US5740295A — Low fiber count optical cable

Claim 1

Independent Claim 235 words

A low fiber count optical fiber cable comprising: a hollow tubular member of dielectric material and substantially circular cross section having an inside diameter D; the exterior surface of said tubular member being coated with a hydrophilic material; at least one optical fiber configuration enclosed within said tubular member and having a diameter of d f ; said inside diameter D being sized for containing one or more of a plurality of any of said fiber configurations and being greater than a critical dimension d c where d c is that value of D just sufficient to enclose all of the fiber within said tubular member; said fiber member having a length within said tubular member that is greater than the length of said tubular member by an excess length l e and is given in part by the ratio d d /D, and a bend radius within the tubular member given by the ratio D b /D, where D b is twice said bend radius; said ratio d c /D and the value of D i and of l e being an optimum value regardless of the type of fiber configuration enclosed within said tubular member; and wherein at the optimum value of D, a maximum packing density commensurate with excellent optical and mechanical performance including low bending strain and low attenuation within said tubular member results for supporting any of said fiber configurations.

Claim 2

Dependent Claim 235 words

A low fiber count optical fiber cable comprising: a hollow tubular member of dielectric material and substantially circular cross section having an inside diameter D; the exterior surface of said tubular member being coated with a hydrophilic material; at least one optical fiber configuration enclosed within said tubular member and having a diameter of d f ; said inside diameter D being sized for containing one or more of a plurality of any of said fiber configurations and being greater than a critical dimension d c where d c is that value of D just sufficient to enclose all of the fiber within said tubular member; said fiber member having a length within said tubular member that is greater than the length of said tubular member by an excess length l e and is given in part by the ratio d d /D, and a bend radius within the tubular member given by the ratio D b /D, where D b is twice said bend radius; said ratio d c /D and the value of D i and of l e being an optimum value regardless of the type of fiber configuration enclosed within said tubular member; and wherein at the optimum value of D, a maximum packing density commensurate with excellent optical and mechanical performance including low bending strain and low attenuation within said tubular member results for supporting any of said fiber configurations.

Claim 3

Dependent Claim 40 words

A low fiber count optical fiber cable as claimed in claim 1 wherein the critical dimensions d c is that for two buffered fibers and the dimension D is an optimum for two buffered fibers contained within said tubular member.

Claim 4

Dependent Claim 25 words

A low fiber count optical fiber cable as claimed in claim 2 wherein said tubular member contains three fiber bundles of six fibers per bundle.

Claim 5

Dependent Claim 28 words

A low fiber count optical fiber cable as claimed in claim 2 wherein said tubular member contains at least one fiber ribbon having a plurality of fibers therein.

Claim 6

Dependent Claim 20 words

A low fiber count optical fiber cable as claimed in claim 1 wherein said hydrophilic material is in powder form.

Claim 7

Dependent Claim 33 words

A low fiber count optical fiber cable as claimed in claim 1 wherein the excess fiber length l e is related to the diameter D and the critical diameter d c by ##EQU3##

Claim 8

Dependent Claim 26 words

A low fiber count optical fiber cable as claimed in claim 1 wherein the interior of said tubular member is filled with a water blocking compound.

Claim 9

Dependent Claim 212 words

A dielectric low count optical fiber drop cable comprising: a core tube having an inside diameter D; at least two optical fibers of any of a plurality of fiber configurations within said core tube having a total diameter d f said fiber having an excess length l e ; said inside diameter D sized for containing one or more of a plurality of any of said fiber configurations and being greater than a critical diameter d c which is the minimum diameter sufficient to encompass all of said optical fibers, and having a value wherein a packing density within said core tube supports any of said fiber configurations; the outer surface of said core tube being coated with a hydrophilic powder material; first and second diametrically opposed dielectric strength members extending along the length of said core tube in a helical configuration and in contract with said hydrophilic coating material; a plurality of longitudinally extending dielectric tensile strength members in helical configuration about said core tube and in contact with said hydrophilic coating material; said first and second strength members and said tensile strength members being coated with hydrophilic powder material; and a dielectric jacket member enclosing said core tube and said strength members and being in contact with said hydrophilic material.

