Abstract: An optical fiber cable with a plastic core having longitudinally extending plastic tubes embedded therein, each plastic tube loosely containing at least one optical fiber. The materials of the core and the tubes are selected so that there is no significant bond or link between the outer surfaces of the tubes and the core to permit easy separation of the tubes from the core. Alternatively, there may be layers of a fluid or powder intermediate the outer surfaces of the tubes and the core so that, if desired, the tubes and the core can be made of the same plastic material although, even with this structure, the tubes may be made of a plastic material different from the plastic material of the core.

Abstract: An optical fiber cable with an elongated core of transparent plastic material having a plurality of readily visible tubes of a dull material embedded therein and extending longitudinally thereof. Each tube loosely receives at least one optical fiber. The core has a plurality of grooves at the outer surface thereof which extend parallel to the paths of the tubes and which are spaced from the tubes, and the grooves have a hydrogen retaining material therein. Each groove is on a radial line intermediate pairs of tubes.

Abstract: Process and apparatus for forming a core for optical fiber cables, the core having a central reinforcing element surrounded and contacted by a layer of plastic having helical grooves at its surface. The helical grooves are formed by passing the reinforcing element through a plastic extruder having a groove forming die and while the plastic is being applied at the extruder, the element is alternatley rotated in opposite directions in advance of its entry into the extruder. The reinforcing element may be rotated by a pair of driven belts which frictionally engage the element and which are mounted on rotatable rings driven by an alternating rotation motor drive or may be rotated by a pulley which frictionally engages the element and which is carried by a support rotatable around the longitudinal axis of the element by an alternating rotation motor drive.

Abstract: A process and apparatus for laying optical fibers in the helical grooves of a core for an optical fiber telecommunication cable in which the rotatable bobbins carrying the optical fibers are held in axially fixed positions while the core with helical grooves and the fibers are fed to and through a rotatable fiber inserting device which has projections extending into the grooves which cause rotation of the device as the core is advanced. Between the bobbins and the fiber inserting device there is a supporting tube through which the core passes and the outer surface of which engages and supports the fibers. The downstream end of the tube terminates in advance of the fiber inserting device so that the fibers may enter the grooves in the core at the fiber inserting device.

Abstract: Methods and apparatus for forming a cable element comprising a core of plastic material with helical surface grooves containing one or more optical fibers. The core has one or more reinforcing elements resistant to tension and compression and is covered with a covering of tape or thermoplastic. The core is fed to a rigid body having tongues corresponding to and entering into the grooves, and the optical fiber or fibers are fed into the grooves through through-holes in the body which extend from the exterior surface of the body to the tongues and which are inclined with respect to the axis of the core. The core feeding means may be a pay-off bobbin or a core extruder with a threading die, and by increasing the feed rate of the fibers relative to the feed rate of the core or by stretching the core in advance of the rigid body, the lengths of the fibers in the grooves may be longer than the lengths of the grooves.

Abstract: A method of manufacturing elements for an optical cable, such elements including a tube of an elastic material, e.g. a synthetic resin or an elastomer, which loosely encloses one or more optical fibers. Preferably, the fiber or fibers are longer than the enclosing tube and the tube is filled with a material which prevents the migration of water, etc. The tube in mechanically stabilized form and the optical fiber or fibers are advanced toward a traction zone where the tube is pulled. Prior to the traction zone, the tube is slit or cut longitudinally through one thickness of the wall, the cut edges are spread apart and the optical fiber or fibers are inserted into the tube through the gap between the cut edges. Optionally, filling material is also inserted into the tube through such gap or a downstream gap subsequently formed. The tube-optical fiber assembly follows a straight line downstream of traction zone to a collecting point.

Abstract: A method of manufacturing elements for an optical cable, such elements including a tube of an elastic material, e.g. a synthetic resin or an elastomer, which loosely encloses one or more optical fibers. Preferably, the fiber or fibers are longer than the enclosing tube and the tube is filled with a material which prevents the migration of water, etc. The tube in mechanically stabilized form and the optical fiber or fibers are advanced toward a traction zone where the tube is pulled. Prior to the traction zone, the tube is slit or cut longitudinally through one thickness of the wall, the cut edges are spread apart and the optical fiber or fibers are inserted into the tube through the gap between the cut edges. Optionally, filling material is also inserted into the tube through such gap or a downstream gap subsequently formed. The tube-optical fiber assembly follows a straight line downstream of traction zone to a collecting point.

Abstract: A process and apparatus for forming the stranded conductor portion of a fully-filled electric cable in which the components of the strand in side-by-side relation are fed through an inlet die at one end of a chamber in which a filling medium at a temperature at least 5.degree. C above the dropping point temperature of the medium and under a pressure above atmospheric pressure is circulated in a direction opposite to the conductor feed direction. In the chamber, the components, preferably groups of conductors, are spread apart by a perforated disc through which they pass and are then twisted together at an outlet die at the opposite end of the chamber to form a strand with a coating of the medium and with the medium filling the spaces between components. From the outlet die the strand passes directly into a bath of the medium in a temperature controlled tank at atmospheric pressure but which maintains the medium at least 5.degree. C above its dropping point temperature.

Abstract: Apparatus for forming the stranded conductor portion of a fully-filled electric cable in which the components of the strand in side-by-side relation are fed through an inlet die at one end of a chamber in which a filling medium at a temperature at least 5.degree. C. above the dropping point temperature of the medium and under a pressure above atmospheric pressure is circulated in a direction opposite to the conductor feed direction. In the chamber, the components, preferably groups of conductors, are spread apart by a perforated disc through which they pass and are then twisted together at an outlet die at the opposite end of the chamber to form a strand with a coating of the medium and with the medium filling the spaces between components. From the outlet die the strand passes directly into a bath of the medium in a temperature controlled tank at atmospheric pressure but which maintains the medium at least 5.degree. C. above its dropping point temperature.