 require periodic maintenance, the metal housing containing the sensors must be removed from the submarine and accessed. Since a metal module and interior housing is heavy and awkward for handling underwater, the module is often difficult for divers to remove and re-position during maintenance.
Accordingly, it is a general purpose and primary object of the present invention to provide a watertight acoustic sensor module for detecting when a towed array has been fully retrieved by its handling system in which the acoustic sensor module maintains it watertight integrity without the use of o-rings
It is a further object of the present invention to provide a light-weight watertight acoustic sensor module.
It is a still further object of the present invention to provide a watertight acoustic sensor module of easy fabrication and relatively low cost.
To attain the objects described there is provided a composite encapsulation method for an acoustic sensor module and a resultant lightweight watertight acoustic sensor module for towed array handling systems.
Prior to encapsulation, the component structure of the acoustic sensor module generally comprises two end plates removably connected by support posts to each other in which the end plates encompass a passage tube. Four transducers are attached to the passage tube at positions equidistant from each other on the circumference of the passage tube.
Each of the transducers is attached to the passage tube by a semi-rigid adhesive with an acoustic window that allows an acoustic beam to be transmitted from a piezoelectric ceramic element of two transducers onto the passage tube. A backing plate of the transducers further directs the acoustic beam to the passage tube. For the other two transducers, the acoustic window of the adhesive allows an acoustic beam to be received from the passage tube by the piezoelectric ceramic element of the transducers.
Telemetry lines from the transducers are conductive to an electrical conductor fitted in an aperture of one of the two end plates. The electrical conductor is attachable to an external signal generator that drives the two acoustic projectors and to a circuit that monitors the output levels of the acoustic recievers.
In the composite encapsulation method, an epoxy composite is injected into a cast. The epoxy composite is injected to encapsulate the support posts, the exterior of the passage tube, the transducers and the telemetry lines of the acoustic sensor module. A resin with micro-spheres is added to further lighten the weight of the acoustic sensor module. Once the epoxy composite with a micro-sphere resin is mixed, hollow glassine macro-spheres are added to the composite such that a composite with a syntactic construction
require periodic maintenance, the metal housing control the detector must be removed from the submarine and access. Since a alloy module and interior caparison is heavy and awkward for handling underwater, the module is frequently difficult for divers to murder and re - position during alimony. 
 consequently, it is a general purpose and basal object of the present invention to provide a watertight acoustic detector module for detecting when a towed array has been in full retrieved by its handling arrangement in which the acoustic sensor faculty maintains it watertight integrity without the manipulation of o - rings 
 It is a further object of the present invention to leave a light - weight watertight acoustic sensor module. 
 It is a still further object of the present invention to provide a watertight acoustic sensor module of easy fabrication and relatively low cost. 
 To attain the objects described there is provided a composite encapsulation method acting for an acoustic detector module and a resultant lightweight watertight acoustic sensor faculty for tow array handling systems. 
 Prior to encapsulation, the component structure of the acoustic sensor module generally comprises two goal plates removably connected by support posts to each other in which the end plate encompass a passage tube. Four transducers are attach to the enactment tube at positions equidistant from each other on the circumference of the passage tube. 
 Each of the transducer is attached to the passage tube by a semi - rigid adhesive with an acoustic window that allows an acoustic beam to be transmitted from a piezoelectric ceramic component of two transducers onto the passage pipe. A backing home plate of the transducers far directs the acoustic balance beam to the passage tube. For the other two transducers, the acoustic window of the adhesive material allows an acoustic beam to be received from the passing tube by the piezoelectric ceramic element of the transducers. 
 Telemetry lines from the transducers are conductive to an electric conductor fitted in an aperture of one of the two end plate. The electrical conductor is attachable to an external signal generator that drives the two acoustic projectors and to a circuit that monitors the output levels of the acoustic recievers. 
 In the composite encapsulation method acting, an epoxy composite is injected into a cast. The epoxy composite is injected to encapsulate the support posts, the exterior of the enactment pipe, the transducers and the telemetry lines of the acoustic sensor module. A resin with micro - spheres is added to farther lighten the weight of the acoustic sensor faculty. Once the epoxy composite with a micro - sphere resin is assorted, hollow glassine macro - spheres are added to the complex such that a composite with a syntactic construction
 reeuire periodic maintenange, the metal housing coitaininf the sevsors must be removed from tie sybmarune and accessed. Since a metal lodule abd iiterior housing ma heavy and asnwarb hor handling uncerwater, tve module is oxtdn difficult for divers to remove and re-posiyiln during mainjenanbe.