Claim 10

Dependent Claim 212 words

A dielectric low count optical fiber drop cable comprising: a core tube having an inside diameter D; at least two optical fibers of any of a plurality of fiber configurations within said core tube having a total diameter d f said fiber having an excess length l e ; said inside diameter D sized for containing one or more of a plurality of any of said fiber configurations and being greater than a critical diameter d c which is the minimum diameter sufficient to encompass all of said optical fibers, and having a value wherein a packing density within said core tube supports any of said fiber configurations; the outer surface of said core tube being coated with a hydrophilic powder material; first and second diametrically opposed dielectric strength members extending along the length of said core tube in a helical configuration and in contract with said hydrophilic coating material; a plurality of longitudinally extending dielectric tensile strength members in helical configuration about said core tube and in contact with said hydrophilic coating material; said first and second strength members and said tensile strength members being coated with hydrophilic powder material; and a dielectric jacket member enclosing said core tube and said strength members and being in contact with said hydrophilic material.

Claim 11

Dependent Claim 63 words

A dielectric optical fiber drop cable as claimed in claim 8 and further comprising an electrically conducting cable member having an exterior dielectric jacket, said exterior dielectric jacket being in contact with said dielectric jacket of said fiber drop cable; and a sheath of dielectric material encasing said dielectric drop cable and said electrically conducting cable member to form a FIG. 8 configuration.

Claim 12

Dependent Claim 22 words

A dielectric optical fiber drop cable as claimed in claim 9 wherein said electrically conducting cable member contains twisted pairs of conductors.

Claim 13

Dependent Claim 20 words

A dielectric optical fiber cable as claimed in claim 9 wherein said electrically conducting cable member is a coaxial cable.

Claim 14

Dependent Claim 33 words

A dielectric optical fiber drop cable as claimed in claim 8 wherein said optical fibers are in the configuration of one or more fiber ribbons, each ribbon having a plurality of fibers therein.

Claim 15

Dependent Claim 29 words

A dielectric optical fiber drop cable as claimed in claim 8 wherein the unoccupied volume of the interior of said core tube is filled with a water blocking compound.

Claim 16

Dependent Claim 36 words

A dielectric optical fiber drop cable as claimed in claim 8 wherein the length of the fibers in said core tube exceeds the length of said core tube by a percentage given by the expression ##EQU4##

Claim 17

Dependent Claim 28 words

A dielectric optical fiber drop cable as claimed in claim 8 wherein said optical fibers are in the configuration of three bunches of six optical fibers per bunch.

Claim 18

Dependent Claim 23 words

A dielectric optical fiber drop cable as claimed in claim 8 wherein said optical fibers are in the configuration of two buffered fibers.

Claim 19

Dependent Claim 175 words

An armored low count optical fiber cable comprising: a core tube having inside diameter D; at least two optical fibers of any of a plurality of fiber configurations within said core tube having a total diameter d f ; each fiber being an excess length l e ; said inside diameter D being sized for containing one or more of a plurality of any of said fiber configurations and being greater than a critical diameter d c which is the minimum diameter sufficient to encompass all of said optical fibers and compatible for use with any of said configurations; the outer surface of said core tube being coated with a hydrophilic powder material; a sheath of metallic material surrounding said core tube in contact with said hydrophilic material; first and second diametrically opposed metallic strength members extending along the length of said core tube in contact with said metallic sheath; said first and second strength members and said metallic sheath being coated with a hydrophilic powder material; and a dielectric jacket encasing said sheath member.

Claim 20

Dependent Claim 175 words

An armored low count optical fiber cable comprising: a core tube having inside diameter D; at least two optical fibers of any of a plurality of fiber configurations within said core tube having a total diameter d f ; each fiber being an excess length l e ; said inside diameter D being sized for containing one or more of a plurality of any of said fiber configurations and being greater than a critical diameter d c which is the minimum diameter sufficient to encompass all of said optical fibers and compatible for use with any of said configurations; the outer surface of said core tube being coated with a hydrophilic powder material; a sheath of metallic material surrounding said core tube in contact with said hydrophilic material; first and second diametrically opposed metallic strength members extending along the length of said core tube in contact with said metallic sheath; said first and second strength members and said metallic sheath being coated with a hydrophilic powder material; and a dielectric jacket encasing said sheath member.

