EP2022716A1

EP2022716A1 - Countermeasure apparatus release device

Info

Publication number: EP2022716A1
Application number: EP07425454A
Authority: EP
Inventors: Giancarlo Bottaini; Giovanni Calvo
Original assignee: Whitehead Alenia Sistemi Subacquei SpA
Current assignee: Whitehead Sistemi Subacquei SpA
Priority date: 2007-07-24
Filing date: 2007-07-24
Publication date: 2009-02-11
Anticipated expiration: 2027-07-24
Also published as: ATE451299T1; DE602007003713D1; EP2022716B1

Abstract

A release device (1) for releasing a countermeasure apparatus (5) housed inside a cavity of the countermeasure having an exit opening (7) through which to expel the apparatus (5). The device has a body (11) plugging the opening (7); at least a first actuating member (27) movable axially between a first and a second position as the countermeasure is fired; and at least one retaining member (38) movable axially between a retaining position, in which it engages a portion of the countermeasure, and a release position, in which it disengages the portion of the countermeasure to detach the device (1) from the countermeasure. Movement of the first actuating member from the first position to the second position activates drainage of a fluid from inside a seat (17, 19), so as to move the retaining member from the retaining position to the release position.

Description

The present invention relates to a countermeasure apparatus release device.
Release devices are known which are fitted to a rear portion of a countermeasure (jammer or decoy) comprising a tubular body housing an apparatus (e.g. receiver or transmitter) that must be released after the countermeasure is fired into the water.
The apparatus is normally housed in the cavity defined by the tubular body, and is pushed against the release device by a spring.
The release device plugs an exit opening in the tubular body to prevent expulsion of the apparatus by the spring.
Detachment of the release device from the tubular body clears the exit opening to permit expulsion of the apparatus by the spring.
The countermeasure is launched from launch tubes equipped with a high-pressure (200-250- or even 300-bar) compressed air cylinders to achieve the necessary range.
Expansion of the compressed air inside the launch tube exerts severe stress on the countermeasure, so the release device, in addition to withstanding this stress, must also ensure a given decoupling delay so that it detaches from the countermeasure at some distance from the launch tube. Decoupling in advance, thus resulting in early expulsion of the apparatus, may result in damage to the apparatus (e.g. if the release device is detached inside the launch tube), whereas too long a decoupling delay may impair the effectiveness of the countermeasure.
It is an object of the present invention to provide a countermeasure apparatus release device designed to ensure accurately-timed release of the apparatus.
According to the present invention, there is provided a countermeasure apparatus release device, as claimed in Claim 1.
A preferred, non-limiting embodiment of the invention will be described by way of example with particular reference to the accompanying drawings, in which:

Figure 1 shows a longitudinal section of a countermeasure equipped with the release device according to the teachings of the present invention;
Figure 2 shows a partly sectioned view in perspective of the release device;
Figure 3 shows a cross section of the release device;
Figures 4 and 5 show two operating positions of the release device according to the present invention.

Number 1 in Figure 1 indicates as a whole a release device for releasing an apparatus housed inside a countermeasure.
More specifically, device 1 is fitted to a rear portion 2 of the countermeasure (only shown partly), comprising a circular-section tubular body 3 housing an apparatus 5 (e.g. receiver or transmitter) that must be released after the countermeasure is fired into the water.
In the example shown, tubular body 3 has a first end 3a connected to a connecting member 6; and a second exit end 3b having a circular exit opening 7 closed, in use, by device 1.
Apparatus 5 is housed in the cylindrical cavity defined by tubular body 3, and is pushed against release device 1 by a spring 9 interposed between apparatus 5 and connecting member 6.
Release device 1 plugs circular exit opening 7 to prevent expulsion of apparatus 5 by spring 9.
As explained in detail below, detachment of release device 1 from tubular body 3 clears exit opening 7 to permit expulsion of apparatus 5 by spring 9.
With particular reference to Figure 2, device 1 comprises a disk-shaped body 11 comprising two integral portions: a first cylindrical portion 11a of radius R1, and a thinner second cylindrical portion 11b of radius R2 greater than Rl. First cylindrical portion 11a fits inside exit opening 7, and second portion 11b rests against end edges of tubular body 3.
Inside body 11 are formed (Figures 4 and 5) :

a first cylindrical seat 13 coaxial with an axis A1, and which extends radially up to the cylindrical outer wall of portion 11a, and is closed outwardly by a flat circular plug 14 having a central hole 14b coaxial with axis A1;
a second cylindrical seat 15 coaxial with axis A1, and which extends radially, on the opposite side to seat 13, up to the cylindrical outer wall of portion 11a, and is closed outwardly by a flat circular plug 16;
a third cylindrical seat 17 coaxial with an axis A2, and which extends radially up to the cylindrical outer wall of portion 11a, and is closed outwardly by a flat circular plug 18 having a central hole 18b coaxial with axis A2; and
a fourth cylindrical seat 19 coaxial with axis A2, and which extends radially, on the opposite side to seat 17, up to the cylindrical outer wall of portion 11a, and is closed outwardly by a flat circular plug 20 having a central hole 20b coaxial with axis A2.

