Abstract: Various implementations described herein are directed to a trolling device having a motor with a propeller coupled to the motor and a shaft configured to couple or mount the motor to a watercraft. The trolling device may include a housing encapsulating the motor and the housing may include a nosecone. A sonar transducer assembly may be incorporated within the housing or nosecone including a phased array configured to transmit sonar beams into an underwater environment.

Abstract: Methods and apparatus for transmitting acoustic energy to a liquid sample within a vessel are described. The acoustic energy may have a peak incident power to enhance cooling of the sample.

Abstract: An image forming apparatus includes a main body, a cover, a driving unit, and a film. The main body is configured to accommodate an image forming portion which forms an image on a recording material. The cover is provided on the main body and covers the image forming portion. The driving unit is provided on the main body and drives the image forming portion. The film is attached to the cover with a gap formed against an inner wall of the cover. The film faces the inner wall of the cover while a tension is given thereto and without coming into contact with the driving unit.

Abstract: Methods and systems for acoustically treating material using a continuous process in which material may be caused to flow in a continuous or intermittent fashion into/out of an acoustic treatment chamber where the material is exposed to focused acoustic energy. The methods and systems may be arranged to permit continuous processing for extended periods while an acoustic energy source operates at a relatively high power output. Treatment chambers may include features such as an acoustic window and/or a chamber wall which may comprise an acoustically reflective material or a gas/wall interface that serves to reflect acoustic energy to form one or more secondary focal zones. Treatment system configurations relating to arrangements of a treatment chamber relative to an acoustic source and coupling medium, material flow paths, and others are provided.

Abstract: A marine acoustic sensor assembly includes an acoustic panel having a forward surface and an after surface, a laser scanner oriented so as to project a laser beam onto the acoustic panel after surface, and a sensor oriented so as to receive reflections of the laser beam off the acoustic panel and to transmit data from which a position of a sound generating source can be determined, wherein the acoustic panel is provided with an absorber layer extending over the after surface thereof, and the absorber layer is provided with holes extending therethrough, the holes being of a size sufficient to permit passage of the laser beams to the acoustic panel after surface and the reflections to pass to the sensor, whereby to minimize reflections and noise originating from aft of the after surface, while permitting sound incoming from forward of the acoustic panel to be measured.

Abstract: A submarine bow dome acoustic sensor assembly comprises an outer hull bow portion, an inner pressure hull wall extending athwartships and in conjunction with the outer hull bow portion defining a free-flood compartment, and an acoustic bow panel disposed in the compartment and connected to the pressure hull wall by acoustically isolating supports. A laser scanner is disposed in the compartment and is oriented so as to project a laser beam onto a surface of the acoustic bow panel, and a sensor is disposed in the compartment and oriented so as to receive reflections of the laser beam off the acoustic panel and to transmit data from which a position of a sound generating source can be determined.

Abstract: A compact, modular sonar assembly for use on the bow of a ship having separate transmitting and receive arrays confined within a single acoustic housing. The narrow and compact design fits much better into the hydrodynamically desirable bulbous bow deign than the typical bow dome sonar design and achieves good performance at a low cost with reduced size and weight.

Abstract: An anti-fouling system for producing vibrations in an underwater structure to inhibit the attachment of aquatic life forms to the structure. The system includes a controller which drives one or more transducer. The transducer comprises a housing, one end of which is closed by a resilient diaphragm. An electromagnet with soft magnetic core is contained in the housing spaced from an unsupported portion of the diaphragm. The unsupported portion of the diaphragm is mounted over an underwater structure. In operation, the electromagnet is excited with a current pulse, which deforms the diaphragm so that the housing moves towards the structure. As the current drops off, the diaphragm is restored to its original shape and the housing moves away from the structure imparting a vibrational force to the structure. The transducer includes an elastic membrane to compensate for changes in temperature and pressure commonly found when working under water.

Abstract: A sensor for determining both the presence of a liquid in a container or conduit, and identifying its type has a sensor housing body containing both a pair of piezoelectric elements used as the transmitter and receiver of ultrasonic waves directed across a gap therebetween in an ultrasonic liquid presence detecting circuit and a pair of electrodes exposed to any of such liquid in the gap used in a circuit for identifying the liquid type. The liquid identification circuit is either of the capacitance type, which produces a variable amplitude output signal depending on the type of liquid in the gap between the two electrodes, or operates to measure the difference in response time between pulses applied to each of the electrodes with one serving as a reference.

Abstract: An underwater transducer assembly (T or P) is mounted on an elongated cylindrical piston (32 or 90) received in a pneumatic cylinder (31 or 91). One or more springs (41 or 92) normally bias the piston (32 or 90) inward into the cylinder (31 or 91) to retract the transducer assembly (T or P) into a sea chest (S'). Air under pressure introduced into the cylinder (31 or 91) is effective to overcome the force of the springs (31 or 91) and project the transducer assembly (T or P) to a position operative for scanning. Force applied to the transducer assembly (T or P) tends to move the piston (32 or 90) inward into the cylinder and thereby increase the pressure of the system. The transducer assembly (T or P) is retracted automatically if the pressure exceeds a predetermined pressure. A separate mechanical sensor is mounted adjacent to the sea chest S' to detect the presence of obstacles or debris and automatically actuate retraction of the transducer assembly (T or P).

