EP1895263B1

EP1895263B1 - Torpedo

Info

Publication number: EP1895263B1
Application number: EP06425608A
Authority: EP
Inventors: Luca Corbinelli; Giovanni Calvo; Luca Frediani; Germano Pratelli
Original assignee: Whitehead Alenia Sistemi Subacquei SpA
Current assignee: Whitehead Sistemi Subacquei SpA
Priority date: 2006-09-01
Filing date: 2006-09-01
Publication date: 2008-11-26
Anticipated expiration: 2026-09-01
Also published as: ATE415612T1; EP1895263A1; DE602006003898D1

Abstract

A torpedo (1) has a main body (2), and a guidance wire (3) , which has a first portion (15) connected to the main body (2) and forming a hollow coil (13), and a second portion (16) connectable to a launch tube of a naval vessel; the main body (2) has a casing (17), and supporting means (18,28); the supporting means (18) define with the coil a first chamber (49) and which is filled with a fluid when flooding the launch tube; the supporting means (18) define with the casing (17) a second chamber (50); the torpedo has fluidic connecting means (75) between the first chamber (49) and second chamber (50); and the fluidic connecting means (75) permit fluid flow between the first chamber (49) and second chamber (50) to maintain the pressure gradient between the second chamber (50) and the first chamber (49) below a predetermined value.

Description

The present invention relates to a torpedo.
A torpedo according to the preamble of claim 1 is known from US 3 831 879 A .
Torpedoes are known comprising a main body movable in the sea to strike a target; and a guidance wire for continuous information exchange between a naval vessel, e.g. a submarine or warship, and the torpedo.
More specifically, the main body of the torpedo comprises a number of stages housing respective equipment of the torpedo, such as the propulsion system, an acoustic detection unit, and a warhead.
The main body of the torpedo also comprises a control and guidance stage, to which a first end of the guidance wire is fixed. More specifically, the first end of the guidance wire is wound into a first hollow coil.
The opposite end of the guidance wire is wound into a second hollow coil fixed to a supporting member.
More specifically, the control and guidance stage comprises a casing housing the first coil.
The first coil is maintained in a predetermined position inside the casing by a supporting structure integral with the first coil.
The supporting structure comprises two flanges, each cooperating with a respective axial-end lateral surface of the wire in the first coil; and a cylindrical body interposed between the flanges and cooperating with the outer lateral surface of the wire in the first coil.
A first chamber is thus defined inside the first coil, and is bounded externally by an inner lateral surface of the wire in the first coil, and by the flanges of the coil supporting structure.
The first chamber is connected by a wire feed duct to a marine environment externally surrounding the torpedo.
The control and guidance stage also defines a second chamber bounded externally by the casing, and internally by the supporting structure.
The second chamber surrounds the first coil externally, and is separated from the first coil by the interposition of the flanges and the cylindrical body.
During torpedo launch training, the supporting member is fixed to a launch tube of the vessel, and the aft portion of the torpedo is connected releasably to the supporting member.
Preparatory to launching, the torpedo is flooded and pressurized so the pressure inside the launch tube equals the pressure in the area of sea surrounding the torpedo exit point.
When flooding the torpedo, water fills the wire feed duct and, from this, the first chamber.
The aft portion is then released from the supporting member to allow the torpedo to leave the launch tube.
The motion of the torpedo and vessel unwind the first and second coil respectively, while the wire stretched between the first and second coil remains substantially stationary with respect to the sea.
The Applicant has observed several drawbacks of known torpedoes.
A first lies in the fact that, in the event of the torpedo climbing, the first coil collapses inside the first chamber, thus damaging the wire and so impairing feed of the wire and data transmission along it.
A second lies in the fact that, whenever it becomes necessary to depressurize and empty the launch tube, owing to a malfunction of the launch tube, the wire is seriously damaged by the time depressurization is completed.
It is an object of the present invention to provide a torpedo designed to eliminate, in a straightforward, low-cost manner, at least one of the aforementioned drawbacks typically associated with known torpedoes.
According to the present invention, there is provided a torpedo, as defined in Claim 1.
