Abstract: A compliant tube baffle for use in a marine environment wherein a boxlike structure (10) is surrounded by an elastomeric cover (64) and includes a pair of beam plates (12,14) separated by suitable means such as bent plate springs (18,20) which may be engageable with elastic cushioning layers (54) adhered to side shields (52). The beam plates (12,14) may be tapered with the tapered sections (34) having curved surfaces in the form of an ellipse. Damping may be provided by piezoelectric elements (58) or by constrained layers (66) of elastomeric material stressed during flexing movement of the beam plates (12,14). The beam plates (72,74) may also be separated at the edges (84) by elongated members (78,80) of solid elastomer or members (92,94) of a laminate of elastomer and rigid material.

Abstract: An improved cableless seismic digital recording system is disclosed which records seismic-trace data generated by any type of seismic source, including high energy impulsive seismic sources, such as dynamite, and low energy surface seismic sources, such as vibrators and hammers. A seismometer, or geophone, is connected to a remotely deployed radio-controlled portable recorder which contains circuitry for sampling, digitizing, processing, storing, and recording seismic-trace data. Coded radio signals instruct each recorder to commence an operation or sequence of operations from a predetermined set of programmed instructions stored in program read only memory included in each recorder. Such operations include seismic-trace data acquisition; optional weighting and vertical stacking (summing); normalization; recording; and seismic source initiation.

Abstract: The position of a projectile travelling at a supersonic velocity is sensed by two triangular arrays of transducers 10,11 which are located below and close to the plane of a target area 14 through which the projectile passes. Signals from the transducers are processed to obtain data indicative of the direction of the trajectory from each array. This data can be processed to obtain the position of the trajectory in a cartesian coordinate system.

Abstract: An automatic resetting apparatus for a water sound-source which apparatus includes a source of high pressure resetting liquid, conduit means for connecting the source to the sound-source, a valve in the conduit means, which valve is, in use, under the direct or indirect influence of an actuating pressure of a sound source charging fluid, is actuable from a first position to a second position at a predetermined low actuating pressure within the charging fluid and will remain in said second position until the pressure within the charging fluid falls to said predetermined low pressure, whereupon the valve returns to the first position, the second position allowing the resetting liquid to pass along the conduit means to reset the sound-source and the first position allowing discharge of the resetting liquid from the sound-source after the sound-source has been reset.

Abstract: In order to avoid noise and error-sources a marine streamer (3) for use in seismic exploration is provided with a buoyancy member (8) which is snake-shaped or tubular-shaped and slightly flexible and supports the active member (9) of the streamer by the aid of narrow suspension ropes (10). The streamer may be made adjustable as regards its height and it may be dividable into sections.

Abstract: The present invention is an improved wellbore tool for coupling to a drill string at a threaded junction and adapted for use in a wellbore during drilling. A sensor is disposed in the wellbore tool for sensing a condition and producing a data signal corresponding to the condition. A self-contained power supply is disposed in the wellbore tool and coupled to the sensor for providing power to the sensor as required. The Hall Effect coupling transmitter means is carried by the sensor and for transmitting data from the Hall Effect coupling transmitter means to a Hall Effect coupling receiver carried by the drill string and disposed across the threaded junction from the wellbore tool, wherein data is transmitted across the threaded junction without requiring an electrical connection at the threaded junction.

Abstract: A device for reflecting electromagnetic energy comprises a solidified foam mass which has reflector agents embedded therein for reflecting at least one frequency of electromagnetic energy. The frequency or frequencies of electromagnetic energy reflected are within the region of the electromagnetic spectrum utilized for radar signaling, the infrared region, the visual region or within any combination of those regions. A variety of dyes are used for reflecting frequencies within the infrared region of the electromagnetic spectrum and a variety of phosphorous compounds are utilized for reflecting frequencies within the infrared region of the electromagnetic spectrum. Radar energy is reflected by a multitude of discreet electrically conducting elements or dipoles of a length approximately equal to one-half (1/2) the wave length of the radar energy to be reflected which dipoles are distributed in an approximately uniform manner throughout the mass during the formation of the foam mass.

Abstract: An accelerometer for blast monitoring comprises at least one piezoelectric transducer having a piezoelectric membrane attached along the edge thereof to the sidewall of a suitable container and mounted for free movement in such container for generating a high impedance electrical output signal upon deformation of the piezoelectric membrance by vibration during a blast, a high to low impedance converter connected to the piezoelectric membrane for converting the high output impedance of the piezoelectric membrane into a low impedance signal for transmission through long cables to recording equipment, and means for encapsulating the piezoelectric transducer and converter into epoxy or other solid material to minimize response of the transducer to surrounding acoustic signals.

Abstract: An optic fiber hydrophone comprises a wide spectrum optical source, a super-luminescent diode for example, associated with an optic fiber assembly comprising chiefly a side-hole optic fiber, subjected to the field of pressure, forming a sensor, transmitting the optic radiation in the slow and fast modes respectively, and a second fiber, not subjected to the field of pressure, the neutral axes of which are oriented with respect to the neutral axis of the first fiber so that the wave transmitted in slow mode in one fiber is transmitted in fast mode in the other fiber, it being possible to connect these two fibers by a polarization maintaining fiber in the event that the sensor is offset with respect to the source, a polarizing fiber enabling the creation of the interferences, and a radiation detector at the output of the fiber assembly.

