Abstract:
A weatherproofed interconnection junction includes: a first cable having a first connector at one end; a second connector; a sealing cylinder with an internal cavity, wherein the first connector and second connector are joined and reside within the cavity; and an elastomeric sealing boot having a cable section and a connector section. The first cable is conformably received in the cable section and the sealing cylinder is conformably received in the connector section.

Description:
RELATED APPLICATION 
       [0001]    The present invention claims priority from and the benefit of U.S. Provisional Patent Application No. 62/041,934, filed Aug. 26, 2014, the disclosure of which is hereby incorporated herein in its entirety. 
     
    
     FIELD OF THE INVENTION 
       [0002]    The invention relates generally to a device for environmentally sealing and securing the interconnection between communications cables and/or communications cables and electronic equipment. 
       BACKGROUND 
       [0003]    Interconnection junctions, such as the interconnection between two cables or a cable and a piece of electronic equipment, may be subject to mechanical degradation from environmental factors such as moisture, vibration and repeated expansion and contraction from daily temperature changes. As an example, a fiber optic cable assembly might be terminated with a dual LC connector (DLC) where the end customer might desire SC terminations. A cable assembly configured to provide a DLC interface on one end and SC on the other would provide the interface desired. Unfortunately, LC connectors are not weatherproof, and if exposed to harsh conditions will not perform at an optimal level for any significant time period. Therefore, it is desirable that the connection be isolated from moisture, ice, dust, oil, and other contaminants which could cause premature failure. 
         [0004]    Outer sealing enclosures that surround or enclose a cable interconnection have been used to protect such interconnections. Enclosures often apply rigid clamshell configurations that, once closed, may be difficult to open, especially when installed in exposed or remote locations, such as atop radio towers; gaskets or gel seals may be applied at the enclosure ends and/or along a sealing perimeter of the shell. 
         [0005]    Elastic interconnection seals are also known. Elastic seals can be advantageous by virtue of being more easily installed over the typically uneven contours of a cable or cable/equipment interconnection. Exemplary configurations are described in U.S. Pat. No. 6,429,373 and in U.S. patent application Ser. No. 13/646,952, filed Oct. 8, 2012; Ser. No. 13/938,475, filed Jul. 10, 2013; and Ser. No. 14/245,443, filed Apr. 4, 2014, the disclosures of each of which are hereby incorporated by reference herein. 
         [0006]    The continued development of additional configurations and varieties of connectors can necessitate additional sealing configurations and techniques. 
       SUMMARY 
       [0007]    As a first aspect, embodiments of the invention are directed to a weatherproofed interconnection junction. The interconnection junction comprises: a first cable having a first connector at one end; a second connector; a sealing cylinder with an internal cavity, wherein the first connector and second connector are joined and reside within the cavity; and an elastomeric sealing boot having a cable section and a connector section. The first cable is conformably received in the cable section and the sealing cylinder is conformably received in the connector section. 
         [0008]    As a second aspect, embodiments of the invention are directed to a weatherproofed interconnection junction, comprising: a first cable having a first connector at one end; a second connector having a second connector at one end; a sealing cylinder with an internal cavity, wherein the first connector and second connector are joined and reside within the cavity; a first elastomeric sealing boot having a cable section and a connector section, wherein the first cable is conformably received in the cable section and the sealing cylinder is conformably received in the connector section; and a second elastomeric sealing boot having a cable section and a connector section, wherein the second cable is conformably received in the cable section. 
         [0009]    As a third aspect, embodiments of the invention are directed to a weatherproofed interconnection junction, comprising: a first cable having a first connector at one end; a second connector mounted on a mounting structure, the mounting structure including a receptacle; a sealing cylinder with an internal cavity, wherein the first connector and second connector are joined and reside within the cavity, the sealing cylinder sealingly engaging the receptacle; and an elastomeric sealing boot having a cable section and a connector section. The first cable is conformably received in the cable section and the sealing cylinder is conformably received in the connector section. 
         [0010]    As a fourth aspect, embodiments of the invention are directed to a sealing boot for an interconnection junction, comprising: an annular cable section having a first diameter; an annular connector section having a second diameter that is greater than the first diameter; and a transition section that extends between the cable section and the connector section. The transition section is configured to enable the transition section to fold upon itself to move the connector section to a retracted position in which the connector section is adjacent the cable section. The sealing boot comprises an elastomeric material. 
     
    
     
       BRIEF DESCRIPTION OF THE FIGURES 
         [0011]      FIG. 1  is a perspective view of a cable-connector assembly according to embodiments of the invention, the assembly being shown in a mated condition. 
