Power/fiber hybrid cable

The present disclosure relates to a hybrid cable having a jacket with a central portion positioned between left and right portions. The central portion contains at least one optical fiber and the left and right portions contain electrical conductors. The left and right portions can be manually torn from the central portion.

TECHNICAL FIELD

The present disclosure relates generally to hybrid communication systems. More particularly, the present disclosure relates to telecommunications cables capable of transmitting both optical signals and electrical power.

BACKGROUND

Rapid growth of portable high-speed wireless transceiver devices (e.g., smartphones, tablets, laptop computers, etc.) continues in today's market, thereby creating higher demand for untethered contact. Thus, there is growing demand for integrated voice, data and video capable of being transmitted wirelessly at high data transmission rates. To provide the bandwidth needed to support this demand will require the cost effective and efficient deployment of additional fixed location transceivers (i.e., cell sites or nodes) generating both large and small wireless coverage areas. Telecommunications cables capable transmitting both electrical power and optical signals that are capable of being manufactured and installed in an effective, cost effective manner can greatly enhance the ability of service providers to implement coverage areas suitable for meeting growing market demands.

SUMMARY

One aspect of the present disclosure relates to a cable carries both electrical power and optical communications. In certain examples, the electrical power and optical communications can be directed to a device for generating a cellular coverage area (e.g., a macrocell, a microcell, a metrocell, a picocell, a femtocell, etc.)

Another aspect of the present disclosure relates to telecommunications cables that facilitate the fast, low cost and simple deployment of optical fiber and power to interface with active devices such as devices for generating wireless communication coverage areas (e.g., wireless transceivers) and other active devices (e.g., cameras).

Still other aspects of the present disclosure relate to hybrid power/optical fiber cables that facilitate the deployment of wireless communication coverage areas at various locations such as stadiums, shopping areas, hotel, high rise office buildings, multi-dwelling units, suburban environments, corporate and university campuses, in-building areas, near-building areas, tunnels, canyons, roadside areas and coastal areas. Still further aspects of the present disclosure relate to power/optical fiber hybrid cables that enhance the coverage areas provided by cellular technologies (e.g., GSM, CDMA, UMTS, LTE, IiMax, WiFi, etc.).

A further aspect of the present disclosure relates to a hybrid cable having an outer jacket including a transverse cross-sectional profile that defines a major axis and a minor axis. The outer jacket has a height measured along the minor axis and a width measured along the major axis. The width is greater than the height such that the transverse cross-sectional profile of the outer jacket is elongated along the major axis. The outer jacket includes a left portion, a right portion and a central portion. The left, right and central portions are positioned along the major axis with the central portion being disposed between the left and right portions. The left portion defines a left passage, the right portion defines a right passage and the central portion defines a central passage. The hybrid cable also includes a left electrical conductor positioned within the left passage, a right electrical conductor positioned within the right passage and at least one optical fiber positioned within the central passage. The hybrid cable includes a left pre-defined tear location positioned between the central portion and the left portion of the outer jacket and a right pre-defined tear location positioned between the central portion and the right portion of the outer jacket. The left pre-defined tear location is weakened such that the left portion of the outer jacket can be manually torn from the central portion of the outer jacket. The left pre-defined tear location is configured such that the left portion of the outer jacket fully surrounds the left passage and the central portion of the outer jacket fully surrounds the central passage after the left portion of the outer jacket has been torn from the central portion of the outer jacket. The right pre-defined tear location is weakened such that the right portion of the outer jacket can be manually torn from the central portion of the outer jacket. The right pre-defined tear location is configured such that the right portion of the outer jacket fully surrounds the right passage and the central portion of the outer jacket fully surrounds the central passage after the right portion of the outer jacket has been torn from the central portion of the outer jacket.

DETAILED DESCRIPTION

Various examples will be described in detail with reference to the figures, wherein like reference numerals represent like parts and assemblies throughout the several views. Any examples set forth in this specification are not intended to be limiting and merely set forth some of the many possible variations of the inventive aspects disclosed herein.

FIG. 1shows a system10in accordance with the principles of the present disclosure for enhancing the coverage areas provided by cellular technologies (e.g., GSM, CDMA, UMTS, LTE, WiMax, WiFi, etc.). The system10includes a base location11(i.e., a hub) and a plurality of wireless coverage area defining equipment12a,12b,12c,12d,12eand12fdistributed about the base location11. In certain example, the base location11can include a structure14(e.g., a closet, hut, building, housing, enclosure, cabinet, etc.) protecting telecommunications equipment such as racks, fiber optic adapter panels, passive optical splitters, wavelength division multi-plexers, fiber splice locations, optical fiber patching and/or fiber interconnect structures and other active and/or passive equipment. In the depicted example, the base location11is connected to a central office16or other remote location by a fiber optic cable such as a multi-fiber optical trunk cable18that provides high band-width two-way optical communication between the base location11and the central office16or other remote location. In the depicted example, the base location11is connected to the wireless coverage area defining equipment12a,12b,12c,12d,12eand12fby hybrid cables20. The hybrid cables20are each capable of transmitting both power and communications between the base location11and the wireless coverage area defining equipment12a,12b,12c,12d,12eand12f.

