Molding apparatus for a reinforcement resin coating of glass optical fiber exposing portion of an optical fiber junction, method for molding reinforcement resin coating of a glass optical fiber exposing portion of an optical fiber junction, and optical fiber cable

A method for molding a reinforcement resin coating of a glass optical fiber exposing portion of an optical fiber junction comprising the steps of:

• using a molding die constituted by upper and lower dies at least one of which is made of a material transparent to an ultraviolet light, said molding die having a cavity constituted by grooves of said upper and lower dies linearly penetrating therethrough along respective parting faces thereof, each groove having a semicircular lateral cross section, said molding die having a resin injection gate and a resin exit gate communicating with said cavity, said resin injection gate is not positioned at a center of said cavity in a longitudinal direction thereof;
• inserting fusion-spliced optical fibers including said glass optical fiber exposing portion in which end faces of glass optical fibers exposed by removing a coating at end parts of two optical fibers are butted against each other and said exposed end parts are fused-spliced into said cavity of said molding die;
• positioning one coating end of said fusion-spliced fibers near said resin injection gate so that a fusion-spliced point of said fusion-spliced optical fibers is not opposed to said resin injection gate;
• positioning the other coating end of said fusion-spliced optical fibers near said resin exit gate so that fusion-spliced point of said fusion-spliced optical fibers is not opposed to said resin exit gate;
• injecting a UV-curable resin into a void surrounding said glass optical fibers within said cavity from said resin injection gate;
• and then emitting said ultraviolet light through said die made of said UV-curable resin from the outside of said molding die, so as to cure said UV-curable resin injected into said cavity and form a reinforcement resin coating, wherein
• said parting face of said upper and lower dies are provided with an UV-light-blocking layer extending along a part of said parting face including a position in contact with said groove in a segment including said resin injection gate and said resin exit gate, said UV-light-blocking layer is not formed on said grooves.

A molding apparatus for a reinforcement resin coating of a glass optical fiber exposing portion of an optical fiber junction comprising a molding die and an ultraviolet light source,

• said molding die comprising upper and lower dies at least one of which is made of a material transparent to an ultraviolet light emitted from said ultraviolet light source,
• said molding die having a cavity constituted by grooves of said upper and lower dies linearly penetrating therethrough along respective parting faces thereof, each groove having a semicircular cross section,
• said molding die being provided with a resin injection gate and a resin exit gate on said cavity,
• wherein said resin injection gate positioned near one coating end of fusion-spliced optical fibers inserted into said cavity so that a fusion-spliced point of said fusion-spiced optical fibers is not opposed to said resin injection gate;
• wherein said resin gate is positioned near the other coating end of fusion-spliced optical fibers inserted into said cavity so that the said fusion-spliced point of said fusion-spliced optical fibers is not opposed to said resin exit gate;
• and
• wherein said parting faces of said upper and lower dies are provided with a UV light-blocking layer extending along a part of said parting face including a position in contact with said grooves in a segment including said resin injection gate and said resin exit gate, said UV light-blocking layer is not formed on said grooves.

A molding apparatus for a reinforcement resin coating of a glass optical fiber exposing portion of an optical fiber junction comprising a molding die and an ultraviolet light source,

• said molding die comprising upper and lower dies at least one of which is made of a material transparent to an ultraviolet light emitted from said ultraviolet light source,
• said molding die having a cavity constituted by grooves of said upper and lower dies linearly penetrating therethrough along respective parting faces thereof, each groove having a semicircular cross section,
• said molding die being provided with a resin injection gate and a resin exit gate on said cavity,
• wherein said resin injection gate is positioned near one coating end of fusion-spliced optical fibers inserted into said cavity so that a fusion-spliced point of said fusion-spliced optical fibers is not opposed to said resin injection gate;
• wherein said resin exit gate is positioned near the other coating end of fusion-spliced optical fibers inserted into said cavity so that said fusion-spliced point of said fusion-spliced optical fibers is not opposed to said resin injection gate;
• wherein said resin exit gate is positioned near the other coating end of fusion-spliced optical fibers inserted into said cavity so that said fusion-spliced point of said fusion-spliced optical fibers is not opposed to said resin exit gate;
• and
• wherein said parting face of said die irradiated with said ultraviolet light provided with a UV-light-blocking layer extending along a part of said parting face including a position in contact with said grooves in a segment including said resin injection gate and said resin exit gate, said UV-light-blocking layer is not formed on said grooves.

