Abstract:
A through-fitting for a box or bulkhead contains a cavity which holds grease. When the through-fitting is tightened, grease from the cavity is automatically injected to seal the through-fitting. The through-fitting may be used in below-grade junction boxes. A junction box has various useful features. The junction box can be conveniently injection-molded. The junction box has application in fields including wired telephone connections.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS  
       [0001]    This application is a continuation of U.S. patent application Ser. No. 10/270139, filed on 15 Oct. 2002 and entitled “THROUGH-FITTINGS AND BELOW GRADE JUNCTION BOXES EQUIPPED WITH SAME”, which claims the benefit of the filing date of Canadian Patent Application No. 2,359,125, filed 12 Oct. 2001. 
     
    
     
       TECHNICAL FIELD  
         [0002]    This invention relates to through-fittings for sealing around cables, tubes, sensors or the like. The invention may be embodied in junction boxes which may be installed and used below grade (and may also be used in other applications). The invention has particular application to junction boxes for telephone lines, cable television lines, fiber optic data communication lines, electrical circuits, and the like.  
         BACKGROUND OF THE INVENTION  
         [0003]    Underground junction boxes may remain buried for years. During that time they should protect their contents against the entry of ground water. It is known to completely fill underground junction boxes with a water-displacing medium such as grease. This is messy, however, both at the time the junction box is filled with grease and later if it becomes necessary to access any components or conductors inside the junction box.  
           [0004]    There is a need for cost-effective, durable junction boxes suitable for use in below-grade applications. There is also a general need for through-fittings capable of sealing around a cable or the like at the point where the cable passes through a bulkhead.  
         SUMMARY OF THE INVENTION  
         [0005]    This invention provides through-fittings which may be used to seal around cables or the like. The invention also provides junction boxes equipped with such through-fittings and methods for sealing around cables or the like.  
           [0006]    Accordingly, one aspect of the invention provides a through-fitting for a cable or the like. The through-fitting comprises a stub having a bore; an annular seal within the bore; and a cap in threaded engagement with the stub. The cap is movable between a first position and a second position. A sleeve is disposed within the bore and has an inwardly-angled end surface. The sleeve is movable axially within the bore relative to the annular seal in response to motion of the cap. When the cap is in the first position, the seal is not substantially compressed. When the cap is in the second position, the end surface of the sleeve compresses the seal radially inwardly. In addition or in the alternative, the end surface of the sleeve may compress a portion of the seal radially outwardly. In some embodiments the sleeve is attached to the cap so that it moves axially as the cap is screwed onto the stub. In such embodiments the sleeve may be formed integrally with the cap, or affixed to the cap by an adhesive, snap fastening, threading, plastic welding, or other suitable fastening means.  
           [0007]    In some embodiments of the invention the through-fitting comprises a chamber and a passageway communicating between the chamber and the bore. The chamber has a variable volume. When the cap is in the first position the chamber has a first volume and when the cap is in the second position the chamber has a second volume smaller than the first volume. In such embodiments a sealant such as grease, silicone grease, gel and other types of sealing materials well known in the art may be extruded from the chamber into the bore as the cap is tightened.  
           [0008]    The through-fitting may comprise a burst member blocking the passage. The burst member may, for example, comprise a thin plastic member blocking an aperture in the sleeve.  
           [0009]    Another aspect of the invention provides a method for sealing a through-fitting around a cable. The method comprises: passing a cable through the through-fitting; compressing a seal in the through-fitting against the cable; and, extruding a sealant around the cable within the through-fitting. Both compressing the seal and extruding the sealant are performed by threading a cap onto the through-fitting.  
           [0010]    Further aspects of the invention and features of specific embodiments of the invention are described below. 