As regards the first drawback, tests conducted by the Applicant show collapse of the first coil to be caused by the inner lateral surface of the first coil being subjected to a first pressure, and the outer lateral surface of the first coil being subjected to a second pressure greater than the first.
More specifically, tests conducted by the Applicant show the first pressure to be exerted by the water inside the first chamber, and the second pressure to be exerted by water seeping into the second chamber through the clearances of the flanges and the cylindrical body.
When the torpedo is climbing, the first pressure in the first chamber falls rapidly, on account of the first chamber being connected directly to the sea, whereas the second pressure falls much more slowly, on account of the water seeping slowly from the second chamber to the first.
At this stage, the second pressure on the outer surface of the coil is therefore greater than the first pressure on the inner surface, thus causing the wire wound into the first coil to collapse.
As regards the second drawback, tests conducted by the Applicant show this to be caused by an air bubble trapped at least partly inside the control and guidance stage following flooding and pressurization.
When the launch tube is emptied and depressurized, the air bubble expands and seeps into the first chamber through the clearances in the supporting structure, so that a stream of air flows into the first chamber and expels the wire, thus impairing data transmission.
The present invention eliminates the above drawbacks by employing fluidic connecting means interposed between the first and second chamber to allow a predetermined amount of air and water to circulate between the first and second chamber to maintain the pressure gradient between the second and first chamber below a predetermined value.
A preferred, non-limiting embodiment of the present invention will be described by way of example with reference to the accompanying drawings, in which:

Figure 1 shows a side view of a torpedo in accordance with the present invention;
Figure 2 shows a schematic, with parts removed for clarity, of the Figure 1 torpedo;
Figures 3 and 4 show larger-scale, axial sections of details of Figures 1 and 2;
Figure 5 shows a larger-scale, exploded section of details of Figure 3;
Figure 6 shows the Figure 5 details as assembled;
Figure 7 shows a section along line VII-VII in Figure 6.

Number 1 in Figures 1 and 2 indicates a torpedo substantially comprising a main body 2; and a guidance wire 3 for in-mission guidance of torpedo 1 and data exchange between main body 2 and a naval vessel, in particular a warship or submarine.
More specifically, main body 2 comprises a fore portion 4 with acoustic sensors (not shown); and an aft portion 6 housing a number of propellers 7 immersed in the sea to propel torpedo 1.
Main body 2 also comprises a central portion 8 in an intermediate position between fore portion 4 and aft portion 6.
From fore portion 4 to aft portion 6, central portion 8 houses a unit 9 containing the explosive charge; an energy storage unit 10; and a control and guidance unit 11. Central portion 8 also houses a propulsion unit 5 connected operatively to unit 9 to rotate propellers 7. During launch training, torpedo 1 is housed inside a launch tube of a naval vessel, e.g. a warship or submarine.
More specifically, aft portion 6 (as shown in Figure 1) is housed inside and connected to a hollow member 12 integral with the launch tube.
Aft portion 6 is connected to member 12 by means of a number of hydraulic jaws (not shown) on member 12, which cooperate with a shank (not shown) on aft portion 6.
When launching torpedo 1, the hydraulic jaws release the shank to allow aft portion 6 to leave member 12 and the launch tube. Wire 3 comprises a first portion 15, and a second portion 16 (Figures 2, 3, 4).
More specifically, portion 15 and portion 16 have respective first ends fixed to unit 11 and member 12 respectively; and respective second ends opposite the first ends and connected to each other by a connector 71 (Figure 5) housed inside member 12.
As shown in Figures 2 to 4, the first end of portion 15 is wound into a hollow, cylindrical first coil 13 (Figures 2 and 3) extending along an axis A and housed in unit 11; and the first end of portion 16 is wound into a hollow, cylindrical second coil 14 (Figures 2 and 4) housed in member 12.
As shown in Figures 3 and 4, from first coil 13 to connector 71, portion 15 is unwound off first coil 13 inside unit 11, and is fed along a wire duct 63 having a first mouth fixed to unit 11, and a second mouth facing the inside of member 12 prior to launching torpedo 1; portion 15 is then fed through a fitting 67 (Figure 4) for positioning part of portion 15 adjacent to connector 71 positioned crosswise to and offset with respect to axis A.
