EP2300771B1

EP2300771B1 - Apparatus and method for cleaning gun barrels

Info

Publication number: EP2300771B1
Application number: EP08789980A
Authority: EP
Inventors: Carlo Paolo Pennisi
Original assignee: Carosi Ariela
Current assignee: Carosi Ariela
Priority date: 2008-06-11
Filing date: 2008-06-11
Publication date: 2012-05-02
Anticipated expiration: 2028-06-11
Also published as: WO2009150674A1; ATE556292T1; EP2300771A1

Abstract

An apparatus (1) for cleaning the barrel (10) of guns, such as cannons, mortars, machine-guns, comprises a generator of ultrasonic pulses (40) operatively connected by a cable (45) to at least one transmitter (5) constrained to a support rod (4). In operative conditions, the support rod (4) is put into the chamber (13) of the barrel (10) with a measured amount of a cleaning fluid (20). The latter comprises at least one surfactant, in particular an anionic surfactant, mixed with water in a determined ratio. The apparatus (1) cleans the barrel (10) of guns in an effective way in particular removing both metal residues and carbonaceous residues of the propelling charge.

Description

Field of the invention

The present invention relates to the military field and, in particular, it relates to an apparatus for cleaning a gun barrel, in particular for large calibre and large size not easily portable weapons such as cannons, howitzers, mortars, etc..
Furthermore, the invention relates to a method for cleaning gun barrels carried out with this apparatus.

Description of the technical problem

As well known, the operators that use large weapons, such as cannons, howitzers, mortars, rifles etc. during a launch campaign, contact the dust of the burnt propelling charges, containing among others, mercury fulminate, potassium chlorate, antimony sulphide, lead with presence of antimony 2,5%-3%, residues of brass, steel plated with tomback (90% copper and 10% zinc, phosphorus, dust of nitrocellulose and nitro-glycerine).
Such substances, if inhaled or introduced directly in the body, also through small wounds of the skin, can cause serious damages to the health of the operators.
Therefore, to avoid an excessive accumulation of these substances and then a high probability that they contact the operators when they introduce the propelling charge, the gun barrels are periodically subject to cleaning.
The method commonly used for cleaning the guns comprises, in the parts subject to explosion of the propelling charge, the use of solvents derived from hydrocarbons.
However, the use of solvents derived from hydrocarbons has many drawbacks.
Firstly, the above described solvents are not suitable for a perfect cleaning of the gun barrels, since to an effective removal of the carbon residues of the propelling charge an effective removal does not correspond of the metal residues present in them.
In particular residues of copper, brass, lead, steel plated to the tomback, can be removed exclusively through a mechanical action, by means of swabs, brushes, or other metal tools. Such methods produce many small abrasions in the barrels that cause early wear of the weapons.
Furthermore, owing to their high inflammability (flash point about 70°-80°C) the hydrocarbon-based solvents are classified as dangerous substances, called toxic-noxious substances, and are then subject to strict regulations concerning their use, transport and storage. In particular, the regulations for their use require protecting masks or rebreathers for uses in a long period.
A further drawback deriving from the use of hydrocarbon-based solvents for cleaning gun barrels is their disposal after use that is expensive and difficult especially in a use during distant military exercises.
Furthermore, systems exist that provide the immersion of the weapons to clean in a basin containing water that is subject to action of ultrasonic pulses for removing the stuck residues of the propelling charges. EP1464913 A , which forms a starting point for independent claims 1 and 15, describes such a system.
However, the use of basins does not allow a precise action on the inner surfaces the weapons, such as the barrel where projectiles are housed.
Furthermore, such method with water and ultrasounds is often not enough for effectively removing the residues. In particular the water alone is not capable of softening the particles that are strongly stuck to the surfaces.