       
    
    
     BRIEF DESCRIPTION OF DRAWINGS  
       [0011]    In drawings which illustrate non-limiting embodiments of the invention:  
         [0012]    [0012]FIGS. 1A, 1B 1 C are cross-sectional views through a through-fitting according to a currently preferred embodiment of the invention;  
         [0013]    [0013]FIGS. 1D and 1E are respectively longitudinal and transverse cross-sections through a sleeve portion of the through-fitting of FIG. 1A;  
         [0014]    [0014]FIG. 2 is an isometric view of a clip that may be used to prevent premature operation of the through-fitting of FIG. 1A;  
         [0015]    [0015]FIG. 3A is an exploded view of a small sub-grade junction box according to one embodiment of the invention;  
         [0016]    [0016]FIG. 3B is a section through the junction box of FIG. 3A;  
         [0017]    [0017]FIGS. 4A and 4B are longitudinal cross-sectional views of a through-fitting according to an alternative embodiment of the invention in open and sealed configurations respectively;  
         [0018]    [0018]FIG. 5 is a bottom perspective view of a junction box according to an alternative embodiment of the invention;  
         [0019]    [0019]FIG. 6 is a cross-sectional view through a through-fitting according to another embodiment of the invention;  
         [0020]    [0020]FIGS. 7A, 7B,  7 C and  7 D are additional views of the through-fitting of FIG. 6;  
         [0021]    [0021]FIG. 8 is a front perspective view of a terminal mounting plate which may be used in a junction box like that of FIG. 5;  
         [0022]    [0022]FIG. 9 is a back perspective view of the plate of FIG. 8;  
         [0023]    [0023]FIG. 10 is a top plan view of the plate of FIG. 8;  
         [0024]    [0024]FIG. 11 shows the interior of the junction box of FIG. 5;  
         [0025]    [0025]FIG. 11A is a partially cut away view of the box of FIG. 5;  
         [0026]    [0026]FIG. 12 is a detailed view of a grounding connection to a cable;  
         [0027]    [0027]FIG. 13 is a view of the box of FIG. 5 in an open configuration with a branch cable installed;  
         [0028]    [0028]FIG. 14 is a partial sectional view through a portion of the box of FIG. 5 showing a seal and clasp;  
         [0029]    [0029]FIG. 15 is a section through a hinge of the box of FIG. 5; and,  
         [0030]    [0030]FIG. 16 is a section through a through-fitting according to an alternative embodiment of the invention. 
     
    
     DESCRIPTION  
       [0031]    Throughout the following description, specific details are set forth in order to provide a more thorough understanding of the invention. However, the invention may be practiced without these particulars. In other instances, well known elements have not been shown or described in detail to avoid unnecessarily obscuring the invention. Accordingly, the specification and drawings are to be regarded in an illustrative, rather than a restrictive, sense.  
         [0032]    [0032]FIGS. 1A, 1B and  1 C are a cross-sections through a through-fitting  10  according to a currently-preferred embodiment of the invention. FIG. 1A shows through-fitting  10  in a non-sealed state, as initially supplied. FIG. 1B shows through-fitting  10  in an intermediate state and FIG. 1C shows through-fitting  10  in a sealed state. Through-fitting  10  comprises a threaded stub  12  which projects from a base  14 . Base  14  could, for example, be a wall of a junction box. A bore  16  passes through stub  12 . A cable C may be inserted through bore  16 .  
         [0033]    Stub  12  bears male threads  18 . A cap  20  bears female threads  22  which engage threads  18 . The outer end of stub  12  projects into an annular chamber  24  in cap  20 . In the illustrated embodiment, annular chamber  24  is defined between a concentrically arranged sleeve  36  which extends axially into bore  16 . Sleeve  36  is a reasonably close fit into the bore of stub  12 . Chamber  24  may be filled with a sealant such as a suitable grease. For example, chamber  24  may be filled with a suitable grade of grease, silicone grease, gel or other types of sealing materials well-known in the art. An elastomeric seal  28  is located in stub  12 . Seal  28  is preferably retained in bore  16  of stub  12 . This prevents seal  28  from being displaced if cable C is pulled outwardly during installation. In the illustrated embodiment, seal  28  has a circumferential groove which receives a flange  29  which projects into bore  16 .  
         [0034]    Seal  28  has an inner lip seal  30  which seals around cable C and an outer seal  32 . In the illustrated embodiment, outer seal  32  comprises an annular groove  34  in seal  28 . Groove  34  divides the outer part of seal  28  into a first annular part  35 A and a second annular part  35 B. Sleeve  36  is located in bore  16 . Preferably sleeve  36  is formed integrally with cap  20 , such that sleeve  36  is joined to cap  20  at their respective outer ends. In alternative embodiments, cap  20  and sleeve  36  may be separate parts and sleeve  36  may simply abut against cap  20  at its outer end. Sleeve  36  extends inwardly inside bore  16 , such that an inner end of sleeve  36  is located to enter annular groove  34 . As shown in FIGS. 1A and 1B, sleeve  36  has apertures, such as slots  37 .  