From second coil 14 to connector 71, portion 16 is fed along a corrugated protective duct 65 and a tubular body 64, the function of which is described below.
Duct 63 and tubular body 64 are connected to each other, so as to yield under a given load, by a shell 62.
With particular reference to Figure 3, unit 11 substantially comprises a casing 17 extending symmetrically with respect to axis A and housing first coil 13.
More specifically, first coil 13 is maintained in a predetermined position inside casing 17 by a supporting structure 18 integral with first coil 13.
Casing 17 is housed inside a compartment bounded by an inner surface of a wall 54 (shown only partly in Figure 3) of main body 2.
Casing 17 comprises two opposite, axial end walls 19, 20 extending crosswise to axis A; and an annular wall 21 extending between walls 19, 20.
Structure 18 comprises two axially spaced, annular flanges 22, 23 perpendicular to axis A; and a tubular cover 24 housing flanges 22, 23.
More specifically, flange 22 comprises an outer radial end portion 25 cooperating with an axial end wall 26 of cover 24.
Similarly, flange 23 comprises an outer radial end portion 27 cooperating with an axial end wall 37, opposite wall 26, of cover 24.
At opposite axial ends, casing 17 houses a pin 28 and a member 32, which cooperate with structure 18 to maintain first coil 13 in a predetermined position inside casing 17.
More specifically, an axial end 31 of pin 28 is fixed to wall 19.
An axial end 30, opposite end 31, of pin 28 is connected to a member 77 in turn fixed to a radially-inner portion 29 of flange 22.
Pin 28 provides for taking up any slack caused by the movement of first coil 13, and is described in more detail below.
Member 32 comprises a first axial end 34 fixed to a radially-inner portion 33 of flange 23; and a second axial end 35 opposite end 34 and fixed to wall 20.
Member 32 defines internally a conduit 36, of axis A, decreasing radially in size from end 34 to end 35.
Wire 3 is wound into first coil 13 so that the first coil is bounded by two annular, axial end surfaces 41, 42; by an outer lateral surface 43; and by an inner lateral surface 44 defining a hole 45 coaxial with first coil 13.
More specifically, first coil 13 is unwound from inside hole 45, which has opposite axial ends 46, 47.
Surfaces 41, 42 of first coil 13 cooperate with flanges 22, 23 respectively, and lateral surface 43 faces cover 24.
First coil 13 is positioned inside casing 17 so that end 46 of hole 45 is engaged by member 77, and end 47 of hole 45 cooperates with end 34 of member 32.
A cylindrical chamber 49, of axis A, is thus defined inside first coil 13. More specifically, chamber 49 is bounded at opposite axial ends by member 77 and by end 34 of member 32, and is bounded radially by lateral surface 44.
End 47 of hole 45 faces the inside of conduit 36 to fluidically connect chamber 49 and conduit 36.
An annular layer 39 of shock-absorbing material is interposed radially between cover 24 and lateral surface 43.
Structure 18 and casing 17 also define an annular chamber 50 coaxially surrounding first coil 13.
More specifically, chamber 50 comprises a first axial end defined by a portion 52; and a second axial end opposite the first and defined by a portion 53.
Chamber 50 also comprises a portion 51 extending between portions 52, 53.
Portion 52 is bounded by flange 22 and wall 19, partly surrounds pin 28 and member 77, and extends substantially radially with respect to axis A. Portion 53 is bounded by flange 23 and wall 20, partly surrounds member 32, and extends substantially radially with respect to axis A.
Portion 51 extends axially, and is defined between cover 24 and wall 21 of casing 17.
Duct 63 extends along axis A, and is connected, at the opposite end to chamber 49, to fitting 67 (Figure 4).
Shell 62 has a first end connected to a mouth 72 of tubular body 64; and a second end connected to a mouth of fitting 67 at the opposite end to duct 63.
At the opposite end to mouth 72 of tubular body 64, shell 62 defines two portions 48 connected to respective projections 40 on the fitting 67 end of duct 63.
More specifically, projections 40 are connected to respective portions 48 by connecting means which yield under a predetermined load, on reaching which, duct 63 is free to withdraw from shell 62 and tubular body 64.
