The disclosure relates to an optical fiber cable and, more particularly, to a fiber optic cable having a jacket that is configured to provide enhanced sealing during operation of the cable and provide enhanced access to the optical fiber of the cable so as to facilitate field terminations and/or splicing of the optical fiber, such as by configuring the jacket to tear along the length of the jacket at certain weakened portions.
Broadband network architecture may use optical fiber cables to provide all or part of the local loop used for last mile telecommunications. These optical fiber cables—also known as “drop cables”—should provide good protection to optical fibers while allowing an easy access thereto; they should be suitable for being directly buried into the ground, or installed in a duct, either by pulling, pushing, or blowing, or for aerial installation.
Some conventional optical cable includes a cylindrical support that is hollowed out to form a longitudinal cavity in which one or more optical fibers are loosely accommodated. The cable comprises of one or more strain bearing elements embedded in the cylindrical support, provided longitudinally and symmetrically with respect to the cable axis. The longitudinal cavity may be radially extended between the couple of bearing elements and the plane comprising the couple of strain bearing elements transverses the slot. The support is made of a thermoplastic material, for example polyethylene. The couple of bearing elements are made, for example, of glass fiber, aramid fiber or carbon fiber. Such conventional cables are difficult to tear along their longitudinal length.
Some conventional optical cable, such as the CasaLink Block Terminal (“CBT”) Drop cable of the Prysmian Group illustrated in
It may be desirable to provide a fiber optic cable having a jacket configured to include one or more selectively teared or weakened portions or configurations such that the jacket is configured to selectively tear along the length of the jacket at such selectively teared portions so as to selectively expose the optical fiber in the cavity and thus provide enhanced sealing during operation and enhanced access to the optical fiber to better facilitate field terminations and/or splicing. It may be desirable to provide the jacket with a cavity along the length of the cable that provides the selectively teared portions. It also may be desirable to embed one or more strengthening members or portions in the jacket proximate or spaced away from the selectively teared portions. It further may be desirable to provide one or more enhanced access indicator portions on the outer surface of the jacket to identify the selectively teared portions.
In accordance with various exemplary embodiments of the disclosure, an optical fiber cable for providing enhanced sealing during operation and for providing enhanced access to an optical fiber to better facilitate field terminations and/or splicing of the optical fiber may include a hollow jacket that includes a cavity having an oblong shape in a cross section of the hollow jacket that extends along a length of the hollow jacket, an optical fiber that is located in the cavity and extends the length of the hollow jacket, and a strengthening member embedded in the hollow jacket. The cavity is configured to have a cavity length in a first direction transverse to the length of the hollow jacket that is greater than a maximum cavity width in a second direction that is perpendicular to the first direction and transverse to the length of the hollow jacket, and the cavity includes a first end and a second end in the first direction along a first axis. An outer surface of the hollow jacket is configured to include an indicator portion aligned with the first end and the second end in the first direction along the first axis. The hollow jacket is configured to include first portions between the first end of the cavity and the outer surface of the jacket and between the second end of the cavity and the outer surface of the jacket in the first direction along the first axis, and a center of the cavity in the first direction has a largest width in the second direction extending from a first side of the cavity to a second side of the cavity along a second axis in the second direction. The hollow jacket is configured to include second portions between the first side of the cavity and the outer surface of the hollow jacket and between the second side of the cavity and the outer surface of the hollow jacket in the second direction along the second axis, and the strengthening member is located in one of the second portions between the cavity and the outer surface of the hollow jacket in the second direction along the width axis. Each of the first portions is configured to include a first thickness, each of the second portions is configured to include a second thickness, and the second thickness is greater than the first thickness. The thinner first portions are weaker than the thicker second portions such that the hollow jacket is configured to tear along the length of the jacket at the first portions so as to provide enhanced access to the optical fiber in the cavity, and the thinner first portions created by the oblong cavity are configured to permit the outer surface of the jacket to include a continuously circular, curved, or arcuate outer surface portion that is configured to provide enhanced sealing during operation of the optical cable.
