Abstract: A connection system for connecting external devices to specified locations on a marine seismic streamer. Inner collars are clamped to the cable at specified locations along its length. Each inner collar forms a circular race encircling the cable. An outer collar attached to an external device rotatably receives the inner collar and the encircled streamer in its bore to allow the streamer to rotate freely within the outer collar relative to the external device. The outer collar has an inner face bounding and defining the shape of the bore. The inner face is tapered from an intermediate position outward toward front and rear edges of the outer collar to form a bore that is wider at the front and rear edges than at the intermediate position. This flaring out of the bore provides the streamer three degrees of angular freedom to position itself within the bore.

Abstract: A connection system for connecting external devices to a streamer. The connection system comprises three outer collars maintained collinearly aligned by a stabilizing member, such as a lightweight, rigid tube, attached to each outer collar. The tube extends parallel to the bores of the outer collars. The forward and aft outer collars ride on races formed on the periphery of inner collars clamped around mounting structure in the interior of the streamer. An external device is attached to the forward collar and to the intermediate collar, which does not ride on an inner collar. The spacing between the forward and intermediate collars is fixed by the standard spacing of the two attachment points in standard external devices. The spacing between the forward and aft collars is set by the specified spacing of mounting structures in the interior of the streamer.

Abstract: A device and a method for laterally steering a streamer cable towed underwater behind a seismic survey vessel. The device includes a cable-steering assembly rotatably attached to a streamer cable. The assembly includes a body to which one or more wings are mounted. The wings are arranged to pivot about pivot axes. The assembly is ballasted so that the pivot axes of the wings are largely in a vertical plane. A conventional cable-leveling bird is converted to one version of a cable-steering device by ballasting to maintain the pivot axes of the bird's wings largely vertical. With an orientation sensor for sensing the orientation of the wings, the cable-steering device adjusts the angle of the wings to provide a sideward component of force to steer the streamer.

Abstract: A device and a method for laterally steering a streamer cable towed underwater behind a seismic survey vessel. The device includes a cable-steering assembly rotatably attached to a streamer cable. The assembly includes a body to which one or more wings are mounted. The wings are arranged to pivot about pivot axes. The assembly is ballasted so that the pivot axes of the wings are largely in a vertical plane. A conventional cable-leveling bird is converted to one version of a cable-steering device by ballasting to maintain the pivot axes of the bird's wings largely vertical. With an orientation sensor for sensing the orientation of the wings, the cable-steering device adjusts the angle of the wings to provide a sideward component of force to steer the streamer.

Abstract: A connection system for connecting external devices to specified locations on a marine seismic streamer. Inner collars are clamped to the cable at specified locations along its length. Each inner collar forms a circular race encircling the cable. An outer collar attached to an external device rotatably receives the inner collar and the encircled streamer in its bore to allow the streamer to rotate freely within the outer collar relative to the external device. The outer collar has an inner face bounding and defining the shape of the bore. The inner face is tapered from an intermediate position outward toward front and rear edges of the outer collar to form a bore that is wider at the front and rear edges than at the intermediate position. This flaring out of the bore provides the streamer three degrees of angular freedom to position itself within the bore.

Abstract: A device and a method for laterally steering a streamer cable towed underwater behind a seismic survey vessel. The device includes a cable-steering assembly rotatably attached to a streamer cable. The assembly includes a body to which one or more wings are mounted. The wings are arranged to pivot about pivot axes. The assembly is ballasted so that the pivot axes of the wings are largely in a vertical plane. A conventional cable-leveling bird is converted to one version of a cable-steering device by ballasting to maintain the pivot axes of the bird's wings largely vertical. With an orientation sensor for sensing the orientation of the wings, the cable-steering device adjusts the angle of the wings to provide a sideward component of force to steer the streamer.

Abstract: The present invention provides an underwater cable arrangement includes an underwater cable having one or more external devices mounted on the cable. In one form of the invention, the external devices are powered primarily or entirely by inductive coupling between a coil disposed in the cable and a coil disposed in the external device. The invention also provides a variety of external devices capable of use with an underwater cable. The invention further provides a coil support arrangement for supporting a coil within an underwater cable in a manner protecting a core of the coil from damage.

Abstract: A device for controlling the position of an underwater cable comprises a body, first and second actuators, and a pair of wings. The body is stationarily mountable to the underwater cable and the first and second actuators are disposed in the body. Each wing has an axis of rotation and the wings are coupled to the first and second actuators to control the depth and the horizontal position of the underwater cable in the water.

Abstract: A connection system for connecting external devices to specified locations on a marine seismic streamer. Inner collars are clamped to the cable at specified locations along its length. Each inner collar forms a circular race encircling the cable. A cuff attached to an external device is in the form of a C-shaped cylindrical ring with a circular inner surface. A gap in the ring interrupts the inner surface. A throat is formed in the ring by the gap, which extends the full length of the cuff across the ends of the C. The spacing between the ends of the C across the throat defines the width of the gap. The width of the gap is slightly larger than the diameter of the cable so that the cuff can be slipped over the cable through the throat. The width of the gap is smaller than the diameter of the circular race so that, when the cuff is slid into position on the race, the cuff cannot be removed radially from the race. The inner surface of the cuff rides on the race to allow the cable to rotate inside the cuff.

