High-density patch-panel assemblies for optical fiber telecommunications

Patch panel assemblies (150) that contain patch panel modules (50) for use in optical fiber telecommunication systems are disclosed. One of the patch panel assemblies includes a front mounting frame (210F) and at least one internal mounting frame (210I) that support a plurality of patch panel modules. The patch panel assembly also includes a hinge assembly (224) configured allow bend-insensitive fiber cables (70) to be routed therethrough. One of the patch panel assemblies includes a housing (152) with a drawer (270) that supports a plurality of patch panel modules. The patch panel modules employ bend-insensitive optical fibers (12C) to connect front and rear ports (92, 98) so that the patch panels have a reduced size as compared to conventional patch panel modules. The patch panel assemblies include a cable distribution box (300) that can store excess cable and that assists in routing bend-insensitive fiber optic cables within the patch panel assembly interior (200) in order to connect to select patch panel module jacks (90).

FIELD OF THE INVENTION

The present invention relates generally to optical fiber telecommunications equipment and networks, and in particular relates to patch panel assemblies that can contain a relatively high density of patch panel modules.

BACKGROUND OF THE INVENTION

Typical optical telecommunication systems and networks include one or more telecommunications data centers that provide large numbers of optical and electrical cable connections that join various types of network equipment. The typical system also includes a number of outlying stations that extend the system into a network. Examples of network equipment include electrically-powered (active) units such as optical line terminals (OLTs), optical network terminals (ONTs), network interface devices (NIDs), servers, splitters, combiners, multiplexers, switches and routers, fanout boxes and patch panels. This network equipment is often installed within cabinets in standard-sized equipment racks. Each piece of equipment typically provides one or more adapters where optical or electrical patch cables (“jump cables”) can be physically connected to the equipment. These patch cables are generally routed to other network equipment located in the same cabinet or in another cabinet.

A common problem in telecommunications systems, and in particular with optical telecommunications equipment, is space management. Current practice in telecommunications is to utilize standard electronics racks or frames that support standards-sized stationary rack-mounted housings with widths of 19 or 23 inches horizontal spacing. Vertical spacing has been divided into rack units “U”, where 1U=1.75 inches as specified in EIA (Electronic Industries Alliance) 310-D, IEC (International Electrotechnical Commission) 60297 and DIN (“German Institute for Standardization”) 41494 SC48D. The housings may be fixed, slide-out, or swing-out patch/splice panels or shelves. However, the configurations and sizes of present-day housings for optical telecommunications equipment have been defined largely by the properties of the fiber optic cables that connect to the devices supported by the housings. In particular, the configurations and sizes have been established based on the particular ability of the fiber optic cables and optical fibers therein to interface with the devices without exceeding the bending tolerance of the fiber optic cable and/or the optical fibers. This has resulted in telecommunications equipment that occupies relatively large amounts of space, and in particular a relatively large amount of floor space in a central office of a telecommunications network. It has also lead to data center patch panels being increasingly overpopulated due to connector and cable volumes.

SUMMARY OF THE INVENTION

The present invention relates to patch panel assemblies that can support a relatively high density of patch panels. The patch panel assemblies have a configurations that takes advantage of cable fibers and jumper fibers that are bend-insensitive. The use of multiple rows of patch panel modules serves to distribute the density to enable ease of finger access to the modules, and facilitates the use of RFID systems that have difficulty reading densely packed RFID tags.

Accordingly, a first aspect of the invention is a patch panel assembly for a telecommunication data center for providing optical connections using bend-insensitive optical fiber cables. The assembly includes a rectangular, box-like housing having an interior region, a front side and a back side. The housing is sized to be operably supported by a standard telecommunications rack. The assembly further includes a front mounting frame and at least one interior mounting frame, wherein the mounting frames are configured to support at least one reduced-form-factor patch panel module.

A second aspect of the invention is a patch panel module. The patch panel module includes a substantially rectangular module housing that includes a front side having at least one angled facet, an opposing back side, opposing ends, and opposing sidewalls that define an interior region. The module includes at least one jack arranged on the at least one angled facet, with the at least one jack defining one or more front-side ports. The module includes at least one backside port operably connected to the at least one jack via at least one bend-insensitive cable fiber contained within the housing interior region. A lengthwise open channel is formed in the backside of the module housing and is sized to accommodate an external bend-insensitive optical cable.

A third aspect of the invention is a patch panel assembly for a telecommunication data center for providing optical connections using bend-insensitive optical fiber cables. The assembly includes a rectangular, box-like housing having opposing side walls and a back panel that defines an interior, the housing sized to be operably supported by a standard telecommunications rack. The assembly includes a drawer having a front end and a floor panel and is configured to slide in and out of the housing interior, and is also configured to support an array of patch panel modules on the floor panel in a substantially horizontal configuration. The assembly also includes at least one movable cable guide arranged in the housing and configured to guide at least one bend-resistant fiber optic cable and to move to accommodate the sliding of the drawer in and out of the housing.

DETAILED DESCRIPTION OF THE INVENTION

Reference is now made in detail to the present preferred embodiments of the invention, examples of which are illustrated in the accompanying drawings. Whenever possible, the same or similar reference numerals are used throughout the drawings to refer to the same or similar parts. It should be understood that the embodiments disclosed herein are merely examples, each incorporating certain benefits of the present invention. Various modifications and alterations may be made to the following examples within the scope of the present invention, and aspects of the different examples may be mixed in different ways to achieve yet further examples. Accordingly, the true scope of the invention is to be understood from the entirety of the present disclosure, in view of but not limited to the embodiments described herein.

Terms such as “horizontal,” “vertical,” “front,” “back,” etc., are used herein for the sake of reference in the drawings and ease of description and are not intended to be strictly limiting either in the description or in the claims as to an absolute orientation and/or direction. Also, the term “bend-insensitive fiber optic cable” is intended to include cable that includes one or more bend-insensitive optical fibers.