According to various aspects of the above embodiment, the optical cable further comprises a water swellable material portion that is located in the cavity.
According to various aspects of the above embodiments of the optical cable, the strengthening member comprises twisted strands of brass plated steel.
According to various aspects of the above embodiments, the cable further comprises a rip cord in the cavity that is configured to assist with tearing of the jacket at the first portions.
According to various aspects of the above embodiments of the optical cable, the indicator portion comprises a color portion of the outer surface of the hollow jacket that contrasts with a remainder of the outer surface of the hollow jacket.
According to various exemplary embodiments of the disclosure, an optical fiber cable for providing enhanced sealing during operation and selectively teared access to an optical fiber so as to facilitate field terminations and/or splicing of the optical fiber cable includes a jacket including a cavity having an oblong shape in a cross section of the jacket and extending along a length of the jacket and an optical fiber that is located in the cavity and extends the length of the jacket. The cavity is configured to have a length in a first direction that is greater than a width in a second direction that is perpendicular to the first direction, and the cavity includes a first end and a second end in the first direction along a first axis. An outer surface of the jacket includes an indicator portion aligned with the first end and the second end in the first direction along the first axis, the jacket is configured to include first portions between the first end of the cavity and the outer surface of the jacket and between the second end of the cavity and the outer surface of the jacket in the first direction along the first axis, and the jacket is configured to include second portions between a first side of the cavity and the outer surface of the jacket and between a second side of the cavity and the outer surface of the jacket in a second direction along a second axis that is perpendicular to the first axis. The first portions are configured to be weaker than the second portions such that the jacket is configured to tear along the length of the jacket at the first portions, thereby exposing the optical fiber in the cavity, and the first portions created by the oblong shape of the cavity are configured to permit the outer surface of the jacket to include a curved or arcuate outer surface portion adjacent the first portions that is configured to provide enhanced sealing of the optical fiber cable during operation.
According to various aspects of the above embodiments of the optical cable, a center of the cavity in the first direction has a largest width in the second direction extending from a first side of the cavity to a second side of the cavity along a second axis.
According to various aspects of the above embodiments of the optical cable, each of the first portions is configured to include a first thickness and each of the second portions is configured to include a second thickness, and the second thickness is greater than the first thickness.
According to various aspects of the above embodiments, the optical cable further comprises a strengthening member embedded in one of the second portions between the cavity and the outer surface of the hollow jacket in the second direction along the width axis.
According to various aspects of the above embodiments of the optical cable, the strengthening member comprises twisted strands of brass plated steel.
According to various aspects of the above embodiments, the optical cable further comprises a rip cord located in the cavity and configured to assist with tearing of the jacket at the first portions.
According to various aspects of the above embodiments of the optical cable, the indicator portion comprises a color portion of the outer surface of the jacket that contrasts with a remainder of the outer surface of the jacket.
According to various aspects of the above embodiments, the optical cable further comprises a water swellable material portion that is located in the cavity.
According to various aspects of the above embodiments, the curved outer surface portion comprises a continuously curved or arcuate outer surface portion.
In accordance with various exemplary embodiments of the disclosure, an optical fiber cable for providing enhanced sealing and enhanced access to an optical fiber for field terminations and/or splicing includes a jacket including a cavity extending along a length of the jacket and an optical fiber that is located in the cavity and extends the length of the jacket. The cavity is configured to have a length in a first direction that is greater than a width in a second direction that is perpendicular to the first direction. The jacket is configured to include a selectively teared portion that is located between the cavity and an outer surface of the jacket in the first direction such that the jacket is configured to tear along the length of the jacket at the selectively teared portion so as to allow for enhanced access to the optical fiber in the cavity, and the selectively teared portion created by the cavity is configured to permit the outer surface of the jacket to include a surface portion adjacent the selectively teared portion that is configured to provide enhanced sealing during operation of the optical fiber cable.
