Abstract: An ultrasonic sensor which is particularly suited to measuring the sound-pressure amplitude in the focus range of a lithotripter and includes in a region a piezoelectrically activated polymeric foil, which is coupled to electrodes. The polymeric foil is mounted in a housing, which has a convex curved, dome-shaped surface at least in one region located opposite one of the flat sides of the polymeric foil. A simple measurement of the sonic field is thus made possible directly on the rubber-diaphragm encased, water-filled delay path of the lithotripter.

Abstract: An ultrasonic ground speedometer utilizing Doppler effect comprises an ultrasonic transmitter for outputting an ultrasonic wave having a particular wavelength at a predetermined angle against a road surface, an ultrasonic receiver for receiving a reflected ultrasonic wave caused by reflection of the output ultrasonic wave from the road surface, and a signal processor for deriving ground speed from Doppler shift between the output ultrasonic wave and the reflected ultrasonic wave. The particular wavelength is set to a value within a range of 2.6 mm through 3.4 mm to assure the highest possible S/N ratio for the Doppler shift signal obtained from the signal processor.

Abstract: An acousto-optical seismic sensor array includes a distributed set of optical-fiber sensing coils. A light pulse is launched through the sensing coils in serial order. The light pulse is cumulatively data-modulated by the respective sensing coils and is returned as a time-division multiplexed pulse train. The pulse train is split into a first pulse train and a retarded second pulse train. The retardation time equals the travel-time delay of a light pulse between sensors. The retarded pulse train is compared with the first pulse train to determine the phase shift therebetween for consecutive pulses. The phase shift is an analog of the quantity being sensed.

Abstract: A sonar projector having a pair of opposed oscillating pistons driven by an electromagnetic assembly is rendered capable of operating at reduced resonant frequency by providing liquid mass loading for the pistons. The mass loading is achieved by utilizing a structure which constricts a body of liquid on one side of the piston. The constricted liquid may be sea water or a liquid sealed within the body of the unit. In accordance with a further aspect of the invention, a seal assembly is provided for the moving pistons which not only provides a sealing function but which also acts to radially center the pistons and to provide an axially directed restoring force thereto during piston oscillation. The electromagnetic assembly, in accordance with still a further aspect of the invention, is formed with a permanent magnet structure arranged in a cylindrical configuration with the opposed pistons on opposite axial ends thereof to reduce magnetic leakage losses.

Abstract: A sonar transducer wherein a plurality of transducer modules are affixed along the length of a mounting member in the form of an elongated bar. The bar is contained within a protective housing and the mid point of the mounting member is affixed to the back wall of the housing in a manner that the mounting member stands off from the back wall of the housing. The mounting member is cantilevered on either side of the mounting position and is totally enclosed within the outer housing which is affixed along its entire length to a host structure so as to isolate and protect the alignment of the transducer modules from distortions.

Abstract: The invention relates to an agricultural machine for soil-cultivation, comprising, in the direction (F) of travel of the machine, a first row of cutting wheels arranged at right-angles to the said direction of travel and having substantially horizontal axes, in front of which is arranged a cylindrical roller with the aid of which weeds and/or the remains of past cultivation, such as stalks, stubble, and the like may be broken up. A subsequent row of ripping elements, with blades preferably running out to a point, rips up and loosens the soil, without ploughing it in, and is associated with plough-mould-boards which partially plough in the loosened soil. A transverse row of rotor-tools, with substantially horizontal axes, acts as a harrow and is used for final ploughing through 180.degree. and for crumbling the soil. The cutting wheels and the rotor-tools are arranged with their axes at an angle to the perpendiculars to the direction of travel (F) of the machines, preferably at an angle of between 5.degree.