The wireless coverage area defining equipment12a,12b,12c,12d,12eand12fcan each include one or more wireless transceiver22. The transceivers22can include single transceivers22or distributed arrays of transceivers22. As used herein, a “wireless transceiver” is a device or arrangement of devices capable of transmitting and receiving wireless signals. A wireless transceiver typically includes an antenna for enhancing receiving and transmitting the wireless signals. Wireless coverage areas are defined around each of the wireless coverage area defining equipment12a,12b,12c,12d,12eand12f. Wireless coverage areas can also be referred to as cells, cellular coverage areas, wireless coverage zones, or like terms. Examples of and/or alternative terms for wireless transceivers include radio-heads, wireless routers, cell sites, wireless nodes, etc.

In the depicted example ofFIG. 1, the base location11is shown as a base transceiver station (BTS) located adjacent to a radio tower24supporting and elevating a plurality the wireless coverage area defining equipment12a. In one example, the equipment12acan define wireless coverage areas such as a macrocells or microcells (i.e., cells each having a coverage area less than or equal to about 2 kilometers wide). The wireless coverage area defining equipment12bis shown deployed at a suburban environment (e.g., on a light pole in a residential neighborhood) and the equipment12cis shown deployed at a roadside area (e.g., on a roadside power pole). The equipment12ccould also be installed at other locations such as tunnels, canyons, coastal areas, etc. In one example, the equipment12b,12ccan define wireless coverage areas such as microcells or picocells (i.e., cells each having a coverage area equal to or less than about 200 meters wide). The equipment12dis shown deployed at a campus location (e.g., a university or corporate campus), the equipment12eis shown deployed at a large public venue location (e.g., a stadium), and the equipment12fis shown installed at an in-building or near-building environment (e.g., multi-dwelling unit, high rise, school, etc.). In one example, the equipment12d,12e, and12fcan define wireless coverage areas such as microcells, picocells, or femtocells (i.e., cells each having a coverage area equal to or less than about 10 meters wide).

FIG. 2is a transverse cross-sectional view taken through one of the hybrid cables20ofFIG. 1. Hybrid cable20includes an outer jacket100having a transverse cross-sectional profile that defines a major axis102and a minor axis104. The outer jacket has a height H measured along the minor axis104and a width W measured along the major axis102. The width W is greater than the height H such that the transverse cross-sectional profile of the outer jacket100is elongated along the major axis102.

The outer jacket100can include a left portion106, a right portion108and a central portion110. The left portion106, the right portion108and the central portion110can be positioned along the major axis102with the central portion110being disposed between the left portion106and the right portion108. The left portion106can define a left passage112, the right portion108can define a right passage114and the central portion110can define a central passage116. The passages112,114and116can have lengths that extend along a central longitudinal axis118of the cable20for the length of the cable. A left electrical conductor120is shown positioned within the left passage112, a right electrical conductor122is shown positioned within the right passage114and at least one optical fiber124is shown positioned within the central passage116. The left electrical conductor120, the right electrical conductor122and the optical fiber124have lengths that extend along the central longitudinal axis118of the cable20.

Still referring toFIG. 2, the hybrid cable20includes a left pre-defined tear location126positioned between the central portion110and the left portion106of the outer jacket100, and a right pre-defined tear location128positioned between the central portion110and the right portion108of the outer jacket100. The left pre-defined tear location126is weakened such that the left portion106of the outer jacket100can be manually torn from the central portion110of the outer jacket100. Similarly, the right pre-defined tear location128is weakened such that the right portion108of the outer jacket100can be manually torn from the central portion110of the outer jacket100. The left pre-defined tear location126is configured such that the left portion106of the outer jacket100fully surrounds the left passage112and the central portion110of the outer jacket100fully surrounds the central passage116after the left portion106of the outer jacket100has been torn from the central portion110of the outer jacket100. In this way, the left electrical conductor120remains fully insulated and the optical fiber120remains fully protected after the left portion106has been torn from the central portion110. The right pre-defined tear location128is configured such that the right portion108of the outer jacket100fully surrounds the right passage114and the central portion110of the outer jacket100fully surrounds the central passage119after the right portion108of the outer jacket100has been torn from the central portion110of the outer jacket100. In this way, the right electrical conductor122remains fully insulated and the optical fiber124remains fully protected after the right portion108has been torn from the central portion110.