         [0035]    Through-fitting  10  may be used by passing cable C through bore  16 , sleeve  36 , seal  28  and outer seal  31 . Cap  20  is then turned so that it screws onto stub  12 . As this occurs, sleeve  36  encounters annular groove  34  and wedges apart annular parts  35 A and  35 B of seal  28 . As they are wedged apart, annular part  35 A is pressed against a wall  13  of bore  16  and annular part  35 B is pressed against cable C. In preferred embodiments, the inner end of sleeve  36  and the outer end of seal  28  are sized and shaped so that one of annular parts  35 A and  35 B is fully displaced before the other. In the illustrated embodiment, the portion of the inner end of sleeve  36  that contacts annular part  35 B is more gradually tapered than the portion that contacts annular part  35 A. Annular part  35 A may be slightly longer than annular part  35 B. With this configuration, as cap  20  is tightened, part  35 A is fully pressed against wall  13  of bore  16  before part  35 B is fully pressed toward cable C. In the illustrated embodiment, annular part  35 B is thicker than annular part  35 A. Annular part  35 B may also comprise notches (not shown) which may be used to make annular part  35 B more pliable.  
         [0036]    Preferably, seal  28  is forced tightly enough against cable C that seal  28  can serve as a strain relief.  
         [0037]    As shown in FIGS. 1B and 1C, when cap  20  is tightened, the volume of chamber  24  is reduced. This forces grease out of chamber  24  into bore  16 . To facilitate this, a number of longitudinal grooves  38  may optionally be provided in bore  16  of stub  12 . Tightening cap  20  causes grease to be forced along grooves  38  (if present) and through slots  37  of sleeve  36  and discharged into bore  16  around cable C. Cap  20 , sleeve  36  and seal  28  are dimensioned so that the grease flows between seal  28  and cable C. Initially, inner seal  30  acts to help block the grease from traveling inwardly along cable C. However, as annular part  35 B is forced tightly against cable C, annular part  35 B prevents grease from traveling inwardly along cable C.  
         [0038]    Chamber  24  preferably has a volume greater than or equal to the volume which remains in the bore of stub  12  after cable C has been placed through it. Thus, excess grease will be forced out along cable C in each direction. The volume of chamber  24  may be, for example, 120% or more of the volume of that part of the bore of stub  12  which is not expected to be occupied by cable C. The volume of chamber  24  may be significantly more than this.  
         [0039]    The aperture  39  by way of which cable C passes through cap may have a diameter similar to that of cable C. This helps to ensure that grease will not tend to flow out through aperture  39 . A seal  31  similar to seal  30  may also be provided in aperture  39 . A seal ring  33  may be secured or attached to cap  20  and may be sized and shaped to fit over a flange in seal  31  to strengthen the seal provided by seal  31  and to retain the position of seal  31 . Preferably seal  30  is more flexible than seal  31  so that when grease in bore  16  initially becomes pressurized, it may tend to escape through inner seal  30  instead of through seal  31 . However, once annular part  35 B is forced tightly against cable C, annular part  35 B prevents grease from traveling inwardly along cable C and escaping through inner seal  30 . Consequently, some excess grease may escape through seal  31 .  
         [0040]    Through-fitting  10  preferably includes a mechanism for preventing cap  20  from being screwed down prematurely. This mechanism may take any of various forms. For example, the mechanism could comprise:  
         [0041]    a tab  40  (See FIG. 1A) located to block cap  20  from being screwed down until tab  40  has been broken off or bent out of the way;  
         [0042]    a clip  42 , as shown for example in FIG. 2, which clips around stub  12  below cap  20  and blocks cap  20  from being screwed down until clip  42  has been removed. Clip  42  has a grasping tab  43  and a pair of arms  44 A and  44 B which are dimensioned to snap into place around stub  12  when cap  20  is in the unscrewed position shown in FIG. 1A; and/or,  
         [0043]    an adhesive sticker spanning cap  20  and some adjacent structure, such as stub  12 .  