In the example shown, the yielding connecting means are calibrated screws.
Connector 71 extends crosswise to and is offset with respect to axis A.
Connector 71 and shell 62 are connected to each other by a magnet (not shown) integral with shell 62, and a metal bush (not shown) integral with connector 71.
When the force on wire 3 and shell 62 is less than the magnetic attraction between the magnet on shell 62 and the bush on connector 71, shell 62 and connector 71 therefore remain in a predetermined relative position (shown in Figure 4).
Conversely, when the force on wire 3 and shell 62 is greater than the magnetic attraction between the magnet on shell 62 and the bush on connector 71, shell 62 can slide with respect to connector 71.
Shell 62 also comprises a number of slits 73 (only shown partly in Figure 4) open to the sea and which, when the launch tube is flooded, allow water to flow into fitting 67 and, therefore, into duct 63 and chamber 49.
Preparatory to launching, fitting 67, duct 63, and chamber 49 are full of air.
Member 12 (Figures 1, 2, 4) is only described below as required for a clear understanding of the present invention.
Very briefly, member 12 comprises an axially symmetrical casing 55 (Figure 2) open at the fore end to house aft portion 6 of main body 2, and closed at the aft end by a wall 56 (not shown in Figure 4).
More specifically, when aft portion 6 is housed inside member 12, the axis of symmetry of casing 55 is coincident with axis A.
Casing 55 houses a supporting structure 57 fixed to casing 55 and cooperating with second coil 14 to maintain it in a predetermined position inside casing 55; casing 55, furthermore, houses and an annular wall 58 surrounding structure 57.
Second coil 14 is similar to first coil 13 and therefore not described in detail.
Structure 57 comprises two axially opposite flanges 59, 60 cooperating with respective axial end surfaces of second coil 14; and a cover 61 interposed axially between flanges 59 and 60 and cooperating with an outer lateral surface of second coil 14.
Structure 57 is bounded at the aft end by a member 66, of axis A, cooperating with flange 60. More specifically, member 66 provides for threading through wire portion 16, and cooperates with flange 60.
Second coil 14 is positioned inside structure 57 so that the cylindrical inner chamber 38 of the coil is coaxial with axis A, and one axial end of hole 38 faces member 66.
Wall 58 and casing 55 define, radially, an annular compartment 79 for housing tubular body 64 when this is wound.
Tubular body 64 comprises an end mouth 74 at the opposite end to mouth 72 and connected to a mouth of corrugated duct 65 at the opposite end to member 66.
Mouth 74 of tubular body 64 is also connected to a member 78 fixed inside member 12.
Tubular body 64 is a flexible corrugated tube made of metal and comprising two numbers of turns (not shown) wound into a dual coil about a longitudinal axis of tubular body 64.
Each turn is made axially slack with respect to the adjacent turns in the same number, so as to slide with respect to the adjacent turns within a given limit depending on the manufacturing process of tubular body 64.
When compressed, tubular body 64 assumes a minimum-length configuration, in which the turns are packed together.
When main body 2 of torpedo 1 is housed inside the launch tube, tubular body 64 is wound inside compartment 79 and in the minimum-length configuration.
When pulled, the turns of tubular body 64 slide with respect to one another until tubular body 64 assumes a maximum-length configuration, in which each turn is separated from the adjacent turns.
By virtue of the turns being able to slide with respect to one another, tubular body 64, when pulled, stretches more than a portion R of wire portion 16 housed inside tubular body 64.
Portion R of portion 16, in fact, can only extend elastically, whereas tubular body 64 can also extend anelastically, by virtue of the turns sliding and so recovering the slack between them.
As shown in Figure 4, when aft portion 6 is housed inside member 12, tubular body 64 is wound into a number of layers 69 (only one indicated in Figure 4) superimposed radially to form a number of radial columns 68 (only one indicated in Figure 4).
Columns 68 of layers 69 are located side by side inside compartment 79.
Torpedo 1 advantageously comprises fluidic connecting means 75 (Figures 5, 6, 7) interposed between chamber 49 and chamber 50 to allow a predetermined amount of water and air to circulate between chamber 49 and chamber 50 to maintain the pressure gradient between chamber 50 and chamber 49 below a predetermined value.
