11 13025Francis(l9)N21JDls63pl245 .'' ` 1l1 I ` 1()37~:90 . I
1 1 The present invention relates in general ~ 2 ¦ to mean~ ~or measurement of various properties of - ~ 3 1 water ~uch aa temperature and pres~ure, with depth, 4 1 and in particular to a novel system utilizlng an aquatic 1 mis~lle probe having a cable spool as3embly positioned 6 1 therein to thereby effect a free falling body.
7 , In the present invention a housing having the general shape of a missile, to reduce the surface 9 ~rlction of the missile, carrles a spool mounted therein.l Sens1ng elements mounted within the missile probe are 11 utilized to detect the properties of the ambient liquid 12 through which the missile is descending. A wire, 13 connected to the ~ensing element i8 wound about the ~ 14 spool and allowed to exit from the rear of the missile.
;~ 15 The wire is wound and connected at lts other end, 16 pre~erably to a second~spool mounted upon a ship or ;" 17 other carrler mea~ which is utilized to carry the second 18 spool and receiving apparatus, to whlch the end of the , ., ~
19 wire aboard the ship is electr~cally connected.
Signal~ transmitted from the sensing element~
21 are sent back along the wire to the receiving apparatu~ I
22 whlch include~ mean~ to distingulsh the signals and `
23 interpret them.
24 The cable ~pool located on board the signal-receivlng ship pays out a suf~iclent length o~ wire to 26 account ~or the horizontal distance between the ship 27 and the point in the water below which the probe ls to ~ -28 freely fall. Thls, ln ef~ect obvlates any horizontal 29 motion of the probe with res~ect to the water. The ¦ unwinding of the wire from the spool ln the probe~provide's 11 .
..' ' 11 ' ' ' ,.
11 ' ' ' ' , 103'^JtZ~0 for the vertical motion of the probe. Thus, the free-falling descent of the probe is provided for by the combination of the two spools when the probe is released from a moving carrier.
`~ It is therefore an object of the invention to provide an aquatic probe for testing various properties of water at varying known depths.
More specifically, the invention lies generally in the provision of a probe for sensing a property of a fluid at varying depths, which probe comprises a housing member, conductor means within this housing member for deployment therefrom as the housing r member moves through the fluid and a sensing element connected to the conductor means.
According to a preferred embodiment of the invention, the housing member is a ballistically shaped hollow body open to the fluid and having a nose portion, the conductor means is wound to be payed out in a direction substantially parallel to the axis of the probe and the sensing element is in contact with the fluid.
The probe of this preferred embodimen* further comprises wire guide means in the after end of the hollow body, the conductor means extending therethrough. The nose portion is preferably weighted sufficiently to cause the probe to descend through the fluid.
Other and further objects of this invention will be , apparent from the following description and claims and may be understood with reference to the accompanying drawings which are by way of illustration showing the preferred embodiment of the invention and what is now considered to be the best mode of applying the principles thereof.
Fig. 1 is a pictorial drawing of an expendable Il 13025Francl819N21JDls63plO2 ., ,1 I
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Il ~ 10372g~ .
1 ¦ balllstlc bathythermometer system according to the