           [0012]      FIG. 2  is a perspective view of the sealing cylinder of the assembly of  FIG. 1 . 
           [0013]      FIG. 3  is a perspective view of the one of the sealing boots of the assembly of  FIG. 1 . 
           [0014]      FIG. 4  is a cross-sectional view of the cable-connector assembly of  FIG. 1 . 
           [0015]      FIG. 5  is a perspective view of a cable-connector assembly according to additional embodiments of the invention, with the bistable sealing boots being retracted. 
           [0016]      FIG. 6  is a perspective view of one of the sealing cylinders of the assembly of  FIG. 5 . 
           [0017]      FIG. 7  is a perspective view of the other of the sealing cylinders of the assembly of  FIG. 5 . 
           [0018]      FIG. 8  is a cross-sectional view of the assembly of  FIG. 5 , with the sealing boots in their unfolded positions. 
           [0019]      FIG. 9  is a perspective view of a cable-connector assembly according to further embodiments of the invention, with the sealing boot shown in its retracted position. 
           [0020]      FIG. 10  is a perspective view of the assembly of  FIG. 9 , with the sealing boot shown in its unfolded position. 
           [0021]      FIG. 11  is an exploded perspective view of a protective sleeve adapted to attach to a shroud of a bulkhead of a RRU according to alternative embodiments of the invention. 
           [0022]      FIG. 12  is an assembled perspective view of the sleeve and shroud of  FIG. 11 . 
       
    
    
     DETAILED DESCRIPTION 
       [0023]    The present invention is described with reference to the accompanying drawings, in which certain embodiments of the invention are shown. This invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments that are pictured and described herein; rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the invention to those skilled in the art. It will also be appreciated that the embodiments disclosed herein can be combined in any way and/or combination to provide many additional embodiments. 
         [0024]    Unless otherwise defined, all technical and scientific terms that are used in this disclosure have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. As used in this disclosure, the singular forms “a”, “an” and “the” are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will also be understood that when an element (e.g., a device, circuit, etc.) is referred to as being “connected” or “coupled” to another element, it can be directly connected or coupled to the other element or intervening elements may be present. In contrast, when an element is referred to as being “directly connected” or “directly coupled” to another element, there are no intervening elements present. 
         [0025]    Referring now to the drawings, an assembly  20  is shown in  FIGS. 1 and 4 . The assembly  20  includes two fiber optic cables  25 ,  30 , each of which is terminated with a respective connector  26 ,  31  that mate with each other (see  FIG. 4 ). The assembly also includes a weatherproofing unit  40  comprising two sealing boots  45 ,  50  and a sealing cylinder  55 . These components are described in detail below. 
         [0026]    Referring to  FIGS. 1 ,  3  and  4 , the sealing boot  45  is generally conical and includes a cable section  46  with a bore  47  that is sized to fit over the cable  25 . At the opposite end, the sealing boot  45  includes an open-ended connector section  48  that is larger in diameter than the cable section. The connector section  48  has a radially-inwardly extending ridge  49 . The cable section  46  and the connector section  48  each merge with a transition section  51 . Referring to  FIGS. 1 and 4 , the sealing boot  50  is similar to the sealing boot  45 , with the exception that it lacks a ridge in its connector section  52 . 
         [0027]    Typically, the sealing boots  45 ,  50  are formed of a polymeric material. As used herein, a “polymeric” material includes elastomeric materials, such as rubbers, as well as harder polymeric materials. An exemplary rubber material may be selected from the group consisting of silicone, fluorosilicone, EPDM, and nitrile rubbers. 
         [0028]    Referring now to  FIGS. 1 ,  2  and  4 , the sealing cylinder  55  is generally cylindrical and includes an internal cavity C. The sealing cylinder  55  also includes an external groove  56  that is sized to receive the ridge  49  of the sealing boot  45 . The sealing cylinder  55  is typically formed of a hard plastic, such as polypropylene or acrylonitrile-butadiene-styrene (ABS). 
         [0029]    In the illustrated embodiment, the end of the sealing cylinder  55  nearest the groove  56  is slipped into the connector section  48  of the sealing boot  45  until the ridge  49  fits within the groove  56 , with the sealing cylinder  55  conformably received by the connector section  48 . The sealing cylinder  55  is adhered to the connector section  48  of the sealing boot  45  via an adhesive; in other embodiments, the sealing cylinder  55  may be attached to the sealing boot  45  by other means, or may be formed as a separate piece that slips inside the sealing boot  45 . 
