid propellant into the combustion chamber.

In the preceding figures,the volume of the reservoir chamber is delimited by the barrel 1 and the breech 2 in the front stoD position. However, as the volume of the reservoir chamber is determined by the relative position of the breech and the bar rel, it can be adjusted. This adjustment can be carried out in several ways, Either the quantity of liquid charge is determined a priori by positive-displacement pumps; the injection of the desired quantity of liquid propellant into the chamber 5 then places the breech 2 in a given position.

or the gun is fitted with means for positioning the breech 2 as shown in Figures 5.

Figures 5a and 5b thus show the gun of the present invention in two embodiments including means for positioning the breech, which consequently ensure the adjustment of the volume of the reservoir chamber 5.

Figure 5a is, therefore, similar to Figures 1, with the exception that it includes in addition mechanical stops 51 positioned by means of hydraulic or air cylinders that have 11 1 1 the function of stopping the breech 2 in its (forward) motion during the filling of the reservoir chamber 5 by the liquid charge. The stops 51 are attached to the barrel 1, for example at the anchoring point of the restraining means 15 and rest against the front portion of the breech 2. The stops 51 can also be controlled manually or by means of electric motors.

Figure 5b is similar to Figure 5a, but with the stops now denoted by 52 being attached to the breech 2 and disposed in the combustion chamber 7. During the filling of the reservoir chamber 5, the forward motion of the breech 2 is stopped by the stops 52 coming to rest on the portion 11 of the barrel The various filling means described above are easily automatized. In addition, the liquid charge does not fill a preexisting volume, which would entail the risk of presence of air, of burnt gases, etc., but creates it by itself during its introduction. Finally, the quantity of liquid charge can be matched, round by round, to the desired performance and to the type of munition being used.

Claims (11)

1. A gun using a liquid propulsive charge, said gun comprising:

a barrel intended to receive a projectile, a breech closing said barrel at one of its ends, said breech being movable relative to the barrel, a combustion chamber for said charge. delimited by said end of the barrel. the rear of said projectile and said breech, a chamber forming a reservoir for said liquid propulsive charge, said reservoir chamber being disposed between the outer surface of said barrel and the inner surface of said breech, and means for injecting said liquid charge into said combustion chamber during the recoil of said breech.

2. A gun as claimed in claim 1, wherein said propulsive charge is a liquid propellant.

3. A gun as claimed in claim 1, further comprising motion restraining means and/or position restoring means connected to said barrel.

4. A gun as claimed in claim 1, wherein said injection means comprise a valve-type device, in closed position during the injection of said liquid charge in said reservoir chamber, and in open position during the ejection of said projectile. 30

5. A gun as claimed in claim 1, wherein said injection means comprise a sleeve having at least one aperture, said sleeve being disposed on the inner surface of said breech so that said aperture be freed by the barrel -A5 during the recoil of the breech.

.I 1

6. A gun as claimed in claim 5, wherein the area of said aperture is increasing so as to ensure the injection of an increasing quantity of liquid charge during the recoil of the breech.

7. A gun as claimed in claim 1, wherein said injection means include at least a rod attached to the breech, disposed parallel to the barrel, said barrel having an aperture provided in its end, said rod closing said aperture so that the aperture be freed during the recoil of said breech, thus allowing the injection.

8. A gun as claimed in claim 7, wherein said injection means comprise a plurality of rods whose lengths are different so that the apertures they close are successively freed during said recoil of the breech, thus ensuring the injection of an increasing quantity of liquid charge during said recoil of the breech.

9. A gun as claimed in claim 1, wherein said breech comprises a chock allowing the loading of the projectile.

10. A gun as claimed in claim 1, wherein said projectile comprising an igniter cartridge, the ignition of said cartridge permitting the injection of said liquid charge into said combustion chamber.

11. A gun substantially as hereinbefore described and as shown in Figures la and lb, or Figure 2 and Figure or Figure 4 or Figures 5a and 5b, of the accompanying drawings.

- to- Amendments to the claims have been filed as follows 6. A gun as claimed in claim 5,..jherein the area of said aperture is increasing so as to ensure the injection of an increasing quantity of liquid charge during the recoil of the breech.

i- e

11. A gun substantially as hereinbefore described and as shown in Figures la and lb, or Figure 2 and Figure 3, or Figure 4 or Figures 5a and 5b, or Figures 6a and 6b of the accompanying drawings.

)L 7. A gun as claimed in claim 1, wherein said injection means include at least a rod attached to the breech, disposed parallel to the barrel, said barrel having an aperture provided in its end, said rod closing said aperture so that the aperture be freed during the recoil of said breech, thus allowing the injection.

8. A gun as claimed in claim 7, wherein said injection means comprise a plurality of rods whose lengths are different so that the apertures they close are success- ively freed during said recoil of the breech, thus ensuring the injection of an increasing quantity of liquid charge during said recoil of the breech.

9. A gun as claimed in claim 1, wherein said breech comprises a chock allowing the loading of the projectile.

10. A gun as claimed in claim 1, wherein said projectil comprising an igniter cartridge, the ignition of said cartridge permitting the injection of said liquid charge into said combustion chamber.