Nkk Corporation

Hitachi Cable, Inc.

Sumitomo Electric Industries, Limited

Helios Inc.

Yasunori Yoshie

Takashi Tsukui

Tatsuo Teraoka

Yoshiyuki Hiramoto

Shigeo Toya

Koichi Abe

Takashi Kanazawa

Hirokazu Shiga

Koji Sasaki

Takeo Yamada

Takeshi Nakamura

Akira Matsuzaki

Ryosuke Hata

Yoshiharu Sugimoto

Masaru Sagiyama

Masayuki Nakada

Hiroaki Miyahara

Yasushi Kaneda

Saburou Ishiro

Metallic tubes for housing optical fibers and process for producing the same

A temperature measuring device includes an optical fiber; a metallic protective tube for covering the optical fiber to form a metal-covered optical fiber; and a radiation thermometer connected to the metal-covered optical fiber. A heat insulation coating may be added to cover the metallic protective tube.

Temperature measuring device

An apparatus for manufacturing an optical fiber cable covered with a metal pipe forms a metal pipe by abutting two sides of a metal strip to be pulled, introduces an optical fiber or an optical fiber bundle into the metal pipe, and seals the opening of the metal pipe by laser welding. A squeeze shoe is arranged immediately before a welding position. The inner circumferential surface of the squeeze shoe is brought into contact with the metal pipe, and the section of this inner circumferential surface conforms to the outer circumferential surface of the metal pipe. The squeeze shoe is vertically divided into halves. Since the squeeze shoe is provided immediately before the welding position, the opening of the metal pipe can have a predetermined width and be welded. The opening width is adjusted in accordance with at least one of a diameter, thickness and composition of the metal strip and in accordance with at least one of a welding rate, laser beam power and laser beam focus shift amount of the laser welder. Thus, thermal damage to the optical fiber can be reliably prevented, and defective welding caused by a spatter can be prevented, so that a long-time continuous operation is enabled. An elongated optical fiber cable covered with a metal pipe can be manufactured.

Method of manufacturing optical fiber cable covered with metal pipe, and

An apparatus for connecting metal tubes covering optical fiber cables includes at least two clamp units 10, 10' for holding a metal sleeve (C5) and two metal tubes (C2, C2') covering two optical fiber cables (C, C') in close position. A laser welding head is placed between two adjacent clamp units. Each clamp unit has a gear (22) as a rotation body to be driven by a drive gear, a clamp device (28, 33, 34) for clamping the metal tube covered optical fiber cables which are introduced in inserting holes (31) where the metal tube covered optical fiber cables are inserted. The clamp device is supported by the rotation body (22) so as to be movable together with the rotation body. The rotation body and the clamp device each are provided with a radially extending selectively open or blocked extraction path (36, 22') to remove, in a radial direction, the metal tube optical fiber cable which has been connected by the apparatus.

Apparatus for connecting metal tubes covering optical fiber cables and

A method and apparatus for manufacturing a metal pipe-covered optical fiber cable perform extra length control of the metal pipe with respect to the optical fiber in accordance with length adjustment by reducing the diameter of the metal pipe while applying minimum tension or without applying any tension for extra length control to the optical fiber by means of a pair of rollers, so that a crack in the optical fiber is avoided and the service life of the optical fiber is prolonged.

A test piece 1 is prepared having the same metal tube 2 and metal sleeve 4 as in the case of metal tube covered optical fiber cables 10 and 20 to be connected and a sensor 5 for measuring temperatures in the vicinity of a welding part, prior to connection of the cables an optimum welding condition is set by variously changing welding conditions using the test piece 1 and measuring temperatures in the vicinity of the welding part with the sensor 5, the connection is made under such an optimum welding condition, and after this connection welding is done under one and the same condition as in the case of the connection using the other test piece 1, and then by the output of the sensor 5 it is to be made sure that the connection has been carried out almost under the same condition as the optimum welding condition.