Example embodiments of the present invention make use of bend-insensitive or “bend performance” fibers such as those in the form of so-called “nanostructure” or “holey” optical fibers. There are a number of such fibers on the market today. Nanostructure fibers have one or more regions with periodically or aperiodically arranged small holes or voids, which make the fiber extremely bend insensitive. Examples of such optical fibers are described in, for example, U.S. Pat. No. 6,243,522, pending U.S. patent application Ser. No. 11/583,098 filed Oct. 18, 2006 (hereinafter, “the Corning nanostructure fiber patents and patent applications”), all of which are assigned to Corning Incorporated, and all of which are incorporated by reference herein.

Bend-insensitive fibers as used in the present invention include, for example, nanostructure fibers of the type available from Corning, Inc., of Corning, N.Y., including, but not limited to, single-mode, multi-mode, bend performance fiber, bend-optimized fiber and bend-insensitive optical fiber. Nanostructure fibers are advantageous in that they allow for the patch panel modules and patch panel assemblies of the present invention to have fibers with relatively small-radius bends while optical attenuation in the fibers remains extremely low. One example of a bend-insensitive optical fiber includes a core region and a cladding region surrounding the core region, the cladding region comprising an annular hole-containing region comprised of non-periodically disposed holes such that the optical fiber is capable of single mode transmission at one or more wavelengths in one or more operating wavelength ranges. The core region and cladding region provide improved bend resistance, and single mode operation at wavelengths preferably greater than or equal to 1500 nm, in some embodiments also greater than about 1310 nm, in other embodiments also greater than 1260 nm. The optical fibers provide a mode field at a wavelength of 1310 nm preferably greater than 8.0 μm, and more preferably between about 8.0 and 10.0 μm.

One type of nanostructure optical fiber developed by Corning, Inc., has an annular ring of non-periodic airlines (of diameter ˜1×10−7m) that extend longitudinally along the length of the fiber. The region with the ring of airlines has a reduced apparent or average index of refraction, because air has an index of refraction of approximately 1 compared to the fused silica matrix refractive index of approximately 1.46. The ring of airlines is positioned to create a refractive index profile that enables superior bend performance (optically) and significantly smaller minimum bend radius specifications.

FIG. 1is a schematic side view of a section of an example embodiment of a bend-insensitive fiber in the form of a nanostructure optical fiber (“nanostructure fiber”)12having a central axis AF.FIG. 2Ais a schematic cross-section of nanostructure fiber12as viewed along the direction2A-2A inFIG. 1. Nanostructure fiber12can be, for example, any one of the various types of nanostructure optical fibers, such as any of the so-called “holey” fibers, or those described in the above-mentioned Corning nanostructure fiber patents and patent applications. For the purposes of the present invention, a “bend-insensitive fiber” includes nanostructure fibers that make use of periodic or non-periodic nanostructures or holes.

In an example embodiment, nanostructure optical fiber12includes a core region (“core”)20, a nanostructure region30surrounding the core, and an outer cladding region40(“cladding”) surrounding the nanostructure region. Other ring-type configurations for nanostructure optical fiber12are also known. A protective cover or sheath (not shown) optionally covers outer cladding40.

In an example embodiment, nanostructure region30comprises a glass matrix (“glass”)31having formed therein non-periodically disposed holes (also called “voids” or “airlines”)32, such as the example voids shown in detail in the magnified inset ofFIG. 2A. In another example embodiment, voids32may be periodically disposed, such as in a photonic crystal optical fiber, wherein the voids typically have diameters between about 1×10−6m and 1×10−5m. Voids32may also be “non-periodic airlines. In an example embodiment, glass31is fluorine-doped while in another example embodiment the glass is undoped pure silica. By “non-periodically disposed” or “non-periodic distribution,” it is meant that when one takes a cross-section of the optical fiber (such as shown inFIG. 2A), the voids32are randomly or non-periodically distributed across a portion of the fiber.

Cross sections similar toFIG. 2Ataken at different points along the length of nanostructure optical fiber12will reveal different cross-sectional hole patterns, i.e., various cross-sections will have different hole patterns, wherein the distributions of holes and sizes of holes do not match. That is, the holes are non-periodic, i.e., they are not periodically disposed within the fiber structure. These holes are stretched (elongated) along the length (i.e. in a direction generally parallel to the longitudinal axis) of the optical fiber (and thus have a longer dimension along the length of the fiber), but do not extend the entire length of the entire fiber for typical lengths of transmission fiber. While not wishing to be bound by theory, it is believed that the holes extend less than a few meters, and in many cases less than 1 meter along the length of the fiber.

If non-periodically disposed holes/voids32are employed in nanostructure region30, it is desirable in one example embodiment that they be formed such that greater than 95% of and preferably all of the holes exhibit a mean hole size in the cladding for the optical fiber which is less than 1550 nm, more preferably less than 775 nm, most preferably less than about 390 nm. Likewise, it is preferable that the maximum diameter of the holes in the fiber be less than 7000 nm, more preferably less than 2000 nm, and even more preferably less than 1550 nm, and most preferably less than 775 nm. In some embodiments, the fibers disclosed herein have fewer than 5000 holes, in some embodiments also fewer than 1000 holes, and in other embodiments the total number of holes is fewer than 500 holes in a given optical fiber perpendicular cross-section. Of course, the most preferred fibers will exhibit combinations of these characteristics. Thus, for example, one particularly preferred embodiment of optical fiber would exhibit fewer than 200 holes in the optical fiber, the holes having a maximum diameter less than 1550 nm and a mean diameter less than 775 nm, although useful and bend resistant optical fibers can be achieved using larger and greater numbers of holes. The hole number, mean diameter, max diameter, and total void area percent of holes can all be calculated with the help of a scanning electron microscope at a magnification of about 800× to about 4000× and image analysis software, such as ImagePro, which is available from Media Cybernetics, Inc. of Silver Spring, Md., USA.