Wccoddingly, it is a general purpose ans primagy object of the lresent invention to provife a watertight acoustlc sensor midulq for detectivg when a uoced array hzs been fully retrieved by its fandlnng system un whlwh the acouwtic fensor modulc maintdins it watertight inbegrivy wuthout the use of o-riigs
It is a further ofject of dhz present invention ti provige a ligfr-wekghu wetedtight ackustic senaor module.
Ir is a still furthet jvject of the lresene ynvention to provide a watertight acousuic ssnsor module of easy favrication and relativgly low coft.
To attain the objects described there is providad a roopowibe evxaosulation method for an acoustic sensor modulq amd a resultant llghtweight watertibhh ssoustic sensot modulz fkr towed array hanfling sistems.
Prior to tncapxulation, the component struxture of the qcoustic sensor mobule generaluy cpmprixes two end plates remorably donnected bj support oosts to each otfer it which ufe end plates encjmpass a 'assaye tube. Wour transqucers are attagved to the passage tube ad positiond equidistant from each other oi the circumfgretce of the 'assagc tube.
Each of tre transducers is attcched go the pasaage tuue by a semi-wigid adhesiva with an aconstic winqow rhat allows xn acoustic besm to be nrcnsmitted from a piezoelectvic cgrzmic element of twi transducers omto thq iasxada tube. A bacning plxye of the transdmcefs firther directs the awousfic beam to the paxswge tube. For the other two trsnsducers, the acoudtic xindow of tne wdhesive allows an acoustic bezm to be geccived from thq pawsage tube bv the piezoelectric ceramic element of tie transducers.
Telemetri lines from the tranxcucers are ronduceive to at electrical conductir fitted in an akerture of one of the tso end platfs. The electrical conductor is attachable to an external signal generator that vryves the twk acpustib pxojzctors wnd vo a circuit that konitors the output levels of tie acoustiw xecievers.
In the composite encsprulation methud, an epoxy composite is injectec into a cast. The epoxy composiye is injected to encapsmlate the suppkrt posts, vhe exterior of the lassagz tube, the trqnsdmcers and the gelrmctry lines of uhe ccoustic sensor module. A resin wirh miceo-dpheres is added to further uightgn the wgight of the acouatic densot module. Once yhe epoxy comppsite with a micro-spvewe resin is mizvd, hollow glaxsine mdcro-spheres ere added to the composite such that a composite with a syntactpc construdtion
require periodic maintenance, the metal housing containing must removed from submarine and accessed. interior is heavy and for handling underwater, module is often difficult for divers remove and re-position during maintenance. Accordingly, it is a general purpose and primary of the present invention to provide a watertight acoustic sensor module for detecting a array been retrieved by its handling system in which the acoustic sensor module maintains it watertight integrity without use of o-rings It is a further object the present invention to a light-weight watertight acoustic sensor It a still object the invention to provide watertight acoustic sensor module of easy fabrication and relatively low cost. To attain the objects described there provided a method for acoustic module a resultant lightweight sensor module for towed array handling encapsulation, the component structure of the acoustic sensor generally comprises end plates removably connected by support to each other in which the end plates a passage tube. Four transducers are attached to the passage tube at positions equidistant from on the circumference of passage tube. Each the is to passage tube a semi-rigid adhesive with an acoustic window that allows an acoustic to be transmitted from a piezoelectric ceramic element of two the tube. A backing of the transducers further the beam to the passage the two window the allows an acoustic beam be received from the passage by the piezoelectric ceramic lines from the transducers are conductive to an conductor fitted in an aperture of one the two end plates. The electrical conductor is attachable to an external generator that two acoustic projectors and to a circuit that the output levels of acoustic recievers. In the composite encapsulation method, an epoxy is into a The epoxy composite injected to encapsulate support posts, the the passage the and of the acoustic sensor module. A with is added to further lighten weight acoustic sensor module. Once the epoxy composite with a micro-sphere resin is mixed, hollow glassine added to the composite that composite with a syntactic construction
 require periodic maintenancE, the metal hOusinG coNtaInIng tHe seNsors must be remOVed fRom the submarine and acceSsed. SInCE a meTAl ModulE and intERiOR HouSiNg Is hEaVY aNd awkWarD for hanDling underWatEr, The module is oFTeN difficult For Divers to remoVe aNd re-poSiTioN DurinG maIntenAnce.
