3m Innovative Properties Company

Minnesota Mining and Manufacturing Company

Leonard A Johnson

Jay W Dawson

Trevor Wayne MacDougall

Trevor W MacDougall

Edward Hernandez

John A Valenti

Roy D Erickson

Edward I Porwit

A high voltage insulator for use with optical fibers includes an insulative support rod with at least one optical fiber wrapped about the support rod. The optical fiber and support rod are covered by an outer elastomeric skirted insulative sleeve which squeezes the optical fibers against the support rod. A dielectric sealant, such as a silicone gel, is dispersed along the optical fiber to fill any voids which occur adjacent the optical fiber, thereby providing a void-free bond between the interior surfaces of the insulator. The elastomeric outer sleeve provides a resilient barrier against the ingress of moisture. In a preferred embodiment, an inner layer of elastomeric material is provided between the support rod and the optical fiber to provide additional cushioning of the fiber and to reduce the size of voids which may occur adjacent the fiber.

High voltage insulator for optical fibers

An annealing mold and fiber retaining device includes a fiber holding plate having fiber channels and an annealing insert. Retainers are provided for attachment to the plate to retain fibers in the channels. After annealing, the annealing insert is replaced by a packaging insert. The fiber holding plate is mounted between a support plate and a cover plate. The mounted plates include a coextensive current conductor port and the plates are mounted in a housing which includes vibration mounts for isolating the plates from vibration within the housing.

Annealing mold and retainer for making a fiber optic current sensor

A fiber optic subassembly for a Faraday-effect current sensor has an optical sensing fiber supported by a tubular holder in a square or rectangular configuration, with the three of the four corners thereof designed with bends which have a net zero bend-induced birefringence. The bends are formed by providing two loops which have effective angles of about 90.degree., the two loops lying in orthogonal planes, such that the fast axis of birefringence in the first loop is parallel to the slow axis of birefringence in the second loop, and the slow axis of birefringence in the first loop is parallel to the fast axis of birefringence in the second loop. In this manner, retardance accumulated in the first loop is offset by retardance accumulated in the second loop. If the loops are substantially identical, the offsetting of the retardance is effectively complete such that the bend exhibits negligible bend-induced birefringence.

Fiber optic current sensor with bend birefringence compensation

A means for relieving dielectric stress at a termination of a shielded and insulated high voltage cable. A smooth geometry high permittivity homogeneous material tube coaxially contacts both the ground electrode and the high voltage electrode. The tube consists of an elastomeric material having a permittivity in a range of from 10 to 25. The elastomeric material is non-rigid, thereby enabling the tube to be more readily fitted firmly around the cable and into the housing of the stress relief means. The ground electrode is the outer portion of the housing and diverges from the opening of the housing at the vicinity thereof in a direction toward the high voltage electrode. This dielectric stress relief means provides a satisfactory electric field gradient in applications wherein the rating is in a range from 15 kilovolts to 35 kilovolts.

Growing community of inventors

Austin, TX, United States of America

Leonard A Johnson