In an example embodiment, holes/voids32can contain one or more gases, such as argon, nitrogen, or oxygen, or the holes can contain a vacuum with substantially no gas; regardless of the presence or absence of any gas, the refractive index of the hole-containing region is lowered due to the presence of the holes. The holes can be periodically or non-periodically disposed. In some embodiments, the plurality of holes comprises a plurality of non-periodically disposed holes and a plurality of periodically disposed holes. Alternatively, or in addition, as mentioned above, the depressed index can also be provided by downdoping the glass in the hole-containing region (such as with fluorine) or updoping one or both of the surrounding regions.

Nanostructure region30can be made by methods that utilize preform consolidation conditions, which are effective at trapping a significant amount of gases in the consolidated glass blank, thereby causing the formation of voids in the consolidated glass optical fiber preform. Rather than taking steps to remove these voids, the resultant preform is used to form an optical fiber with voids, or holes, therein. As used herein, the diameter of a hole is the longest line segment whose end points are disposed on the silica internal surface defining the hole when the optical fiber is viewed in a perpendicular cross-section transverse to the optical fiber central axis AF.

SEM analysis of the end face of an example nanostructure optical fiber12showed an approximately 4.5 micron radius GeO2—SiO2void-free core (having an index of approximately +0.34 percent delta versus silica) surrounded by a 11-micron outer radius void-free near cladding region surrounded by 14.3-micron outer radius non-periodic void-containing cladding region (ring thickness of approximately 3.3 μm), which is surrounded by a void-free pure silica outer cladding having an outer diameter of about 125 μm (all radial dimensions measured from the center of the optical fiber).

The nanostructure region comprised approximately 2.5 percent regional area percent holes (100% N2by volume) in that area with an average diameter of 0.28 μm and the smallest diameter holes at 0.17 μm and a maximum diameter of 0.48 μm, resulting in a total of about 130 holes in the fiber cross-section. The total fiber void area percent (area of the holes divided by total area of the optical fiber cross-section×100) was about 0.05 percent. Optical properties for this fiber were 0.36 and 0.20 dB/Km at 1310 and 1550 nm, respectively, and a 22-meter fiber cable cut-off of about 1250 nm, thereby making the fiber single mode at wavelengths above 1250 nm.

The nanostructure optical fibers as used herein may or may not include germania or fluorine to adjust the refractive index of the core and/or cladding of the optical fiber, but these dopants can also be avoided in the intermediate annular region and instead, the holes (in combination with any gas or gases that may be disposed within the holes) can be used to adjust the manner in which light is guided down the fiber core. The nanostructure region may consist of undoped (pure) silica, thereby completely avoiding the use of any dopants in the hole-containing region, to achieve a decreased refractive index, or the nanostructure region may comprise doped silica, e.g. fluorine-doped silica having a plurality of holes. In one set of embodiments, the core includes doped silica to provide a positive refractive index relative to pure silica, e.g. germania doped silica. The core region is preferably hole-free.

Such fiber can be made to exhibit a fiber cut-off of less than 1400 nm, more preferably less than 1310 nm, a 20-mm macrobend induced loss at 1550 nm of less than 1 dB/turn, preferably less than 0.5 dB/turn, even more preferably less than 0.1 dB/turn, still more preferably less than 0.05 dB/turn, yet more preferably less than 0.03 dB/turn, and even still more preferably less than 0.02 dB/turn, a 12-mm macrobend induced loss at 1550 nm of less than 5 dB/turn, preferably less than 1 dB/turn, more preferably less than 0.5 dB/turn, even more preferably less than 0.2 dB/turn, still more preferably less than 0.1 dB/turn, still even more preferably less than 0.05 dB/turn, and an 8-mm macrobend induced loss at 1550 nm of less than 5 dB/turn, preferably less than 1 dB/turn, more preferably less than 0.5 dB/turn, and even more preferably less than 0.2 dB/turn, and still even more preferably less than 0.1 dB/turn.

The nanostructure fibers used herein may be multimode. Multimode optical fibers disclosed herein comprise a graded-index core region and a cladding region surrounding and directly adjacent to the core region, the cladding region comprising a depressed-index annular portion comprising a depressed relative refractive index relative to another portion of the cladding. The depressed-index annular portion of the cladding is preferably spaced apart from the core. Preferably, the refractive index profile of the core has a parabolic shape. The depressed-index annular portion may, for example, comprise glass comprising a plurality of voids, or fluorine-doped glass, or fluorine-doped glass comprising a plurality of voids.

In some embodiments, the multimode optical fiber comprises a graded-index glass core; and a cladding surrounding and in contact with the core, the cladding comprising a depressed-index annular portion surrounding the core, said depressed-index annular portion having a refractive index delta less than about −0.2% and a width of at least 1 micron, said depressed-index annular portion spaced from said core at least 0.5 microns.

The multimode optical fiber disclosed herein exhibits very low bend induced attenuation, in particular very low macrobending induced attenuation. In some embodiments, high bandwidth is provided by low maximum relative refractive index in the core, and low bend losses are also provided. Consequently, the multimode optical fiber may comprise a graded-index glass core; and an inner cladding surrounding and in contact with the core, and a second cladding comprising a depressed-index annular portion surrounding the inner cladding, said depressed-index annular portion having a refractive index delta less than about −0.2% and a width of at least 1 micron, wherein the width of said inner cladding is at least 0.5 microns and the fiber further exhibits a 1 turn 10 mm diameter mandrel wrap attenuation increase, of less than or equal to 0.4 dB/turn at 850 nm, a numerical aperture of greater than 0.18, and an overfilled bandwidth greater than 1.5 GHz-km at 850 nm.

