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Publication numberUS3351897 A
Publication typeGrant
Publication dateNov 7, 1967
Filing dateMar 11, 1966
Priority dateMar 11, 1966
Publication numberUS 3351897 A, US 3351897A, US-A-3351897, US3351897 A, US3351897A
InventorsSidney Baron
Original AssigneeSidney Baron
Export CitationBiBTeX, EndNote, RefMan
External Links: USPTO, USPTO Assignment, Espacenet
Quiet hydraulic depression-elevation drive for sonar transducer reflector independently rotatable ina zimuth
US 3351897 A
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Description  (OCR text may contain errors)

- Nov. 7, 1967 s. BARON 3,351,897

QUIET HYDRAULIC DEPRESSION-ELEVATION DRIVE FOR SONAR TRANSDUCER REFLECTOR INDEPENDENTLY ROTATABLE IN AZIMUTH Filed March 11, 1966 4 Sheets-Sheet 1 3,351,897 QUIET HYDRAULIC DEPRESSION-ELEVATION DRIVE FOR SONAR S. BARON Nov. 7, 1967' TRANSDUCER REFLECTOR INDEPENDENTLY ROTATABLE IN AZIMUTH 4 Sheets-Sheet 2 Filed March 11, 1966 INVENTOR.

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QUIET HYDRAULIC DEPRESSION-ELEVATION DRIVE FOR SONAR TRANSDUCER REFLECTOR INDEPENDENTLY ROTATABLE IN AZIMUTH Filed March 11, 1966 4 Sheets-Sheet 5 l{l:| I l I INVENTOR.

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1 6 s. BARON 3,351,897

, QUIET HYDRAULIC DEPRESSION-ELEVATIONDRIVE FOR SONAR TRANSDUCER REFLECTOR INDEPENDENTLY ROTATABLE IN AZIMUTH Filed March 11, 1966 4 Sheets-Sheet 4 S/DNEY BARON LZA/JMUL 1 e m/L QTTO/ZNEY United States Patent M 3,351,897 QUIET HYDRAULIC DEPRESSION-ELEVA- TIGN DRIVE FOR SONAR TRANSDUCER REFLEQTOR INDEPENDENTLY RGTATA- BLE IN AZHMUTH Sidney Baron, New London, Conm, assignor to the United States of America, as represented by the Secretary of the Navy Filed Mar. 11, 1966, Ser. No. 535,303 4 Claims. (Cl. 340-) The invention described herein may be manufactured and used by or for the Government of the United States of America for governmental purposes without the payment of any royalties thereon or therefor.

This invention relates to improvements in training mechanisms for an underwater acoustic transducer-reflector assembly.

A transducer-reflector assembly that has been in use heretofore on a submarine includes a drive shaft that extends from within the submarine approximately vertically through a water-tight bearing arrangement in the pressure hull of the submarine and is coupled to azimuthal training mechanism inside the submarine. A mounting yoke is secured to the end of the drive shaft outside the hull. A cylindrical transducer is secured to the yoke perpendicular to the drive shaft. The axis of the drive shaft intersects the center of the axis of the transducer. A cylindrical parabolic underwater acoustic reflector is secured to the yoke alongside but spaced from the transducer and with the focal line of the reflector and the axis of the transducer coincident. The reflector is surfaced with any conventional underwater acoustic reflector mate-rial or commercially marketed underwater acoustic reflector material e.g. Goodrich Isoper, cemented on a rigid aluminum frame that shapes the reflector material to define a parabolic reflecting surface. In use the assembly is selectively oriented in azimuth, and while in a selected azimuthal orientation, pulse power in the lower audio frequency range is supplied to the transducer. The transducer-reflector intercepts echoes of the projected pulsed acoustic power. Additionally the transducer-reflector may intercept other waterborne acoustic energy in the same frequency range including energy which originates as noise and vibration generated by the azimuthal training mechanism for the drive shaft. The azimuthal training mechanism for the transducer-reflector is designed for quiet operation.