FIG. 3shows the hybrid cable20with both the left portion106and the right portion108torn away from the central portion110. In this configuration, both the left electrical conductor120and the right electrical conductor122are fully insulated by their corresponding left and right portions106,108. Additionally, the central portion110has a rectangular transverse cross-sectional shape that fully surrounds the central passage116so as to protect the optical fiber or fibers124.

It will be appreciated that the left and right electrical conductors120,122have a construction suitable for carrying electricity. It will be appreciated that the electrical conductors can have a solid or stranded construction. Example sizes of the electrical conductors include 12 gauge, 16 gauge, or other sizes.

The outer jacket100is preferably constructed of a polymeric material. In one example, the hybrid cable20and the outer jacket100are plenum rated. In certain examples, the outer jacket100can be manufactured of a fire-retardant plastic material. In certain examples, the outer jacket100can be manufactured of a low smoke zero halogen material. Example materials for the outer jacket include polyvinyl chloride (PVC), fluorinated ethylene polymer (FEP), polyolefin formulations including, for example, polyethylene, and other materials.

The central passage116can contain one or more optical fibers124. In certain examples, the optical fibers124can be coated optical fibers having cores less than 12 microns in diameter, cladding layers less than 140 microns in diameter, and coating layers less than 300 microns in diameter. It will be appreciated that the core and cladding layers typically include a silica based material. In certain examples, the cladding layer can have an index of a refraction that is less than the index of refraction of the core to allow optical signals that are transmitted through the optical fibers to be confined generally to the core. It will be appreciated that in certain examples, multiple cladding layers can be provided. In certain examples, optical fibers can include bend insensitive optical fibers having multiple cladding layers separated by trench layers. In certain examples, protective coatings (e.g., a polymeric material such as actelate) can form coating layers around the cladding layers. In certain examples, the coating layers can have diameters less than 300 microns, or less than 260 microns, or in the range of 240 to 260 microns. In certain examples, the optical fibers124can be unbuffered. In other examples, the optical fibers can include a tight buffer layer, a loose buffer layer, or a semi-tight buffer layer. In certain examples, the buffer layers can have an outer diameter of about 800 to 1,000 microns. The optical fibers can include single mode optical fibers, multi-mode optical fibers, bend insensitive fibers or other fibers. In still other embodiments, the optical fibers124can be ribbonized.

As shown atFIG. 4, the left and right portions106,108can be trimmed relative to the central portion110after the left and right portions106,104have been torn away from the central portion110. In this configuration, the central portion110extends distally beyond the ends of the left and right portions106,108. In certain examples, insulation displacement connectors can be used to pierce through the jacket materials of the left and right portions106,108to electrically connect the left and right electrical connectors120,122to an electrical power source, ground, active components or other structures. It will be appreciated that the optical fibers124can be directly terminated with optical connectors. In other examples, connectorized pigtails can be spliced to the ends of the optical fibers124.

Referring back toFIG. 2, the outer jacket100includes a top side130and a bottom side132separated by the height H. As depicted, the top and bottom sides130,132are generally parallel to one another. Each of the left and right pre-defined tear locations126,128includes an upper slit134that extends downwardly from the top side130, a lower slit136that extends upwardly from the bottom side132and a non-slitted portion138positioned between the upper and lower slits134,136. In one example embodiment, the upper and lower slits134,136are partially re-closed slits. In the depicted embodiment, the left and right pre-defined tear locations126,128also include jacket weakening members140that are imbedded in the non-slitted portions138. By way of example, the jacket weakening members140can include strands, monofilaments, threads, filaments or other members. In certain examples, the jacket weakening members140extend along the central longitudinal axis118of the cable20for the length of the cable20. In certain examples, the jacket weakening members140are aligned along the major axis102. In certain examples, the upper and lower slits130,136as well as the jacket weakening member140of the left pre-defined tear location126are aligned along a left tearing plane PLthat is oriented generally perpendicular relative to the major axis102. Similarly, the upper and lower slits134,136as well as the jacket weakening member140of the right pre-defined tear location128are aligned along a right tearing plane PRthat is oriented generally perpendicular with respect to the major axis102.

Referring again toFIG. 2, the hybrid cable20can include a tensile strength structure142that provides tensile enforcement to the hybrid cable20so as to prevent tensile loads from being applied to the optical fibers124. In certain embodiments, the tensile strength structure142can include reinforcing structures such as Aramid yarns or other reinforcing fibers. In still other embodiments, the tensile strength structure142can have an oriented polymeric construction. In still other examples, a tensile strength structure142can include a reinforcing tape. In certain examples, the reinforcing tape can be bonded to the outer jacket100so as to line the central passage116. In certain examples, no central buffer tube is provided between the optical fibers124and the tensile reinforcing structure142. In certain examples, the tensile strength structure142can include a reinforcing tape that extends along the length of the hybrid cable20and has longitudinal edges/ends144that are separated so as to define a gap144therein between. In use, the tensile strength member142can be anchored to a structure such as a fiber optic connector, housing or other structure so as to limit the transfer of tensile load to the optical fibers124. It will be appreciated that the tensile strength structure142can be anchored by techniques such as crimping, adhesives, fasteners, bands or other structures.