         [0044]    Optionally apertures  37  in sleeve  36  may be covered by rupture members  37 A (See FIGS. 1D and 1E). Rupture members  37 A may comprise very thin skins of plastic which rupture to permit passage of grease from chamber  24  when through-fitting  10  is closed around a cable C. Rupture members  37 A may help to hold grease in place in chamber  24  until it is desired to seal through-fitting  10  around a cable C.  
         [0045]    Cap  20  may be pre-charged with grease when through-fitting  10  is put into service. Where this is done, service personnel do not need to insert grease into through-fitting  10  from a separate container of grease.  
         [0046]    A through-fitting  10  may be used in many contexts. For example, a through-fitting  10  may be mounted to a flange and used as a bulkhead fitting. A through-fitting  10  may also be used to pass cables into a junction box. Stub  12  may be formed integrally with the junction box.  
         [0047]    [0047]FIG. 3A shows a junction box  40  according to one embodiment of the invention. Box  40  comprises a base portion  42  which supports a number of through-fittings  10 . Base portion  42  is threaded to receive a cover portion  44 . An O-ring  46  seals the joint between cover portion  44  and base portion  42 .  
         [0048]    [0048]FIG. 3B is a section through junction box  40  being used to protect splice connections between two cables C 1  and C 2 . In the illustrated embodiment, a web  48  projects from base  42  into junction box  40  between two through-fittings  10 . Web  48  keeps a splice S from being pulled too far toward base  42 .  
         [0049]    [0049]FIG. 4A shows a through-fitting  110  according to an alternative embodiment of the invention. The parts of through-fitting  110  are identified by reference numerals which are incremented by 100 relative to corresponding parts of through-fitting  10 . Through-fitting  110  has a threaded stub  112  and a cap  120  which together define an annular chamber  124 . Chamber  124  may be filled with grease. The inner wall of chamber  124  is defined by a sleeve  136  which extends axially inside cap  120 . An annular elastomeric seal  128  is located within a bore  116  of stub  112 . Seal  128  may, in some cases, comprise a one-quarter inch long flat o-ring.  
         [0050]    Through-fitting  110  differs from through-fitting  10  primarily in details of the design of seal  128 . The through-fitting  10  of FIGS. 1A, 1B and  1 C is currently preferred because it is believed that seal  28  will, in general, provide a seal superior to the seal provided by seal  128 .  
         [0051]    Seal  128  projects axially into bore  116  from a groove  129 . The inner end  136 A of sleeve  136  is beveled. As cap  120  is tightened, the inner end of sleeve  136  engages the outer end of seal  128  and compresses seal  128  radially inwardly around cable C. Seal  128  is thick enough to accommodate variations in the diameter of cable C. Typically cable C will not be exactly round but may instead be oval in shape. Cap  120  may hit a stop, or the end of threads  118 , or, in some other manner, be positively stopped at the point when it has been properly tightened and a proper seal has been made to cable C.  
         [0052]    As cap  120  is screwed toward its closed position, which is shown in FIG. 4B, grease is extruded from chamber  124 , through grooves  138  and into bore  116 . The beveled end of sleeve  136  helps to pack the grease around cable C. Ridge  139  may help to minimize the amount of excess grease that escapes from along cable C to the outside end of through-fitting  110 . A chamber  166  may be provided to receive and hold any excess grease which is displaced along cable C toward the inside end of through-fitting  110 .  
         [0053]    A plug  168  (shown in dashed outline in FIG. 4A) may be supplied to seal through-fittings  110  which are not in use. A junction box which includes through-fittings  10  or  110  may be shipped with plugs  168  in place in some or all through-fittings. When a cable is to be installed in such through-fittings, plug  168  may be removed and may be stored inside the junction box for possible reuse.  
         [0054]    Plug  168  has a inner end  168 A which bears against seal  28  or  128  and an outer end  168 B which abuts against ridge  39  or  139 . Cap  20  or  120  is screwed on so that ridge  39  or  139  engages outer end  168 B and presses plug  168  into a position so that its inner end  168 A is compressing and is sealed against seal  28  or  128 . Plug  168  is long enough so that, even when it is installed as described above, chamber  24  or  124  remains open.  