According to various aspects of the above embodiment of the optical cable, the cavity includes a first end and a second end in the first direction along a first axis and a first side and a second side in the second direction along a second axis.
According to various aspects of the above embodiments of the optical cable, the selectively teared portion comprises first portions between the first end of the cavity and the outer surface of the jacket and between the second end of the cavity and the outer surface of the jacket in the first direction along the first axis.
According to various aspects of the above embodiments of the optical cable, the jacket is configured to include second portions between the first side of the cavity and the outer surface of the jacket and between the second side of the cavity and the outer surface of the jacket in the second direction along the second axis, wherein the weakened portions are configured to be weaker than the second portions.
According to various aspects of the above embodiments of the optical cable, an outer surface of the jacket includes an indicator portion aligned with the first end and the second end in the first direction along the first axis.
According to various aspects of the above embodiments of the optical cable, a center of the cavity in the first direction has a largest width in the second direction extending from a first side of the cavity to a second side of the cavity along a second axis.
According to various aspects of the above embodiments of the optical cable, each of the first portions is configured to include a first thickness, each of the second portions is configured to include a second thickness, and the second thickness is greater than the first thickness.
According to various aspects of the above embodiments, the optical cable further comprises a strengthening member portion embedded in the jacket between the cavity and the outer surface of the hollow jacket in the second direction.
According to various aspects of the above embodiments of the optical cable, the strengthening member portion comprises twisted strands of brass plated steel.
According to various aspects of the above embodiments, the optical cable further comprises a rip cord that is located in the cavity and is configured to assist with tearing of the jacket at the first portions.
According to various aspects of the above embodiments of the optical cable, the indicator portion comprises a color portion of the outer surface of the jacket that contrasts with a remainder of the outer surface of the jacket.
According to various aspects of the above embodiments, the optical cable further comprises a water swellable material portion that is located in the cavity.
According to various aspects of the above embodiments, the surface portion comprises a continuously curved or arcuate outer surface portion.
In accordance with various exemplary embodiments of the disclosure, an optical fiber cable for providing notchless cable sealing and selectively teared access to optical fiber of the cable for fiber termination or splicing includes a selectively teared access portion that is configured to be selectively torn into a torn state, where access to optical fiber of the cable is provided for fiber termination or splicing. The selectively teared access portion is configured to allow a notchless cable sealing portion to form a seal around the cable with a sealing member when the selectively teared portion is in an untorn state, where access to the optical fiber of the cable is not provided for fiber termination or splicing. The notchless cable sealing portion is shaped to sealingly fit the sealing member so as to form the seal around the cable with the sealing member when the selectively teared portion is in the untorn state.
In accordance with various exemplary embodiments of the disclosure, an optical fiber cable for providing notchless cable sealing and selectively teared access to optical fiber of the cable for fiber termination or splicing includes a selectively teared access portion that is configured to be selectively torn into a torn state, where access to optical fiber of the cable is provided for fiber termination or splicing. The selectively teared access portion comprises a notchless cable sealing portion that is configured to form a seal around the cable with a sealing member when the selectively teared portion is in an untorn state, where access to the optical fiber of the cable is not provided for fiber termination or splicing. The notchless cable sealing portion is shaped to sealingly fit the sealing member so as to form the seal around the cable with the sealing member when the selectively teared portion is in the untorn state.
Further advantages and features of the present disclosure will become apparent from the following description and the accompanying drawings, to which reference is made. In which are shown:
Reference will now be made in detail to presently preferred embodiments and methods of the present disclosure, which constitute the best modes of practicing the present disclosure presently known to the inventors. However, it is to be understood that the disclosed embodiments are merely exemplary of the present disclosure that may be embodied in various and alternative forms. Therefore, specific details disclosed herein are not to be interpreted as limiting, but merely as a representative basis for any aspect of the present disclosure and/or as a representative basis for teaching one skilled in the art to variously employ the present disclosure.