Longer distance echo ranging is now carried out by directing the projected acoustic energy for bouncing 0d the bottom to a target area and then listening for echoes returned by a target via the bottom. The depression angle at which the reflector is set is a function of desired range, the distance of the transducer-reflector assembly from the bottom, and the distance of the target from the bottom. To adapt the above-described transducer-reflector assembly for use in the bottom bounce mode, the reflector requires means for adjusting the reflector angularly about the axis of the transducer. Mechanisms for training in depression-elevation are known. For example, gun mounts include a pinion and sector gear. However, depression-elevation adjusting mechanisms known heretofore are too noisy in the lower audio range for the following reason. Acoustic energy projected via the bottom bounce mode and the corresponding echoes returned via the bottom bounce mode do not traverse the same path due to the bending action of the water. After a pulse of acoustic energy is projected in the bottom bounce mode, the depression-elevation angle of the reflector needs to be adjusted to the depression angle along which a target echo might be returned or needs to scan a range of depression angle to search for an echo.

Patented Nov. 7, 1967 If substantial noise is generated by the depression-elevation angle adjustment mechanism and delivered to the water during the time following a projected pulse corresponding to the range of interest echoes of the noise may be returned as a spurious target or may be returned at the same time that an echo might be returned from a target in the selected target area. Noise is emitted non-directionally and thus noise emitted after the pulse may 'be reflected from an obstruction at much shorter range than the selected target area. Noise echoes returned from a short range may have sufficient amplitude to register as a spurious target or to mask an echo from a more distant target and even if no echo is returned from a target the doubt introduced by the noise seriously interferes with the echo-ranging. If the circuitry is in the listen mode when the depression angle of the reflector is changing, any noise generated by the change is detected directly.

An object of this invention is to provide a quiet depression-elevation training mechanism for a transducerreflector assembly independently traina'ble in azimuth.

Other objects and advantages will appear from the following description of an example of the invention, and the novel feature will be particularly pointed out in the appended claims.

FIGS. 1 and 2 are front and rear perspective views of a transducer-reflector assembly including part of a hydraulic depression-elevation training means in accordance with this invention,

FIG. 3 is a view on an enlarged scale partly in section and partly in elevation of the rotary coupling in FIG. 2 including adjacent parts, and

FIG. 4 is a schematic hydraulic diagram of the depression-elevation angle adjusting system.

In FIGS. 1 and 2 there is shown an underwater acoustic transducer-reflector assembly 10 that is trainable in azimuth and wherein the reflector is trainable in depressionelevation. The assembly 10 includes a rigid framework having a pair of substantially identical spaced parallel vertical supports 12 rigidly joined near their bottom ends by a pair of horizontal pipes 14. A cylindrical elongate transducer 16 is secured to the upper ends of the vertical supports 12 and a cylindrical parabolic reflector 18 is journalled on the upper ends of vertical supports 12. The axis of the transducer 16 and the focal line of the parabolic reflector are coincident. The assembly 10 is secured to an end of a vertical shaft 20 by means of structural means 22 secured to intermediate portions of pipes 14. The axis of the shaft 20 intersects the axis of transducer 16. The shaft 20 extends through water-tight bearing means, not shown, in the pressure hull of the submarine, and is connected to azimuth drive means, not shown, inside the submarine for training or continuously rotating the assembly in azimuth.

The transducer 16 comprises one or a plurality of inline segmented cylinder transducers of the type disclosed in US. Patent 3,043,967. A brace 24 secured to the structural means 22 and including a circular member 26 intermediate the ends of the transducer assembly and a vertical member 28 adds support to the transducer.

Each of the vertical supports 12 includes a pancakeshaped container 30 supporting inductors, not shown, therein in an oil filled environment for resonance with the capacitance of the electrostrictive transducer at the design frequency. Electrical cables 32 connect the transducer and inductors and extend through the shaft 20 which is hollow to slip rings on the shaft inside the submarine, as is conventional.

Flexible hydraulic conduit means 40 and 42 communicate with opposite ends of the cylinder.

A rotary hydraulic coupling 44 is supported above the assembly coaxial with the shaft 20. A vertical rod 46 is secured to the circular member 26 and to one part of.

coupling 44. The vertical member 28 and the rod 46 extend through elongated slots 48 and 50 in the reflector.