Summary of the invention

It is therefore a feature of the present invention to provide an apparatus for cleaning a gun barrel that is capable of providing an effective removal of both metal and carbonaceous residues.
It is also a feature of the invention to provide an apparatus for cleaning a gun barrel that is structurally easy and that is compact and allows an easy transportation.
It is another feature of the invention to provide an apparatus for cleaning a gun barrel that ensures an effective operation also in case of extreme environmental conditions, such as temperature below 0°C.
These and other objects are accomplished by an apparatus for cleaning a gun barrel, such as of cannons, howitzers, mortars, rifles, said barrel having an inner chamber, said apparatus comprising:

a generator of ultrasonic waves;
a support rod for at least one transmitter of ultrasonic pulses operatively connected to the generator of ultrasonic waves by a connection cable, said support rod being arranged, in use, in the gun barrel with a measured amount of a cleaning fluid, said ultrasonic waves being such that cavitation conditions are established in said fluid to remove impurities, in particular residues of propelling charge, from the inner surface of the barrel, said fluid comprising at least one surfactant.

Preferably, the surfactant is an anionic surfactant.
In particular the anionic surfactant can be selected from the group comprised of:

alkaline soaps, in particular potassium stearate and palmitate;
metal soaps, in particular lead (Pb) and calcium (Ca) soaps;
amine soaps, in particular comprising amino methylpropanediol (AMP);
sulphates and sulfonic esters, for example the sodium-lauryl sulphate, or sodium-dodecyl sulphate (SDS);
sulfonates: in particular alkan or alkyl-aryl sulfonates.

In particular the above described fluid comprises water and the anionic surfactant mixed in a determined ratio.
Advantageously, in addition to the water and to the surfactant the above described fluid comprises also a measured amount of an antifreeze substance, such as ethylene glycol.
In particular the transmitter of ultrasonic pulses can comprise at least one piezoelectric transducer,
Alternatively, the transmitter of ultrasonic pulses may be of magnetostrictive type,
In particular the support rod has at least one housing within which the, or each, transmitter of ultrasonic pulses is housed.
Advantageously, the support rod has an aperture with respect in which the or each transmitter is arranged.
Preferably, the support rod is associated with a plurality of transmitters of ultrasonic waves connected in series.
In particular the support rod can comprise guiding means suitable to assist the introduction/extraction of the support rod towards/away from said barrel.
For example, the guiding means can comprise a ring spacer constrained to the outer surface of the support rod.
In particular the ring spacer is constrained in a releasable way to the surface of the support rod, said ring spacer having a size corresponding to the size of the barrel.
In addition, the guiding means can comprise a handling rod adapted to engage with the support rod to assist its correct location in the gun barrel.
According to another aspect of the invention, a method for cleaning a gun barrel, such as of cannons, mortars, machine-guns, handguns, rifles, said barrel having an inner chamber, provides the following steps:

hermetically closing an end of the gun barrel;
feeding a measured amount of a cleaning fluid into the barrel;
introducing a support rod equipped with at least one transmitter of ultrasonic pulses in the barrel, said support rod being connected to a generator of ultrasonic pulses;
turning on the generator of ultrasonic pulses so that the, or each, transmitter, generates a beam of ultrasonic waves at a determined frequency that propagates in the cleaning fluid being such that cavitation conditions are established that remove the residues of the propelling charge from the inner surface of the barrel,- said fluid comprising at least one surfactant.

Brief description of the drawings.

The invention will be made clearer with the following description of an embodiment thereof, exemplifying but not limitative, with reference to the attached drawings wherein:

Fig. 1 shows a perspective view of an apparatus, according to the invention, for cleaning a gun barrel, such as of cannons, mortars, machine-guns, handguns, rifles;
Fig. 2 shows a cross sectional view of a barrel of a generic gun for which it is possible to use the method, according to the invention, for cleaning a gun barrel, such as of cannons, mortars, machine-guns, handguns, rifles;
Fig. 3 shows diagrammatically in an exploded view an elevational side view of the apparatus of Fig. 1 and the gun barrel of Fig. 2;
Fig. 4 shows a partially cross sectional elevational side view of a possible structure of a flexible auxiliary duct provided in the apparatus of Fig. 1;
Fig. 5 shows a partially cross sectional elevational side view of the apparatus of Fig. 1 in operative conditions;
Figs. from 6A to 6C show diagrammatically the succession of steps during the phenomenon of cavitation in the cleaning fluid, which allows to clean the gun barrel using the apparatus of Fig. 1;
Fig. 7 shows in detail a cross sectional portion of a barrel used in the method, according to the invention, showing diagrammatically the cleaning action the bubbles, formed by the phenomenon of cavitation, on the inner walls of the chamber of the barrel;
Fig. 8 shows diagrammatically the step for discharging the fluid containing the impurities removed from the inner surface at the end of treating the gun barrel with the apparatus of Fig. 1;
Figs. 9A and 9B show diagrammatically a partially cross sectioned elevational side view of two possible exemplary embodiments of a handling rod of the invention for handling the support rod, according to the invention;
Figs. 10 and 11 show diagrammatically a perspective partial cross sectional views of the apparatus for highlighting a possible exemplary embodiment of a sealing element of the gun barrel of the invention;
Fig. 12 shows a cross sectional view of the muzzle of a barrel of an gun to which an exemplary embodiment is applied of the apparatus, according to the invention, for highlighting some technical aspects;
Figs. 13 and 14 show diagrammatically an elevational side view and a perspective view of an apparatus for cleaning gun barrels, respectively in operative conditions and in rest conditions.

Description of preferred exemplary embodiments.

