Optical cable
AssigneeNorthern Telecom Limited
InventorsMichael S. Fedoroff, Johannes I. Greveling
Life of this patent
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Abstract
An optical cable with a loosely contained optical fiber which is inside a weak walled sheath together with water swellable powder. The sheath is surrounded by grease or gel. If the powder contacts water within the sheath, it expands, splits the sheath, and displaces the grease into the sheath to surround the fiber. Hence although grease is employed immediately around the fiber as a water block, under installation procedures the fiber surface is not contaminated with grease.
Claims6
An optical cable formed with a longitudinally extending passage and an optical fiber unit loosely located within and extending along the passage;
- the optical fiber unit comprising at least one optical fiber loosely contained within a flexible tubular member which is capable of being split under internal pressure and a swellable water blocking means also disposed within the flexible tubular member, the swellable water blocking means operable upon swelling to pressurize and split the flexible tubular member;
- and the passage containing a water blocking grease or gel material surrounding the optical fiber unit, the water blocking grease or gel material being pressurized upon swelling of the swellable water blocking means so as to be forced into the split flexible tubular member and into surrounding contact with the fiber.
Dependencies are inferred from the claim text.