Abstract: A sonar array connected to a data unit includes a substantial number of hydrophone units distributed along a small diameter cable having a substantial number of connecting wires, a center strength member and a tough polyurethane jacket. The hydrophone units each include a strong metal bracket bifurcated at each end and fastened to the strength member. A generally cylindrical hydrophone member is fastened to the bracket as is a circuit board including a preamplifier and the entire unit is sealed with paraxylene resin and then molded into a smooth generally cylindrical unit which is tapered at the ends and sealed to adjacent parts of the cable jacket. To minimize the cross-sectional area and the effects of cross currents, the cable is composed of a plurality of interconnected sections, each of which is of smaller cross-section and carries fewer conductors than the section next closer to the data unit.

Abstract: A funnel construction for a dipping sonar system carried in a helicopter includes the opening to a cylindrical housing of glass epoxy material for storing an underwater transducer which is deployed by suspending it into a body of water at the end of a thin cable. The housing opening includes a flared funnel structure including an entrance aperture member of thin wall aluminum alloy, a backing structure including a frustoconical strut member secured to the bottom of the helicopter and a resilient foam material positioned between and bonded to the entrance aperture member and the strut member which permits the entrance aperture member to move somewhat when impacted by the transducer. The aluminum alloy material in the entrance aperture is very light and yet transfers the heat of friction from rubbing of the small diameter cable against itself sufficiently rapidly that very little wear or damage is caused to either the cable or the funnel structure from repeated high speed reeling cycles.

Abstract: A construction for an electrical cable which carries an underwater transducer and is repeatedly reeled onto and from a hoist in a helicopter into the ocean to substantial depths. The cable includes a coaxial construction of copper conducting wires including a center conductor wound in a helix angle around a nylon center rod with the wires covered with a significant layer of polypropylene insulation and a tubular construction of fine copper wires wrapped around the polypropylene insulation in a helix angle and, in turn, wrapped with a copper-mylar tape with the copper layer adjacent the conducting wires. The tape is covered with a layer of polyvinylchloride insulation covered with an open-weave light Dacron braid bedding layer. The bedding layer serves to distribute forces from the armor layers which consist of a first layer of steel wires wound in a helix angle smaller than that of the conducting wires and in the opposite direction.

Abstract: A readily separable fastening structure for holding a pair of cylindrical sections together in axial alignment includes annular rim members attached to the inside surfaces near the ends of the cylindrical members, one of which has an outwardly extending flange spaced from the end of its corresponding cylindrical member to form an annular groove and the other of which is adapted to telescope within the first such rim member, the other such rim member also including an inwardly extending flange. A plurality of spaced members having spring fingers are attached to the outside of the second cylindrical member and extending beyond the end thereof, the spring fingers each having an inwardly extending ridge and a groove on the outside of the ridge. A small diameter cable is positioned in said grooves, and tensioning members are included for pulling said cable tightly around said fingers to pull the inwardly extending ridges into said annular groove to lock said cylindrical members together.

Abstract: A fish counter primarily for counting migrating salmon in streams includes a narrow beamwidth side-scanning sonar transducer which is directed to insonify a volume of water in the stream directly above a mechanical structure serving as an artificial bottom. This structure consists of a lightweight, ladder-like frame with transverse support members of arcuate form over which is stretched a thin skin of sheet metal such as aluminum, thereby providing a structure of great stiffness to avoid sagging. The transducer is supplied with transmitting pulses of short duration at regular intervals. After a delay, a receiver is enabled to permit reception of echo signals returning from any fish crossing the artificial bottom. During the period the receiver is enabled, a ring counter separates the return echoes on the basis of the return time from respective sectors of the bottom structure, and these returns are separately counted for each sector to permit each sector to be read out separately or printed out separately.

Abstract: A connector assembly is disclosed which serves both to mount a piezoelectric element at a distance from an electronic housing and to complete an electrical circuit between them. The preferred form is made part of a submersible sonic transducer which has a central housing for electronics which is surrounded by a baffle on which an array of piezoelectric staves are mounted. The connector permits plug-in replacement of piezoelectric elements in an arrangement that is especially rigid when assembled to insure effective operation of seals against the entry of sea water.

Abstract: To avoid possible damage to an associated hoist and sheaves, a cable termination is provided which has the capability of permitting a cable to be separated cleanly from a firmly anchored connector at the hoist when the cable is subjected to a limited force. To insure that resistance of the cable to being separated from the connector is limited, the individual conductors are trimmed to varying lengths before being soldered or fastened to the connector. The wires and connections are then potted with a first potting material which has limited shear strength, and this assembly then has a jacket of high strength insulating material molded to its outside covering part of the connector, the first potting material, and a portion of the cable jacket, thereby forming a good watertight seal at the connector and around the cable.