2 I inventlon;

3 ~ Fig. 2 1~ a cross-sectlonal view of the

4 1! bathythermometer o~ Fig. l;
1 Fig, 3 i~ an exploded view o~ a portion of 6 ¦ the bathythermometer talccn ~long lino E 3 3 of Fig, 2; and 7 ¦ Fig, 4 is an exploded vlew o~ the cable 8 ¦ spool mounted on the shlp of Fig. 1.
9 ¦ me present inventlon disclo~es an aquatic ¦ probe which may be utilized a~ a vehicle for various 11 ¦ oceanlc sensors. However, the embodiment de~cribed 12 ¦ herein, employing a temperature sen~or, serves to 13 delineate the work princ~ple~ involved in the invention.
14 In the drawing~, Fig. 1 denotes in general an improved bathythermometer sy~tem in accordance with the invention.
~6 As can be seen more clearly from Fig. 2,~he 17 bathythermometer 10 includes a housing 12, and a nose 18 portion 14 whlch comblne into a teardrop 3hape having a 19 smooth, rounded, forward end extending rearwardly to a relatlvely ~mall pointed rear portion 15. Mounted 21 I wlthln the housing, and centrally po3itloned therein is 22 ¦ a tube 16 lntegrally formed with the housing. A
23 ¦ thermlstor element 18 i~ po3itioned in the forward 24 ¦ portlon 14 of the housing within the cavity 19 formed I by tube 16, to allow exposure of the thermistor to the 26 ambient llquid. The forward end 20 of thermi~tor 18 27 form~ ln con~unction with 3uitable ga~ket means (not 28 shown) a means to seal off tube 16 from the ambient 29 liquld. Electrically connected to thermlstor 18 are i wire leads 22 and 23.;~ Lead9 22 and 23 extend through jj _3_ '' ' I

!1 13025Francl~(l9)N21JDls63pll4 I' .
:1 103~29~ -1 ~¦ tube 16, to cable 24 which is coiled upon cable spool 2 ¦1 as~embly 26. Assembly 26 is mounted upon tube 16 by ~uitable means (not shown). Mounted concentrically about 4 ¦ tube 16 in a ~gmmetrical manner i~ a weight 28 which may ¦ ¢on~lst o~ any ~uitable materlal such as lead to prov~de 6 ¦ the bathythermometer with auf~icient weight to move the 7 ¦ unlt down through the liquid at the desired rate o~
8 ~ descent.
9 In the ~ingle wire system illu~trated in 10 ¦ Flg. 2, wire 23 leading ~rom thermistor 18 i8 electri-Il ¦ cally connected to the conductive housing 12, while 12 ¦ lead 22 ls connected to the innermost end o~ the cable 24 coiled about the spool 26. Thus, the ocean in this 14 ¦ embodiment 1s utilized as the return signal path for the ¦ ay~tem, In the rear portion 15 o~ housing 12 there is 16 ¦ Iocated a~ openlng 32 which serves to allow the exit o~ ¦
17 ¦ cable 24 therethrough. The opening 32 through which the 18 ¦ cable 24 exits may be provided with suitable plug elements 19 ¦ (not shown), i~ desired, which will allow the cable 2 ¦ to be payed out therethrough, but which w~ll also be 21 1 watertight and prevent the ambient liquid from entering 22 into the housing.
23 It will be noted that in the two-wire system 24 ¦ both wires 22 and 23 are fed into the cable 24 and therethrough to the slgnal-receiving ship 33, thereby 26 eliminatlng the necesslty of employing the ocean as a 27 return ~or the system, 28 Cable 24 ~9 payed out through the rear of 29 ¦ housing 12 to the ~ignal-receiving vehicle 33, as shown 30 11 in Fig. 1, Cable 2~ i~ connected to cable 36 which is 1,- . 1.
~ 4 - ` I
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Il !

~ 13025Franc~s(l9)N12JDls63pl20 3~290 1 ¦I mounted upon spool a~sembly 34 as shown more cIearly in 2 Fig. 4, A male~connector 38 is secured to the end of ~ cable 24 and female connector 40 iB secured to the end of cabl~ 36, thereby providlng for the connection of the two cables, Lead 22, extending through cable 24 is ~-6 ¦ electrically connected to male connector 38. Thu~ the 7 ¦ electrical connection with the thermistor extends to 8 ¦ cable 36 through insulating cable 24. Cable 36 is payed 9 ¦ out through opening 42 in hous~ng 44 of cable spool ¦ assembly 34 The inner end o~ cable 36 1B connected 11 ¦ through conduit 46 to suitable electronic receiving ¦ equlpment 48 which interprets the signals recei~ed from 13 I the sensing elements 14 ¦ . The embodiment described her~inabove relate~
¦ to a temperature measuring device; however, it should be 16 understood that a system as described may be uti~lzed to 17 ¦ measure the pre~sure, salinity, speed of sound, light 18 conductlvity, density, etc of the amblent liquid. Thus, 19 the aquatlc device described herein may be employed in a I
variety of liquid property measuring capacities, 21 In the present invention a system is describe~
22 whlch provldes for the continuous measurement of the 23 temperature of the ambient liquid relative to its depth.
24 ~he operation of the system can best be understood with reference to Fig, 1.
26 The cable spool assembly 34, positioned 27 aboard the slgnal-receiving ~hip 33 allows cable 36 to 28 be freely payed out to therebyErovide for the horlzontal ~
29 ¦ motion of the cable. Cable 24 stored within housing 12 ! : :
¦ upon ~pool as~embly 26 is freely payed out through opening 3 1 1 32 to thereby provide for the vertical motion of the . . . .
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1l 13025Francis(l9)Nl21JdlE~63Pl25 '' Ii l Il 10;~7290 1 ll bathythermometer, It can be readily under~tood that by 2 ¦I posltionlng a cable ~pool within the housing o~ the 3 1 bathythermometer and another ~pool assembly aboard a 4 ¦ moving ship a means i~ provided whlch ~llow~ the bathy-