         [0055]    [0055]FIG. 5 shows a junction box  200  according to another embodiment of this invention. Junction box  200  may be used, for example, for joining telephone cables. Junction box  200  receives a telephone cable containing, for example, twenty-five pairs of conductors, each pair capable of serving one telephone line. Inside junction box  200 , connections are made to a number of other cables which each may carry a fewer number of pairs of conductors. For example, the box may be used to make connections to branch cables which each carry three pairs of conductors. Each of the branch cables could, for example, be connected to supply telephone lines to a house or business. Junction box  200  is sealed to prevent the entrance of moisture, either where the cables enter the box or around the door which permits access to the interior of the box.  
         [0056]    Box  200  comprises a housing  212  which, in this embodiment, comprises a lid  214  and a base  213 . Lid  214  is hinged to base  213  at hinges  216 . A clasp  218  holds lid  214  in a closed position relative to base  213 . Projecting lugs  220  on lid  214  and base  213  permit use of additional fasteners  222 , such as screws, to hold box  210  closed and to serve as a backup in case latch  218  fails.  
         [0057]    Base  213  accommodates through couplings for a main cable C 1  and a number of branch cables C 2 . In the illustrated embodiment, a through-fitting  230  for main cable C 1  is centrally disposed on a bottom of base  213  and is surrounded by through-fittings  240  for eight branch cables. Through-fittings  240  may, for example, comprise through-fittings of the types shown in FIGS. 1A or  4 A. The number of through-fittings and their arrangement on junction box  200  may be varied. In the illustrated embodiment, through-fittings  240  are arranged around a circle centered generally on through-fitting  230 .  
         [0058]    [0058]FIG. 6 is a cross-sectional view through a through-fitting  230 . FIGS. 7A, 7B,  7 C and  7 D show other views of through-fitting  230 . Through-fitting  230  provides both strain relief for cable C 1  and seals against the entry of moisture at the point where cable C 1  enters box  200 . A through-fitting  230  may be used in other contexts such as points where cables, tubes, or the like, pass into boxes, through bulk heads or the like.  
         [0059]    Through-fitting  230  comprises a seal  270 , which may comprise an o-ring. O-ring  270  is compressed against a flange  272  which surrounds an opening  274  through which cable C 1  enters box  200 . A compression member  276  bears a slanting annular face  278 . When compression member  276  is clamped against box  200 , face  278  compresses o-ring  270  inwardly against cable C 1  and also compresses o-ring  270  against surface  272 , thereby providing a seal around cable C 1 . In the illustrated embodiment, compression member  276  is clamped against box  200  by means of screws  285  which pass through holes  279 . In the illustrated embodiment, the screws are received in threaded bosses  280  on box  200 .  
         [0060]    Through-fitting  230  includes a well  282  on the inside of o-ring  270 . Well  282  may be filled with grease to provide additional sealing around cable C 1 . Clamping members  284  cover off the top end of well  282  and additionally clamp against cable C 1  to provide strain relief. In the illustrated embodiment, clamping members  284  are each generally semi-circular and have a central channel  287  for receiving cable C 1 . Clamping members  284  are received in a pan-shaped depression  286  having a flat bottom  286 A and a sloping side wall  286 B. As shown in FIG. 7C, clamping members  284  are initially spaced apart from one enough to permit cable C 1  to be passed between them. Clamping members  284  are forced downwardly into depression  286  by, for example, screws  285 , clamps or the like. As this is done, the outer surfaces of clamping members  284  ride down sloped walls  286 B and are thereby forced against cable C 1  as shown in FIG. 7B. Preferably, clamping members  284  are clamped down until they form a seal against surface  286 A which, as noted above, is preferably flat. Apertures  288  are provided for pumping grease into well  282 . Preferably there is more than one aperture to permit the grease being introduced to displace air within well  282 . This facilitates at least substantially completely filling well  282  around cable C 1  with grease.  
         [0061]    Clamping members  284  preferably include projections, ribs or bumps which dig at least slightly into the sheathing of cable C 1  so as to provide strain relief.  
         [0062]    Terminals  290  (see FIG. 11) are mounted on a plate  292  which fits inside box  200 . FIGS. 8, 9, and  10  are respectively a front perspective view, back perspective view and top plan view of plate  292 . FIGS. 8 and 9 show plate  292  without terminals  290 .  
