Abstract: The present invention provides an acoustic sensor having one or more segments that are electrically coupled to provide a response corresponding to a hydrodynamic pressure applied to the segments. Each segment contains a substrate of a desired shape with a concavity on an outer surface that is sealingly enclosed by an active member made from a flexible, resilient piezoelectric material. PVDF material is preferably used as the piezoelectric active element. The active member is covered with a protective layer of a suitable material, preferably a polyvinyl material. A single segment may be used as a sensor or a plurality of suitably configured segments may be suitably coupled to form the sensor. The sensor may be used as a hydrophone on a hydrophone cable commonly used for performing seismic surveys for geophysical exploration. In such applications, a plurality of hydrophones are placed equally spaced along the cable. In the preferred embodiment, two hydrophone segments are securely be placed around the cable.

Abstract: The present invention discloses an apparatus for rotatably attaching a sensor to a cable. A cable mount having a groove about a substantial portion of its periphery is fixedly placed on the cable. A sensor mount having a key adapted to slide along the groove is rotatably placed on the cable in a manner which enables the key to remain in the groove when the sensor mount rotates about the cable.

Abstract: A dual-mode vibrator for alternately injecting P-waves and S-waves in the earth including a hydraulically driven shaker assembly, a ground-contacting base plate, and a jacking means for raising and lowering the base plate relative to a vehicle. The shaker assembly is supported above, and coupled to the base plate by a supporting means. The supporting means has a first configuration for coupling the shaker assembly to the base plate for generating P-waves and a second configuration for pivotally coupling the shaker assembly to the base plate and to a rigid member associated with the vehicle for injecting S-waves.

Abstract: An air gun of the reciprocating shuttle type includes a split-ring sleeve valve that is expandable against the inner wall of a firing chamber. The sleeve valve encircles the shuttle body. The shuttle body and the sleeve valve include a set of air release orifices that are alignable with a corresponding set of air exhaust ports of the firing chamber.

Abstract: A shuttle valve is slidingly provided within a firing chamber. A shuttle valve actuation control chamber is mounted at each end of the firing chamber. Pressurized air applied to a control chamber at one end of the firing chamber drives the shuttle valve to the opposite end of the firing chamber. An air accumulator chamber having a pressurized-air inlet is mounted adjacent each control chamber. An air passageway having a choke interconnects the firing chamber with the air accumulation chamber. A poppet valve interconnects each accumulator chamber with the adjacent control chamber to selectively apply pressurized air to one or the other of the control chambers. A solenoid vent valve fluidly communicates with each shuttle valve actuation control chamber. A bypass line fluidly interconnects each control chamber with the solenoid vent valve at the opposite end of the firing chamber.

Abstract: A piston and cylinder motion dampening device having a spiral groove metering, an orificed two-way pressure relief valve or a screw-on spring or an over-extension limiting seal retainer.A push-together method of assembling a piston and cylinder motion dampening device.A motion dampening device with a baffle chamber.

Abstract: A piston and cylinder motion dampening device having spiral groove metering, an orificed two-way pressure relief valve or a screw-on spring or an over-extension limiting seal retainer.A push-together method of assembling a piston and cylinder motion dampening device.A motion dampening device with a baffle chamber. A method of dampening the motion between two members utilizing a piston and cylinder motion dampening device having spiral groove means, a fixed orifice means and a two-way valve means to meter the fluid contained in the motion dampening device.

Abstract: A piston and cylinder motion dampening device having spiral groove metering, an orificed two-way pressure relief valve, a screw-on spring and an over-extension seal retainer.

Abstract: A piston and cylinder motion dampening device having spiral groove metering, an orificed two-way pressure relief valve or a screw-on spring or an over-extension limiting seal retainer.A push-together method of assembling a piston and cylinder motion dampening device.A motion dampening device with a baffle chamber.