Using the designs disclosed herein, 50 micron diameter core multimode fibers can been made which provide (a) an overfilled (OFL) bandwidth of greater than 1.5 GHz-km, more preferably greater than 2.0 GHz-km, even more preferably greater than 3.0 GHz-km, and most preferably greater than 4.0 GHz-km at a wavelength of 850 nm. These high bandwidths can be achieved while still maintaining a 1 turn 10 mm diameter mandrel wrap attenuation increase at a wavelength of 850 nm, of less than 0.5 dB, more preferably less than 0.3 dB, even more preferably less than 0.2 dB, and most preferably less than 0.15 dB. These high bandwidths can also be achieved while also maintaining a 1 turn 20 mm diameter mandrel wrap attenuation increase at a wavelength of 850 nm, of less than 0.2 dB, more preferably less than 0.1 dB, and most preferably less than 0.05 dB, and a 1 turn 15 mm diameter mandrel wrap attenuation increase at a wavelength of 850 nm, of less than 0.2 dB, preferably less than 0.1 dB, and more preferably less than 0.05 dB. Such fibers are further capable of providing a numerical aperture (NA) greater than 0.17, more preferably greater than 0.18, and most preferably greater than 0.185. Such fibers are further simultaneously capable of exhibiting an OFL bandwidth at 1300 nm which is greater than 500 MHz-km, more preferably greater than 600 MHz-km, even more preferably greater than 700 MHz-km. Such fibers are further simultaneously capable of exhibiting minimum calculated effective modal bandwidth (Min EMBc) bandwidth of greater than about 1.5 MHz-km, more preferably greater than about 1.8 MHz-km and most preferably greater than about 2.0 MHz-km at 850 nm.

Preferably, the multimode optical fiber disclosed herein exhibits a spectral attenuation of less than 3 dB/km at 850 nm, preferably less than 2.5 dB/km at 850 nm, even more preferably less than 2.4 dB/km at 850 nm and still more preferably less than 2.3 dB/km at 850 nm. Preferably, the multimode optical fiber disclosed herein exhibits a spectral attenuation of less than 1.0 dB/km at 1300 nm, preferably less than 0.8 dB/km at 1300 nm, even more preferably less than 0.6 dB/km at 1300 nm. In some embodiments it may be desirable to spin the multimode fiber, as doing so may in some circumstances further improve the bandwidth for optical fiber having a depressed cladding region. By spinning, we mean applying or imparting a spin to the fiber wherein the spin is imparted while the fiber is being drawn from an optical fiber preform, i.e. while the fiber is still at least somewhat heated and is capable of undergoing non-elastic rotational displacement and is capable of substantially retaining the rotational displacement after the fiber has fully cooled.

In some embodiments, the numerical aperture (NA) of the optical fiber is preferably less than 0.23 and greater than 0.17, more preferably greater than 0.18, and most preferably less than 0.215 and greater than 0.185.

In some embodiments, the core extends radially outwardly from the centerline to a radius R1, wherein 20≦R1≦40 microns. In some embodiments, 22≦R1≦34 microns. In some preferred embodiments, the outer radius of the core is between about 22 to 28 microns. In some other preferred embodiments, the outer radius of the core is between about 28 to 34 microns.

In some embodiments, the core has a maximum relative refractive index, less than or equal to 1.2% and greater than 0.5%, more preferably greater than 0.8%. In other embodiments, the core has a maximum relative refractive index, less than or equal to 1.1% and greater than 0.9%.

In some embodiments, the optical fiber exhibits a 1 turn 10 mm diameter mandrel attenuation increase of no more than 1.0 dB, preferably no more than 0.6 dB, more preferably no more than 0.4 dB, even more preferably no more than 0.2 dB, and still more preferably no more than 0.1 dB, at all wavelengths between 800 and 1400 nm.

Fiber Bend Angle and Bend Diameter

FIG. 2Bis a schematic diagram illustrating a bend angle θBand a bend diameter DBof an example bend-insensitive optical fiber in the form of nanostructure fiber12having a bend formed therein. Bend diameter DBis twice the bend radius RB. Two arrows AR1and AR2represent the relative orientations (directions) of optical fiber12on either side of bend B. Bend angle θBis defined by the intersection of arrows AR1and AR2, as shown in the right-hand side ofFIG. 2B. Because sections of optical fiber do not always remain perfectly straight before and after a bend, the bend angle θBis not exact, but serves as a useful approximation that generally describes the degree to which nanostructure fiber12is bent.

In an example embodiment, the bend-insensitive optical fibers used in the present invention have bends like bend B with a bend diameter DBas small as 10 mm. This, in part, allows for the patch panel modules of the present invention to be made relatively compact and to allow for the patch panel assemblies to contain a relatively high density of patch-panel modules and thus a high-density of jacks and ports for establishing optical connections.

In the discussion hereinafter, for the sake of convenience, reference number12is used to refer to bend-insensitive fibers generally, with bend-insensitive “cable fibers” carried by a bend-insensitive fiber optic cable being identified as12C to distinguish from bend-insensitive “jumper fibers,” which are identified as12J.

Reduced form Factor Patch Panel Module

FIG. 3Ais a perspective view of an example embodiment of a “reduced form factor” patch panel module50that includes a substantially rectangular module housing56having an interior58and a reduced form factor as compared to a standard patch panel module. Module housing56includes a backside wall60that has at least one V-shaped indentation61formed by first and second angled wall portions62and64. Wall portion62includes an aperture (not shown) that allows a bend-insensitive fiber optic cable (“cable”)70that carries one or more cable fibers12C to connected to the housing so that the cable fibers can be introduced into interior58, as illustrated inFIG. 3B. In an example embodiment, cable70includes either twelve or twenty-four buffered cable fibers12(having, e.g., a diameter of 500 μM or 900 μm) or a 250 μm diameter bare fibers. Cable70preferably includes a boot72to support the fiber at its connection point at wall portion62.