         [0063]    [0063]FIG. 11 shows the interior of a box  200  according to one embodiment of the invention. In this embodiment, the conductors of cable C 1  enter box  200  and extend to terminals  290  which are positioned at spaced apart locations in a ring surrounding cable C 1 . Terminals  290  may be numbered for reference. The individual pairs of conductors C 1 -A exit from cable C 1  and are connected to terminals  290  on the underside of plate  292 .  
         [0064]    As best seen in FIGS. 8 and 10, plate  292  preferably includes indicia including numbers or letters which identify individual sets of terminals  290 . Preferably plate  292  includes ridges, lines, grooves, or the like which visually segregate terminals  290  into groups. One group of terminals  290  may be associated with each through-fitting  240 . In the illustrated embodiment, terminals  290  are grouped together to provide three sets of two terminals  290  adjacent each ingress point where a cable C 2  can be received into box  200 .  
         [0065]    Plate  292  preferably provides channels  294  by way of which cables C 1 -A can be routed to each group of terminals  290 . Channels  294  may, for example, be provided by indentations in the lower surface of plate  292 . FIG. 11A shows a partially cutaway view of a box  200  which illustrates how conductors C 1 -A can be carried through channels  294  beneath plate  292  to make electrical connections to the undersides of terminals  290 .  
         [0066]    Plate  292  preferably makes a tight contact with base  213  of box  200 . This closes off the top of the grease cavities  166  of through-fittings  240  (see FIG. 6). Plate  292  includes an aperture  296  for each incoming cable C 2  (see FIGS. 8 and 9). Each aperture  296  is preferably a relatively tight fit to the expected cable C 2  so that there is not too much of a tendency for excess grease to be extruded from cavities  166  through aperture  296  around cable C 2 .  
         [0067]    In many applications, properly grounding cables C 1  and C 2  is important. There is a desire for a robust grounding mechanism. The illustrated embodiment of the invention provides a grounding ring  298  (see FIGS. 11 and 12). Grounding ring  298  is connected to a ground conductor, which is typically a shield, of cable C 1  by a strap  298 A. Strap  298 A may be integral with grounding ring  298 . A number of grounding terminals  299  are provided on grounding ring  298 . Grounding terminals  299  are preferably located adjacent through-fittings  240  (see FIG. 6) to permit grounding of cables C 2 .  
         [0068]    The precise manner in which grounding is achieved will depend upon the structure of cable C 1 . FIG. 12 illustrates a possible means of connection to the ground conductor of cable C 1 . This structure may be used where cable C 1  has a shield which surrounds the conductors of cable C 1 . This connection is known in the trade as a “bullet bond”. Curved metal conductors  300  and  301  which match the curvature of sheath S are placed inside and outside sheath S respectively. A bolt  302  is connected to conductor  300 . Bolt  302  passes through an aperture in shielding S and also passes through an aperture in strap  298 A. A nut  303  clamps conductor  300  tightly to shield S and also provides a good electrical contact with strap  298 A. The bullet bond may be installed by slitting sheath S and peeling back a portion of sheath S to permit the conductors to be moved away to allow the insertion of member  300 . In FIG. 12, the conductors and other portions of cable C 1  have been cut away to provide a view of member  300 .  
         [0069]    [0069]FIG. 13 shows a box  200  according to the invention in which a cable C 2  has been installed. Cable C 2  protrudes through aperture  296  into the interior of box  200 . A section of the sheath of cable C 2  is stripped away to expose the shielding conductor which, in the illustrated embodiment, surrounds the conductors of cable C 2 . FIG. 6 shows grounding clamp  308  in side view. A ground clamp  308  is clamped onto cable C 2  to make electrical contact with the sheath of cable C 2 . The inward end of ground clamp  308  has a slot which receives one of ground terminals  299 . A nut (not shown) on the ground terminal  299  can then clamp the ground clamp  308  against grounding conductor  298  to provide a good ground connection for cable C 2 . Individual conductors C 2 -A from cable C 2  can be attached to selected ones of terminals  290 . Hooks  310  may be provided for neatly storing conductors out of the way.  
         [0070]    Ridges  293  (see FIG. 8) on plate  292  prevent grounding clamp  308  from twisting to one side or the other after grounding clamp  308  is installed.  