The rotary coupling 44 includes an outer collar-shaped part 52 and an inner cylindrical part 54 journalled therein and secured to vertical rod 46. The inner part has two coaxial integral portions of different diameters defining a bearing face therebetween for engaging the outerpart. The outer part is formed with opposed axially spaced radial bores 60 and 62 for conduits 92 and 94. Fluid passages 68 and 70 are formed in the inner part 54 in fluid communication with the bores 60 and 62. The smaller diameter portion of the inner part is formed with circular grooves 72 and 74 in fluid communication with the passages 68 and 70. The fluid passages 68 and 70 terminate in bores that seat pipe fitting terminations 56 and 58 on the ends of hydraulic conduit means 40, 42. Three circular grooves 76, 78, 80 formed in the smaller diameter portion of the inner part seat O-ring seals. The smaller diameter portion of the inner part is slightly longer than the outer part whereby a disk 82 secured coaxially to the end of the smaller diameter portion retains the outer part on the inner part but does not impede relative rotation. A flat annulus 84 having thickness equal to the thickness of the disk 82 plus the difference in length between the outer part and the smaller diameter portion of the inner part is bolted to the end of the outer part coaxial therewith and concentric with the disk 82. The annulus 84 serves as securing means to a support above the assembly. Only so much of the hydraulic conduit means 40 and 42 is flexible as is needed for relative movement between cylinder 34, and the support structure. The remainder of the hydraulic conduit means 40 and 42. between the cylinder 34 and the inner part of the rotary coupling may be rigid piping to minimize transfer of acoustic energy by the hydraulic fluid to the water.

An electrical device 86 responsive to vertical orientation is secured to the reflector for providing an output which is a function of the orientation of the reflector in depressionelevation angle. Device 86 may include a potentiometer having an arcuate resistor element and a pivotal gravityresponsive pendulum-operated tap electrically connected by means of leads extending through the shaft 20, and slip rings on the shaft inside the submarine, not shown, to a direct current source and a calibrated meter inside the submarine in a simple inexpensive resistance measuring arrangement for indicating depression-elevation angle of the reflector. Conventional servo techniques can be included to maintain constant a selected reflector angle.

An essentially noise-free hydraulic system for adjusting the reflector in depression-elevation is shown in FIG. 4. The rotary hydraulic coupling 44 couples the opposite ends of cylinder 34 to a pump 90 and to a high pressure hydraulic supply, not shown. Hydraulic conduit means 92, 94 extend between the rotary hydraulic coupling and the high pressure supply and pump 90 respectively. The pump is driven by a reversible electric motor 96. Pressure relief valves 98 and 160 are connected between the conduit 92, 94 to limit the pressure differential when the piston reaches a limit of travel in cylinder 34. An accumulator 102 having air therein is connected to the hydraulic conduit 94 between the pump and rotary hydraulic coupling; the pump is operated to raise or lower the pressure in the conduit 94 relative to the on-board high pressure supply. The accumulator allows for change in volume of hydraulic fluid as the piston rod in the cylinder 34 moves between the inside of the cylinder and the water. The accumulator also functions as an acoustic capacitive loading chamber to minimize pump pressure pulsation. The hydraulic conduits 92, 94 include short lengths of flexible tubing 104, 106 adjacent the pump to reduce hydraulic sound transmission. Because the depression-elevation angle adjustment means is operated at high pressure, pump noise is minimized; a major part of pump noise is caused by low suction pressure. High operating pressure has the further advantage of overcoming sea water pressure on the exterior piping, part of which is rubber tubing, and also prevents reaction on the piston in the hydraulic cylinder 34.

Preferably the pump is a reversible hydraulic angle pump with a plurality of pistons for gradual piston action e.g. a commercially marketed Vickers angle pump with nine pistons, for low noise. The motor shall have sleeve bearings rather than ball bearing to reduce noise. A V- belt coupling between motor and pump is preferable because it contributes to vibration-isolation. Vibrationisolation mountings for the motor and for the entire hydraulic assembly in the submarine also reduces noise.

