Abstract:
A grommet ( 150 ) is securable to and along an edge ( 46 ) of a wall ( 36 ) of an enclosure ( 10 ) to provide sealing about lengths of cable extending through recesses ( 48 ) along the edge ( 46 ). Grommet ( 150 ) includes a cable-receiving section ( 152 ) having a diaphragm ( 168 ) traversing each of the recesses and includes a virtual slit ( 156 ) extending from a thick top edge portion ( 154 ) and through the diaphragm to the thick bottom edge portion ( 158 ). A cable ( 22 ) is insertable into the virtual slit ( 156 ) until seated in and through the diaphragm; stiff opposed portions ( 176 ) of the top edge ( 154 ) of the grommet close after being deflected temporarily as the cable is urged therepast; thin resilient opposed strips ( 170 ) of the diaphragm ( 168 ) similarly close upon said cable being urged therepast, while strips ( 170 ) adjacent the cable remain deflected by and biased against the cable. Upstanding wall sections ( 50,52 ) of the enclosure wall ( 36 ) are received through apertures ( 164 ) through the grommet and latch therewith.

Description:
FIELD OF THE INVENTION 
     The present invention is directed to the field of enclosures for electrical connectors and more particularly to grommets for use with enclosures for terminal blocks for interconnecting service and distribution cables of telephone wires. 
     BACKGROUND OF THE INVENTION 
     In the telecommunications industry telephone distribution cable is introduced to individual telephone sites such as residences, mainly through use of a splice of pairs of tip and ring signal wires of the cable to tip and ring wires of a respective service cable at a junction located outside the house. The junction is housed within a protective enclosure which is mounted usually to an outside wall of the house. 
     A variety of enclosures are known, mountable to poles or walls, within which are mounted one or more terminal blocks used to interconnect tip and ring wires of distribution cable and a plurality of service cables, including a rugged enclosure such as disclosed in U.S. The enclosure includes arrays of openings along both side edges of the rear wall and to each side of the array of terminal blocks, and also through the bottom wall, through which extend respective service cables. Sealing about the openings around the cables is provided by a pair of elongate strips traversing the array of openings, held in place by the structure of the enclosure. A first strip adjacent the rear wall includes discrete slits aligned with the wall&#39;s openings, and a second strip outwardly of and adjacent the first strip includes small diameter holes punched therethrough aligned with the centers of the cable openings, all permitting insertion therethrough of cable ends and sealing therearound, and also closing off any particular opening into which no cable is inserted. 
     Other such enclosures are disclosed in U.S. patent applications Ser. No. 098/032,890 and Ser. No. 08/085,129; both filed Mar. 18, 1993; assigned to the assignee hereof; the enclosures similarly contain terminal blocks mountable therein each interconnecting conductors of a distribution cable and an array of service wires, or two arrays of service wires, and which are easily openable to stable positions permitting access thereinto. 
     It is desired to provide a grommet for a telephone line enclosure having a plurality of cable exits which provides for environmental sealing about the cables extending through the respective cable exits. 
     It is also desired to provide such a grommet that seals about each of a plurality of such cables and closes off unused ones of the cable exits, and is replaceable. 
     SUMMARY OF THE INVENTION 
     The present invention is a grommet for an enclosure in which are mountable interconnection or crossconnection modules, and into which extend ends of a plurality of service cables for the tip and ring conductors thereof to be connected to a distribution cable or crossconnected to each other. An array of recesses define individual service cable exits and are provided along the forward edge of the front wall of the box, with edge grommet members secured along the forward edge providing sealing about the respective cables and closing off unused exits. 
     The edge grommet is molded of elastomeric material and includes sections associated with the cable-receiving recesses of the enclosure which coextend from a top edge which will extend along the forward edge of the front wall of the enclosure, as the sections are disposed within respective ones of the cable-receiving recesses. Each section includes a vertical virtual slit from and through the thick top edge to the thick bottom edge and which is openable as a cable is moved laterally into the section from the top edge, and which is somewhat stiffly elastic to grip the cable and close off the recess about the cable. The edge grommet is so formed that the portion adjacent the edge surfaces of the enclosure comprising the forward edge of the front wall and also the side and bottom edges of each cable-receiving recess is thick and sturdy, and the thickness is reduced between the thick top and bottom edge portions in each cable-receiving section extending from opposing sides to the slit to define a diaphragm. The thick contoured edge includes outer and inner lips or flanges defining a channel into which the edge surfaces of the enclosure wall are received to provide a sealed interface. 
     Preferably the edge grommet is mechanically securable to the enclosure front wall. The front wall includes a plurality of upstanding wall sections of limited width between the cable-receiving recesses and also beside the outer recesses, which are receivable into close fitting apertures through the thick contoured edge of the edge grommet. Latching projections are formed on the upstanding wall sections adjacent the forward edge of the front wall, which latchingly engage corresponding latching recesses of the edge grommet at trailing ends of the close fitting apertures after the edge grommet has been fully inserted onto the front wall. This arrangement permits removal and replacement of an edge grommet if desired. 