With reference to Figs. from 1 to 3, an apparatus 1 for cleaning a gun barrel 10, such as cannons, mortars, machine-guns, handguns, rifles, etc. comprises a generator of ultrasonic pulses 40 operatively connected by a connection cable 45 to at least one transmitter 5 constrained to a support rod 4. For example, the transmitters of ultrasonic waves are indicated as 6, 5a-5f, housed in series in an aperture co-axial to support rod 4.
In operative conditions, support rod 4 is put into the chamber 13 of barrel 10 with a measured amount of a cleaning fluid 20. This comprises at least one surfactant, in particular an anionic surfactant, mixed with water in a determined ratio.
The introduction of support rod 4 into chamber 13 can be assisted by the presence of a guide ring 6. It can be constrained in a removable way to the outer surface of the support rod 4, in order to use in turn guide ring 6 of a size corresponding to chamber 13 of barrel 10.
As shown in Fig. 9A, to assist a correct arrangement of support rod 4 in gun barrel 10, a handling rod 21 can be provided that engages with it at respective ends 4' and 21'. The use of handling rod 21 is particularly advantageous in case of a gun having a long barrel, such as a cannon/howitzer FH70.
The end 21' of the handling rod 21 can be, for example engaged at the end 4' of support rod 4 by means of respective connection flange 22 and 25 steadily fixed with respect to each other by means of bolts 23.
The handling rod 21 can be made of a plurality of segments, for example three segments 21a-21c, which are connected in series for example by means of respective screw threaded ends, up to reaching a determined length. In particular the first segment 21a of the series is connected by flange 22 to support rod 4, whereas the last segment 21c has a handgrip for assisting a grip by an operator 150.
In an exemplary embodiment shown in Fig. 9B, the handling rod 21 is of tubular shape, in particular it has a longitudinal aperture 26 in which the connection cable can be housed 45.
As shown in Figs. 10 and 11, the muzzle 11 of barrel 10 can be closed by means of a sealing element, or plug, 60 having at least one portion of compliant material, resiliently equipped with an opening 61 defined by walls 62 movable towards/away from each other resiliently. Therefore, when handling rod 21 is operated for actuating support rod 4, walls 62 of opening tightly adhere to the outer surface of support rod 4 same, thus avoiding leakage of the cleaning fluid from barrel 10.
In particular, as shown in detail in Fig. 12, lock means can be provided adapted to keep sealing element 60 in a correct position.
More in detail, the lock means can comprise a locking element, for example a disc 71, which in use is next to sealing element 60, and a push element for pushing with a suitable force locking element 71 against sealing element 60, for avoiding a movement of the latter away from a correct sealing position in operative conditions.
The push element can, for example, provide an elongated element 75 having a first end 75a connected to locking element 71, and a second end 75b free of sliding with respect to locking element 71, for example by means of a telescopic coupling, for contacting a contrast surface 72 integral to gun 10 and external to the barrel.
Locking element 71 and the plug 60 have in this case respective apertures 77 and 61, through which support rod 4 is put in/extracted from barrel 10. Furthermore, a discharge duct 76a and a feeding duct 76b of the fluid towards/away from barrel 10 can be provided, arranged at respective apertures made in sealing element 60 and in locking element 71.
The feeding the cleaning fluid 20 in barrel 10 is carried out preferably through the gun front end 11, or muzzle, after hermetically closing the rear end 12, or breech, made by a cover 16 formed by a special disc of rubber material that is introduced in the cap is normally associated to the gun. For example, cover 16 can be pivotally connected to barrel 10 by a hinge 17.
According to the invention, fluid 20 can be advantageously fed into barrel 10 using a duct, for example a flexible duct, constrained to the muzzle 11 of the gun barrel 10. More in detail, the fluid 20 is fed into barrel 10 up to a determined head H within duct 30, when the latter is arranged orthogonal to barrel 10.
As shown in Figs. 13 and 14, the cleaning fluid can be fed into gun barrel 10 by a pump 250 in hydraulic connection with a storage reservoir 260 and with the inside of barrel 10 by a flexible duct 80. Pump 250 can be used both for taking the fluid from the reservoir 260, feeding it into barrel 10, for cleaning it from the pollutants in it present, and for removing the polluted fluid from barrel 10 once ended the cleaning operation. In a further exemplary embodiment not shown in the figures, two different pumps can be provided, one for feeding and one for discharging the fluid. The apparatus, according to the invention, can provide furthermore a filter 255 through which the polluted liquid passes, when discharging barrel 10 for separating the pollutants, which are stored in sealed containers, from the cleaning fluid containing the water and the surfactant that can be therefore reused.
Reservoir 260, pump 250, filter 255 and the generator of ultrasonic waves in addition to transducers support 4 can be arranged on a carriage 300 to provide a device for cleaning a gun barrel 10 easily portable in an area of operation.
Then, the generator 40 is turned on, causing the transmission of ultrasonic waves to the mass of fluid 20 by transmitters 5a-5f. These can be piezoelectric microtransducers, or magnetostrictive microtransducers, or a combination thereof.
In particular the ultrasonic waves comprise compression and depression waves of that following one another at a high speed giving rise to a so-called "cavitation" phenomenon. More in detail, during the first phase of cavitation, called acoustic depression, in the fluid 20 there is the production of microscopic gas bubbles 50, or gaseous cavities, from which the name of the phenomenon comes.
As diagrammatically shown in Fig. 6A, during the step of depression, the small gas bubbles 50 starting from a starting size 50a grow reaching a final size 50d, running through intermediate size 50b-50c.
During the second step, i.e. of ultrasonic compression, diagrammatically shown in Fig. 6B, the high pressure P applied on each small bubble 50d compresses the same deforming it and increasing the temperature of the gas in it contained. This causes collapse of the small bubble 50e, which deforms and implodes releasing a certain energy E (Fig. 6C).
The energy produced by the implosion of small gas bubbles 50, hits the inner surface 14 of barrel 10 interacting with it both physically, with a "brushing" action, and chemically with washing effect owing to the presence of the surfactant in the fluid 20 (Fig. 7).
The cleaning fluid 20 in addition to the water and to the surfactant can also have a measured amount of an antifreeze substance, for example ethylene glycol. In this way an ideal operation is ensured of the apparatus 1 also in case of cold temperature, even much below zero. At such temperatures conditions, in fact, the phenomenon of cavitation above described could be impeded.
At the end of the cleaning step above described the fluid 20' containing the impurities 55 removed from the inner surface of the chamber 13 is expelled through a discharge valve 35 and collected in a storage reservoir 60. This way, it is possible to avoid polluting the environment, and to prevent fluid 20', which contains the residues of the propelling charge, from contacting the operators who are cleaning barrel 10.