Abstract: An apparatus for supporting a seismic transducer under water adjacent a towing vessel includes an elongated substantially rigid towing arm. A lower connector assembly is operably associated with the towing arm for connecting a lower end thereof to the transducer. An upper connector assembly is operably associated with the towing arm for connecting an upper end thereof to the vessel. The upper connector assembly includes a first pivot arrangement for permitting the lower end of the towing arm and the connected transducer to be lowered into the body of water. The upper connector assembly further includes a torsional support structure for resisting rotation of the towing arm about a longitudinal axis thereof. Preferably the upper connector assembly also includes a second pivot arrangement for permitting the lower end of the towing arm and the connected transducer to move laterally relative to the towing vessel.

Abstract: This invention is basically, an ultrasonic transducer that can be configured with good reproducibility, that includes an acoustic impedance matching member that gradually changes the acoustic impedance, and which is characterized byAn acoustic impedance matching member(2) configured with multiple unit layers (21, 22, 23, . . . 2n), each layer being thinner than a quarter-wavelength of an ultrasonic wave, andeach unit layer having a laiminated structure make up of heavy metal(52) and plastic(51) layers with a thickness ratio set between them to change gradually from the unit layer close to the ultrasonic oscillator to the unit layer close to the subject.

Abstract: An agricultural implement having a wing frame which can be folded up relative to another portion of the frame from a working position to a transport position, and having a hinge connection between the frame which permits the wing frame to float relative to the other frame when in the working position but which readily accommodates pivoting of the wing to the transport position. The hinge connection includes pivot pins which provide a pair of parallel pivot axis so that the floating action of the wing frame is such that the wing frame can pivot about its inner end or in effect move straight up and down relative to the other frame, and thereby provide a motion by way of which the wing readily accommodates uneven terrain. While a type of universal floating action of the wing member takes place when in the working position, a simple type locking mechanism is included in the hinge so as to prevent pivoting about the axis of one of the pins when the wing frame is raised to the transport position.

Abstract: An improved method and apparatus for initiating seismic data storage in an Isolated Distributed Recording System. An encoded acoustic signal is generated by an acoustic energy source which is detected at an isolated distributed recorder where it is correlated with a preselected correlating signal. Upon sufficient correlation between the encoded acoustic signal and the preselected correlating signal, seismic data are stored. In the preferred embodiment, the invention relates to a method and apparatus for generating an encoded seismic signal utilizing a seismic energy source. The encoded seismic signal is correlated with a preselected correlating signal at an isolated distributed recorder; upon sufficient correlation between said signals, the isolated distributed recorder is triggered to store incoming seismic data commencing at the time the seismic data were generated and extending for a predetermined time interval.

Abstract: A subsurface valve-actuator combination for well production tubing is described. The valve is urged to closed position but held open by a battery-operated latch of the actuator. A receiver-relay in the battery-actuator circuit maintains a switch closed to permit the latch to be energized as long as the receiver-relay receives an electromagnetic signal transmitted from the earth's surface. The latch is deenergized upon interruption of the signal and/or if the battery power is insufficient to energize the same.

Abstract: A low frequency sonar transducer comprising a head (1) having first and second stacks of piezo ceramic elements (2,3) in two spaced apart planes between common nodal end supports (7,8), the stacks being oppositely polarized to act in push-pull action with one stack expanding and the other contracting to cause the head (1) to bow. The transducer is prestressed with fibres (6) to prevent fracture.

Abstract: A coupling member for coupling forces generated by a seismic transducer into an elastic medium, such as the earth, wherein the coupling member includes a plurality of discrete cleat members that project downwardly from the lower surface of the coupling member and each of the cleat members has lateral sides, including arcuate portions arranged generally tangent to the sides and to the lower surface of the coupling member whereby the elastic medium is compressed, thereby preventing movement of the coupling member.

Abstract: A towed piezoelectric cable having a plurality of receiver element units which are arranged on a nonshrinking flexible core with leaving a buffer zone therebetween, each of said receiver element units having two piezoelectric elements which are polarized in a predetermined direction, and are provided with inner electrodes connected to each other and outer electrodes between which an output signal is produced, respectively, the assembly of said receiver element units and said flexible core being contained in a flexible tube which is filled with an insulating oil.

Abstract: An apparatus for measuring one or more parameters of the subsurface environment, and telemetering one or more parameters of the subsurface environment to the surface. Apparatus at the surface includes a source of intermediate frequency and voltage, electrical energy for transmission down one or more conductors of a power cable or separate instrument wire to a downhole instrument package. This intermediate frequency voltage is converted to a power supply voltage for generating a high frequency FM signal, in accordance with the magnitude of one or more parameters of the environment. This frequency modulated signal is sent to the surface over the conductors of the power cable and ground. At the surface the signal is demodulated to produce a signal indicative of the transmitted parameter.

Abstract: This invention relates to an underwater transient sound generator capable of operating at substantial depths. The pulse produced by the generator is used to determine subbottom terrain in underwater surveying. Essentially, the invention consists of an electromagnetic coil, which is embedded in an annular support body with a central hole. A piston is located next to the coil, but is separated therefrom by a dielectric sheet. A rubber seal and spring are used to locate the piston in position. A body portion extends back from the support body with two open ends. The rear end is covered with a water tight flexible diaphragm and the front end connects with the central hole of the support body, defining a watertight pressure transfer space, containing a pressure transfer medium. The coil is capable of being energized to rapidly displace the piston to a forward position. Two embodiments are shown in which the pressure transfer medium is either a gas or a fluid.

Abstract: Apparatus for simultaneously generating elliptically polarized seismic shear waves and compression waves downhole for coupling energy through the fluid into the borehole wall. The apparatus includes an elongate frame for support in the borehole and the frame includes a drive means energizable to impart an orbital motion to at least a portion of the frame thereby to generate an orbital shear wave.