Abstract: A method of cleaning fiber of dust and particulate matter thereon includes the steps of directing the fiber passage having an entrance end and an exit end; protecting the fiber from abrasion at the entrance end and the exit end; passing the fiber through a vacuum chamber in the fiber passage; directing a fluid spray against the fiber in a direction opposite to the direction of movement of the fiber along the passage at a velocity sufficient to dislodge particulate matter from the fiber; and exhausting the fluid and the particulate matter from the vacuum chamber.

Abstract: A noncontact fiber cleaning and tensioning device for cleaning optical fibers of dust and other particulate matter collected thereon. The noncontact fiber cleaning and tensioning device includes a housing formed from a cleaning and an exhaust section and includes a fiber passage formed therethrough and through which the optical fibers are passed. A series of spray nozzles are mounted to the cleaning section of the housing, and communication with the fiber passage and direct fluid sprays under pressure against the fiber as the fiber moves through the fiber passage to dislodge dust and particulate matter therefrom. A vacuum means is connected to the exhaust section and draws the dust and particulate matter dislodged from the fibers by the fluid sprays through the fiber passage and out through the exhaust housing to exhaust the dislodged particulate matter for collection and removal under controlled conditions.

Abstract: An apparatus and method for reducing or preventing damage to a strand wound at relatively high speed on a machine-rotated spool, caused by flailing of a loose end of the strand includes capture brushes arranged at intervals in proximity to the machine. The capture brushes are aligned to be approximately perpendicular to the loose end of the strand when the loose end of the strand rotates with the spool into contact with the brushes. At respective ends, the brushes have respective tips with a taper that tends to guide or deflect the loose end of the strand to a slot defined by two adjacent brushes. The brushes have bristles extending from a bristle-mounting member, which capture the loose end of the strand. The bristles can be treated with a friction enhancing substance to improve the ability of the brushes to capture and entrap the loose end of the strand. Preferably, the bristles are angled with respect to the bristle-mounting member in a direction away from a respective tapered tip.

Abstract: Spliced end portions (30--30) of two optical fibers are recoated in a manner which results in the cross section of the spliced length of fiber transverse to a longitudinal axis thereof being substantially constant. This is accomplished without compromising the adhesion of a curable recoating material (51) to an adjacent original coating material (38). In order to provide such a recoated portion, original coating material which is removed to permit splicing is removed in such a manner as to leave a tapered portion (52) remaining on the end portion of each optical fiber. As a result, the interface between the recoating material and the original coating material is increased sufficiently to avoid having to overlap some of the recoating material with original coating material on adjacent portions of the fibers being spliced.

Abstract: An optical fiber package of this invention applies a friction enhancing material to the smooth surface of a bobbin or mandrel onto which the optical fiber is wound. The friction enhancing material adheres the initial layer of fiber to the smooth surface of the bobbin, thereby eliminating the need for an independent base structure for establishing and maintaining a winding path for the fiber. Furthermore, the friction enhancing material prevents the lateral movement at initial layer of fiber relative to the bobbin. In accordance with the present invention, the friction enhancing material is preferably a plastic material such as room temperature vulcanized (RTV) silicones and Styrene Butadiene Rubber (SBR) or the like. In addition, the optical fiber package of this invention may combine the use of both a friction enhancing material between the initial fiber layer and the bobbin, as well as an adhesive material coating applied along the length of the optical fiber.

Abstract: An optical fiber package (15) includes a support surface such as a hub of a bobbin (17) for convolutions of a length of optical fiber. The optical fiber includes a light transmitting portion such as a core and a cladding with inner and outer layers of coating material disposed thereabout. The coating material comprises an ultraviolet light curable material. Disposed throughout the curable coating material of the outer layer is an adhesive constituent which after having been solidified by the exposure of the optical fiber to ultraviolet light energy and subsequent to the winding of the optical fiber into a package for use in high speed payout is subjected to heat treatment to cause the adhesive constituent of each convolution to become tacky and cause the convolutions to be tacked together. The adhesion between adjacent convolutions is less than that between inner and outer layers of the coating materials and that between the inner layer and the cladding.

Abstract: An optical fiber package (52) includes a length of optical fiber (22) wound in a plurality of convolutions on a bobbin (50). In order to maintain the convolutions in a precision wound package and to prevent snags during payout, it is necessary that each convolution of optical fiber be adhered to at least a portion of an adjacent convolution. This is accomplished by providing the length of optical fiber with an adhesive material (32) which is not tacky at room temperature but which becomes tacky at a predetermined temperature. After the convolutions have been wound on the bobbin, the bobbin is treated to cause the adhesive material to become tacky and cause each convolution to adhere to at least a portion of adjacent convolutions. Suitable adhesion is caused to occur with any adhesive material for which molecular bonding can occur across the interface between contiguous portions of adjacent convolutions as a result of suitable treatment.