Axes A1 and A2 are perpendicular to each other.
First and second seat 13, 15 are connected to each other by a cylindrical conduit 22 extending, coaxially with axis A1, between the bottom walls of seats 13, 15.
First seat 13 houses in fluidtight manner the cylindrical head 24 of a piston 25 having a rod 27 extending coaxially with axis A1.
More specifically, a first portion 27a of rod 27 engages hole 14b, and a second portion 27b of the rod engages cylindrical conduit 22.
Piston 25 is movable between a first stop position (Figure 4), in which cylindrical head 24 rests on plug 14, and first portion 27a of the rod projects radially by a length H from plug 14; and a second stop position (Figure 5), in which cylindrical head 24 is much closer to (or rests on) the bottom wall of seat 13, and first portion 27a of the rod does not project from plug 14.
Second seat 15 houses a programmed break member 30 fitted to plug 16, and which is broken as piston 25 moves from the first to the second stop position.
Each seat 17, 19 houses a retaining device 32 comprising a cylindrical head 34 coaxial with axis A2 and slid axially along seat 17, 19 by a spring 36 interposed between head 34 and plug 18, 20. Head 34 is connected to a cylindrical rod 38 coaxial with axis A2 and engaging hole 18b, 20b.
Cylindrical head 34 is movable axially between :

a first retaining position (Figure 4), in which head 34 rests on plug 18, 20, spring 36 is compressed, and rod 38 projects by a length K from plug 18, 20; and
a second release position (Figure 5), in which head 34 is much closer to or rests on the bottom wall of seat 17, 19, spring 36 is extended, and rod 38 does not project from plug 18, 20.

Each seat 17, 19 has a drain conduit 40 extending from the bottom wall to conduit 22.
When piston 25 is in the first axial stop position (Figure 4), drain conduit 40 is closed by the cylindrical surface of second portion 27b of the rod; and, when piston 25 is in the second stop position (Figure 5), drain conduit 40 communicates with a drain conduit 41 formed in rod 27 and for connecting seats 17, 19 to seat 15.
When release device 1 is ready for use, seats 17, 19 are full of oil, cylindrical heads 34 are in the retaining position with rods 38 projecting from plugs 18, 20, and piston 25 is in the first stop position.
In this position, rods 38 engage respective holes F (Figure 4) in tubular body 3 to connect release device 1 stably to tubular body 3.
When the countermeasure is fired inside the launch tube (not shown), an inclined part P (shown schematically in Figures 4, 5) contacts and presses portion 27a of rod 27 from the first axial stop position into the second axial stop position.
The oil in seats 17, 19 therefore begins draining along conduits 40, 41 into seat 15, and springs 36 move heads 34 to withdraw rods 38, which, a few seconds after the countermeasure is fired, disengage the holes in tubular body 3 (Figure 5) to detach release device 1 from tubular body 3 and permit expulsion of apparatus 5 from tubular body 3 by spring 9. Rod 27 being axially free of tubular body 3. It is thus created a delayed opening of rear portion 2 of the countermeasure. Oil drainage time is determined beforehand to determine the precise instant in which device 1 detaches from the countermeasure.

Claims

A release device (1) for releasing a countermeasure apparatus (5) housed inside a cavity of the countermeasure; said cavity having an exit opening (7) closed by said release device (1) and through which to expel said apparatus (5);
said release device (1) comprising :
- a body (11; 11a, 11b) plugging said exit opening (7);

- at least a first actuating member (27) movable axially between a first and a second position as said countermeasure is fired; and

- at least one retaining member (38) movable axially between a retaining position, in which it engages (F, 38) a portion (3) of the countermeasure, and a release position, in which it disengages the portion (3) of the countermeasure to detach the release device (1) from the countermeasure;
characterized in that movement of the first actuating member from the first position to the second position activates drainage of a fluid from inside a seat (17, 19), so as to move the retaining member (38) from the retaining position to the release position.
A device as claimed in Claim 1, wherein said seat (17, 19) houses a head (34) movable axially along the seat (17, 19), as said fluid is drained, by the pressure of elastic means (36) housed inside the seat; said retaining member (38) being integral with said head (34).
A device as claimed in Claim 1 or 2, wherein said actuating member (27) has an internal drain conduit (41) which, when said actuating member is in said second position, is connected to a drain conduit (40) communicating with said seat (17, 19).
A device as claimed in any one of the foregoing Claims, and comprising a drain cavity (15) which receives the fluid from said seat (17, 19).
A device as claimed in any one of the foregoing Claims, wherein said first actuating member comprises a rod (27) extending radially inside said body (11).
A device as claimed in any one of the foregoing Claims, wherein said retaining member (38) comprises a rod (38) extending radially inside said body (11), and which engages a hole (F) formed in said countermeasure.
A device as claimed in any one of the foregoing Claims, wherein said first actuating member comprises a rod (27) extending radially inside said body (11) and coaxially with a first axis (A1); and said retaining member (38) comprises a rod extending radially inside said body (11) and coaxially with a second axis (A2) crosswise, in particular perpendicular, to the first.
A device as claimed in any one of the foregoing Claims, and comprising a programmed break member (30) which is broken as the first actuating member moves from the first to the second position.