     It is an objective of the present invention to provide an enclosure adapted to permit mounting in the interior thereof of terminal blocks and modules useful in interconnecting service cables to a distribution cable of a telephone line, and which environmentally seals the interior. 
     It is additionally an objective to provide a grommet member for sealing a plurality of cable-receiving entrances into an enclosure for an array of service cables. 
     It is further an objective to provide a grommet member which is easily assembled to the enclosure and which is removable and replaceable. 
     An embodiment of the invention will now be described by way of example with reference to the accompanying drawings. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is an isometric view of an enclosure having secured thereon an edge grommet of the present invention, with the enclosure lid in an open position exposing a protected module mounted therewithin having conductors of a representative service cable connected to conductors of a distribution cable within respective housing sections of the module; 
     FIG. 2 is an isometric view of the enclosure with the lid in a closed position; 
     FIG. 3 is an isometric view of the enclosure of FIG. 1 with no module mounted therein, showing one of the edge grommets of the present invention exploded from the front wall thereof; 
     FIG. 4 is an elevation view of the enclosure with the edge grommets removed from the front wall thereof and showing cable-receiving recesses therethrough; and 
     FIGS. 5 to  9  are isometric, plan, elevation and bottom views and an enlarged cross-sectional view of a virtual cable-receiving slit of a section thereof respectively, of an edge grommet of the present invention, with FIG. 5 illustrating assembly of the edge grommet with the enclosure. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     In FIG. 1 enclosure  10  is shown with lid  12  in an open position exposing the interior of box section  14  having a protected module  200  mounted therein. Enclosure  10  is of the type disclosed in U.S. patent application Ser. No. 08/035,129 filed Mar. 18, 1993. Distribution cable  16  is shown extending into enclosure  10  at cable entry  18  through grommet  20 . A representative service cable  22  having tip and ring conductor wires  24 , 26  is shown extending into enclosure  10  at a cable entry  28 ; wires  24 , 26  are interconnected with respective conductors (not shown) of distribution cable  16 . Cable entry  28  is sealed about service cable  22  by portions of edge grommet  150  at a cable entry section  152  thereof. 
     Protected module  200  is of the type disclosed in U.S. Pat. No. 5,296,646. Distribution cable  16  is shown entering the protector housing portion  202  where its array of conductors are electrically connected in-line with protector devices (not shown) which protect the circuits against voltage surges. A ground circuit  204  is shown extending from protector housing portion and is electrically connected to a ground post in a forward portion of enclosure  10  for connection to an external ground (not shown) as is conventional. Conductors (not shown) extend from the protector devices to respective terminals within individual housing sections  206  into which have been inserted respective ones of the tip and ring wires of the service cables for electrical connection thereto, as is disclosed in U.S. Pat. No. 5,296,646. 
     Lid  12  is fastened to box section  14  in a manner similar to that of U.S. Pat. Nos. 5,145,388 and 5,146,650, which permits pivoting between closed and open positions. The fastening arrangement enables the lid to remain in an open position without assistance overcoming gravity and wind depending on the physical location and on the particular orientation in which the enclosure is mounted upon installation, thus facilitating electrical connection of the array of service cables and also repair and servicing thereof and of protector devices and terminals in module  200  after installation in the field. The durable fastening arrangement also utilizes no separate fastening elements and is easily moldable integrally with the box section  14  an the lid  12 . 
     FIG. 2 illustrates an enclosure  10  with lid  12  in a closed position, having been pivoted forwardly and latched whereafter a security fastener (not shown) disposal in aperture  30  is actuatable by special tools by authorized personnel of the telephone company, to lock the lid in its closed position, all as is conventional. Latching and locking sections  60  of box section  14  and  62  of lid  12  are seen in greater detail in FIG.  3 . Grommet  20  is seen at cable entry  18  having a virtual slit therein which will seal about a distribution cable upon installation in the enclosure, if required in the particular use to which the enclosure is put, and which otherwise remains sealed if no such distribution cable is to be used. 
     In FIGS. 3 and 4, enclosure  10  is shown in greater particularity, again with lid  12  in its open position exposing the interior, with no modules mounted therein nor cables shown. An edge grommet  150  of the present invention is seen exploded from box section  14 . Box section  14  includes a bottom wall  34 , front wall  36  side walls  38 , 39  and rear wall  40 . A distribution cable region  32  is defined adjacent front wall  36  extending between opposed cable entries  18  through side walls  38 , 39 . Rear wall  40  includes integral hook-shaped projections  42  within which are pivotally movably held dowels  44  of lid  12 . 
     Front wall  36  includes a forward edge  46  having recesses  48  extending into front wall  36  from forward edge  46  for eventual receipt therethrough of service cables. Upstanding wall sections  50  along with upstanding wall sections  52  to each side of the arrays of recesses  48 , separate and define recesses  48 , all extending to leading ends  54 , and having opposed edge surfaces  56  defining parallel sides of recesses  48  which conclude in arcuate recess bottom edges  58 . Arrays of recesses  48  are disposed to either side of latching and locking section  60  centrally located along front wall  36  cooperable with the complementary latching and locking arrangement  62  of lid  12 . Latching may be by means of an inwardly directed latching projection  64  along the inner surface of tab  66  which latches beneath ledge  68  extending forwardly from front wall  36 , upon lid closing. Outwardly directed lips  70  extend from top edges of side walls  38 , 39  and becomes seated within corresponding recesses  72  of lid  12  upon closing thereof. 