Abstract: A connection system for connecting external devices to specified locations on a marine seismic streamer. Inner collars are clamped to the cable at specified locations along its length. Each inner collar forms a circular race encircling the cable. A cuff attached to an external device is in the form of a C-shaped cylindrical ring with a circular inner surface. A gap in the ring interrupts the inner surface. A throat is formed in the ring by the gap, which extends the full length of the cuff across the ends of the C. The spacing between the ends of the C across the throat defines the width of the gap. The width of the gap is slightly larger than the diameter of the cable so that the cuff can be slipped over the cable through the throat. The width of the gap is smaller than the diameter of the circular race so that, when the cuff is slid into position on the race, the cuff cannot be removed radially from the race. The inner surface of the cuff rides on the race to allow the cable to rotate inside the cuff.

Abstract: An internal device for use in an underwater cable may comprise a body having an outer periphery, body being mountable inside the cable with the cable surrounding the outer periphery of the body. The body may include a cutaway portion, a slot, or a dovetail joint. An underwater cable arrangement may comprise an underwater cable and an internal device disposed in the cable with the cable surrounding the device. The underwater cable may include a stress member connected to the internal device by an interference fit or the internal device may include a slot for receiving the stress member. A method of connecting a stress member of an under water cable to an internal device includes forming an interference fit between a region of increased diameter of the stress member and the internal device.

Abstract: A connection system for connecting external devices to specified locations on a marine seismic streamer. Inner collars are clamped to the cable at specified locations along its length. Each inner collar forms a circular race encircling the cable. A cuff attached to an external device is in the form of a C-shaped cylindrical ring with a circular inner surface. A gap in the ring interrupts the inner surface. A throat is formed in the ring by the gap, which extends the full length of the cuff across the ends of the C. The spacing between the ends of the C across the throat defines the width of the gap. The width of the gap is slightly larger than the diameter of the cable so that the cuff can be slipped over the cable through the throat. The width of the gap is smaller than the diameter of the circular race so that, when the cuff is slid into position on the race, the cuff cannot be removed radially from the race. The inner surface of the cuff rides on the race to allow the cable to rotate inside the cuff.

Abstract: A connector for attaching equipment to an underwater cable includes a cylindrical race having a plurality of sections pivotably connected by a hinge. The sections can pivot about the hinge to enable the race to be opened and detached from the cable. The hinge includes a plurality of sockets and a hinge pin rotatably received in the sockets. The hinge pin can preferably be retracted from the sockets to unlock the hinge and inserted into the sockets to lock the hinge. A retaining member prevents the hinge pin from falling out of the sockets when the hinge pin is retracted.

Abstract: A battery operated system 20 responds to coded acoustic signals 15 for releasing a buoyed housing from an underwater anchor 21 to carry a retrieval line attached to a retrievable underwater object to the water surface. A novel tethering mechanism 26 is provided for attaching the housing to a line 25 tethered to the anchor and for releasing it in response to the coded acoustic signals. The tethering mechanism operates in two diverse modes. Thus the housing is released from its tether line thermally by battery power which melts an expandable wax body in a thermal actuator 36 to move an actuating member 37 through a line release stroke. However, the tether line is attached by a manually actuated latching mechanism 45, 47 provided for retethering the housing at a different location without draining battery power for resetting the latching mechanism.

Abstract: A general-purpose, pressure-sensitive electrical switch, having a frangible electrically conductive path that is irreversibly broken by an excessive applied pressure differential, The switch includes a pressure-deflectable diaphragm and an interior chamber. The diaphragm forms an interface between the internal chamber and the external environment. As the pressure differential across the diaphragm exceeds a specified level, the diaphragm deflects. The internal chamber can also be sealed with an internal pressure P.sub.1 so that the diaphragm deflects for a specified absolute external pressure P.sub.2. The force of the deflection is transmitted to brittle, inelastic structure within the switch through an intermediate load transmission element. The electrical path, which is along the brittle structure, terminates in a pair of externally-accessible terminals.

Abstract: For confidently coupling towed external devices to a marine seismic cable, a latch mechanism having a novel swing plate to improve the adjustability of the mechanism and provide a positive, clearly visible indication of latched and unlatched conditions. The swing plate serves as an external linkage between a rotatable adjustment head for a locking pin and a translatable lever arm for a locking rod. The locking pin and the locking rod extend from a latch housing on a towed device, such as a cable-leveling bird, and engage with a keyhole slot in a locking collar on the streamer. The swing plate engages the adjusting head, which protrudes from a side of the housing, in a push-nut engagement.

Abstract: A miniaturized electronic magnetic compass system, or the like, is mounted in a substantially cylindrical gimbal ring unit of about 0.75 in diameter, and 1.25 in length. Critical to the small size is the pendulum that positions the internal magnetic detector by gravity relative to the earth's surface. Thus, a pendulum formed of tungsten has its curved bottom surface formed of a central spherical surface and two flanking cylindrical surfaces meeting in two planes disposed at an angle intersecting with the pendulum axis of rotation. The mass of the detector is centered by resilient conductive spring plates bearing on gimbal pivot shafts, which also serve as electrical connectors for the detector. Thus, two separated shaft ends journalled in one gimbal ring, which is insulated to electrically isolate the shaft ends serve as two conductors. The gimbal system is damped in a perfluorocarbon oil.

Abstract: A person-raising device, designed for lifting a person in bed, rests atop a bed and is activated by a linear actuator comprising a dual-threaded lead screw and a small electric motor and gear reduction unit. The small electric motor and gear reduction unit drives the dual-threaded lead screw to raise a pair of support arms, which raises a person resting on the device. The lead screw is enclosed in a slotted tube; this decreases the chance of the lead screw coming into contact with a person using the device.