It is also to be understood that this disclosure is not limited to the specific embodiments and methods described below, as specific components and/or conditions may, of course, vary. Furthermore, the terminology used herein is used only for the purpose of describing particular embodiments of the present disclosure and is not intended to be limiting in any way.
It must also be noted that, as used in the specification and the appended claims, the singular form “a,” “an,” and “the” comprise plural referents unless the context clearly indicates otherwise. For example, reference to a component in the singular is intended to comprise a plurality of components.
As shown in
The cable 10 includes an outer surface 60 or portion thereof that may include a cable sealing surface 61 or portion thereof, for example, an outer cable sealing surface or portion thereof, that is shaped to form a seal with a sealing structure or member, such as in the form of a grommet, gland, O-ring, or other sealing structure or member at an enclosure box, a connector that terminates the cable, or the like. In the illustrated embodiment, the outer surface 60 comprises an outer surface 64 of the jacket 14. In some aspects, the outer surface 60 or portion of the cable may not be the jacket 14. The outer surface 64 of the jacket 14 may include a jacket sealing surface 63 or portion thereof that is shaped to form a seal with a sealing structure or member, such as in the form of a grommet, gland, O-ring, or other sealing structure or member at an enclosure box. For instance, the jacket sealing surface 63 or portion thereof (or the cable sealing surface 61 or portion thereof, or an outer cable sealing surface or portion thereof) may be shaped as a smooth or un-notched surface or portion thereof so as to form a seal with an inner surface or portion of such a sealing structure or member. Alternatively, the jacket sealing surface 63 or portion thereof (a cable sealing surface or portion thereof, or an outer cable sealing surface or portion thereof) may include a continuously circular or curved surface 67 or portion thereof that forms a seal with the sealing member or structure.
The cavity 12 includes a first end 22 and a second end 24 in the first direction, that is, the length direction, along a length axis 43. The outer surface 64 of the jacket 14 includes indicators 30, or indicator portions, aligned with the first end 22 and the second end 24 in the first direction along the length axis 43. For example, the indicators 30 may be diametrically opposed to one another at the outer surface 64 of the jacket 14. The indicators 30 thus identify a directional location of the first end 22, the second end 24, and the first portions 26. As shown, the jacket 14 includes first portions 26 that are between the first end 22 of the cavity 12 and one of the indicators 30 and between the second end 24 of the cavity 12 and the other one of the indicators 30 in the first direction along the length axis 43.
In some aspects, the indicators 30 may comprise a color that contrasts with a color of the remainder of the outer surface 64 of the jacket 14. For example, the indicators 30 may be a bright yellow color while the remainder of the outer surface 64 of the jacket 14 is black. In some aspects, the jacket 14 and the indicators 30 may comprise coextruded polymeric materials, such as, for example, polyethylene. The polymeric material of the indicators 30 may be dyed or colored to provide the contrasting color between the indicators 30 and the outer surface 64 of the jacket 14. The jacket 14 and/or the indicators 30 may, but not necessarily, comprise High-Density Polyethylene (HDPE) or Medium Density Polyethylene (MDPE) or another polymer material such as a fiber reinforced composite material or PVC. The jacket 14 may be produced via an extrusion process, by UV curing and/or any other known technique. The extrusion manufacturing process results in a product having consistent dimensions.