         [0030]    Referring now to  FIGS. 1 and 4 , the assembly  20  is formed by slipping the sealing boots  45 ,  50  onto respective cables  25 ,  30 , with the cable section of each snugly fitting over its cable  45 ,  50  to form a seal. The sealing cylinder  55 , conformably attached to the sealing boot  45 , is positioned over the connector  26 . The connectors  26 ,  31  are mated in conventional fashion. The end of the sealing cylinder  55  opposite the sealing boot  45  is then conformably received by the connector section  52  of the sealing boot  50 . In this configuration, the weatherproofing unit  40  can provide a watertight enclosure to the mating connectors  26 ,  31 , which reside in the cavity C of the sealing cylinder  55 . 
         [0031]    An alternative embodiment of an assembly is shown in  FIGS. 5-8  and designated broadly at  120 . The assembly  120  includes two fiber optic cables  125 ,  130 , each of which is terminated with a respective connector  126 ,  131  that mate with each other as described above. A weatherproofing unit  140  includes two sealing boots  145 ,  150  of the configuration described above. However, the weatherproofing unit  140  also includes two sealing cylinders  155 ,  160  that are configured to sealingly engage each other. These are described in greater detail below. 
         [0032]    Referring now to  FIGS. 5 ,  6  and  8 , the sealing cylinder  155  is similar to the sealing cylinder  55  described above, with a groove  156  located near one end. However, the sealing cylinder  155  also includes a pair of latches  157  on opposite sides of the cylinder  155 , and further includes diametrically opposed alignment ridges  158  positioned between the latches  157 . An O-ring groove  159  is present at the end of the sealing cylinder  155  opposite the groove  156 . 
         [0033]    Referring now to  FIGS. 5 ,  7  and  8 , the sealing cylinder  160  is slightly larger in diameter than the sealing cylinder  155 . The sealing cylinder  160  has a groove  161  at one end. At the opposite end, the sealing cylinder  160  includes two diametrically opposed lugs  162  that extend radially outwardly. Two alignment recesses  163  are located on the inner surface of the sealing cylinder  160 . 
         [0034]    Referring to  FIGS. 5 and 8 , interconnection of the assembly  120  begins with the placement of the sealing boots  145 ,  150  on the cables  125 ,  130 . The sealing cylinders  155 ,  160  are then positioned in the sealing boots  145 ,  150 , with the ridges  149 ,  154  of the sealing boots  145 ,  150  being inserted into respective grooves  156 ,  161 . The sealing cylinders  155 ,  160  are then assembled, with the sealing cylinder  160  fitting over the sealing cylinder  155 . The alignment ridges  158  of the sealing cylinder  155  nest within the recesses  163  of the sealing cylinder  160  to aid with alignment of the sealing cylinders  155 ,  160 , so that the latches  157  of the sealing cylinder  155  engage the lugs  162  of the sealing cylinder  160  to hold them together. An O-ring  167  is included in the groove  159  of the sealing cylinder  155  to provide a moisture seal between the two sealing cylinders  155 ,  160 . Thus, the sealing boots  145 ,  150  and the sealing cylinders  155 ,  160  create the weatherproofing unit  140  that provides the connectors  126 ,  131  with a watertight enclosure. 
         [0035]    It can also be seen from  FIG. 5  that the sealing boots  145 ,  150  are “bistable,” meaning that they can take a second, retracted configuration for ease of assembly. As shown in  FIG. 8 , the transition section  151  of the sealing boot  145  includes an annular recessed area  151   a  on its inner surface (this can also be seen in  FIG. 4  in the sealing boot  45 ). The recess  151   a  enables the transition section  151  to fold on itself so that the connector section  148  can retract to a rearward position near the cable section  146 . The sealing boot  145  is stable in this position, which can facilitate assembly of the connectors  126 ,  131 . The sealing cylinder  155  can then be moved to and into engagement with the sealing cylinder  160  by returning the sealing boot  155  to its original, unfolded configuration.  FIG. 8  also shows that the sealing boot  150  has a similar recess  154   a  in its transition section  154  that allows the sealing boot  150  to fold onto itself to facilitate assembly. 
         [0036]      FIGS. 9 and 10  illustrate another assembly, designated at  220 , according to embodiments of the invention. The assembly  220  includes a cable  225 , a sealing boot  245 , and a sealing cylinder  255  as described above. However, the cable  225  is mated to a connector (not shown) mounted to a structure  230 , such as a flange, bulkhead or panel. The structure  230  includes a mounting receptacle  260  with lugs  262  for engaging the latches  257  of the sealing cylinder  255 , and further includes recesses  263  that receive the alignment ridges  258  of the sealing cylinder  255 . 
