Kokusai Denshin Denwa Co., Ltd.

Kokusai Denshin Denwa Kabushiki Kaisha

Kazuomi Yamamura

Yoshinao Iwamoto

Kenichi Asakawa

Hideo Ishihara

Shizuo Suzuki

Yuichi Sirasaki

Hifumi Sakaguchi

Masao Morita

Yoshihiro Ejiri

Yuichi Shirasaki

Masayuki Fujise

Teruji Watanabe

Toshio Izawa

Kikuo Shirai

Takashi Mizuguchi

Takasuke Fukui

There is disclosed a submarine cable grapnel which is tied to the two rope of a cable ship and is dragged on the bottom of the sea, one grappling unit and at least one attitude stabilizer is connected while this assembly is connected at one end the two rope of the cable ship and at the other end a chain. In this instance, front and rear coupling portions of the grappling element and the attitude stabilizer are positioned so that the center of gravity of each element under the water stays nearer the seabed than a straight line joining the coupling centers of the coupling portions of the elements when the grapnel lands in the normal attitude on the bottom of the sea.

Submarine cable grapnel

A device for burying a submarine cable under water by easily and accurately detecting the cable position and a method for guiding the same by utilizing the characteristics unique to submarine cables, by supplying an AC only to the portion of the cable between two arbitrary repeaters through a so-called transformer-coupling system to generate an AC magnetic field, and by detecting the magnetic field with a magnetic field detector.

Burying device for submarine cables and method for guiding the same

A device for burying a submarine cable under water by easily and accurately directing the cable position and a method for guiding the same by utilizing the characteristics unique to submarine cables, by supplying an AC only to the portion of the cable between two arbitrary repeaters through a so-called transformer-coupling system to generate an AC magnetic field, and by detecting the magnetic field with a magnetic field detector.

Apparatus for supplying AC current to an underwater cable

A device for burying a submarine cable under the water by easily and accurately detecting the cable position and a method for guiding the same by utilizing the characteristics unique to submarine cables, by supplying an AC only to the portion of the cable between two arbitrary repeaters through a so-called transformer-coupling system to generate an AC magnetic field, and by detecting the magnetic field with a magnetic field detector.

Alternating current induction method using an annular magnetic coupling

The present invention aims at providing a method and a device therefor which can effectively as well as accurately bury a cable under marine beds not only when a cable is newly laid and buried but also when a cable has to be reburied. The method and the device according to the present invention are characterized in that a burying device is guided to approach the cable by using a travelling member provided on said burying device, a travelling control mechanism thereof being controlled by a receiving output from a transmitter which is mounted on the cable in advance by a receiver provided on the burying device, that the cable is caught and held by a cable engaging member of said burying device while the burying device is detecting the buried cable track and travelling therealong, and that at the same time an excavation member of said burying device digs and forms a groove while the burying device guides and buries the cable within the excavated groove. The method according to the present invention is further characterized in that the burying device is provided with a travelling device which is controlled by the output from a receiver which receives the output from a transmitter on the cable, that said device body is provided at the middle portion thereof with a cable engaging member having a cable engaging mechanism as well as a buried cable route detection mechanism and an excavation member.

Marine cable burying method and device therefor

The present invention has an object to provide an underwater cable burying device which can accurately be guided to align with the cables in the process of burying even if the cables have to be re-buried. The device according to the present invention is characterized in that a travelling device is provided on the body of the device which is further provided with a trenching device at the middle portion thereof, that a cable clamp member and a cable engaging member are provided at an arm projecting forward from the said device body and that said respective devices are controlled through a control cable on the mother ship.

Under-water cable burying device

A cable buried under a sea bottom is located by flowing in the cable an electrical current, and measuring the magnetic flux by said current at four points near the cable. The present cable detecting system comprises nondirectional flux measurement means searching for the cable to be detected and measuring the flux by said electric current at four vertex points forming a horizontal square plane, means for transmitting the measured values to a cable ship, means mounted in said ship for providing squared amplitude ratios of each of said magnetic flux to a selected one of the magnetic flux, and means for providing the distance to the cable from the center of said four vertex points, the angle between the transverse direction to the cable and the extension of the diagonal line of said four vertex points, and the depth between the cable and said horizontal square plane, on the principle that said amplitude ratio is equal respectively to the reciprocal of the corresponding ratio of the distance between said cable and each of said points.

Buried cable locating system

A system for detecting an AC magnetic field of a desired frequency using a magnetic sensing element of the parametrically excited second harmonic oscillator, in which a reference signal having a repetition period substantially equal to the repetition period of the AC magnetic field is adopted for synchronous detection of the detected output of the magnetic sensing element, and in which a current proportional to the intensity of a noise magnetic field is applied to the oscillation winding of the magnetic sensing element to lessen the influence of the noise magnetic field to greatly improve the SN ratio of the detected signal.

Growing community of inventors

Yokohama, Japan

Kazuomi Yamamura