Submarine optical fiber cable with grooved plastic core and manufacture thereof
AssigneeSocieta' Cavi Pirelli S.p.A.
InventorPaolo G. Priaroggia
Life of this patent
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Abstract
An optical fiber submarine cable having only a central rope for withstanding the stresses to which the cable is subjected, a plastic core with interrupted but closed or substantially closed, grooves at its outer portion, at least one optical fiber in each groove, a sheath around the core, and a substantially incompressible fluid filling all otherwise empty spaces within the sheath including any such spaces between the wires of the rope and in the grooves. The grooves are separated by ribs, and before the sheath is applied the diameter of the core at the ribs is greater than the diameter of the inner surface of the sheath and the sides of the ribs are separated to provide grooves opening outwardly of the core. Also, a process for manufacturing such a cable.
Claims10
A submarine, optical fiber telecommunication cable comprising:
- an axially disposed anti-torsional rope formed by a plurality of wires and having the interspaces therein filled with a substantially incompressible fluid;
- a core of plastic material around said rope, said core having a plurality of peripheral spaced, longitudinally extending grooves in the radially outer portion thereof with ribs intermediate said grooves, the wall of each of said grooves being discontinuous in cross-section at the radially outermost surface of said core but having radially extending, facing edge surfaces of said core adjacent to each other where said wall is discontinuous;
- at least one optical fiber received in said grooves;
- a substantially incompressible fluid filling any otherwise empty spaces in said grooves;
- and
- a sheath around and engaging said core, said grooves, in the absence of said sheath, having a curvilinear cross-section and said facing edge surfaces being spaced from each other and the diametral dimension of said core at said ribs, in the absence of said sheath, being greater than the diametral dimension of the inner surface of said sheath, whereby the outer surface of said core conforms to the inner surface of said sheath when said sheath is applied thereto by reason of compression of said core.
Process for manufacturing a submarine, optical fiber telecommunication cable comprising:
- impregnating a rope formed by a plurality of wires with a substantially incompressible fluid;
- extruding a core of plastic material with a plurality of peripherally spaced, outwardly open longitudinal grooves around said rope;
- disposing at least one optical fiber in said grooves;
- inserting a substantially incompressible fluid in said grooves;
- and
- while radially compressing said core, applying to said core a sheath having an inner surface diameter less than the outer diameter of said core before compression thereof around said core.
Dependencies are inferred from the claim text.