A molding apparatus for a reinforcement resin coating of a glass optical fiber exposing portion of an optical fiber junction comprising a molding die and an ultraviolet light source,

• said molding die comprising upper and lower dies at least one of which is made of a material transparent to an ultraviolet light emitted from said ultraviolet light source,
• said molding die having a cavity constituted by grooves of said upper and lower dies linearly penetrating therethrough along respective parting faces thereof, each groove having a semicircular cross section,
• said molding die being provided with a resin injection gate and a resin exit gate on said cavity,
• wherein said resin injection gate is positioned near one coating end of fusion-spliced optical fibers inserted into said cavity so that a fusion-spliced point of said fusion-spliced optical fibers is not opposed to said resin injection gate;
• and
• wherein said resin exit gate is positioned near the other coating end of fusion-spliced optical fibers inserted into said cavity so that said fusion-spliced point of said fusion-spliced optical fibers is not opposed to said resin exit gate;
• and
• wherein said resin exit gate is positioned near the other coating end of fusion-spliced optical fibers inserted into said cavity so that said fusion-spliced point of said fusion-spliced optical fibers is not opposed to said resin exit gate;
• and
• wherein said resin injection gate and said resin exit gate are positioned on the parting faces of either one of the upper and lower dies opposite from each other with respect to said groove.

A molding apparatus for a reinforcement resin coating of a glass optical fiber exposing portion of an optical fiber junction comprising a molding die and an ultraviolet light source,

• said molding die comprising upper and lower dies at least one of which is made of a material transparent to an ultraviolet light emitted from said ultraviolet light source,
• said molding die having a cavity constituted by grooves of said upper and lower dies linearly penetrating therethrough along respective parting faces thereof, each groove having a semicircular cross section,
• said molding die being provided with a resin injection gate and a resin exit gate on said cavity,
• wherein said resin injection gate is positioned near one coating end of fusion-spliced optical fibers inserted into said cavity so that a fusion-spliced point of said fusion-spliced optical fibers is not opposed to said resin injection gate;
• and
• wherein said resin exit gate is positioned near the other coating end of fusion-spliced optical fibers inserted into said cavity so that said fusion-spliced point of said fusion-spliced optical fibers is not opposed to said resin exit gate;
• and
• wherein said parting face of said die irradiated with said ultraviolet light is provided with a UV light-blocking layer extending along a part of said parting face including a positioned in contact with said groove in a segment including said resin injection gate and said resin exit gate, said UV light-blocking layer is not formed on said groove;
• and
• wherein the other die has a UV-nonreflecting layer on an ultraviolet light exit surface.

A molding apparatus for a reinforcement resin coating of a glass optical fiber exposing portion of an optical fiber junction comprising a molding die and an ultraviolet light source,

• said molding die comprising upper and lower dies at least one of which is made of a material transparent to an ultraviolet light emitted from said ultraviolet light source,
• said molding die having a cavity constituted by grooves of said upper and lower dies linearly penetrating therethrough along respective parting faces thereof, each groove having a semicircular cross section,
• said molding die being provided with a resin injection gate and a resin exit gate on said cavity,
• wherein said resin injection gates are not disposed at a center of said cavity in a longitudinal direction thereof, but are disposed near coating ends of said fusion-spliced optical fibers so that a fusion-spliced point of said fusion-spliced optical fivers is not opposed to said two resin injection gates, respectively;
• wherein said resin exit gate is disposed on said cavity located at a center between said two resin injection gates;
• and
• wherein said resin injection gate and said resin exit gate are positioned on the parting face of either one of the upper and lower dies opposite from each other with respect to said groove.