     Referring to FIGS. 3 to  5 , edge grommets  150  are associated with each array of recesses  48  with cable-receiving sections  152  associated with respective recesses  48 . Edge grommets  150  are mountable to forward edge  46  such as by means of latching projections  74  adjacent leading ends  54  of upstanding wall sections  50 , 52  of front wall  36  cooperable with latching recesses formed in edge grommets  150 . The coplanar, virtually continuous upper surface  154  of edge grommet  150  engages and is compressible against an opposing ledge surface  76  of lid  12  upon closing, effectively forming an environmental seal. 
     Referring now to FIGS. 5 to  9 , an edge grommet  150  is molded of elastomeric material such as of SARLINK 1360 elastomer/PVC alloy, oil resistant thermoplastic elastomer sold by DSM Thermoplastic Elastomers, Inc. Leominster, Mass. Edge grommet  150  includes sections  152  associated with the cable-receiving recesses  48  of the enclosure which coextend from upper surface  154  which will extend along the forward edge  46  of front wall  36  of box section  14  as sections  152  are disposed within respective ones of cable-receiving recesses  48 . Each section  152  includes a virtual slit  156  openable as a cable is moved laterally into the section from upper surface  154 , and which is somewhat stiffly elastic to grip the cable and close off the recess about the cable. The edge grommet includes bottom edge portion  158  which upon assembly onto front wall  36  will be adjacent the edge surfaces thereof comprising top edge surfaces  54  of wall sections  50 , 52  of front wall  36  and also opposed edge surfaces  56  and bottom edges  58  of each cable-receiving recess  48 . Bottom edge portion  158  is thick and sturdy, and the thickness is reduced inwardly thereof at each respective cable-receiving section  152  extending from opposing sides to the slit  156 . The thick contoured bottom edge portion  158  preferably includes outer and inner lips or flanges  160  defining a channel  162  into which the edge surfaces of the enclosure wall are received to provide a sealed interface. 
     Preferably the edge grommet is mechanically securable to the enclosure front wall. Front wall  36  includes a plurality of upstanding wall sections  50 , 52  of limited width between the cable-receiving recesses  48  and also beside the outer recesses, which are receivable into close fitting apertures  164  through the thick contoured edge  158  of edge grommet  150 . Latching projections  74  on upstanding wall sections  50 , 52  adjacent forward edge  46  of front wall  36 , latchingly engage corresponding latching recesses  166  of edge grommet  150  at trailing or upper ends of the close fitting apertures  164  after the edge grommet has been fully inserted onto front wall  36 . This arrangement permits removal and replacement of an edge grommet if desired. 
     Referring especially to FIGS. 7 and 9, a thin diaphragm section  168  extends across most of the cable-receiving opening  48  which is traversed by a section  152  of edge grommet  150 , vertically bisected by virtual slit  156 . Diaphragm  168  is thick enough to retain sufficient stiffness to grip against the insulative outer jacket of a service cable extending therethrough slid into slit  156  from upper surface  154  of edge grommet  150 . Preferably diaphragm  168  is defined by several pairs of small horizontal strip sections  170  having ends  172  along virtual slit  156  and which are initially joined to vertically adjacent others thereof at frangible sections  174 , which upon insertion of a service cable into slit  156  become controllably torn, permitting forward or rearward deflection of ends  172  of strips  170 . Ends  172  remain biased against the insulative outer jacket of a service cable by the resilience of the elastomeric material. Upper ones of strips  170  located above a service cable pushed downwardly therepast will resile and substantially close the opening above the service cable, with ends  172  of the horizontally adjacent strips  170  returning to their adjacent state at virtual slit  156 . The upper entrance of each section  152  is defined by stiff opposed pointed structures  176  along upper surface  154  which meet at virtual slit  156 . Stiff opposed structures  176  are shown to be joined initially to uppermost ones of strip sections  170  by frangible sections in similar fashion to frangible sections between vertically adjacent strip  170 . Structures  176  permit a service cable to be urged therethrough from above but close completely after the cable has been urged into the region of diaphragm  168 . 
     The edge grommet and sealing system of the present invention can also be used for a single cable-receiving recess, with the grommet having a single cable-receiving recess, with the wall of the enclosure preferably having a pair of limited-width wall sections beside the recess to extend upwardly through corresponding apertures through the thick bottom and top edge portions of the grommet. The edge grommet of the present invention can also be mounted or affixed to the wall of the enclosure by adhesive rather than by use of the latching system described herein. Also the diaphragm need not be a constant thickness but could be of increasing thickness extending from the virtual slit to the thick side portions. 
     Still other variations may occur to those skilled in the art, which are within the spirit of the invention and the scope of the claims.