With reference to Figures 5 to 7, fluidic connecting means 75 define, inside pin 28, a fluidic connecting path P (Figures 3 and 6) extending between chambers 49 and 50.
Fluidic connecting means 75 comprise pin 28 and member 77.
More specifically, member 77 extends along axis A and defines, coaxially, a through hole 83 connected fluidically to chamber 49.
One end 87, facing pin 28, of member 77 has a number of - in the example shown, six - holes 90 (only one indicated in Figure 7) having respective radial axes with respect to axis A.
More specifically, holes 90 are located radially outwards with respect to hole 83, and are equally spaced with respect to axis A.
Each hole 90 has a respective radially outer end 98 (indicated in Figures 5 to 7) communicating fluidically with chamber 50; and a respective radially inner end 99 (only indicated in Figures 5 to 7) facing hole 83.
Member 77 also comprises, at the opposite end to end 87, a portion 88 projecting radially and fixed to flange 22.
Pin 28 extends along axis A, and comprises an axial end portion 84 fixed to wall 19 of casing 17; and a portion 85 at the opposite axial end to portion 84 and engaging hole 83 in member 77.
Pin 28 also comprises a portion 86 interposed axially between, and smaller radially than, portions 84 and 85.
Pin 28 defines a dead hole 92, which extends through portions 85 and 86 and partly inside portion 84.
Portion 86 has a number of - in the example shown, four - through holes 91 (only one indicated in Figure 7) extending radially with respect to axis A.
More specifically, holes 91 are equally spaced angularly with respect to axis A, and each have a radially inner end 102 communicating fluidically with hole 92.
As shown in Figure 6, pin 28 is housed inside member 77 so that portions 85, 86 engage hole 83 in member 77 to fluidically connect hole 92 and hole 83, and so that portion 84 rests axially against end 87 of member 77.
More specifically, portion 86 cooperates externally with an inner surface of hole 83.
Pin 28 is also housed inside member 77 so that portion 85 is located radially at end 87 of member 77.
Portion 86 being radially smaller than portion 85, portion 86 of pin 28 and end 87 of member 77 define between them a toroidal compartment 89 of axis A (Figures 6 and 7).
More specifically, compartment 89 is connected fluidically, at its outer circumferential edge, to holes 90 in end 87, and, at its inner circumferential edge, to holes 91 in portion 86.
The radially inner end 99 of each hole 90 and the radially outer end 103 of each hole 91 are open towards compartment 89.
As shown in Figure 7, pin 28 and member 77 are so connected that two diametrically opposite holes 91 in pin 28 are coaxial with two diametrically opposite holes 90 in member 77.
From chamber 50 to chamber 49, path P therefore comprises holes 90 in end 87 of member 77; compartment 89; holes 91 in portion 86 of pin 28; hole 92 in pin 28; and hole 83 in member 77.
Hole 92 in portion 85 is located at a distance from surface 44 to prevent water flow from chamber 50 to chamber 49 from interfering with the unwinding of first coil 13.
A conduit 94 (Figures 3, 5, 6), parallel to and eccentric with respect to axis A, extends through portion 88 of member 77 and flange 22 to further connect chamber 49 and chamber 50.
More specifically, conduit 94 is defined by a hole 95 formed in portion 88 of member 77, and by a hole 96 in flange 22. Hole 95 and hole 96 are contiguous, and extend along the same axis parallel to and at a distance from axis A.
Conduit 94 allows all the air in chamber 49 to flow into chamber 50 when flooding the launch tube.
Conduit 94 is sized to avoid interfering with the unwinding of first coil 13, and to permit correct air flow from chamber 49 to chamber 50.
With reference to Figure 3, torpedo 1 also comprises a conduit 110 fluidically connecting chamber 50 to an environment outside main body 2, i.e. the sea.
Conduit 110 is made of flexible material, and has a first end 111 connected by a fitting 113 to the sea; and a second end 112 opposite end 111 and connected by a fitting 114 to portion 51 of chamber 50.
Fittings 113, 114 extend through walls 54, 21 respectively, and are orientable in space to compensate the movements of conduit 110.