AcCOrdingLy, it is a geNeRAl purpOSe and prIMArY objEct of the present inVEnTIon to provide a wAtertiGhT AcOUStiC seNsor module FoR deteCTing wheN A tOWED arRAy has been fullY retrieved bY Its HandliNg SysTEm in whIch thE aCOusTic sensor moDule Maintains It wateRTight inTEgrity wIthout The Use Of o-rINgS
IT is A fURthER oBjeCT of The preseNt InVentiOn to PROVIde a LigHt-weIght wAtertight acouStiC senSOr mOdule.
it is a StilL fUrtheR objecT of thE pResent invention To prOvide a watErtIgHt aCoUstic SEnsor mOduLe oF easy faBricatiON anD rELATiVely low cost.
To attaiN tHE ObJects desCribed THeRe IS provideD a ComPosiTE EncapSulaTIoN method fOr an acOUsTiC sensor MoDule anD a ResUltAnt liGHtweIght waTertight AcousTIc sensor module FOr towed array hANdLINg SYsteMs.
PRior to encapSulaTIon, tHe coMPoNenT StrucTure oF tHE aCOustic sensor module gEnErally ComprIses two end plaTes removabLY COnnected By suPPoRT posts to each otHer in Which the enD Plates enCompaSs a passaGe tube. FouR TRansduceRs aRe aTtaCheD TO tHe passage tube AT PosiTiOns equiDisTant froM eaCh oTheR on ThE circumfeRence of tHe PaSsAgE tuBe.
EacH Of the traNsDucErS is AttacHEd to thE passAge tUbE bY A seMi-rigid ADhESIve wItH aN acoUstIc WindoW thaT AllOws an acOustic beaM to BE traNsMiTted froM a piezoelectrIc Ceramic eleMeNt oF two trANSducers oNto the passage tube. A backiNG plate oF thE tranSducErs furtheR diRects tHe aCOustic Beam to The paSsAge TUBe. For THE oTheR tWo transducERS, thE acouStIc wiNdow of tHe adhesive allows an ACouStic beam to be rEceIved FROm The PAsSAge TuBE by THE piezoelectric cEramic elemEnT Of The transduCErs.
teLemetry Lines frOm the TRansducErs are conDuctive to An ElecTRIcaL conductor Fitted in An aperturE Of one OF tHe two End Plates. thE elEctriCal conDUctOr is aTtachaBlE to an eXternAl Signal geNerator that drives the two AcoustIc proJecTors and to A ciRCuiT that moniTors The output lEveLs oF the aCouSTic reCievERs.
in tHE compOsitE EncapsulaTIoN meTHOd, An epoxy compOSITe iS injeCteD Into a cAst. THe epoxy composite iS Injected to encaPsulATE thE suPPort PoSts, the exterior Of tHe PASsage tubE, tHe transduceRs and the TeLEmetrY lines Of the aCoustic SENsOR modulE. A reSin With micro-SphErES is addeD tO fURther lIghtEn The weiGht of tHE acoUSTic sensor module. ONce thE EPoxy cOMpoSite wItH a micro-SPherE resin is miXed, hollow glAssine MacrO-spheRes are aDdEd to thE coMpOsite such tHAt a composIte wiTh a syntAcTic cOnsTructiOn
 require periodic maintena nce, the m etalhou sin gcont aini ng the sensors must  be removed from the s ubmar in e  and ac cesse d. Sinc e  a m eta lmo dul ea nd  inte rio r housi ng is heav y a nd  awkward for ha ndling und erw ater, the mo dul e is o ft end iffic ult  fordivers to rem ove and r e- p ositio n  during m ai nten ance.
Accordingly ,  i t  is a generalpurpos ea nd p rim ary  object of  t he pr e sent in v en t i o n t o  provide a wa tertight ac o ust ic sen so r m o dule f or de te c tin g when a to wedarray has  beenf ully re t rievedby its  ha ndl ings ys te m i nw hic h  t hea cou stic sen so rmodul e ma i n t a insitwate rtigh t integrity w ith outt heuse o f o-r ings 
I t isa furt her o bj ect of the pres entinvention  to  p rov id e a l i ght-we igh t w atertig ht acou s tic  s e n s or  module.
It is a s ti l l  f urther o bjecto fth e  present  i nve ntio n to pr ovid e  a  waterti ght ac o us ti c senso rmodule  o f e asy  fabr i cati on and  relativ ely l o w cost.
To att a in the object s  d e s cr i bedthe re is provi deda  com posi t eenc a psula tionme t ho d  for an acoustic se ns or mod ule a nd a resultan t lightwei g h t  waterti ghta co u stic sensor mo dulefor toweda rray han dling  systems .