This depression-elevation adjustment means described is simple, reliable, quiet, enables continuous adjustment and provides an indication of the orientation on board the submarine. It does not generate interfering noise during operation in the listening mode.

It will be understood that various changes in the details, materials and arrangements of parts (and steps), which have been herein described and illustrated in order to explain the nature of the invention, may be made by those skilled in the art within the principle and scope of the invention as expressed in the appended claims.

I claim:

1. An underwater acoustic transducer assembly that is trainable relatively noiselessly comprising:

a cylindrical transducer,

a cylindrical parabolic reflector of approximately the same length as said transducer,

means mounting said cylindrical transducer and journalling said parabolic reflector in spaced parallel coextensive relationship with the axis of the cylindrical transducer and the focal line of the parabolic reflector coincident,

a shaft secured at one end to said mounting means with the axis substantially perpendicular to the axis of the cylindrical transducer and the focal line of the reflector,

means journalling said shaft vertically,

a hydraulic cylinder and a piston reeiprocable therein and a piston rod extending from the piston through one end of the cylinder, the other end of the cylinder and the free end of the piston rod being pivotally joined to said mounting means and said reflector for angularly adjusting said reflector about the transducer axis and focal line of the reflector,

a fluid coupling having coaxial relatively rotatable parts for providing continuous fluid communication between respective pairs of hydraulic conduits independently of relative angular orientation of the parts mounted above said reflector coaxial with said shaft,

rigid means secured to said mounting means and to one part of said fluid coupling,

said reflector being slotted transversely to its length for providing clearance therethrough for said rigid means over a range of angular orientation of the reflector relative to said mounting means, said rigid means extending through the slotted portion of the reflector,

fluid conduits extending between the fluid coupling and opposite ends of said cylinder, and

a hydraulic system connected to the fluid coupling for selectively establishing a pressure differential across said cylinder for adjusting the depressionelevation angle of the reflector.

2. An underwater acoustic transducer assembly as defined in claim 1 wherein said hydraulic system includes:

a reversible motor-driven pump,

a pair of conduits connecting the pump and rotary coupling,

pressure relief valve connected between the pair of conduits,

a high pressure source connected to one of said conduits, and

an air accumulator connected to the other conduit between the rotary coupling and the pressure relief valves.

3. An underwater acoustic transducer assembly as defined in claim 1 further including electrical means for providing information of the angular orientation of the reflector.

4. An underwater acoustic transducer assembly as defined in claim 1 wherein:

one part of the coupling is collar-shaped and has two ports that extend radially through longitudinally spaced portions thereof and are approximately opposite relative to the axis of the rotary coupling, the other part of the coupling has a cylindrical portion of slightly greater length than the length of the one part and terminates at a step of larger transverse dimension for seating the one part, the surface of the cylindrical portion of the other part has two circular grooves in registration with the ports of the one part and has packing between and packing on opposite sides of two grooves that register with the ports in the one part,

means on the two parts retaining the two parts in assembled relatively rotatable relationship,

said other part also having approximately opposite ports beyond its cylindrical portion joined by internal hydraulic passages to said two circular grooves.

References Cited UNITED STATES PATENTS 11/1957 Smaltz et a]. 1810.5 6/1962 Lasky et a1. 3405

Patent Citations
Cited PatentFiling datePublication dateApplicantTitle
US2813591 *Jul 12, 1954Nov 19, 1957Mckiernan Terry CorpGear for projecting and retracting underwater sound translating apparatus
US3039077 *May 21, 1957Jun 12, 1962Fehlner Leo FSonar dome unit
Referenced by
Citing PatentFiling datePublication dateApplicantTitle
US4620285 *Apr 24, 1984Oct 28, 1986Heath CompanySonar ranging/light detection system for use in a robot
Classifications
U.S. Classification367/151, 367/173, 367/104
International ClassificationG10K11/28, G10K11/00
Cooperative ClassificationG10K11/004, G10K11/28
European ClassificationG10K11/00G, G10K11/28