         [0037]    As can be seen in  FIG. 9 , the sealing boot  245  is inserted onto the cable  225 , the sealing cylinder  255  is inserted into the sealing boot  245 , and the sealing boot  245  is retracted to its folded position. The connector  226  is connected with the connector (not shown) of the structure  230 , and the sealing boot  245  is extended to its unfolded position ( FIG. 10 ) to enable the latches  257  of the sealing cylinder  255  to engage the lugs  262  of the mounting receptacle  260  as the sealing cylinder  255  slips within the receptacle  260 . The o-ring  267  provides a seal between the sealing cylinder  255  and the receptacle  260 . 
         [0038]    The weatherproofing units can protect fiber optic connectors that typically do not have cylindrical sealing surfaces as part of the connectors like those typically found on RF connectors. Nonetheless, it should be noted that this sealing system may be suitable for use with other connectors, such as coaxial and/or power connectors, often employed alongside fiber optic connectors in wireless installations. 
         [0039]    A further embodiment of a sealing cylinder for protecting an interface between optical fibers of a fiber optic cable and a RRU is illustrated in  FIG. 11  and designated broadly at  310 . The sealing cylinder  310  has a generally cylindrical body  312 . A groove  314  is present near one end of the body  312 . Another groove  316  is located adjacent the opposite end of the body  312 . A pair of diametrically opposed ridges  318  are positioned near the groove  314 ; the ridges  318  each extend approximately 120 degrees about the circumference of the body  312 , such that gaps  322  are formed. 
         [0040]    Two latches  320  are mounted in diametrically opposed locations on the body  322 . Each latch  320  includes a stem  324  that extends radially outwardly from the body  312 , an arm  326  that extends from the stem  324  toward the groove  314  and that has a hook  328  at its free end, and a tab  330  that extends from the stem  324  toward the groove  316 . Like the sealing cylinders  55 ,  155 ,  160 , the sealing cylinder  310  can be formed of a variety of materials. 
         [0041]      FIG. 11  also illustrates a mounting receptacle  340  for mounting on a RRU or other structure (not shown) that is similar to the mounting receptacle  260  described above. The mounting receptacle  340  includes a circular rim  342  from which two fingers  344  extend. Each of the fingers  344  has a lug  346  on its outer surface. The rim  342  and fingers  344  are mounted on a base  348  that is in turn mounted on a RRU. 
         [0042]    To assemble the sealing cylinder  310  with the fitting  340 , an O-ring (not shown) is positioned in the groove  314 . A technician grasps the tabs  330  of both latches  320  (typically with one hand) and presses the tabs  330  toward each other (i.e., radially inwardly). This action causes the arms  326  of each latch to pivot away from the base  312  (i.e., radially outwardly). The sealing cylinder  310  is then advanced toward the mounting receptacle  340  with the latches  320  in this deflected condition. The sealing cylinder  310  is rotated about its longitudinal axis until the gaps  322  between the ridges  318  align with the fingers  344  of the mounting receptacle  340 . The end of the body  312  and the groove  314  (with the O-ring in place) then slide between the fingers  344  and within the rim  342  until the ridges  318  of the sleeve  310  engage the edge of the rim  342 . In this position, the hooks  328  of the latches  320  are positioned just beyond the lugs  346  of the fingers  344 . The latches  320  can then be released by the technician, which enables the hooks  328  to engage the lugs  346 , thereby securing the sealing cylinder  310  to the mounting receptable  340  (see  FIG. 12 ). 
         [0043]    At the opposite end of the sealing cylinder  310 , a protective cover like the sealing boots  145 ,  155  described above can be attached. As described above, such a cover is typically resilient and has a lip that fits within the groove  316 , thereby forming a seal. At the opposite end, the cover seals with a furcation tube of one or more optical fibers. Other exemplary covers are shown in U.S. Provisional Patent Application Ser. No. 62/017,802, filed Jun. 26, 2014, the disclosure of which is hereby incorporated herein in its entirety. 
         [0044]    As can be discerned by examination of  FIGS. 11 and 12 , the sealing cylinder  310  can be secured relatively easily with the mounting receptacle  340 , and can be so secured using only one hand. The resulting connection provides a weather-sealed environment for the interface between the optical fibers that form an interface with the RRU or other structure. 
         [0045]    The foregoing is illustrative of the present invention and is not to be construed as limiting thereof. Although exemplary embodiments of this invention have been described, those skilled in the art will readily appreciate that many modifications are possible in the exemplary embodiments without materially departing from the novel teachings and advantages of this invention. Accordingly, all such modifications are intended to be included within the scope of this invention as defined in the claims. The invention is defined by the following claims, with equivalents of the claims to be included therein.