Abstract: The invention is an apparatus for distributing a lubricant to the air guns in a single airline seismic air gun subarray which utilizes an air-lubricant mixture to operate and lubricate the air guns in the subarray. The air-lubricant mixture from the single airline is supplied to each air gun through a separate adapter and a cut-off valve. The lubricant tends to accumulate near the first several air guns, which wind up using most of the lubricant contained in the mixture while leaving no or very little lubricant for the remaining air guns. To prevent this uneven distribution of the lubricant, a lubricant metering device is placed in certain adapters to control the amount of the lubricant supplied to their associated air guns. Using the lubricant metering device to control the lubricant supply to the air guns in a subarray ensures that all the air guns receive adequate lubricant supply.

Abstract: A marine seismic cable comprising a core, a body of flotation material positioned around the core, an acoustic energy transducer positioned proximate the core, and a body of acoustically transparent material positioned around the acoustic energy transducer.

Abstract: A downhole seismic exploration device comprises a seismic detector such as a geophone and a magnetic clamp, supported by O-rings in an open cradle carrier which can be secured to a cable linking several such devices into an array. The array is lowered into a cased borehole and the magnetic clamps are operated to clamp the devices temporarily to the casing. Seismic signals detected by the geophones are transmitted to the surface via the cable, the O-ring supports acting to reduce or eliminate transmission of vibrations from the borehole fluid and the cable via the carrier to the geophone. The array is then unclamped and moved to another location in the borehole and the operation repeated. The magnetic clamp comprises a rotatable permanent magnet with radial poles disposed between a pair of parallel pole piece plates protruding on each side of the device and separated by non-magnetic blocks on eahc side of the magnet.

Abstract: A loading strip (1) for supplying individual explosive powder charges in a setting tool is formed of an elongated belt-shaped member (2). The member has openings (2a) therethrough with a hollow receptacle (3) projecting outwardly at each opening from one surface of the member (2). The interior of the hollow receptacle (3) in combination with the corresponding opening (2a) form a space for holding an explosive powder charge. Annular gap (2b) encircles each opening (2a) and extends inwardly from the opposite side of the member from the receptacles. A bulge-like projection extends into the space formed by the receptacle and the member. The projection has a hollow recess (2c) located eccentrically relative to the opening and the hollow space and faces the opposite side of the member (2). An ignition medium (6) is placed in the hollow recess (2c). A base plate (7) forms a closure for the explosive powder charge space and the ignition medium hollow recess.

Abstract: An acoustic levitator includes a pair of opposed sound sources which have interfering sound waves producing acoustic energy wells in which an object may be levitated. The phase of one sound source may be changed relative to the other in order to move the object along an axis between the sound sources.

Abstract: A real time soil chemical sensor and precision agricultural chemical delivery system includes a plurality of ground-engaging tools in association with individual soil sensors which measure soil chemical levels. The system includes the addition of a solvent which rapidly saturates the soil/tool interface to form a conductive solution of chemicals leached from the soil. A multivalent electrode, positioned within a multivalent frame of the ground-engaging tool, applies a voltage or impresses a current between the electrode and the tool frame. A real-time soil chemical sensor and controller senses the electrochemical reaction resulting from the application of the voltage or current to the leachate, measures it by resistivity methods, and compares it against pre-set resistivity levels for substances leached by the solvent. Still greater precision is obtained by calibrating for the secondary current impressed through solvent-less soil.

Abstract: A hydrophone for the detection of sound or vibrational waves, comprising a piezo electric transducer within a Faraday cage such that it is in contact with and yet isolated from a deformable pressure transmitting medium that carries vibrations. The Faraday cage reduces noise interference. The deformable medium is usually a fluid and preferably a vegetable oil, but can also include a silastic compound couple. One side of the Faraday cage is a ground plane of a surface-mount printed circuit board. Components of an electronic circuit for conditioning the signal are mounted on the printed circuit board and include a buffer having an ultra-high impedance input and a very low impedance output. The circuit has a low power draw and is powered by a replaceable battery.