Abstract: A method and an apparatus are disclosed serving to reduce acoustic emission from submerged submarines in which vibrations from moving mechanical elements within an inner region are transmitted to an outer hull via a vibration transmission path. For decoupling the outer hull as completely as possible from the moving mechanical elements, for example periodically moving nuclear reactor control rods, the vibrations are actively damped. Means are provided for ascertaining the motion of the mechanical elements relative to the outer hull and for superimposing upon said motion of counter-motion of opposite direction.

Abstract: A sensing apparatus capable of delivering a control signal in response to contact between an element of the apparatus and an external object should respond readily to a predetermined level of contact, and should be sensitive along all portions of the contact sensing surface. The instant invention provides a contact sensing apparatus including a conduit having a generally hollow tubular construction and being formed a resilient deformable material. A sonic generator is connected to one end of the conduit and a sonic detector is connected to the other end of the conduit. An electrical circuit is connected to the sonic generator and sonic detector, and is adapted to controllably produce a control signal in response to contact between the conduit and an external object.

Abstract: A motion detector is physically attached to a boat's anchor. Upon abnormal motion or movement of the anchor, indicative of a dragging anchor, a pulse generator is initiated by the motion detector to actuate a transmitting transducer and generate an acoustic or sonar wave in the water. The acoustic wave is sensed by a receiving transducer on the boat, and a warning alarm is produced. In a preferred embodiment, the receiving transducer actuates an RF transmitter which generates a radio wave, and an RF receiver which is tuned to receive the radio wave actuates the alarm.

Abstract: A float for use in seismic surveys of the sea bed supports a plurality of seismic pulse transmitters (6) which are suspended on lines (7) beneath the float (1). At a distance from the front end of the float (1), on one sidewall thereof, a fastening device for a towing cable and a lead-in for control lines and lines for supplying operating medium to the pulse transmitters are provided. These lines and cables are gathered in a common line (3) which extends behind the tow ship. The line (3), at a distance away from the float (1), is connected to a line (4) which leads to a length-regulating device (12) inside the front section of the float. The float is also provided with at least one motor (10) with a drive shaft (9)leading to hoisting drums (8) for the lines (7) to the respective seismic pulse transmitters (6). Both the motors (10, 12) and the seismic pulse transmitters (6) are connected to the pneumatic supply line.

Abstract: An assembly is provided for mounting a sonar depth sounder transducer on an electric trolling motor such that the transducer is protected from entaglement with vegetation and from being knocked out of a predetermined orientation relative to the boat. The conventional bearing cap connected to the nose of a trolling motor is replaced by a bearing cap having a sonar tranducer integrally mounted therein such that the power cable, extending from the depth sounder in the boat to the transducer, is routed through the inside of the trolling motor housing and through the hollow tubular trolling motor support shaft. A power cable guide is mounted inside the trolling motor housing and is supported by a guide ring for positioning the power cable along a path preventing engagement with the armature, rotor and other moving parts in the trolling motor.

Abstract: A float for use in seismic surveys of the sea bed supports a plurality of seismic pulse transmitters (6) which are suspended on lines (7) beneath the float (1). At a distance from the front end of the float (1), on one sidewall thereof, a fastening device for a towing cable and a lead-in for control lines and lines for supplying operating medium to the pulse transmitters are provided. These lines and cables are gathered in a common line (3) which extends behind the tow ship. The line (3), at a distance away from the float (1), is connected to a line (4) which leads to a length-regulating device (12) inside the front section of the float. The float is also provided with at least one motor (10) with a drive shaft (9) leading to hoisting drums (8) for the lines (7) to the respective seismic pulse transmitters (6). Both the motors (10, 12) and the seismic pulse transmitters (6) are connected to the pneumatic supply line.

Abstract: Disclosed is an acoustic transducer which includes a pressure tight vessel with a window in the vessel which is transparent to acoustic wave energy. A gas is disposed within the vessel, while an electromechanical transducer is located within the vessel at an antinode for a resonant wave of the gas. A port communicates with the interior of the vessel, with a pressure control coupled to the port and to a source of the gas for controlling the pressure of the fluid within the vessel.

Abstract: 1. A chemical canister for generating gas in a noisemaker beacon comprising canister case for holding a chemical for generating a buoyant gas, a canister cover adapted to be mounted on said case, a watertight seal between said cover and said case, means for ejecting said cover from said case, and means for temporarily locking said cover and said canister; said ejecting means comprising a conical spring adapted to be compressed within its outer diameter, and said locking means comprising a rod extending from the bottom of said canister to said cover, a groove in said rod near said cover, a locking pin mounted in said cover having one end adapted to lock with said rod by means of said groove and having a piston at the other end, and a locking pin ejecting spring mounted on said pin for moving said locking pin out of engagement with said rod by means of said groove.

Abstract: A method of calibrating acoustic emission transducers. The sensitivity of a standard transducer is first determined utilizing a reciprocity calibration technique, and the standard transducer and the acoustic emission transducer are then connected to a bounded acoustic medium. Random acoustic white noise is transmitted into the acoustic medium thereby establishing a multi-mode reverberant sound field, and the output responses from the standard transducer and the acoustic emission transducer to the reverberant sound field are obtained and compared to determine the sensitivity of the acoustic emission transducer.

Abstract: A marine acoustic seismic generator carried on the deck of a boat is coupled to a body of water in which the boat floats by a column of water in a pipe extending between the generator and the body of water. Post explosion oscillations are damped or terminated by venting the pipe of gas, either through an orifice or a valve, at a selected time, to a selected pressure, to the atmosphere or below water.