Abstract:
A grounding terminal block assembly that includes a conduit adapter, a grounding bar, and a detachable cover. The conduit adapter enables attachment to a wall and to electrical conduit for grounding the assembly. The conduit adapter includes one or more conduit receiving ports for attachment of electrical conduit. The grounding terminal block includes a plurality of grounding terminals for establishing connection points for grounding multiple electrical systems, including phone, data, and cable TV systems. A channel on one end of the grounding bar includes a channel and fastener for establishing a secure connection to a ground wire. Legs are provided on the grounding bar for providing direct connection to the conduit adapter. The detachable insulating cover is secured to the grounding bar to shield the grounding body and all wiring connections to the grounding body.

Description:
This application is a Continuation-In-Part of U.S. patent application Ser. No. 12/288,968 filed Oct. 24, 2008 now U.S. Pat. No. 7,591,656, which is a Continuation-In-Part of U.S. patent application Ser. No. 12/287,244 filed Oct. 7, 2008, now U.S. Pat. No. 7,537,467, the entire contents of which are incorporated herein by reference. 
    
    
     FIELD OF THE INVENTION 
     This invention relates to terminal blocks for grounding electrical systems and specifically to a grounding terminal block assembly for grounding multiple services that is adaptable for use with electrical conduit. 
     BACKGROUND OF THE INVENTION 
     The National Electrical Code (NEC) now requires the grounding of data, cable TV, and phone lines. Grounding is the establishment of an electrical connection to earth through a path of sufficiently low impedance. As it relates to data, cable TV, and phone lines, the purpose of grounding is to assist in preventing the destruction of electrical components and property damage from superimposed voltage from lightning and voltage transients. Grounding the various connections to the earth also helps in reducing static charges on equipment surfaces to ensure the proper performance of sensitive electronic equipment. Grounding communications equipment to the earth reduces high voltage from lightning and keeps it from entering into the building or structure via metal cables or raceways. If the metal portions of communication equipment are not grounded in accordance with the NEC, a significant amount of the high energy from the lightning strike will be dissipated within the structure, which can result in equipment and property damage as well as the potential for electric shock. Grounding also helps establish a zero voltage reference point to ensure proper performance of sensitive communications equipment. 
     In related and commonly owned patent application Ser. No. 12/287,244, now U.S. Pat. No. 7,537,467, which has been incorporated herein by reference, there was provided a grounding block assembly for multiple services that included a die-cast tubular body with a plurality of threaded bores and a plurality of threaded fasteners for cooperating with the threaded bores for securing multiple electrical services to the tubular body for the purpose of grounding each of the separate electrical services. The grounding block assembly included integral legs that enabled direct attachment of the tubular body to a wall or similar structure. For those situations in which the grounding block assembly was used in conjunction with an electrical service panel or meter can, a threaded nose portion and lock nut on the tubular body enabled direct connection to the service panel or meter can. Side ports were provided in the tubular body for inspection purposes to enable rapid viewing of the integrity of grounding connections therein. The grounding block assembly provided a device for meeting the NEC&#39;s requirements for grounding all the electrical systems leading into the home including line voltage, data, cable TV, and phone lines. 
     In related and commonly owned patent application Ser. No. 12/288,968, which has been incorporated herein by reference, there was provided a grounding block assembly for grounding multiple services in conjunction with a meter can. The grounding block assembly included die-cast tubular body with a threaded nose portion and a lock nut for securing the grounding terminal block assembly to a meter can. 
     Although the grounding block assembly of the related applications provided grounding block assemblies for grounding multiple electrical services with connection to a meter can or directly to a wall, the grounding assemblies were not adaptable for use with electrical conduit. The present invention is a grounding terminal block assembly that includes a conduit adapter that enables connection of the grounding bar within the assembly to a ground wire routed through electrical conduit. 
     SUMMARY OF THE INVENTION 
     The invention is a grounding terminal block assembly that includes a conduit adapter, a grounding bar, and a detachable cover. The conduit adapter enables attachment to a wall and to electrical conduit for grounding the assembly. The conduit adapter includes one or more conduit receiving ports for attachment of electrical conduit. The grounding terminal block includes a plurality of grounding terminals for establishing connection points for grounding multiple electrical systems, including phone, data, and cable TV systems. A channel on one end of the grounding bar includes a channel and fastener for establishing a secure connection to a ground wire. Legs are provided on the grounding bar for providing direct connection to the conduit adapter. The detachable insulating cover is secured to the grounding bar to shield the grounding body and all wiring connections to the grounding body. 
     OBJECTS AND ADVANTAGES 
     Several advantages are achieved with the grounding terminal block assembly of the present invention, including:
         (1) The grounding block assembly includes a conduit adapter with conduit receiving ports to enable rapid connection to electrical conduit.   (2) A ground to earth wire can be routed through electrical conduit to the grounding terminal assembly.   (3) A grounding block includes a plurality of grounding terminals establishing grounding for a plurality of electrical systems, including phone, data, and cable TV systems.   (4) An open channel is provided at one end of the grounding block assembly to enable rapid connection to an existing installed ground wire.   (5) The grounding block portion of the grounding block assembly is die cast in one piece of metal alloy with superior electrical conduction properties for establishing proper ground to an existing ground wire.   (6) The grounding terminal block assembly includes integral legs for direct connection to the conduit adapter and to a wall.   (7) The grounding terminal block assembly includes a detachable cover constructed of electrically nonconductive material for shielding and protecting the grounding block and its terminals.   (8) After initial installation, the detachable cover can easily be removed and reattached in order to connect additional wiring systems to the grounding terminals.       