5 thermometer to fall ~reely since the cable holding the

6 I bathythermometer does not move in relation to the water I in either a horizontal or vertical directlon. Thls r 8 ¦ phenomenon i~ e~fected becauselthe unwinding of the cable from spo~l34, located aboard the ship compensate~ for 10 ¦ any horizontal motion of the cable wlth respect to the 1 ¦ water and the cable being payed out of the bathythermo-. .
S2 ¦ meter elimlnate~ any vertlcal motion of the cable with 13 ¦ respect to bhe water. Thus the cable represented by theth~cd llne~ in Flg. 1 does not move with respect to ¦
¦ the water in either a vertical or a horizontal direction.
16 ¦ In the present invention the ~ystem para-¦ meters involved are the continuous mea~urement of 18 I temperature with depth, Thus a~ the bathythermometer 19 I fall~ through the llquld the temperature of the liquid ~ changes with t~ change in de,pth, These changes in 21 temperature are sensed by the change ~n the resistance ~2 I of the thermistor contained in the temperature probe 23 ¦ expoE~ to the ambient liq~id. The ~ignal~ representing 24 ¦ the resi~tance values ~ensed by the thermi~tor are ¦ transmltted through cables 24 and 36 o~ the conduit 46 26 1 to the ~hipboard recei~ing equipment ~8, It is essentlal 27 there~ore, in the context of the present invention that Z8 ¦ the dspth o~ the liquid through which the temperature 29 ~ probe i~ passing at any particular instant be accurately ¦
,I known. The rate o~ descent of the missile may be determlned ,. I , . , ~l 6 I .

1~ 13025Francis(19)N21JDls63pl32 , I
I
I 103~290 1 j emplrlcally t~ thereby allow the depth of the bathyther-l mometer at any particular instant to be calibrated ! 3 ¦ through the utll~zation of a time-scaled recordlng.
I 4 I Thu~ the temperature of the liquid at a particular ¦ depth may be accurately determlned. I
6 I From the foregoing it may be understood that ¦

7 any horlzontal or vertical movement o~ the cable relative ¦ to the water would seriously impair the accurate deter~
minatlon o~ the depth o~ the temperature probe because ~ 10 ¦ the veloclty of the misalle would vary due to the fric~
C 11 ¦ tional resiatance o~ the cable caused by any movement ~ ;
12 ¦ o~ the cable relative to the water. Since, as explained ¦
13 1 above~the prèsent invention provide~ a relatively 14 1 stationary cable which doe~ not add any signl~icant - 15 ¦ ~rlction to the system, thls problem has been obviated.
~6 ¦ Thus9 reduclng the ~rictlon o~ the system to a minimum 17 ¦ and provldlng a truly ~ree-falling temperature probe 18 ¦ 18 a primary concern o~ the inventlon, The application 19 1 o~ thl~ concept result3 in a freely falling body whose ¦ velocity is not a~ected by the cab~e attached ~ it ; 21 ¦ - since the aable 1~ not dragged through the water but as 22 a result o~ being payed out by the missile and by the I ~ 23 receivlng vehlcle remain~ statlonary wlth respect to the 24 water.
In the event that the present inventlon is 26 to be utilized by deploying it from a statlonary carrier ¦
27 auch as a dock or a stationary ship the second play out 28 spool 34 will not be neceaa~y. Thus the end of the 29 cable 24 may be attached directly to the recei~ing equipment and th~ temperature probe dropped stralght 1, ' , .
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~ I _7_ ~

