Process and apparatus for fabricating optical fiber cables

A process for fabricating an optical fiber cable assembly having at least one optical fiber housed within a sealed metal or metal alloy tube, said process comprising:

• providing a metal or metal alloy strip;
• applying a flux to said strip;
• forming said strip into a tube characterized by a seam formed by spaced-apart tube portions;
• said tube forming step including providing at least one tube forming die and pulling said strip through said at least one tube forming die;
• inserting said at least one optical fiber within said forming tube;
• providing a bath of molten metallic sealing material having a composition different than that of said metal or metal alloy forming said tube, said bath having an inlet through which said tube and said at least one optical fiber enter said bath and an outlet through which said tube and said at least one optical fiber exit said bath;
• pulling said tube with said at least one fiber through said bath of molten metallic sealing material without any protective structure between said tube and said bath, said tube being in contact with said molten metallic sealing material as it travels from said inlet to said outlet and the motion of said tube through said bath causing said molten sealing material to flow into said seam and seal said tube;
• and
• rapidly solidifying said sealing material after said tube exits said bath by passing said tube through a water quench.

An apparatus for fabricating an optical fiber cable assembly having at least one optical fiber housed within a sealed metal or metal alloy tube, said apparatus comprising:

• means for forming a metal or metal alloy strip into a tube characterized by a seam formed by spaced-apart tube portions;
• means for inserting said at least one optical fiber within said tube;
• means for sealing said seam and forming a coating about substantially the entire periphery of said tube, said sealing means comprising a bath of molten metallic sealing material having a composition different than that of said metal or metal alloy;
• said bath having an inlet through which said tube and said at least optical fiber enter said bath and an outlet through which said tube and said at least one optical fiber exit said bath;
• the outer periphery of said tube being in contact with said molten sealing material from said inlet to said outlet;
• means for pulling said tube and said fiber through said bath without any protective structure surrounding said tube as said tube travels through said bath;
• and
• means for rapidly solidifying said sealing material with a water quench after said tube exits said bath,
• whereby said motion of said tube being pulled through said bath causes said molten sealing material to flow into and substantially fill said seam and form said coating.

An apparatus for fabricating an optical fiber cable assembly having at least one optical fiber housed within a sealed metal or metal alloy tube, said apparatus comprising:

• means for forming a strip of metal or metal alloy into a tube characterized by a seam formed by spaced-apart tube portions;
• said forming means comprising at least one tube forming die and means for pulling said metal or metal alloy strip through said at least one die;
• means for applying a flux to said strip prior to said strip being pulled through said at least one die;
• means for inserting said at least one optical fiber within said tube;
• means for sealing said seam and forming a coating about substantially the entire periphery of said tube;
• said sealing means comprising a bath of molten metallic sealing material;
• said bath having an inlet through which said tube and said at least one optical fiber enter said bath and an outlet through which said tube and said at least one optical fiber cable exit said bath;
• the outer periphery of said tube being in contact with said molten sealing material from said inlet to said outlet;
• means for pulling said tube with said fiber through said bath without any protective structure surrounding said tube as said tube travels through said bath;
• and
• means for rapidly solidifying said sealing material with a water quench after said tube exits said bath,
• whereby said motion of said tube being pulled through said bath causes said molten sealing material to flow into and substantially fill said seam and form said coating.