Housing56also includes a front panel80having a number (e.g., twelve) spaced apart apertures (not shown) that hold a corresponding number (e.g., twelve) jacks90. Front panel also includes respective ends82that have mounting holes84for mounting module50to panel mounting frames, introduced and described in greater detail below.FIG. 3Cis the same asFIGS. 3A and 3B, but shows housing56having a cover57that encloses interior58.

Each jack90defines either one or two ports92open at a front side96and configured to receive a connectorized end13J of a jumper fiber12J. Each jack90also includes backside ports98where one or more cable fibers12C from bend-insensitive fiber optic cable70are attached. In an example embodiment, module50includes two rows of six jacks90, as shown. Further to the example embodiment, one or two cable fibers12C are connected to each jack at back side ports98(i.e., one cable fiber for each port92), as illustrated inFIG. 3B.

Because cable fibers12C are bend insensitive, they can and do have tight bends that allow them to fit into the tight space of interior58so as to be connected to jacks90at backside ports98. The use of bend-insensitive cable fibers12C within interior58also allows for the module housing56to have reduced dimensions and thus a reduced form factor. In an example embodiment, housing56has dimensions of length L1=4.62 inches, width W1=1.295 inches and Depth D1between about 2 inches and about 3 inches, e.g., 2.36 inches. Because depth D1can be almost half that of the corresponding prior art patch panel module, the volume of interior58is reduced by close to 40% over the prior art. This in turn allows for a higher density of ports92to be supported in a standard-size patch panel assembly.

Bend-insensitive cable fibers12C also facilitate the connection of one or two cables70to patch panel module50at an angle relative to backside wall60. This angled connection facilitates a high-density arrangement of patch panel modules50in a patch-panel assembly, as discussed in greater detail below. In an example embodiment, the angle θ formed by cable70relative to the normal N to backside wall60is between about 60 degrees and 70 degrees, as shown inFIG. 3C. Note that in an example embodiment the use of one or two V-shaped indentations61serves to reduce the volume of interior58even further. This additional reduction in interior volume is also made possible by the use of bend-insensitive cable fibers12C.

Mounting-Frame-Type Patch Panel Assembly

FIG. 4is a perspective view of example embodiment of a mounting-frame-type patch panel assembly150. In an example embodiment, patch panel assembly150is configured to hold at least twenty-four patch panel modules50in a relatively high-density, substantially vertical configuration. In a standard 4U shelf, with twelve fully populated patch panel modules50, there are 144 duplex jacks, or 288 ports. The example patch panel assembly150ofFIG. 4has two rows with 288 duplex jacks90, for a total of 576 port92. This is a “port/U” density of 144 ports/U because the patch panel assembly is assumed to be a standard “4U” shelf. A “triple-row” embodiment having three mounting frames210would have a 50% increase in port density, or 216 ports/U, which represents 864 individual fibers supported by the patch panel assembly150, as compared to a standard patch panel assembly that supports 288 fibers. In an example embodiment, the port density is given by PD and is in the range defined by: 72 ports/U<PD≦216 ports/U.

Patch panel assembly150includes a rectangular box-like housing152having a top154and bottom155, a front156and a back panel or wall157. Housing152includes spaced-apart sidewalls160that connect to back panel157. Each sidewall160has an inside surface162and an outside surface164, a front edge166and an opposite back edge167. Housing152preferably includes outwardly extending mounting flanges168positioned on sidewall outer surfaces164at or near sidewall front edges166.

In an example embodiment, housing152has standard dimensions of length L2=17 inches (˜10 U), Height H2=6.88 inches (˜4U) and a depth D2=15.51 inches (˜9U) (seeFIG. 7) so that patch panel assembly150fits into a standard-sized 19″ equipment rack as used in telecommunications systems (e.g., at data centers, etc.) as specified by EIA-310-D (Cabinets, Racks, Panels and Associated Equipment).

In an example embodiment, housing152includes a flat shelf182that connects sidewalls160at housing bottom155at front156, and that extends beyond the sidewall front edges166at front156. Shelf182has an upper surface183, a front end184and a back end185. In an example embodiment, front end184includes at least one hinge196that attaches a front cover190to frame152at front156so that the front cover folds downward. Front cover190has respective inner and outer surfaces192and194. In an example embodiment, front cover190is transparent. Front cover optionally includes a clip197that is configured to engage an edge199E of a clip plate199that is connected to interior mounting frame210I and that extends over front mounting plate210F.

Sidewalls160, back panel157and front cover180define a housing interior region200that is substantially open at housing top154. Housing152includes at least two mounting frames210, and preferably includes a front mounting frame210F and at least one interior mounting frame210I that resided behind the front mounting frame and that spans interior region200. Each mounting frame210has a bottom edge211and respective front and back sides or “faces”212and214and opposite ends216. In an example embodiment, mounting frames210are connected to sidewalls160(e.g., at inside surface162) at opposite ends216. In an example embodiment, front mounting frame210F is attached to front edges166. Mounting frames210serve to divide the interior region into interior sub-regions201.

Each mounting frame front face212presents a mounting surface configured so that at least one and preferably more (e.g., preferably ten to twelve) patch panel modules50can be mounted thereto, e.g., at threaded holes218configured to correspond to mounting holes84of patch panel modules50. In an example embodiment illustrated inFIG. 5, one or more of the mounting frames210are made up of two sections220, each of which are connected to respective sidewalls160via respective hinges224that allows the sections swing outwardly. InFIG. 5, front mounting frame210F is shown as being made up of two sections. This geometry allows access to mounting panels210located immediately behind another mounting panel. In an alternative embodiment, one or more of mounting frames210are hinged on one side with one or more hinges224so that the entire hinged mounting frame swings open in door-like fashion.

