Abstract:
A grounding terminal block assembly for establishing proper grounding or electrical connection to earth through a path of sufficiently low impedance. The grounding terminal block assembly includes an elongated tubular body with a central longitudinal bore and a plurality of threaded bores extending into the body at right angles to the central bore. Fasteners are threaded into one or more of the threaded bores to provide fastening points for one or more phone, data, or cable TV wires. The top of the tubular body includes a threaded nose portion and lock nut for establishing a secure connection to a service panel. Conversely, for providing a grounding block in a standalone configuration without an associated service panel, legs are provided integral with the tubular body for providing direct connection to a wall or other structure.

Description:
FIELD OF THE INVENTION 
   This invention relates to terminal blocks for electrical service boxes and specifically to a grounding terminal block that will connect several devices to a service box. 
   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. 
   It is especially important to ground data, cable TV, phone lines, and other electrical lines as close as possible to the point at which the lines enter the building. Usually this is at the AC service panel or electrical panel that includes the meter can for totalizing the electrical usage. Prior to the NEC&#39;s requirements for grounding data, cable TV, and phone lines, grounding systems for service panels provided essentially one ground connection for grounding all the AC voltage leading into the service panel. 
   Accordingly, what is needed is a device for establishing separate grounding connections to earth for multiple services, including all the various phone, data, and cable TV connections entering the building at the service panel. 
   SUMMARY OF THE INVENTION 
   The invention is a grounding terminal block assembly for establishing proper grounding or electrical connection to earth through a path of sufficiently low impedance. The grounding terminal block assembly includes an elongated tubular body with a central longitudinal bore and a plurality of threaded bores extending into the body at right angles to the central bore. Fasteners are threaded into one or more of the threaded bores to provide fastening points for one or more phone, data, or cable TV wires. The top of the tubular body includes a threaded nose portion and lock nut for establishing a secure connection to a service panel. Conversely, for providing a grounding block in a standalone configuration without an associated service panel, legs are provided integral with the tubular body for providing direct connection to a wall or other structure. 
   OBJECTS AND ADVANTAGES 
   Several advantages are achieved with the grounding terminal block assembly of the present invention, including:
         (1) Grounding terminals are provided for establishing grounding for a plurality of electrical systems, including phone, data, and cable TV systems.   (2) A main body portion is die cast in one piece of metal alloy with superior electrical conduction properties for establishing proper ground.   (3) The grounding terminal block assembly can be connected directly to a service panel or can be used by itself to provide a proper grounding connection for multiple services.       

   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 a side view of a preferred embodiment of a grounding terminal block assembly connected to a service panel according to the present invention. 
       FIG. 2  is a front perspective view of the tubular body portion of the grounding terminal block assembly of  FIG. 1 . 
       FIG. 3  is a rear perspective view of the tubular body portion. 
       FIG. 4  is a front view of the tubular body portion. 
       FIG. 5  is a rear view of the tubular body portion. 
       FIG. 6  is a side view of the tubular body portion. 
       FIG. 7  is a top view of the tubular body portion. 
       FIG. 8  is a bottom view of the tubular body portion. 
       FIG. 9  is a sectional view of the tubular body portion. 
       FIG. 10  is a sectional view of the tubular body portion. 
       FIG. 11  is a side view of the grounding terminal block assembly of the present invention. 
       FIG. 12  is a rear perspective view of the grounding terminal block assembly of the present invention. 
       FIG. 13  is a schematic depicting the grounding terminal block assembly of the present invention connected to a meter can and used to provide grounding for multiple services. 
       FIG. 14  is a sectional view of the grounding terminal block assembly of the present invention with a ground wire secured therein and wiring from several services secured thereto. 
   