FIG. 5shows an alternative hybrid cable20′ having the same construction as the hybrid cable20except two tensile strength structures142A,142B have been provided within the central passage116. Tensile strength members142A,142B each include a tensile reinforcing tape that is bonded to the central portion110of the outer jacket100. The tensile strength members142A,142B can include portions that circumferentially overlap one another within the central passage116. In certain examples, by stripping away an end portion of the central portion110, the tensile strength structures142A,142B can be exposed and readily secured to a structure such as a fiber optic connector, a panel, a housing or other structure. In one example, the tensile strength structures142A,142B can be crimped, adhesively secured or otherwise attached to rods (e.g., epoxy rods reinforced with fibers) that are in turn secured within a ruggedized fiber optic connector such as the fiber optic connector disclosed at U.S. Pat. No. 7,744,288 which is hereby incorporated by reference in its entirety, or the fiber optic connector disclosed at U.S. Pat. No. 7,918,609, which is hereby incorporated by reference in its entirety.

It will be appreciated that cables in accordance with the principles of the present disclosure can be manufactured using a one-pass manufacturing process. In certain examples, the same one-pass manufacturing process can be used to manufacture different types of cables by substituting in different types of electrical conductors (e.g., stranded or non-stranded) and by using different types of optical fibers (e.g., buffered optical fibers, non-buffered optical fibers, ribbonized fibers, multi-mode fibers, single-mode fibers, bend insensitive fibers, etc.).

Referring toFIG. 6, a schematic representation of a system200for making the fiber optic cable20is shown. The system200includes a cross head, generally designated202, that receives polymeric (e.g., thermoplastic) material from an extruder204. A hopper206is used to feed material into the extruder204. A conveyor208can be used to convey material (e.g., base material and possibly additives) to the hopper206. In other embodiments, additional conveyors can be used to convey additional materials to the hopper206. The extruder204is heated by a heating system212that may include one or more heating elements for heating zones of the extruder as well as the cross head202to desired processing temperatures.

One or more of the optical fibers124can be fed into the cross head202from one or more feed rolls214. The system200can also include one or more supply rolls218for feeding the tensile strength structure142or structures to the cross-head202and a longitudinal shaping tool220. The tensile strength structure142is disposed on the supply roll218. The shaping tool220is used to form/shape the tensile strength structure142(e.g., one or more pieces of reinforcing tape) into a generally cylindrical shape that surrounds the one or more fibers124prior to entering the cross-head202. The system200further includes feed rolls250,251for feeding the electrical conductors120,122into the cross-head202, and feed rolls254,255for feeding the jacket weakening members140into the cross-head202.

A water trough222is located downstream from the cross head202for cooling the extruded product that exits the cross head202. The cooled final product is stored on a take-up roll224rotated by a drive mechanism226. A controller228can coordinate the operation of the various components of the system200. The cross-head202can be configured to provide the jacket100with the desired transverse cross-sectional shape ofFIG. 2. The system200further includes a slitting module230located immediately downstream from the cross head202. The slitting module230includes blade slitting blades232that form slits in the outer jacket100corresponding to the upper and lower slits134,136. Preferably, the slitting blades232slit the outer jacket100while the material of the outer jacket is still at least partially molten. In this way, in certain examples, the slits at least partially reclose after slitting. In this way, the slits form weakened portions in the jacket. In other embodiments, the slits may remain fully open.

In use, the optical fibers124, the left and right electrical conductors120,122, the tensile reinforcing structure142and the jacket weakening members140are all fed through the cross head202. Prior to reaching the cross head202, the shaping tool220can shape the tensile strength structure142around the optical fibers120such that the tensile strength member142surrounds the optical fibers as the optical fibers and the tensile strength structure142pass through the cross-head202. As the components pass through the cross head, the material of the outer jacket100is extruded about the cylindrical tensile strength structure142as well as about the left and right electrical conductors120,122and the jacket weakening members140. In certain examples, the material forming the outer jacket100of the cable20leaves the cross-head202having a shape/profile of the type shown atFIG. 2. Thereafter, the cutting blades232of the slitting module230slit the upper and lower slits134,136into the jacket. The cable is then cooled at the trough222and is collected on the take-up spool224.