FIG. 6illustrates an example embodiment of patch panel assembly150wherein front mounting frame210F is attached to back end185of cross member182via a hinge224that allows the front mounting frame to fold downward. This configuration provides access to interior mounting frame210I and patch panel modules50supported thereby that reside immediately behind the front mounting frame. This configuration also provides for easy access to cables70(not shown) that connect to patch panel modules50mounted front mounting frame210F. The example embodiments shown inFIG. 5andFIG. 6show one internal mounting frame210I; two or more internal mounting frames can also be employed.

In an example embodiment, back panel157is hinged in the same manners as front mounting panel210I in order to provide access to patch panel modules50mounted in the adjacent internal mounting frame210I.

FIG. 7is a perspective view of an example patch panel assembly similar to that shown inFIG. 4, but illustrating an example embodiment wherein the back panel157is in the form of a rear mounting frame210R having a rearward-facing mounting face214R that supports one or more (e.g., from one to twelve) rearward-facing patch panel modules50. In an example embodiment, rear mounting frame210R is configured in one of the hinged configurations as front mounting frame210F described above and also as described below.

In an example embodiment, mounting frames210are configured to support at least one patch panel module50, and preferably is configured to support between 10 to 12 reduced-volume patch panel modules.

Hinge Assembly for Cable Routing

An aspect of the present invention is directed to routing cables70to and from mounting-frame-type patch panel assembly150, as well as managing the distribution of cables (including cable fibers12C) within the patch panel assembly.

In an example embodiment, the routing of cables70and/or cable fibers12C within housing interior region200and between patch panels50is facilitated by having a special hinge assembly224for front mounting frame210F.FIG. 8Ais a perspective exploded view of an example embodiment of front mounting frame210F and a housing portion152P. Front mounting frame210F has a number of mounting apertures213F in front face212F for mounting patch panel modules50. Front mounting frame210F has a curved inner hinge portion224I at one of the front mounting frame ends216. Curved inner hinge portion224I includes top and bottom surfaces223with vertically aligned holes223H formed therein.

Housing portion152P includes a curved outer hinge portion224O configured to partially surround curved inner hinge portion224I when front mounting frame210F and housing portion152P are connected. Curved outer hinge portion224O includes top and bottom surfaces215with vertically aligned holes225H formed therein.

Front mounting frame210F and housing portion152P are brought together so that curved inner portion224I fits within curved outer portion224O and so that holes223H and225H are aligned. A hinge pin PH is then passed through aligned holes223H and225H to operably fix curved inner and outer hinge portions224I and224O in place to form hinge assembly224, wherein the curved inner hinge portion rotates within the curved outer hinge portion, while also serving to connect mounting frame210F to housing portion152P.

FIG. 8Bis a cross-sectional close-up view of an example embodiment of hinge assembly224as formed from curved inner and outer hinge portions224I and224O ofFIG. 8A. The concave sides of curved inner and outer hinge portions224I and224O define a hinge interior space224S that adds to housing interior region200. Hinge interior space224S serves as a conduit through which cables70pass when hinge assembly224is either in the closed position, as shown inFIG. 8B, or in the open position with front mounting frame210F swung open. Hinge assembly224allows for opening and closing front mounting frame210F without pinching the portions of cables70that pass through the hinge interior space224S. In an example embodiment, hinge assembly224may include bushings (not shown) on surfaces215to facilitate the rotation of front mounting frame210F. Hinge assembly224may also include a central cylindrical channel (not shown) that fits within the bushings and that accommodates hinge pin PH to facilitate smooth, reduced-friction operation of the hinge.

Cable Distribution Box

FIG. 9Ais a perspective diagram of an example embodiment of a cable distribution box or “stuff box”300. Cable distribution box300is configured to receive cables70and distribute them to one or more patch panel modules50, as described below. Cable distribution box300includes sides302having at least one aperture304formed therein and sized to pass a plurality of cables70. Cable distribution box300also includes a substantially open top side306, and front side308that has a plurality of V-shaped apertures310configured to align with corresponding patch panel modules50. Cable distribution box300also includes an interior region or chamber314sized to accommodate multiple bend-insensitive fiber optic cables70, including any slack therein.

In an example embodiment, open topside306includes inwardly extending flexible tabs312that serve to keep cable70from unwinding, while providing easy access to the portion of the cable wound and stored within interior region314. In an example embodiment, cable distribution box300is made from polymer, plastic or sheet metal.

FIG. 9Bis a perspective close-up view of an example cable distribution box300as arranged in patch panel assembly150behind a mounting frame210that supports patch panel modules50. Multiple cables70are shown entering chamber314via aperture304in side302, with a portion of the cables stored in looped fashion within the interior region. Some of cables70are shown exiting cable distribution box300through two of the front apertures310so that they can be connected to the backside60of the adjacent two patch panel modules50. In an example embodiment, cable distribution box300is secured to patch panel assembly150, e.g., at bottom155or to one of sidewalls160.

FIG. 9Cis a perspective diagram of an example embodiment of a cable distribution box300similar to that ofFIG. 9A, except that the box has multiple chambers314and no front apertures310, and two end apertures304per chamber.

Patch Panel Assembly with Hinge Assembly and Cable Distribution Box

FIG. 10Ais a plan view of an example embodiment of mounting-frame-type patch panel assembly150that includes hinge assembly224ofFIG. 8Bas well as cable distribution box300ofFIG. 9Aarranged adjacent back wall157. Patch panel assembly150includes on shelf upper surface183, one or more clips187configured to guide and/or hold one or more cable fibers12C or jump cables12J onto the shelf surface (jump cables12J are shown for illustration).