Claim 21

Dependent Claim 57 words

An armored optical fiber drop cable as claimed in claim 17 and further comprising an electrically conducting cable member having an exterior dielectric jacket being in contact with said dielectric jacket encasing said sheath; and a sheath of dielectric material encasing said armored drop cable and said electrically conducting cable member to form a FIG. 8 configuration.

Claim 22

Dependent Claim 22 words

An armored optical fiber drop cable as claimed in claim 18 wherein said electrically conducting cable member contains twisted pairs of conductors.

Claim 23

Dependent Claim 21 words

An armored optical fiber drop cable as claimed in claim 18 wherein said electrically conducting cable member is a coaxial cable.

Claim 24

Dependent Claim 32 words

An armored optical fiber drop cable as claimed in claim 17 wherein said optical fibers are in the configuration of a plurality of fibers arranged in bundles of several fibers per bundle.

Claim 25

Dependent Claim 29 words

An armored optical fiber drop cable as claimed in claim 17 wherein the unoccupied volume of the interior of said core tube is filled with a water blocking compound.

Claim 26

Dependent Claim 36 words

An armored optical fiber drop cable as claimed in claim 18 wherein the length of the fibers in said core tube exceeds the length of said core tube by a percentage given by the expression ##EQU5##

Claim 27

Dependent Claim 23 words

An armored optical fiber drop cable as claimed in claim 17 wherein said optical fibers are in the configuration of two buffered fibers.

Claim 28

Dependent Claim 31 words

An armored optical fiber drop cable as claimed in claim 17 wherein said optical fibers are in the configuration of one or more ribbons each having a plurality of fibers therein.

Claim 29

Dependent Claim 203 words

For use in forming a low count optical fiber drop cable having a core tube of inside diameter D, two or more optical fiber members of total outside dimensions d f contained within the core tube of a length greater than the core tube, the core whereby the fibers have a bend radius given by D b /2, and a critical dimension d c diameter of the core tube sufficient to encase the fibers; the method of optimizing the diameter D such that one or more of a plurality of any said fiber members can be contained therein comprising; determining the packing density ratio d f /d c for two buffered fibers; determining the excess fiber length relative to the core tube; determining from the excess fiber length the ratio of d c /D and the ratio D b /D; determining the fiber bending strain ε b from the expression (d.sub.f /d.sub.c)(d.sub.c /D) ε.sub.b (%)=100 (D.sub.b /D) varying the values of the ratios to produce an acceptable fiber bending strain; and solving for D once an acceptable bending strain is achieved, said inside diameter D being sized to result in an allowable packing density for supporting said members other than said buffered fibers.

Claim 30

Dependent Claim 203 words

For use in forming a low count optical fiber drop cable having a core tube of inside diameter D, two or more optical fiber members of total outside dimensions d f contained within the core tube of a length greater than the core tube, the core whereby the fibers have a bend radius given by D b /2, and a critical dimension d c diameter of the core tube sufficient to encase the fibers; the method of optimizing the diameter D such that one or more of a plurality of any said fiber members can be contained therein comprising; determining the packing density ratio d f /d c for two buffered fibers; determining the excess fiber length relative to the core tube; determining from the excess fiber length the ratio of d c /D and the ratio D b /D; determining the fiber bending strain ε b from the expression (d.sub.f /d.sub.c)(d.sub.c /D) ε.sub.b (%)=100 (D.sub.b /D) varying the values of the ratios to produce an acceptable fiber bending strain; and solving for D once an acceptable bending strain is achieved, said inside diameter D being sized to result in an allowable packing density for supporting said members other than said buffered fibers.

Annuity Stage	Window Opens	Payment Deadline	Surcharge Period Until	Estimated Fee	Status
3.5 Years (Year 4)	2001-04-13	2001-10-13	2002-04-14	$2000.00	Window Closed / Lapsed
7.5 Years (Year 8)	2005-04-13	2005-10-13	2006-04-14	$3760.00	Window Closed / Lapsed
11.5 Years (Year 12)	2009-04-13	2009-10-13	2010-04-14	$7700.00	Window Closed / Lapsed

Low fiber count optical cable

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