At&t Technologies, Inc.

Bell Telephone Laboratories

Western Electric Company, Inc.

James V Smith, Jr

Carl Raymond Taylor

Charles J Aloisio, Jr

Terrence A Lenahan

A lightguide fiber (21) which has been drawn from a preform in a furnace (26) and which has a relatively high temperature is cooled prior to its movement through an apparatus (41) which applies a coating to its outer surface. The fiber is cooled by moving it through a liquid material (42) in a reservoir (40) which is interposed between the furnace and the coating apparatus. The liquid material in the reservoir (40) is the same as the coating material contained in the apparatus that is used subsequently to coat the fiber.

Methods of and apparatus for coating a lightguide fiber

Apparatus for coating a lightguide fiber

A coating material is applied to drawn lightguide fiber in a manner which substantially prevents the inclusion of bubbles and which causes the fiber to be disposed substantially concentrically within the coating layer. The lightguide fiber is advanced through a continuum of coating material, which extends from a free surface of a reservoir and through first and second dies that are arranged in tandem, at a velocity which causes air to be entrained in the coating material. A pressure gradient is established between portions of the first die adjacent to its exit orifice. The first die communicates with the reservoir and is spaced from the second die to provide a chamber which communicates with a pressurized supply of the coating material. The pressurized flow sufficiently enhances the pressure gradient in the first die and establishes sufficient volumetric flow of coating material upwardly through the first die to cause any bubbles in the coating material on the advancing fiber to be removed by recirculating streamlines and to be moved upwardly into the reservoir. Not only is the coating in the fiber substantially free of entrained air as it leaves the second die, but the fiber is disposed concentrically within the coating because of a precentering effect of the first die and enhanced self-centering caused by pressure in the chamber.

Methods of and apparatus for coating lightguide fiber

Growing community of inventors

Decatur, GA, United States of America

James V Smith, Jr