1037Z9~) down into the water. The play-out spool 26 located within the housing 12 of the bathythermometer will again pro~ide for a freely falling object. Cable 24, therefore, will not offer any resistance to the water because it will remain ~tationary relative to the water, thereby providing for a more linear and predictable rate of fall ~or the temperature probe.
It should be noted that by designing the temperature probe for positi~e rather than negative buoyancy the system may be adapted to work in reverse. Thus the temperature probe could be released from a ~ubmerged location, for example from a ~ubmarine, and the temperature probe will rise ~ertically up through the water with the cable 24 being payed out through the rear of the probe.
A further embodiment of the invention i9 a probe which has been con3tructed to pe~mit the liquid to flow throughout the whole length of the probe, and exit in the rear, as the probe descends through the fluid medium. The probe consists of a lead weight in its nose and includes a central bore in which an elongated ~upport member is disposed.
The membex contains on ~ts end a receptacle located near the opening of the central bore and contains a thermistor secured within. Electrical conductors coupled with thermistor to the conical winding of wire which is wrapped around a spool secured to the after end of the lead weight. The spool includes a circular flange mounted against the lead weight and provide3 mechanical support for the elongated member which protrudes into the central bore of the weight. The center tube of the spool upon which the wires are wrapped around is of hollow construction and is opened at its end. The central hollow of the BpOOl i8 also open and continuous with the central bore. Accordingly, when the probe is released and begins its path of de3cent through the liquid medium the

-8-liquid will enter into the opening and proceed through the entire len~th of the central bore and the ~pool and exit out of an opening adjacent to where the conductor is being unreeled from the spool. ~loreover, becau~e the wire i~
deployed in both directions, it is possible to utilize a conductor having a smaller cross sectional area than normal due to the reduced stres~es experienced by the wire. Conductors having wire gauge o~ tho or smaller may be utIlized without breakage.
~y permitting the liquid to pass through the entire length of the spool, it is possible to u~e the liquid to wash the thermistor continuously a~ the probe descends, and to lubricate the conductor from the ~pool as it unreels and leaves openings at the tail of the probe. The liquid is thus utilized to eliminate much of the friction of conductor, pa~ing through the end of the probe. ~oreover, the flow of the fluid against the conductor assists in unreeling the ~ire from the BpOOl and helps to guide the conductor as it leaves the hole in the tail of the probe.
The 6pool is made from one piece comprising, a flange, an elongated member, and the hollow central portion to which the conductors are conically wound upon. The elongated member also contain~ a small channel running along its length to house the conductors which interconnect the thermi~tor to the winding OL the conductors. One of the conductors is al~o connected to the lead weight 80 as to provide electrical contact with the sea to which the probe descends. The rate of descent of the probe is controlled by its manufactured weight and close dimen~ional control.
~he weight of the probe by any of the embodiments of this invention may be accurately and automat~cally adjusted by controlling the amount of conductor wire wound onto _9_ . .

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~ 037Z90 the spool within the probe during its manufacture. ~he probe's wei~ht may also be adjusted, if necessary, by removing a portion o~ the lead or other weighted material from its nose.
The actual apparatus de~igned to measure the tempera-ture sensed by the probe employing a ~ingle wire conductor and the sea return path is de~cribed in Canadian co-pending application ~o. 938,346 ~iled on August 16, 1965.
I have described what I believe to be the best embodiment of my invention. I do not wish, however, to be confined to the embodiment shown and what I de~ire to be covered by ~e~ters Patent a~ set forth in the following claim~:

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