VORRICHTUNG UND VERFAHREN ZUR KONTINUIERLICHEN FERTIGUNG VON BEWEHRTEN OPTISCHEN KABELN.

摘要

An apparatus and method for continuously manufacturing optical fiber cable in which optical fiber is encased by an hermetically sealed homogeneous metal tube formed from flat metal strip (11). A first assembly of mating rollers (26, 28) having successively different shapes forms the flat metal strip into a partially formed tube (12) having a longitudinal gap. Optical fiber (13) is guided through the gap to lie within the partially formed tube. The tube (12) is then closed by a second assembly of mating rollers having successively different shapes. A laser beam is used to weld the seam closed without filler metal and without heat shielding between the seam and the optical fiber. The finished tubing with optical fiber therein is sunk by being drawn through wire dies to reduce the diameter. A wheel draws the tubing through the apparatus at constant speed to effect a uniform weld line. In another embodiment, an introducer tube of smaller diameter than the hermetically sealed homogeneous metal tube extends within the metal tube to about the point of tangential approach of the metal tube to the wheel. Gas flows through the introducer tube to carry the optical fiber by viscous drag and blow the optical fiber against the outer circumference of the metal tube as the metal tube wraps around the wheel.