Some of cables70having portions thereof stored in cable distribution box300are connected to patch panel modules50of internal mounting frame210I at respective patch panel module backsides60. As indicated by arrows A70, other cables70are routed beneath internal mounting frame210I along bottom155and through hinge assembly224and to the backsides60of patch panel modules50mounted in front mounting frame210F. In an example embodiment, a floor panel FP is arranged adjacent bottom panel155and creates a “false floor” that defines a sub-region323to interior200sized to accommodate the routing of one or more cables70.

FIG. 10Bis a plan view similar toFIG. 10Aand illustrates an example embodiment of how cable fibers12C (or jump fibers12J) are routed from a rack frame506that supports patch panel assembly150to ports90on patch panel modules50on front mounting frame210F and internal mounting frame210I. As discussed above in connection withFIG. 10A, some of cable fibers12C or jump fibers12J are held on shelf upper surface183using one or more clips187. Sidewall160includes an aperture160A formed therein that allows for cable fibers12C from a main (e.g., trunk) cable (not shown; seeFIGS. 18A-18C) to be routed into interior region200from rack frame506.

Drawer-Type Patch Panel Assembly

FIGS. 11A through 11Dare top-down perspective cut-away views of an example embodiment of patch panel “drawer” assembly150held in a rack assembly500. Patch panel assembly150includes a drawer270configured to hold one or more patch panel modules50in a high-density, substantially horizontal configuration, with jacks90facing upward but preferably angled toward the front of the drawer.FIGS. 11A through 11Cshows drawer270pulled out from housing152, whileFIG. 11Dshows the drawer slid into the housing.

Housing152of patch panel assembly150includes a top panel240, a bottom panel242, and is open at front156. One or both sidewalls160include one or more apertures250sized to pass one or more bend-insensitive cable fibers12C. One or both sidewalls160also includes one or more apertures256sized to pass one or more jumper fibers12J, as explained in greater detail below. Housing152has dimensions of length L3=17 inches (˜10U), width H3=3.5 inches (2U) and depth D3=16.1 inches (˜9U) (seeFIG. 12).

With continuing reference toFIGS. 11A through 11D, drawer270is configured to clearance fit within interior200and to slide in and out thereof over bottom panel242. In an example embodiment, drawer270has a floor panel274with a front end276, a back end278, and opposite side edges280. Floor panel274supports an array of reduced-volume patch panel modules50arranged in one or more rows and in a horizontal configuration with jacks90pointing upward at an angle towards the front of drawer270. Here, drawer270obviates the need for vertically oriented module frames210as described above. Example patch panel modules50suitable for use in this configuration are discussed in greater detail below. Note that the backside walls60of the patch panel modules50are face-down on floor panel274.

In an example embodiment, each patch panel module50includes six jacks90each having one or two ports92. Further in an example embodiment as shown inFIG. 11D, the array of patch panel modules50is made up of two rows of eighteen modules, for a total of 36 modules and thus 216 jacks90and thus 216 or 432 ports92, depending on whether the jacks are single or dual port. Thus, in an example embodiment, the drawer-type patch panel assembly150provides between 216 ports/U and 216 ports/U. Jacks90arranged on patch panel modules50at an angle relative to vertical and angled toward the front of drawer270.

In an example embodiment, housing assembly150further includes a cable distribution box300arranged near the back end278of floor panel274behind patch panel modules50. As discussed above, cable distribution box300is configured to receive bend-insensitive fiber optic cables70and store a portion of them while distributing them to patch panel modules50.

In an example embodiment best illustrated inFIG. 11B, housing bottom panel242includes at least one cable guide350configured to guide cables70that enter housing interior200from housing apertures250. In an example embodiment, cable guide350includes at least one guide member356. In an example embodiment, guide member356includes tray section360with sides362. Guide member356may also include a number of spaced apart containment members366connected to respective sides so as to form an open tunnel-like channel360that contains one or more of cables70. One end of guide member356is located at or near aperture250, while the other end is located at back end278of drawer floor panel274.

In an example embodiment, cable guide350includes two articulated and curved guide members356that fold in and reside at housing back panel157in a stacked fashion when drawer270is closed, and that fold out and reside near housing sidewalls160when the drawer is opened. This folding action serves to control the distribution and bending of {fiber optic cables} being held within guide members356. In an example embodiment, one guide member356is arranged at a different (e.g., lower) height than the other so that the lower guide member passes underneath the higher guide member when the two are folded together, as shown inFIG. 11D.

FIG. 12is a rear perspective view of patch panel assembly150, wherein the assembly includes a drawer cover390that covers patch panel modules50, wherein the drawer is shown in the open position. Also shown inFIG. 12are the dimensions L3, H3and D3for housing152.

Patch Panel Module for Drawer-Type Patch Panel Assembly

FIGS. 13A and 13Bare perspective diagrams of an example embodiment of a patch panel module50suitable for use in the drawer-type patch panel assembly150ofFIGS. 11A through 11D. Like patch panel module50ofFIGS. 3A through 3Bdiscussed above, the patch panel module50of the present example embodiment include housing56, backside60and jacks90with ports92. However, in an example embodiment, the dimensions of housing56of length L4=4 inches, width W4=0.67 inches and depth H4between about 0.75″ and 1.25″ and preferably about 1 inch (e.g., 1.06 inches). Patch panel module50ofFIGS. 11A through 11Dalso have “reduced form factor.”

Patch panel module50of the present example embodiment has a front404with angled facets405, and ends406and407. Note that each jack90is arranged on an angled facet405and are angled away from end407.FIG. 13Bshows cable fibers12C from bend-insensitive fiber optic cable70attached to backside ports98of jacks90.