Abstract: A method of establishing an ultrasonic standing wave in a fluid medium is described in which the standing wave is produced by an acoustic energy output along a path extending through the fluid medium, the frequency of said energy output being changed cyclically while maintaining an essentially constant mean frequency. The cyclic frequency change sweeps said energy output frequency between upper and lower limits that represent a difference of at least one half-wavelength at the mean acoustic frequency over the length of said path, so that a fully resonant standing wave appears in each cycle, regardless of transient ambient variations. For stability, the cycle time of the sweep is maintained substantially greater than the travel time of the acoustic energy output over the length of the path.

Abstract: Method and apparatus for generating seismic energy in offshore areas includes energy propagating means for directing energy downwardly vertically into an earth formation. A carrier contains an elongated rigid coupler means that extends from the carrier at the water level to the seat floor. A base plate may be connected to the lower end of the coupler means. The coupler means may be a section of pipe. Driving means on the carrier drives the coupler means to cause sound energy to emanate from the coupler means or base plate into the sea floor. Such means may be a hammer-type device or a vibrator-type device. Alternatively, the lower end of the coupler means or the base plate may be driven by means of a vibrator-type device to cause sound waves to emanate from the coupler means or the base plate directly into the sea floor.

Abstract: An instrument for sensing seismic waves and determining their direction of propagation is operable at considerable depth in a borehole. It comprises a short, stubby sensor module with means to clamp it to the borehole wall and including three accelerometers, and connected by a flexible umbilical cord to a primary module suspended by a cable. The down-hole electronics and the power supply for the clamp means are provided in the primary module. The sensor module has a fundamental resonant frequency about 1 kHz, well above the frequency of the seismic waves it is subjected to, so that the signals from the accelerometers accurately represent those waves.

Abstract: This disclosure describes apparatus and method for overcoming stroke limitations of moving coil reaction-mass vibration dampers, by recovering armature stroke displacement. The coil housing is selectively coupled or de-coupled to the vibrating structure. If, when the armature reaches its travel limit, sufficient damping energy has not been applied to the structure, the coil-housing assembly is decoupled from the structure while the armature is pulsed back to its zero displacement position. The housing then is re-coupled to the surface, having displaced some determinable distance from its previous location relative to the surface. Additional armature movement in the same direction as the previous armature stroke is applied, thereby generating the needed additional damping force. The resetting of the housing to its normal position vis-a-vis the vibrating structure can occur at a selected time in the damping force-generating cycle when reset does not impart an undesired reaction to the vibrating structure.

Abstract: A device for determining the depth below the ground surface of a working member of an earth moving equipment, comprises a sensor for transmitting ultrasonic signal from underneath and toward the ground surface and for receiving a portion of the signal reflected from the ground surface. The sensor is positioned underneath the ground surface in fixed spatial relationship to the working member such that the sensor means is under the ground surface when at least a portion of the working member is under the ground surface. A circuit is provided for processing the received reflected signal to thereby indicate the depth under the ground surface of the working member, whereby the depth is proportional to the time of travel of the signal to the ground surface and the reflected signal to the sensor means.

Abstract: This invention is an automatic gunnery system, responsive to airborne acoustic shock waves produced by a projectile passing through a target area. Curved elongated acoustic energy conductors are located adjacent to one side of said target area with acoustic transducers attached to the end portions thereof. Said transducers produce an electrical signal when a shock wave from the projectile reaches them through said energy conductors. Electrical signal from the transducers is connected to electronic circuitry which determines the location of each "hit" on or near the target which is registered on display means.

Abstract: Disclosed is an apparatus for generating seismic waves in a well bore, which apparatus includes a tubular expandable and contractible outer anchor wall, a seslf-contained anchor setting hydraulic system to expand the anchor into anchored position in the bore hole, a self-contained vibrator hydraulic system operable to cycle pressure impulses to the interior of the tubular expandable and contractible outer anchor wall effective to produce and radiate seismic waves, a cable including electric lines for locating the apparatus in the well bore, and switch means at the surface for controlling the operation of the apparatus. The apparatus is useful for geophysical investigation including vertical seismic profiling and cross hole tomography.