     These and other objects and advantages of the present invention will be better understood by reading the following description along with reference to the drawings. 
    
    
     
       DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is an exploded perspective view of a grounding terminal block assembly including a grounding bar portion and a detachable cover according to the present invention. 
         FIG. 2  is a front perspective view of the grounding bar portion of the grounding terminal block assembly of  FIG. 1 . 
         FIG. 3  is a rear perspective view of the grounding bar of  FIG. 2 . 
         FIG. 4  is a side view of the grounding bar. 
         FIG. 5  is a front view of the grounding bar. 
         FIG. 6  is a rear view of the grounding bar. 
         FIG. 7  is a sectional view of the grounding bar taken along line  7 - 7  of  FIG. 5 . 
         FIG. 8  is a sectional view of the grounding bar taken along line  8 - 8  of  FIG. 4 . 
         FIG. 9  is a front perspective view of the detachable cover portion of the grounding terminal block assembly of  FIG. 1 . 
         FIG. 10  is a rear perspective view of the detachable cover. 
         FIG. 11  is a rear view of the detachable cover. 
         FIG. 12  is a sectional view of the cover taken along line  12 - 12  of  FIG. 11 . 
         FIG. 13  is a perspective view of a grounding terminal block assembly according to the present invention secured to a wall and with the cover secured to the grounding bar. 
         FIG. 14  is a side view of the grounding terminal block assembly secured to a wall and with the cover in sectional view secured to the grounding bar. 
         FIG. 15  is an exploded perspective view of the preferred embodiment of a grounding terminal block assembly adapted for use with electrical conduit according to the present invention. 
         FIG. 16  is a perspective view of a conduit adapter that forms a portion of the preferred embodiment of the grounding terminal block assembly of  FIG. 15 . 
         FIG. 17  is a plan view of the conduit adapter of  FIG. 16 . 
         FIG. 18  is a side view of the conduit adapter of  FIG. 17 . 
         FIG. 19  is an end view of the conduit adapter of  FIG. 17 . 
         FIG. 20  is a side view of the conduit receiving port portion of the conduit adapter of  FIG. 18 . 
         FIG. 21  is a perspective view of the grounding terminal block assembly of  FIG. 15  mounted on a wall and including electrical conduit in alignment for connection thereto. 
         FIG. 22  is a sectional view of the grounding bar taken along line  22 - 22  of  FIG. 7 . 
     
