Optical fiber cable which includes waterblocking and freeze preventing provisions
AssigneeAT&T Bell Laboratories
InventorsCandido J. Arroyo, James R. Petisce, Jim J. Sheu
Life of this patent
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Abstract
An optical fiber cable (20) includes provisions in a core thereof for preventing the flow of water longitudinally along the core and for preventing freezing of such water. The provisions for preventing freezing of water within the core, which could effect adversely the optical fibers, includes an antifreeze material. Each of two tapes may be impregnated with an antifreeze material such as propylene glycol, for example, and used to provide a laminate with a superabsorbent powder therebetween. Advantageously, the cable may have suitable flame retardance so that it may extend from an outside manhole to distribution points within a building.
Claims19
An optical fiber cable, which includes:
- a core comprising at least one optical fiber transmission medium;
- a tubular member in which is disposed said core and which is made of a plastic material;
- a sheath system which is disposed about said tubular member;
- and
- means disposed within said tubular member for blocking the longitudinal flow of water and for preventing freezing of water within said cable, said means including a superabsorbent material and an antifreeze material, the weight ratio of said antifreeze material to the superabsorbent material is in the range of about 1:1 to about 1:4.
Dependencies are inferred from the claim text.