Conduit 110 defines a flow section S perpendicular to the fluid flow from chamber 50 to the sea.
More specifically, the area of section S is smaller than the total area of holes 91.
The Applicant, in fact, has observed that the above sizing provides for balancing the pressure in chamber 49 and the sea pressure at the travelling depth of torpedo 1.
With reference to Figure 2, unit 11 comprises a converter 104, which receives the optical signal supplied by first coil 13, and supplies an electric signal compatible with the equipment of torpedo 1, or vice versa.
Member 12 comprises a converter 105, which receives the electric signals supplied by the naval vessel, and supplies them in optical form to second coil 14, or vice versa.
Operation of torpedo 1 will be described as of a condition (shown in Figures 1, 3, 4) in which main body 2 is fixed inside the launch tube of the naval vessel.
In the above condition, aft portion 6 is housed inside member 12, and the hydraulic jaws on member 12 cooperate with the shank on main body 2.
Duct 63 and chambers 49, 50 are partly filled with air, and tubular body 64 is in the minimum-length configuration and wound completely inside compartment 79 in member 12.
Connector 71, as shown in Figure 4, is located inside shell 62 and outside tubular body 64.
To launch torpedo 1, the launch tube is first flooded to bring the pressure inside the launch tube to the same pressure as the sea at the launch depth of torpedo 1.
When the launch tube is flooded, water flows through slits 73 into shell 62 and fitting 67, and then into duct 63 and chamber 49.
Connecting means 75 allow the water in chamber 49 to flow along path P.
More specifically, the water in chamber 49 first reaches hole 83 in member 77 and hole 92 in portion 85 of pin 28.
The water then flows radially in a centrifugal direction through holes 91 in portion 86 of pin 28 into compartment 89.
Finally, the water flows through holes 90 from compartment 89 into chamber 50.
The water flow along path P from chamber 49 to chamber 50 balances the pressures in chambers 49 and 50.
The water inside chamber 50 seeps through the clearances between cover 24 and flanges 22, 23, and between cover 24 and layer 39, to the lateral surface 43 of first coil 13.
The water reaching lateral surface 43 has substantially the same pressure as chamber 50, the only difference being the losses caused by seepage.
As a result, inner lateral surface 44 and outer lateral surface 43 of first coil 13 are subjected to substantially the same pressure.
Water flow from duct 63 to chamber 49 and from chamber 49 to chamber 50 forces large part of the air initially inside duct 63 and chamber 49 into chamber 50, from which it is expelled into the sea by conduit 110.
At the same time, the remaining air inside chamber 49 flows through conduit 94 into chamber 50, from which it is expelled into the sea by conduit 110.
Once flooding of the launch tube is completed, duct 63, chamber 49, and chamber 50 therefore contain substantially no air.
At this point, the hydraulic jaws on member 12 release the shank on aft portion 6.
In this condition, torpedo 1 and the naval vessel are connected solely by wire 3.
To launch torpedo 1, the launch tube is first flooded to bring the pressure inside the launch tube to the same pressure as the sea at the launch depth of torpedo 1.
Unit 10 is then activated, and main body 2 leaves the launch tube.
More specifically, unit 11 and duct 63 withdraw from member 12, which remains fixed inside the launch tube.
Initially, by means of the connection between projections 40 and portions 48, withdrawal of duct 63 causes tubular body 64 and portion R of portion 16 inside tubular body 64 to unwind.
At this initial stage, practically no force is exchanged between projections 40 and portions 48, by virtue of the unwinding of tubular body 64 allowing shell 62 and portions 48 to follow projections 40 and duct 63.
At this initial launch stage, tubular body 64 prevents portion R inside it from contacting and being damaged by propellers 7.
Once tubular body 64 is extended, further withdrawal of main body 2 brings tubular body 64 anelastically into the maximum-length configuration, whereas portion R of wire 3 is only stretched elastically.
Relative slide is thus produced between tubular body 64 and portion R, during which, mouth 72 moves with respect to connector 71 towards duct 63 into a position in which connector 71 is housed inside tubular body 64 and adjacent to mouth 72.