Abstract: An optical fiber package (52) includes a length of optical fiber (22) wound in a plurality of convolutions on a bobbin (50). In order to maintain the convolutions in a precision wound package and to prevent snags during payout, it is necessary that each convolution of optical fiber be adhered to at least a portion of an adjacent convolution. This is accomplished by providing the length of optical fiber with an adhesive material (32) which is not tacky at room temperature but which becomes tacky at a predetermined temperature. After the convolutions have been wound on the bobbin, the bobbin is treated to cause the adhesive material to become tacky and cause each convolution to adhere to at least a portion of adjacent convolutions. Suitable adhesion is caused to occur with any adhesive material for which molecular bonding can occur across the interface between contiguous portions of adjacent convolutions as a result of suitable treatment.

Abstract: Spliced end portions (30--30) of two optical fibers are recoated in a manner which results in the cross section of the spliced length of fiber transverse to a longitudinal axis thereof being substantially constant. This is accomplished without compromising the adhesion of a curable recoating material (51) to an adjacent original coating material (38). In order to provide such a recoated portion, original coating material which is removed to permit splicing is removed in such a manner as to leave a tapered portion (52) remaining on the end portion of each optical fiber. As a result, the interface between the recoating material and the original coating material is increased sufficiently to avoid having to overlap some of the recoating material with original coating material on adjacent portions of the fibers being spliced.

Abstract: An optical fiber package (52) includes a length of optical fiber (22) wound in a plurality of convolutions on a bobbin (50). In order to maintain the convolutions in a precision wound package and to prevent snags during payout, it is necessary that each convolution of optical fiber be adhered to at least a portion of an adjacent convolution. This is accomplished by providing the length of optical fiber with an adhesive material (32) which is not tacky at room temperature but which becomes tacky at a predetermined temperature. After the convolutions have been wound on the bobbin, the bobbin is treated to cause the adhesive material to become tacky and cause each convolution to adhere to at least a portion of adjacent convolutions. Suitable adhesion is caused to occur with any adhesive material for which molecular bonding can occur across the interface between contiguous portions of adjacent convolutions as a result of suitable treatment.

Abstract: Spliced end portions (30-30) of two optical fibers are recoated in a manner hich results in the cross section of the spliced length of fiber transverse to a longitudinal axis thereof being substantially constant. This is accomplished without compromising the adhesion of a curable recoating material (51) to an adjacent original coating material (38). In order to provide such a recoated portion, original coating material which is removed to permit splicing is removed in such a manner as to leave a tapered portion (52) remaining on the end portion of each optical fiber. As a result, the interface between the recoating material and the original coating material is increased sufficiently to avoid having to overlap some of the recoating material with original coating material on adjacent portions of the fibers being spliced.

Abstract: A relatively small pair size cable (20) comprising at least one insulated conductor (22) is provided with a flame retardant, smoke suppressive non-metallic sheath system (30). The sheath system has a relatively low thermal conductivity and provides a predetermined delay prior to the thermal decomposition of the conductor insulation. It includes an inner layer (31) of an inorganic cellular material which has a relatively low air permeability and two tapes (41, 42) which are wrapped helically about the inner layer with overlapped sealed seams. Each tape comprises a flame retardant thermosetting material. In an alternative embodiment, the heat absorptivity of the sheath system is increased substantially to facilitate the sealing of the seams as the cable is moved along a manufacturing line. This may be accomplished by using an inorganic cellular material which has a relatively high absorptivity or by facing the inner layer or one of the tapes with a material which is heat absorptive.

Abstract: A method of making a cable (20) specially suited for use in building plenums because of its low flame spread and smoke evolution includes enclosing a multiconductor core (22) in a sheath comprising an inorganic, cellular core wrap (31), a corrugated metallic barrier (40) and dual layers (51) and (52) of a polyimide tape. The tapes are wrapped helically about the barrier in a manner that avoids a compression of the core wrap. The sheath is effective to resist heat transfer inwardly toward the core by conduction while the metallic barrier reflects radiant heat. Advantageously, the sheath containerizes the core without unduly compressing it and thereby allows the intumescence of conductor insulation during a fire to form char which is effective to suppress the evolution of smoke and the propagation of flame.

Abstract: A cable (20) specially suited for use in building plenums because of its low flame spread and smoke evolution includes a multiconductor core (22) which is enclosed in a sheath comprising an inorganic, cellular core wrap (31), a corrugated metallic barrier (40) and dual layers (51) and (52) of a polyimide tape which are wrapped helically about the barrier in a manner that avoids a compression of the core wrap. The sheath is effective to resist heat transfer inwardly toward the core by conduction while the metallic barrier reflects radiant heat. Advantageously, the sheath containerizes the core without unduly compressing it and thereby allows the intumescence of conductor insulation during a fire to form char which is effective to suppress the evolution of smoke and the propagation of flame.