    
    
     TABLE OF NOMENCLATURE 
     The following is a listing of part numbers used in the drawings along with a brief description: 
     
       
         
               
               
             
               
               
             
           
               
                   
               
               
                 Part  
                   
               
               
                 Number 
                 Description 
               
               
                   
               
             
             
               
                   
               
             
          
           
               
                 20 
                 grounding terminal block assembly,  
               
               
                   
                 first embodiment 
               
               
                 22 
                 grounding bar 
               
               
                 24 
                 open channel 
               
               
                 26 
                 first end of grounding bar 
               
               
                 28 
                 detachable cover 
               
               
                 30 
                 ground wire 
               
               
                 32 
                 wall 
               
               
                 34 
                 threaded fastener 
               
               
                 36 
                 screw 
               
               
                 38 
                 cover attachment screw 
               
               
                 40 
                 second end of grounding bar 
               
               
                 42 
                 front surface of grounding bar 
               
               
                 44 
                 rear surface of grounding bar 
               
               
                 46 
                 side surface of grounding bar 
               
               
                 48 
                 threaded bore 
               
               
                 50 
                 boss 
               
               
                 52 
                 side bore 
               
               
                 53 
                 longitudinal axis through grounding bar 
               
               
                 54 
                 wide gap 
               
               
                 56 
                 inner seat 
               
               
                 58 
                 leg 
               
               
                 60 
                 front surface of leg 
               
               
                 62 
                 aperture in leg 
               
               
                 64 
                 threaded bore in boss 
               
               
                 66 
                 central bore in front surface of grounding bar 
               
               
                 68 
                 longitudinal rib 
               
               
                 70 
                 axis of threaded bore 
               
               
                 72 
                 top panel of cover 
               
               
                 74 
                 end panel 
               
               
                 76 
                 side panel 
               
               
                 78 
                 rear edge 
               
               
                 80 
                 aperture in cover 
               
               
                 82 
                 first side opening 
               
               
                 84 
                 second side opening 
               
               
                 86 
                 back surface 
               
               
                 88 
                 cover boss 
               
               
                 90 
                 rear surface of cover boss 
               
               
                 92 
                 first end leg 
               
               
                 94 
                 second end leg 
               
               
                 96 
                 intermediate leg 
               
               
                 98 
                 Y-shaped inner support 
               
               
                 100 
                 rib 
               
               
                 102 
                 longitudinal brace 
               
               
                 104 
                 lateral rib 
               
               
                 106 
                 mounting arrangement 
               
               
                 107 
                 ground wire fastening arrangement 
               
               
                 108 
                 threaded fastener or terminal screws 
               
               
                 110 
                 filet 
               
               
                 112 
                 ground wire 
               
               
                 120 
                 grounding terminal block assembly,  
               
               
                   
                 preferred embodiment 
               
               
                 122 
                 conduit adapter 
               
               
                 124 
                 electrical conduit 
               
               
                 126 
                 base plate 
               
               
                 128 
                 end of base plate 
               
               
                 130 
                 side of base plate 
               
               
                 132 
                 front surface of base plate 
               
               
                 134 
                 conduit receiver 
               
               
                 136 
                 conduit receiving port 
               
               
                 138 
                 aperture in base plate 
               
               
                 140 
                 aperture in base plate 
               
               
                 142 
                 cylindrical side wall 
               
               
                 144 
                 end wall 
               
               
                 146 
                 fastening arrangement 
               
               
                 148 
                 wall 
               
               
                 150 
                 fastener 
               
               
                 152 
                 mounting arrangement 
               
               
                 154 
                 threaded fastener 
               
               
                 156 
                 ground wire 
               
               
                 158 
                 cover fastening arrangement 
               
               
                 160 
                 opening 
               
               
                 162 
                 axial center of threaded bore 
               
               
                 164 
                 axial center of side bore 
               
               
                 D1 
                 distance across wide gap 
               
               
                 θ 1   
                 radius of inner seat portion of open channel 
               
               
                   
               
             
          
         
       
     