As shown in
Each of the first portions 26 includes a first portion thickness 38, and each of the second portions 56 includes a second portion thickness 36. The second portion thickness 36 is greater than the first portion thickness 38 as further described herein. Thus, the thinner first portions 26 are weaker relative to the thicker second portions 56. Consequently, the first portions 26 may comprise weakened or selectively teared portions that are configured to tear along the longitudinal direction 62 (see
By shaping the cavity 12 to provide the weakened or selectively teared first portions 26 of the jacket, instead of notching or otherwise modifying an outer surface of a jacket to provide a weakened portion, the outer surface 64 can include curved or arcuate outer surface portions 65 adjacent the first portions 26, or selectively teared portions. For example, the curved or arcuate outer surface portions 65 may be continuously curved or arcuate without a notch or other surface feature that may otherwise be used to provide a weakened portion of the jacket 12. In some aspects, the outer surface portions 65 and the outer surface 64 may comprise a continuous circle or oval. Thus, the continuously curved outer surface 64 can provide enhanced weathertight sealing of the jacket 14 at a gland or grommet of an enclosure box or at a boot or O-ring of a connector that terminates the cable. That is, the shape of the cavity 12 is configured to define the first portions 26 that permit selective tearing while permitting the curved or arcuate outer surface portions 65 to provide a surface that does not include a notch, a cutout, or discontinuity, and thus can be sealed with a grommet, gland, boot, or O-ring to provide enhanced weathertight sealing of the cable 10 at a gland or grommet of an enclosure box or at boot or O-ring of a connector that terminates the cable 10.
As previously indicated, the cavity 12 may be configured to house one or more optional ripcords 42. In some aspects, the ripcords 42 may facilitate, or assist with, the separation of the jacket 14 along the longitudinal direction into two parts 15, 17 when the ripcords 42 are pulled in opposite directions away from one another by a user or technician in a direction of the length axis 43 toward the respective first portions 26 of the jacket 14. As shown in
In the exemplary embodiment of
An exemplary jacket 14 consistent with the exemplary embodiment of
With respect to an aerial installation, the aforementioned exemplary range of 1.5 to 3.3 for the ratio of the width 36 of the second portion 56 to the length 38 of the first portion 26 optimizes the elongation of the cable 10 and optimizes tearing of the jacket in the first portions 26 when installed at a determinate span under wind and ice loads while also maintaining cable strength. Furthermore, the dimensional proportions enable a user to easily access the cavity 12 defined in the jacket 14. As indicated, the first portions 26 are configured to tear along the longitudinal direction 62 of the cable 10 so that the jacket 14 splits open in two parts 15, 17, as shown in
Referring to
With respect to the strengthening members 54, the cable 10 is configured to flex or bend along the width axis 66, which enables the cable 10 to be wound about a spool (not shown) before the cable is installed. As noted, the strengthening members 54 may be longitudinal wires which may be metallic such as brass plated metal or may be a glass reinforced plastic (GRP) or fiber reinforced plastic (FRP). GRP and FRP strengthening members 54 may be preferred when the cable 10 is implemented in proximity to high power lines, and there is a desire to prevent the high power from interfering with the customer network via the cable 10.
In the exemplary embodiment of
As shown in
Referring to
These aforementioned configurations have a number of advantages, including an easy management (for instance easy coiling) of the cable during manufacturing thereof or an easy positioning of dead-end clamps. Further or different indicia could be provided for locating the opening of the cavity (via the minor portions) from the outer surface of the sheath, such as an indentation or an ink line 41 (see
While example, non-limiting embodiments have been presented in the foregoing detailed description, it should be appreciated that a vast number of variations exist. It should also be appreciated that the exemplary embodiment or exemplary embodiments are only examples, and are not intended to limit the scope, applicability, or configuration of the disclosure in any way. Rather, the foregoing detailed description will provide those skilled in the art with a convenient road map for implementing the exemplary embodiment or exemplary embodiments. It should be understood that various changes can be made in the function and arrangement of elements without departing from the scope of the disclosure as set forth in the appended claims and the legal equivalents thereof.
This application claims the benefit of U.S. Provisional Application No. 63/254,244, filed Oct. 11, 2021, the disclosure of which is hereby incorporated by reference herein in its entirety.
Number | Date | Country | |
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63254244 | Oct 2021 | US |