Tubular body 64 and shell 62 being integral with each other, shell 62 slides with respect to connector 71 in opposition to the magnetic attraction between the magnet on shell 62 and the bush on connector 71.
Once the maximum-length configuration is assumed, tubular body 64 can no longer follow withdrawal of duct 63 from member 12.
Upon a predetermined load being exchanged between projections 40 and portions 48, the connection between projections 40 and portions 48 yields, thus leaving duct 63 free to withdraw from shell 62 and tubular body 64.
When stress on projections 40 and portions 48 exceeds the yield load, tubular body 64 and shell 62 are detached from duct 63.
Tubular body 64, now released, contracts to bring mouth 72 closer to corrugated duct 65.
Next, the relative movement of torpedo 1 and the navel vessel causes first coil 13 and second coil 14 to unwind, while wire 3 stretched between first coil 13 and second coil 14 remains stationary with respect to the seawater.
As torpedo 1 advances, first coil 13 is unwound, thus increasing the volume of chamber 49.
The increase in the volume of chamber 49 causes additional water to be sucked into duct 63 from chamber 49.
As a result, the pressure in chamber 49 falls.
Fluidic connecting means 75 feed the additional water into chamber 49 along path P.
By so doing, fluidic connecting means 75 maintain the pressure gradient between chambers 49 and 50 below a predetermined threshold value.
The pressure on inner lateral surface 44 therefore substantially equals the pressure on outer lateral surface 43, thus preventing first coil 13 from collapsing inside chamber 49.
Tests show the sizing of section S and the total area of holes 91 to be effective, at this stage, in balancing the sea pressure and the pressure in chamber 49.
Upon descent of torpedo 1, the pressure of the water flowing into duct 63 and chamber 49 increases.
Fluidic connecting means 75 transmit an overpressure wave along path P from chamber 49 to chamber 50 to maintain the pressure gradient between chambers 49 and 50 below the predetermined threshold value.
The water inside chamber 50 seeps through the clearances between cover 24 and flanges 22, 23, and between cover 24 and layer 39, to the lateral surface 43 of first coil 13.
The water reaching lateral surface 43 has substantially the same pressure as chamber 50, the only difference being the losses caused by seepage.
As a result, outer lateral surface 43 and inner lateral surface 44 of first coil 13 are subjected to substantially the same pressure.
In the event descent is followed by climbing of torpedo 1, the pressure of the water flowing into duct 63 and chamber 49 falls.
Fluidic connecting means 75 feed a predetermined flow of water along path P from chamber 50 to chamber 49 to maintain the pressure gradient between chambers 50 and 49 below the predetermined threshold value.
In the event of torpedo 1 climbing, outer lateral surface 43 and inner lateral surface 44 of first coil 13 are therefore again subjected to substantially the same pressure.
The pressure on inner lateral surface 44 is thus prevented from falling too far below the pressure on outer lateral surface 43, thus resulting in collapse and relaxation of first coil 13 inside chamber 49.
More specifically, seawater flows from chamber 50 into compartment 89 through holes 90.
From compartment 89, the seawater then flows through holes 91 into hole 92 in pin 28.
Finally, the seawater flows from hole 92 into hole 83 connected fluidically to chamber 49.
More specifically, by virtue of the radial distance between hole 92 and first coil 13, the water flowing from hole 91 into chamber 49 does not interfere with the unwinding of first coil 13, thus preventing damage to the coil.
To interrupt launching of torpedo 1, e.g. due to a malfunction of the launch tube, the launch tube must be depressurized and emptied.
Since the air initially inside chambers 49, 50 and duct 63 has been expelled along conduit 110 into the sea at the pressurization stage, no airflow which could damage first coil 13 is generated inside chamber 49.
The advantages of torpedo 1 according to the present invention will be clear from the foregoing description.
In particular, fluidic connecting means 75 provide for maintaining the pressure gradient between the pressure on outer lateral surface 43 and the pressure on inner lateral surface 44 of first coil 13 below a predetermined value in any travelling condition of torpedo 1.
First coil 13 is thus prevented from collapsing inside chamber 49 and so damaging, and impairing data transmission over, wire 3.
Moreover, conduit 110 provides for expelling all the air from duct 63 when flooding and pressurizing the launch tube.