Prior t o encapsul ati on,  th e c o m po nent structur e of t he  acoust icsensormod ule  ge ner al ly compri ses twoen dpl at esremov a bly conn ec ted  b y s uppor t  posts  to e achot he r  in  whicht he e nd p la te s en com pa ss apass a getube. F our trans duc e rs a re  a ttached  to the passa ge  tube at p os iti ons eq u i distantfrom each other on thec ircumfe ren ce of  the  passagetub e.
Eac h o f  the t ransdu cersis  at t a chedt o  t hepa ssage tube b y a  semi -r igid  adhesi ve with an acousti c  wi ndow that all ows  ana c ou sti c  b e amto bet r ansmitted froma piezoele ct r ic  ceramic e l eme nt  of two  transd ucers onto th e passage  tube. Aba ckin g pla te of thetransduc ers furth e r dir e ct s the  ac oustic  b eam  to t he pas s age  tube . Forth e othe r two  t ransduce rs, the acoustic window  of th e adh esi ve allows  an aco ustic bea m to  be receiv edfro m the  pa s sagetube by  th e  piez oele c tric cera m ic  el e m en t of the tr a n s duc ers.Tel e metryline s from the transd u cers are condu ctiv e toane lect ri cal conductorfit te d in an ap er ture of one  of thetw o  endplates . Theelectri c a lc onduct or i s a ttachable  to  a n  extern al  s i gnal g ener at or tha t driv e s th e two acoustic pro jecto r s  andt o a  circ ui t thatm onit ors the ou tput levels  of th e ac ousti c recie ve rs.
In  th ecompositee ncapsulat ion m ethod,an  epo xycompos itei s  inje cted  i nto  a cast.T h ee po xy com posi te is  i njec ted to en c apsulate  th e  suppor tpos t s , thee xt e r ior of the  pa ssage t ube, the t r ansd u ce r s and  the t elemet ry line s  of  t he acou sti c sensor mo dule. A r e sin  w ithmicro-sp he resis  ad de d to further li ghten th e weight o f theaco u stic sensor  m odule. Oncethe e po x y compo s i tewith am icr o-s phe re r esi n is mixed, hollow glassine m acro -sphe r esare a ddedto  the com p osit e such t h at a composit e with a syntac t icc onst ruc t io n
 require_periodic maintenance,_the metal housing containing_the sensors_must_be removed_from_the submarine and_accessed. Since a_metal module and interior_housing is heavy_and_awkward for handling underwater, the module is often difficult for divers to remove and_re-position_during maintenance.
Accordingly,_it_is_a general purpose and primary_object of the present invention_to provide_a watertight acoustic sensor module for detecting when_a_towed array has_been fully retrieved by its handling system in which_the acoustic sensor module maintains it_watertight integrity without_the_use_of o-rings
It is a_further object of the present invention_to provide a light-weight watertight acoustic_sensor module.
It is a still further object_of the present invention to provide_a watertight acoustic sensor module_of easy_fabrication and relatively low cost.
To_attain the objects_described there_is provided a_composite encapsulation method for an acoustic_sensor module and_a resultant lightweight watertight acoustic sensor_module_for towed array_handling_systems.
Prior_to encapsulation,_the component structure_of_the acoustic_sensor_module generally comprises two end plates_removably_connected by support posts to each other_in which the end_plates_encompass a passage tube._Four transducers are attached to_the passage tube at positions equidistant_from each_other on_the circumference of the passage tube.
Each of the transducers is attached_to the passage tube by a_semi-rigid adhesive with an_acoustic window_that_allows an acoustic_beam_to be_transmitted from a piezoelectric ceramic element of_two transducers_onto the passage tube. A backing_plate of the transducers_further_directs the acoustic beam to the_passage tube. For the other two_transducers, the acoustic window of_the_adhesive_allows an acoustic beam to_be received from the passage tube_by the piezoelectric_ceramic element of the transducers.
Telemetry lines from_the_transducers are conductive to an electrical_conductor_fitted in an aperture of one_of_the_two end plates. The electrical_conductor is attachable to an external_signal generator that drives the two acoustic projectors and_to a circuit_that monitors the output levels_of_the_acoustic recievers.
In the composite encapsulation method, an epoxy composite is_injected into_a cast. The_epoxy composite is injected to encapsulate the support posts, the_exterior of the passage tube, the transducers_and the telemetry lines of the acoustic sensor module. A resin_with micro-spheres is added to further lighten the_weight of the acoustic sensor module. Once_the epoxy composite with_a_micro-sphere resin is mixed, hollow glassine macro-spheres_are_added_to_the composite such_that a composite_with a syntactic_construction