     DETAILED DESCRIPTION OF THE INVENTION 
     With reference to  FIG. 1 , a first embodiment of the present invention comprises a grounding terminal block assembly  20  for attachment to a previously installed ground wire in order to provide several additional grounding terminals for grounding several additional electrical systems to the earth. The grounding terminal block assembly  20  includes an elongated grounding bar portion  22  with an open channel  24  at a first end  26  and a detachable cover  28 . In  FIG. 1  the grounding bar  22  has been slipped over an existing ground wire  30  by orienting the open channel  24  of the grounding bar  22  with the ground wire  30  and slipping it over the installed ground wire  30 . The grounding bar  22  is then secured to the wall  32  with threaded fasteners  34 , A screw  36 , which is provided as part of the grounding terminal block assembly  20 , is then tightened onto ground wire  30  thereby securing the ground wire  30  to the grounding bar  22 . Detachable cover  28  is then secured to grounding bar  22  with cover attachment screw  38 . 
     Referring to  FIGS. 2 and 3 , the elongated grounding bar  22  further includes a second end  40 , a front surface  42 , a rear surface  44 , and two side surfaces  46 . The elongated grounding bar  22  is preferably constructed of electrically conductive metals. The tubular body is preferably produced in one-piece and is die-cast of metal. A threaded bore  48  extends into the grounding bar  22  at the first end  26 . 
     With reference to  FIG. 4 , the grounding bar  22  includes a plurality of bosses  50  extending from the front surface  42 . A plurality of side bores  52  aligned along longitudinal axis  53  extend through the grounding bar  22 . The front  42 , rear  44 , and side surfaces  46  of the grounding bar  22  are flat. The open channel  24  in grounding bar  22  includes a wide gap  54  leading therein and an inner seat  56 . The wide gap  54  enables the channel  24  portion of the grounding bar  22  to be slipped over a ground wire (not shown) and the ground wire advanced until seated in inner seat  56 . 
     As shown in  FIG. 5 , two legs  58  are integral with and extend outwards from the grounding bar  22  with the legs  58  extending from opposite sides  46  of the grounding bar  22 . Each of the legs  58  includes a front surface  60  and an aperture  62  therein. The apertures  62  are at right angles with respect to the front surface  60  of the legs  58  and also with respect to the front surface  42  of the grounding bar  22 . A plurality of threaded bores  64  are provided extending into the bosses  50  and a central bore  66  is provided between the two bosses  50  extending into the front surface  42  of the grounding bar  22 . 
     Referring to  FIGS. 6-8 , the rear surface  44  of the grounding bar  22  includes a longitudinal rib  68  extending there from. The longitudinal rib  68  extends between and joins the two legs  58  thereby providing rigidity and support and bracing the legs  58 . As shown in  FIG. 7 , the plurality of threaded bores  64  extend into the grounding bar  22  and include axes  70  that are perpendicular to the front surface  42  of the grounding bar  22 . 
     With reference to  FIGS. 9 and 10 , detachable cover  28  includes a top panel  72 , end panels  74 , side panels  76  and a rear edge  78 . Top panel  72  includes an aperture  80  therein and side panels  76  include a first side opening  82  and second side opening  84 . The back surface  86  of the top panel  72  includes an integral cover boss  88  projecting therefrom, with cover boss  88  including a rear surface  90 . Side openings  82  and  84  divide the cover  28  into a first end leg  92 , a second end leg  94 , and intermediate legs  96 . 
     Referring to  FIGS. 11 and 12 , second end leg  94  is braced to said end panel  74  and said side panel  76  by Y-shaped inner supports  98  and intermediate legs  96  are braced by ribs  100  extending from the cover boss  88 . A pair of longitudinal braces  102  extends between the Y-shaped inner supports  98  and the first end leg  92  and lateral ribs  104  extend between the side panels  76  and the longitudinal braces  102  to further brace the cover  28 . 