As a result, when depressurizing and emptying the launch tube, no airflow which could damage first coil 13 is produced from chamber 50 to chamber 49.
Tests show the sizing of the area of section S with respect to the total area of holes 91 to be effective in balancing sea pressure and the pressure inside chamber 49 as torpedo 1 advances.
Clearly, changes may be made to torpedo 1 without, however, departing from the protective scope defined in the accompanying Claims.

Claims

A torpedo (1) comprising :
- a main body (2); and

- a guidance wire (3), in turn comprising a first portion (15) connected to said main body (2) and wound into a hollow coil (13), and a second portion (16) connectable to a launch tube of a naval vessel to allow said main body (2) and said naval vessel to move with respect to each other;
said main body (2) comprising a casing (17) housing said coil (13); and supporting means (18, 28, 77) for maintaining said coil (13) in a predetermined position inside said casing (17);
said supporting means (18, 28, 77) defining with said coil (13) a first chamber (49) inside the coil (13); said first chamber (49) being filled at least partly with a fluid when flooding said launch tube;
said supporting means (18, 28, 77) defining with said casing (17) a second chamber (50) externally surrounding said coil (13);
and characterized by comprising fluidic connecting means (75) interposed between said first chamber (49) and said second chamber (50); said fluidic connecting means (75) permitting circulation of a predetermined flow of said fluid between said first chamber (49) and said second chamber (50) to maintain the pressure gradient between said second chamber (50) and said first chamber (49) below a predetermined value.
A torpedo as claimed in Claim 1, characterized by comprising a conduit (110) interposed between said second chamber (50) and an external environment surrounding said torpedo (1).
A torpedo as claimed in Claim 1 or 2, characterized in that said fluidic connecting means (75) are defined by said supporting means (18, 28, 77).
A torpedo as claimed in Claim 3, characterized in that said supporting means (18, 28, 77) comprise a first member (77); said first member (77) comprising a first opening (83) connected fluidically to said first chamber (49), and at least one second opening (90) connected fluidically to said second chamber (50);
said first opening (83) and said second opening (90) being connected fluidically to each other to permit circulation of said predetermined flow between said first chamber (49) and said second chamber (50).
A torpedo as claimed in Claim 4, characterized in that said first member (77) extends along an axis (A), and in that said second opening (90) is located radially outwards with respect to said first opening (83).
A torpedo as claimed in Claim 5, characterized by comprising at least two said second openings (90) equally spaced angularly with respect to said axis (A).
A torpedo as claimed in any one of Claims 4 to 6, characterized in that said supporting means (18, 28, 77) comprise a second member (28) housed at least partly in said first member (77);
said second member (28) comprising a first opening (92) and at least one second opening (91) connected fluidically to each other;
said first opening (92) of said second member (28) being located inside said first opening (83) of said first member (77) so as to be connected fluidically to said first chamber (49);
said second opening (91) of said second member (28) being connected fluidically to said second opening (90) of said first member (77) so as to be connected fluidically to said second chamber (50).
A torpedo as claimed in Claim 7, characterized in that said first opening (92) of said second member (28) is located at a distance from said coil (13), so that said fluid flows between said first and second chamber (49, 50) at a distance from the coil (13).
A torpedo as claimed in Claim 7 or 8, characterized in that said second opening (91) of said second member (28), and said second opening (90) of said first member (77) are connected fluidically by a toroidal compartment (89) bounded externally by said first member (77) and internally by said second member (28).
A torpedo as claimed in any one of Claims 7 to 9, characterized in that said second member (28) comprises at least two said second openings (91) equally spaced angularly with respect to an axis (A) of said second member (28).
A torpedo as claimed in Claim 10, characterized in that said conduit (110) defines a flow section (S) for said fluid; said section (S) having an area smaller than the total area of said second openings (91) of said second member (28), so as to maintain the pressure gradient between said first chamber (49) and said external environment below a predetermined value.
A torpedo as claimed in any one of the foregoing Claims, characterized by comprising a further conduit (94) open at opposite ends facing said first chamber (49) and said second chamber (50); said further conduit (94) being sized to permit flow of a further fluid between said first chamber (49) and said second chamber (50).