Claims

Apparatus (1) for cleaning a gun barrel (10), such as of cannons, mortars, machine-guns, handguns, rifles, said barrel having an inner chamber, said apparatus (1) comprising:
- a generator of ultrasonic waves (40);

- a support rod (4) for at least one transmitter (5) of ultrasonic pulses operatively connected to said generator of ultrasonic waves (40) by a connection cable (45), said support rod (4) being arranged, in use, in said gun barrel (10) with a measured amount of a cleaning fluid (20), said ultrasonic waves being such that cavitation conditions are established in said fluid (20) in order to cause the removal of impurities from the inner surface of said barrel (10), said fluid (20) comprising at least one surfactant. .
Apparatus, according to claim 1, wherein said surfactant is an anionic surfactant.
Apparatus, according to claim 2, wherein said anionic surfactant is selected from the group comprised of:
- alkaline soaps, in particular potassium stearate and palmitate;

- metal soaps, in particular of lead (Pb) and calcium (Ca);

- amine soaps, in particular comprising amino methylpropanediol (AMP);

- sulphates and sulfonic esters, for example the sodium-lauryl sulphate, or sodium-dodecyl sulphate (SDS);

- sulfonates: in particular alkan or alkyl-aryl sulfonates.
Apparatus, according to claim 2, wherein said fluid (20) comprises water and the anionic surfactant mixed in a determined ratio.
Apparatus, according to claim 1, wherein said fluid (20) comprises also a measured amount of an antifreeze substance.
Apparatus, according to claim 5, wherein said antifreeze substance is ethylene glycol.
Apparatus, according to claim 1, wherein said transmitter (5) of ultrasonic pulses comprises at least one transducer selected from the group comprised of:
- a piezoelectric transducer;

- a magnetostrictive transducer.
Apparatus, according to claim 1, wherein said support rod (4) has at least one housing in which said, or each, transmitter (5) of ultrasonic pulses, is housed.
Apparatus, according to claim 8, wherein said housing is an aperture with respect to said support rod.
Apparatus, according to claim 1, wherein said support rod (4) is associated with a plurality of transmitters (6,5a-5f) of ultrasonic waves connected in series.
Apparatus, according to claim 1, wherein said support rod (4) is associated to guiding means suitable to assist its introduction/extraction towards/away from said gun barrel (10).
Apparatus, according to claim 11, wherein said guiding means comprises at least one ring spacer constrained to the outer surface of said support rod (4).
Apparatus, according to claim 12, wherein said ring spacer is constrained in a releasable way to the surface of the support rod (4) said ring spacer having a size corresponding to the size of the barrel (10).
Apparatus, according to claim 11, wherein said guiding means comprises a handling rod (21) adapted to engage with said support rod (4) to assist its correct location in said gun barrel (10).
Method for cleaning a gun barrel (10), such as of cannons, mortars, machine-guns, handguns, rifles, said barrel (10) having an inner chamber, said method comprising the following steps:
- hermetically closing an end of said gun barrel (10);

- feeding a measured amount of a cleaning fluid (20) in said barrel (10);

- introducing a support rod (4) equipped with at least one transmitter (5) of ultrasonic pulses in said barrel (10) containing said fluid (20), said support rod (4) being connected to a generator of ultrasonic pulses (40);

- turning on said generator of ultrasonic pulses (40) so that said, or each, transmitter (5), generates a beam of ultrasonic waves at a determined frequency that propagates in said cleaning fluid (20), such that cavitation conditions are established that remove the residues of the propelling charge from the inner surface of said barrel (10) said fluid (20) comprising at least one surfactant.