     Reference is made to  FIG. 1  for a description of the operation of the present invention. Grounding terminal block assembly  20  includes a mounting arrangement  106  for securing the grounding block  22  to a wall  32  or similar structure. The grounding terminal block assembly  20  is an adjunct grounding block that is designed to be slipped over an existing ground wire  30  as shown in  FIG. 1 . Initially grounding terminal block assembly  20  includes screw  36  in a loosened state thereby providing a wide gap  54  at the entrance to open channel  24 . To operate the grounding terminal block assembly  20 , the installer removes the detachable cover  28 , aligns the open channel  28  with the ground wire  30 , and slips the grounding bar  22  under the ground wire  30  such that the ground wire  30  enters the open channel  24 . Screw  36  is then tightened upon ground wire  30  and the grounding bar  22  is mounted to the wall  32  using mounting arrangement  106  consisting of threaded fasteners  34  tightened through apertures  62  in legs  58  of grounding bar  22 . After the grounding bar  22  is secured to the ground wire  30  and mounted to the wall  32 , then individual ground wires (not shown) are secured to the grounding bar  22  by a ground wire fastening arrangement  107  including a plurality of electrically conductive terminal screws  108 . As the grounding bar  22  is die-cast in one piece of electrically conductive material, all ground wires connected to the grounding bar  22  by terminal screws  108  will conduct any voltage surges through the grounding bar  22  to the existing ground wire  30  and thus to earth ground thereby protecting the electrical systems connected by the terminal screws  108 . 
     After the grounding bar  22  is mounted to the wall  32  and ground wires are connected to the grounding bar  22  by the terminal screws  108 , detachable cover  28  is secured to the grounding bar  22  by cover attachment screw  38  secured into the central bore  66  in the front surface  42  of grounding bar  22 . If only a portion of grounding terminals  108  are in use and additional electrical systems are required to be grounded, detachable cover  28  may be later temporarily removed and additional ground wires connected to the grounding terminals  108 , after which the cover  28  is replaced. In case there are more electrical systems to be grounded than available terminal screws  108 , additional grounding terminal block assemblies  20  could be connected at other locations along the ground wire  30 , in the same manner as described above, to increase the number of available grounding connection points. 
     With reference to  FIG. 13 , after the grounding terminal block assembly  20  is secured to a wall  32 , first and second side openings  82  and  84  provide entry ports for admitting the main ground wire  30  and ground wires for connection to the individual terminal screws (not shown). Thus, the side openings  82  and  84 , included on both sides  76  of the cover  28 , enable many different ground wire configurations and connections with the same detachable cover  28 . Filets  110  are provided around the peripheries of the side openings  82  and  84  to add rigidity and strength to the side panels  76  of the one piece molded detachable cover. 
     As shown in  FIG. 7 , it is critical that the open channel  24  of the grounding bar  22  is sized to accommodate most nominal sizes of ground wires in established grounding systems. Most preferably the radius R 1  of the inner seat  56  of open channel  24  is at least 0.165 inch and the distance D 1  across the wide gap  54  is at least 0.34 inch. 
     Referring to  FIG. 14 , when the detachable cover  28  is secured to the grounding bar  22 , the rear surface  90  of cover boss  88  contacts the front surface  42  of the grounding bar  22 . Cover boss  88  therefore positions the top panel  72  of the cover  28  above the grounding bar  22  and provides sufficient space inside the cover  28  for terminal screws  108  whether they have ground wires connected to them or not. The cover boss  88  also positions the first end leg  92 , second end leg  94 , and intermediate leg  96  flush with the wall  32 . First side opening  82  and second side opening  84  (in dashed lines) enable easy viewing of the ground wire  30  to earth and any ground wires  112  that are connected to electrical systems. 
     With reference to  FIG. 15  there is shown a preferred embodiment of grounding terminal block assembly  120  according to the present invention. The preferred embodiment of the assembly  120  includes the elongated grounding bar portion  22  and detachable cover  28  of the first embodiment and in addition includes a conduit adapter  122  that adapts the grounding assembly for connection to electrical conduit  124 . 
     As shown in  FIG. 16 , conduit adapter  122  includes a base plate  126  having two ends  128 , two sides  130 , and a front surface  132 . At least one conduit receiver  134  is provided extending from one of the sides  130  of the base plate  126 . The embodiment of the conduit adapter  122  depicted in  FIG. 16  includes two conduit receivers  134  each of which includes a cylindrical conduit receiving port  136  therein. 