Method for connecting optical fiber cables

An apparatus for manufacturing a metal tube covered optical fiber cable, having an assembly (2) consisting of a plurality of roller pairs for forming a metal strip (1) subjected to traction and causing both side edges of the metal strip to abut against each other to form a metal tube, a laser welding device (7) for radiating a laser beam on abutment portions of the metal tube to bond the abutment portions, thereby obtaining a sealed metal tube (1c), and an optical fiber guide means (6) for guiding an optical fiber (5) into the formed metal tube (1a), wherein the laser welding device (7) determines a focal point shift amount so that a rear bead width determined by an outer diameter and a wall thickness of the metal tube falls within a predetermined range, and laser welding is performed at a welding rate corresponding to the determined focal point shift amount.

Apparatus for manufacturing metal tube covered optical fiber cable and

An apparatus for manufacturing a metal tube covered optical fiber cable, including an assembly (2) having a plurality of roller pairs, for causing both side edges of a metal strip (1) to abut against each other to form the metal strip into a metal tube, a laser welding device (7) for radiating a laser beam to abutment portions of the metal tube to bond the abutment portions to obtain a sealed metal tube (1c), and an optical fiber guiding element (6) for guiding an optical fiber (5) in a formed metal tube (1a) comprises an extra length control system comprising a tension adjusting element (15) for the metal strip (1) arranged in the upstream of the assembly (2) and a tension adjusting element (14) for the optical fiber (5) arranged in the upstream of the optical fiber guide element (6), and a traction element (11, 13) including tension variable element (11) for the metal tube covered optical fiber cable (1d).

An apparatus for manufacturing a metal tube covered optical fiber cable comprises an assembly of a plurality of roller pairs for forming a metal strip into a metal tube so that both side edge portions abut against each other, a laser (7) for welding the abutment portions with a laser beam to obtain a sealed metal tube (1c), an optical fiber guide for guiding an optical fiber (5) into the formed metal tube (1a), and a traction apparatus including a tension variable element for continuously drawing a sealed metal tube (id). The optical fiber guide is elastically urged against an inner wall opposite to an irradiated surface of the metal tube so that the optical fiber is protected even when the focal point of the laser beam is positioned below the abutment portions of the metal tube. In one embodiment a leaf spring mechanism is used to elastically urge the optical fiber guide.

A method of manufacturing a metal pipe clad cable having a fiber with an excess length housed therein, comprises the steps of preparing a metal pipe clad cable comprising a metal pipe and a fiber housed in the metal pipe, and passing said metal pipe clad cable through a plurality of sets of bending rolls. The metal pipe is repeatedly bent when passing through the plural sets of said bending rolls so as to generate a plastic deformation within the metal pipe and, thus, to impart an excess length to the fiber within the metal pipe.

Method of forming cladded cable having fiber with excess length enclosed

Metal pipes containing optical fibers are connected to each other directly or indirectly by use of a sleeve. In case of using the sleeve, the sleeve is connected at one end to one of the metal pipes, after the optical fibers are connected. Then, the sleeve is elongated by a predetermined length, so that the sleeve is connected at the other end to the other metal pipe. Consequently, no tensile stress resides in the connected optical fibers in the connected structure. When the metal pipes are connected directly to each other, one or both of the metal pipes are elongated, after the optical fibers are connected. Then, the metal pipes are connected by use of the elongated portions. Consequently, the same result is obtained as using the sleeve.

Method for connecting optical fibers sealed in metal pipes

Metal pipes containing optical fibers are connected to each other directly or indirectly by use of a sleeve. In case of using the sleeve, the sleeve is connected at one end to one of the metal pipes, after the optical fibers are connected. Then, the sleeve is elongated by a predetermined length, so that the sleeve is connected at the other end to the other metal pipe. Consequently, no tensile stress resides in the connected optical fibers in the connected structure. When the metal pipes are connected directly to each other, one or both of the metal pipes are elongated, after the optical fibers are connected. Then, the metal pipes are connected by used of the elongated portions. Consequently, the same result is obtained as using the sleeve.

Growing community of inventors

Tokyo, Japan

Yasunori Yoshie