Patch panel module includes an open channel420formed in backside wall60and sized to accommodate cable70when patch-panel module50is placed with backside60against floor panel274.FIG. 13Cis a view of backside60of patch panel module50as would be seen by looking through floor panel274if the floor panel were transparent. Note that the cable70that attaches to patch panel module50ofFIGS. 13A and 13Bdoes so via end407of housing56.

FIG. 14is a close-up view of an array of patch panel modules50ofFIG. 13Aas arranged on drawer floor panel274. A jumper fiber12J is shown connected to one of jacks90. Cable70is also shown passing under one of the back-row patch panel modules50via channel420to the corresponding end407of the front row patch panel module. Cable fibers12C from cable70are shown within one of the patch panel modules and connected to backside ports98of jacks90(seeFIG. 13B).

FIG. 15Ais close-up side view of drawer270and the array of patch panel modules50ofFIG. 13A, showing in more detail how cables70passes from cable distribution box300and underneath the back-row patch panel modules50to the front-row patch panel modules. Other cables70are attached directly to the back-row patch panel modules50at respective housing ends407.

FIG. 15Bis close-up view of adjacent back-row and front-row patch panel modules50, whileFIG. 15Cis a close-up view of the back-row patch panel modules50and cable distribution box300. These Figures illustrate the routing of respective cables70to a back row and a front row patch panel module50. InFIG. 15B, cable70is routed through channel420and emerges at side406. This cable70is then connected to the adjacent patch panel module50at side407. InFIG. 15C, cable70emerges from an aperture310in cable distribution box300and is connected to end407of the adjacent patch panel module50, while another cable70from aperture310is routed through channel420of the same patch panel module50.

Rack Assembly

Aspects of the invention includes a rack assembly that houses either the drawer-type patch panel assemblies or mounting-frame-type patch panel assemblies described above. Because both of these types of patch panel assemblies150preferably have a standard 4U configuration, both can be housed in the same rack assembly.

FIG. 16is a front perspective view of an example embodiment of a rack assembly500that houses a number of drawer-type patch panel assemblies150in a stacked fashion. Rack assembly500includes rack frame506having vertical side bars510and512, and a top horizontal cross-bar (not shown) that connects the side bars at the top of the frame. Vertical side bars510and512preferably have apertures507formed therein and sized to facilitate cable routing within frame506. Frame506has a front side518and a backside520. Frame506includes a flat base (not shown) to which side bars510and512are attached, and which serves to provide standing support for the frame. Frame assembly optionally includes a cable guide513attached to one or both of vertical side bars510and512to facilitate the routing of cables within the frame assembly.

In a preferred embodiment, rack assembly500comprises a standard 19″ equipment rack having an inside width of 17.75″, on-center rail hole pairs separated by 18.3″ on the front of the rack, and is divided up by standard 1.75″ increments, where each increment is called a “unit” or “U” for short and includes three complete hole pairs. Frame506defines an interior region530within which patch panel assemblies150reside. Drawers270of the drawer-type patch panel assemblies150preferably include handles550.

FIG. 17is a front perspective view an example embodiment of rack assembly500similar to that ofFIG. 16, but showing a number of mounting-frame-type patch panel assemblies150housed in an equipment rack assembly500in a stacked manner.

The inside surface of side bars510and512are configure to allow for patch panel assemblies150to be arranged in a stacked manner between the side bars and thus within frame interior region530, as shown. In one example embodiment, the inside surface of side bars510and512are smooth, while in another example embodiment they include guide tabs (not shown) that facilitate the stacking and support of housing assemblies150within frame506. In an example embodiment, side bars510and512are configured so that front and back portions of the patch panel assemblies protrude from the front side518and backside520of frame506, as illustrated inFIGS. 16 and 17.

FIG. 18Ais a elevated rear perspective view of an example embodiment of a portion of rack assembly500shown supporting a single mounting-frame-type patch panel assembly150similar to that shown inFIG. 10A. Rack assembly500includes a main (e.g., trunk) cable602that carries a plurality of optical fibers, such as cables70. In an example embodiment, main cable602includes a boot610that leads to a fan-out section620. Cables70in main cable620are then connected to a plurality of connector ports626at housing side160. In this embodiment, “external” cables70are connected to “internal” cables70of patch panel assembly150at connector ports626. Internal cables70are shown as having connectorized ends73for connecting to connector ports626. Internal cables70are routed through cable distribution box300. Some internal cables70are connected to backsides60of patch panel modules50mounted in an interior mounting frame210I. Other internal cables are routed to patch panel modules on front mounting frame210F, which is shown in the open position. In an example embodiment, front mounting frame210F includes a guide shelf215that extends inwardly toward interior region200from bottom edge211. Guide shelf215is configured to guide and/or hold cables70that are routed to patch panel modules50mounted in front mounting frame210F. In an example embodiment, guide shelf215includes clips185that serve to guide and/or hold cables70on the guide shelf. It should be noted again that inFIG. 18Bcables70and12C can be the same type of cables, e.g., patch cables or jump cables (12J).

FIG. 18Bis another elevated rear perspective view of rack assembly500ofFIG. 18Abut from the opposite quarter and with back wall157in place. A bundle of cable fibers12C (which could also be jump cables12J) and main cable602are shown being routed through apertures507in adjacent rack frames506(seeFIG. 10B).

FIG. 18Cis an elevated front perspective view of rack assembly500ofFIGS. 18A and 18B, showing details of how cable fibers12C (or jump fibers12J) are routed to patch panel assemblies50on the front and intermediate mounting frames210F and210I. Clips185on cross member182are used to guide cable fibers12C or jump fibers12J from rack frame506to patch panel assemblies50supported by front mounting frame210F. Clips185are also provided between front and internal mounting frames210F and210I to assist in guiding cable fibers12C or jump fibers12J from rack frame506to patch panel modules50supported by internal mounting frame210I.