         [0071]    A junction box  200  as described above provides a convenient way for connections to be made from the conductors of cable C 1  to the conductors of individual cables C 2 . Furthermore, the box provides a convenient point at which tests may be made and signals may be sampled to located broken conductors or other defects which interfere with the operation of a system which includes conductors of cable C 1  and/or C 2 .  
         [0072]    [0072]FIG. 14 shows a sealing o-ring  320  which assists in providing a seal between top  214  and base  213  of box  200  when box  200  is closed. O-ring  320  is received between the wall of base  213  and an interface  322  of top  214 . As shown in FIG. 14, o-ring  320  may be received between an interrupted flange  324  and a number of protrusions  326 . This construction permits base  213  to be injection-molded in a relatively straightforward manner while providing retaining means for o-ring  320  both above and below. Each location at which there is a projection  326  corresponds to a gap  324 A in flange  324 .  
         [0073]    It can be appreciated that when top  214  is closed, interface  322  compresses o-ring  320  inwardly against base  213 . To assist in providing the best seal possible, lid  214  has a ramped surface  328  located inwardly from surface  322 . When top  214  is fully closed, ramped surface  328  wedges inside the upper edge of base  213  and urges it outwardly, thereby insuring that a seal will not be lost by excessive inward deflection of the edge of base  213 .  
         [0074]    Hinges  216  should be configured so that they do not interfere with the fitting of top  214  onto base  213 . Hinges  216  preferably permit top  214  to float slightly, so that it can find its own position in respect of base  213 . FIG. 15 is a sectional view through a portion of the interface between top  214  and base  213  which shows ramped surface  328  providing support to the top edge of base  213  when box  200  is closed. FIG. 15 also shows a cross-section through a hinge  216  which has a pin  330  which is free to float somewhat relative to top  214 .  
         [0075]    The main portions of box  200  including top  214  and base  213  may be made from a suitable rigid material. The material is preferalby flame-retardant. By way of example, these components may be injection-molded from a suitable plastic such as PVC, polycarbonate or the like.  
         [0076]    There are various advantages to junction boxes  40  and  200  which are described above. One advantage is that they are quite compact, although the volume of either of these junction boxes may be made as large as required, within practical limits. Another advantage is that all cables come out of the same side of the box. This is beneficial because it facilitates pulling box  40  or  200  out of a vault or other underground enclosure through what can sometimes be a relatively small opening. It can be appreciated that the design of box  200 , in particular, permits organized wiring and also permits new cables C 2  to be readily added.  
         [0077]    A suitable connector may be provided on the end of cable C 1  for joining cable C 1  to another cable or a piece of equipment.  
         [0078]    As will be apparent to those skilled in the art in the light of the foregoing disclosure, many alterations and modifications are possible in the practice of this invention without departing from the spirit or scope thereof. For example:  
         [0079]    The number of conductors in cable C 1  and C 2  may vary.  
         [0080]    Box  200  could be round, as illustrated, or some other shape, such as rectangular, square, octagonal, etc. To enable sealing of box  200  in the manner described above with an o-ring  320 , it is preferable that box  200  be either round or, at least, have rounded corners.  
         [0081]    Through-fittings  40  may comprise another mechanism for automatically injecting grease from a chamber as they are tightened onto a cable or the like. For example, FIG. 16 shows a through-fitting  400  which has a cap  420  which bears against a piston  421 . Piston  421  is located in a cylinder  422  which is filled with an extrudable sealant such as grease. Screwing down cap  420  displaces piston  421  and thereby causes grease to be extruded from cylinder  422  into bore  416  through a passage  423 . A through-fitting of the type shown in FIG. 16 will typically include seals, cable strain reliefs and the like which are not shown in FIG. 16.  
         [0082]    The foregoing description mentions through-fittings and junction boxes which include various components and sub-assemblies. These various components and sub-assemblies do not all need to be used together. They may be used individually, or in combination with each other, or in combination with other elements not disclosed herein.  
         [0083]    The invention is not limited to junction boxes for telephone lines.  
         [0084]    The through-fittings described above, particularly through-fitting  10  may provide good enough sealing that, for some applications, grease is not necessary.  
         [0085]    Accordingly, the scope of the invention is to be construed in accordance with the substance defined by the following claims.