Optical cable

• US 10,061,096 B2
• Filed: 10/03/2014
• Issued: 08/28/2018
• Est. Priority Date: 03/06/2014
• Status: Active Grant

• Current Assignee: Fujikura Limited
• Original Assignee: Fujikura Limited
• Inventors: Takeda, Daiki, Kaji, Tomoaki, Shiobara, Satoru, Yamanaka, Masayoshi, Okada, Naoki
• Primary Examiner(s): Radkowski, Peter
• Application Number:
  US15/116,889
• Publication Number:
  US 20170153404A1
• Time in Patent Office: 1,425 Days
• CPC Class Codes: G02B 6/4433 Double reinforcement laying in straight line with optical transmission element
• CPC Class Codes: G02B 6/449 Twisting
• CPC Class Codes: G02B 6/566 Devices for opening or removing the mantle

Abstract

[Problem] The thickness on a ripcord in a circular optical cable is reduced, to improve workability.

[Solution] An optical cable of the present invention includes: an optical fiber unit including optical fibers; a sheath, having a circular external form, configured to house the optical fiber unit in a housing portion; and two strength members embedded in the sheath; and two rip cords, wherein when a direction of connecting the two strength members sandwiching the housing portion is a first direction and a direction intersecting the first direction is a second direction, in a cross section of the optical cable, a cross-sectional shape of the housing portion has a dimension in the second direction greater than that in the first direction, and the two rip cords is disposed to sandwich the optical fiber unit such that a direction of connecting the two rip cords is in the second direction, in the cross section of the optical cable.

Claims

1. An optical cable comprising:

an optical fiber unit including a plurality of optical fibers;

a sheath configured to house the optical fiber unit in a housing portion, the sheath having a circular external form;

a pair of strength members embedded in the sheath sandwiching the housing portion, each strength member constituting said pair of strength members including at least one strength member; and

two rip cords, wherein

when a direction of connecting the pair of strength members sandwiching the housing portion is a first direction, and a direction intersecting the first direction is a second direction, in any cross section of the optical cable in a longitudinal direction,

a cross-sectional shape of the housing portion has a dimension in the second direction greater than a dimension in the first direction,

the two rip cords are disposed to sandwich the optical fiber unit such that a direction of connecting the two rip cords is in the second direction, in any cross section of the optical cable in the longitudinal direction,

the plurality of optical fibers are twisted in an SZ manner,

the cross-sectional shape of the housing portion is an elliptical shape with a minor axis and a major axis, and

L1/L2 is equal to or greater than 0.55, where L1 is the length of the minor axis and L2 is the length of the major axis.

2. An optical cable comprising:

an optical unit including a plurality of optical fibers;

a sheath configured to house the optical fiber unit in a housing portion, the sheath having a circular external form;

a pair of strength members embedded in the sheath sandwiching the housing portion, each strength member constituting said pair of strength members including at least one strength member; and

two rip cords, wherein

when a direction of connecting the pair of strength members sandwiching the housing portion in a first direction, and a direction intersecting the first direction is a second direction, in any cross section of the optical cable in a longitudinal direction,

a cross-sectional shape of the housing portion has a dimension in the second direction greater than a dimension in the first direction,

the two rip cords are disposed to sandwich the optical fiber unit such that a direction of connecting the two rip cords is in the second direction, in any cross section of the optical cable in the longitudinal direction,

the cross-sectional shape of the housing portion is in such a shape as to be enclosed by two straight portions along the second direction and two arc-shaped portions on both sides in the second direction of the straight portions,

the plurality of optical fibers are twisted in an SZ manner, and

L1/L2 is equal to or greater than 0.60,

where L1 is a dimension of the housing portion in the first direction and L2 is a dimension thereof in the second direction.

3. An optical cable comprising:

an optical fiber unit including a plurality of optical fibers;

a sheath configured to house the optical fiber unit in a housing portion, the sheath having a circular external form;

a pair of strength members embedded in the sheath sandwiching the housing portion, each strength member constituting said pair of strength members including at least one strength member; and

two rip cords, wherein

when a direction of connecting the pair of strength members sandwiching the housing portion in a first direction, and a direction intersecting the first direction is a second direction, in any cross section of the optical cable in a longitudinal direction,

a cross-sectional shape of the housing portion has a dimension in the second direction greater than a dimension in the first direction,

the two rip cords are disposed to sandwich the optical fiber unit such that a direction of connecting the two rip cords is in the second direction, in any cross section of the optical cable in the longitudinal direction,

the cross-sectional shape of the housing portion is in such a shape as to be narrowed at a line connecting the two strength members,

the plurality of optical fibers are twisted in an SZ manner, and

L1/L2 is equal to or greater than 0.75,

where L1 is a dimension of the housing portion in the first direction and L2 is a dimension thereof in the second direction.

4. The optical cable according to claim 3, wherein the strength members are made of a nonmetallic material,

and the cross-sectional shape of the housing portion is in such a shape as to be enclosed by two straight portions along the second direction and two arc-shaped portions on both sides in the second direction of the straight portions.