     With reference to  FIGS. 17 to 20 , the base plate  126  portion of the conduit adapter  122  includes a plurality of apertures  138  therein that will accommodate fasteners (not shown) for mounting the conduit adapter  122  to a wall. Base plate  126  further includes apertures  140  that will accommodate mounting of the grounding bar (not shown) thereto. In the preferred embodiment of the grounding terminal block assembly  120 , the conduit receiving ports  136  include cylindrical side walls  142  and an end wall  144 . 
     Referring to  FIG. 15 , the preferred embodiment of the grounding terminal block assembly  120  of the present invention includes a fastening arrangement  146  for securing the conduit adapter  122  to a wall  148 . The fastening arrangement  146  includes fasteners  150  that may be driven through each of the apertures  138  in the base plate  126  and thence into the wall  148 . A mounting arrangement  152  for mounting the grounding bar  22  to the conduit adapter  122  includes threaded fasteners  154  that are driven through the apertures  62  in each leg  58  of grounding bar  22  and thence into apertures  140  in the base plate  126  portion of the conduit adapter  122 . 
     For the operation of the preferred embodiment of the grounding terminal block assembly  120 , reference is made to  FIG. 15 . In a typical application, an existing electrical conduit  124  has previously been installed on the wall  148  and includes a ground wire  156  therein that is connected to earth ground. The installer secures the conduit adapter  122  to the wall  148  in close proximity to the conduit  124 . The conduit adapter  122  is then secured to wall  148  by driving fasteners  150  of fastening arrangement  146  through apertures  138  into the wall  148 . The end of electrical conduit  124  is glued into conduit receiving port  136  either before or after conduit adapter  122  is secured to the wall  148 . The grounding bar  22  is then secured to the wall and conduit adapter  122  by driving threaded fasteners  154  of mounting arrangement  152  through apertures  62  in legs  58  of grounding bar  22  and through apertures  140  in base plate  126  into wall  148 . The conduit adapter  122  is sandwiched between the grounding bar  22  and the wall  148 . Ground wire  156  is then secured in channel  24  by screw  36 . Wires from the various electrical systems that are desired to be grounded are then routed into side bores  52  and secured therein by terminal screws  108 . Lastly, after all wiring connections are complete, detachable cover  28  is secured to grounding bar  22  by threading cover attachment screw  38  of cover fastening arrangement  158  into central bore  66  of grounding bar  22 . The open channel  24  of grounding terminal block assembly  120  extends between the side surfaces  46  of the grounding bar  22  and includes an opening  160  in the front surface  42  of the grounding bar  22 . 
     With reference to  FIG. 22 , the threaded bores  64  in the grounding bar  22  include axial centers  162  and the side bores  52  in the grounding bar  22  include axial centers  164 . As shown in  FIG. 22 , the axial center  164  of the side bores  52  and the axial centers  162  of the threaded bores  64  extending from the front surface  42  of the grounding bar  22  intersect and are perpendicular to one another. 
     The conduit adapter  122  is preferably molded in one piece of an electrically insulating material such as plastic. The plastic used to form the conduit adapter  122  is preferably polyvinyl chloride (PVC). Conventional electrical conduit is typically constructed of polyvinyl chloride. Conduit adapter  122  is typically constructed of polyvinyl chloride to enable the use of conventional PVC adhesives for securing electrical conduit within the conduit receiving ports  136  of the conduit adapter  122 . 
     The grounding bar  22  of the grounding terminal block assembly is preferably constructed of an electrically conductive material. Preferably the grounding bar  22  is constructed of metal with preferred metals including zinc, aluminum, brass, copper, and zinc alloys including aluminum, magnesium, and copper. Most preferably the elongated grounding bar  22  is die cast in one piece from a die-casting alloy. An especially preferred die-casting alloy is Zamak-7. 
     Detachable cover  28  is preferably molded in one piece of an electrically insulating material such as plastic. The plastic used to form the detachable cover  28  is preferably polypropylene, polyethylene, polyvinyl chloride (PVC), acrylonitrile-butadiene styrene (ABS), or polycarbonate. 
     Having thus described the invention with reference to a preferred embodiment, it is to be understood that the invention is not so limited by the description herein but is defined as follows by the appended claims.