   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 
             
             
               22 
               wall of meter can 
             
             
               24 
               meter can 
             
             
               26 
               ground wire 
             
             
               28 
               tubular body portion 
             
             
               30 
               top end of tubular body 
             
             
               32 
               bottom end of tubular body 
             
             
               34 
               front surface of tubular body 
             
             
               36 
               rear surface of tubular body 
             
             
               38 
               side surface of tubular body 
             
             
               40 
               central bore 
             
             
               42 
               leg 
             
             
               43 
               front surface of leg 
             
             
               44 
               aperture in leg 
             
             
               46 
               flange 
             
             
               48 
               threaded nose portion 
             
             
               50 
               longitudinal rib 
             
             
               52 
               boss 
             
             
               54 
               side bore 
             
             
               56 
               filet 
             
             
               58 
               central axis through longitudinal central bore 
             
             
               60 
               threaded bore 
             
             
               62 
               top bore 
             
             
               64 
               axis of top bore 
             
             
               66 
               axis of side bore 
             
             
               68 
               flat rear surface of leg 
             
             
               70 
               ground wire fastening arrangement 
             
             
               72 
               threaded fastener 
             
             
               74 
               rear wall of central bore 
             
             
               76 
               first mounting arrangement 
             
             
               78 
               locknut 
             
             
               80 
               second mounting arrangement 
             
             
               82 
               fastener 
             
             
               84 
               wall 
             
             
               86 
               ground rod 
             
             
               88 
               ground wire 
             
             
               90 
               cable TV system 
             
             
               92 
               data system 
             
             
               94 
               phone system 
             
             
               96 
               knockout hole 
             
             
               D1 
               offset distance of top bore from central bore 
             
             
               θ 1   
               angle of threaded bore with respect to central axis 
             
             
                 
             
           
        
       
     
   
   DETAILED DESCRIPTION OF THE INVENTION 
   With reference to  FIG. 1 , the present invention comprises a grounding terminal block assembly  20  for grounding several service systems to the earth. The grounding terminal block assembly  20  is shown connected to the wall  22  of a meter can  24 . A ground wire  26  extends from the meter can  24  and will be connected to a ground rod (not shown). The grounding terminal block assembly  20  includes an elongated tubular body portion  28 . 
   Referring to  FIGS. 2 and 3 , the elongated tubular body portion  28  includes a top end  30 , a bottom end  32 , a front surface  34 , a rear surface  36 , and two side surfaces  38 . The elongated tubular body portion  28  is preferably constructed of electrically conductive metals. The tubular body is preferably produced in one-piece and is die-cast of metal. A longitudinal central bore  40  extends through the elongated tubular body  28 . 
   As shown in  FIG. 4 , the tubular body portion  28  includes two legs  42  integral with and extending outwards from the tubular body portion  28 . Each of the legs  42  includes a front surface  43  and an aperture  44  therein. The apertures  44  are at right angles with respect to the front surface  43  of the legs  42  and also with respect to the front surface  34  of the tubular body  28 . The tubular body  28  further includes a flange  46  and threaded nose portion  48  on the top end  30 . 
   Referring to  FIG. 5 , the rear surface  36  of the tubular body  28  includes a longitudinal rib  50  extending there from. The longitudinal rib  50  extends between and joins the two legs  42  and also extends between the top leg  42  and the flange  46 . The longitudinal rib  50  extends between the legs  42  thereby providing rigidity and support and bracing the legs  42 . 
   With reference to  FIGS. 6-8 , the tubular body portion  28  includes a plurality of bosses  52  extending from the front surface  34 . A plurality of side bores  54  extend through the tubular body  28 . A filet  56  is provided around the circumference of tubular body  28  at the juncture of the tubular body  28  with the flange  46 . As shown in  FIG. 8 , the front  34 , rear  36 , and side surfaces  38  of the tubular body  28  are flat. 
   Referring to  FIGS. 9 and 10 , longitudinal central bore  40  extends through the tubular body  28  and includes central axis  58 . A plurality of threaded bores  60  are provided extending into the tubular body  28  from the front surface  34  and intersecting the central bore  40  of the body at right angles Θ 1 . The threaded bores  60  extend through the tubular body  28  and through the bosses  52 . Providing the bosses  52  at the location of each threaded bore  60  thereby thickens the tubular body  28  at the location of the threaded bores  60  and provides additional body length for a longer thread length. As shown in  FIG. 9 , the tubular body  28  includes a top bore  62  within the threaded nose portion  48 . The top bore  62  includes an axial center  64 . The top bore  62  of the threaded nose portion  48  is eccentric with respect to the central bore  40  of the tubular body  28 . The central bore  40  in the tubular body  28  opens into the top bore  62  of the threaded nose portion  48  and the axial center  64  of the top bore  62  is offset from the central bore  40  toward the front surface  34  of the tubular body  28 . The top bore  62  is offset from the central bore  40  by distance D 1  as shown in  FIG. 9 , with offset distance D 1  preferably between 0.1 and 0.5 inches. As shown in  FIG. 10 , the side bores  54  extend through the tubular body  28  from the side surfaces  38 . Side bores  54  include axial centers  66  and the axial centers  66  of the side bores  54  intersect the central axis  58  of the central bore  40 . The legs  42  extending outward laterally from the rear surface  36  of the tubular body  28  include a flat rear surface  68  as shown. 
   With reference to  FIGS. 11 and 12 , the grounding terminal block assembly  20  includes a ground wire fastening arrangement  70 . The ground wire fastening arrangement  70  includes a threaded fastener  72  threaded into one or more of the threaded bores  60  in the tubular body  28 . The length of the threaded fastener  72  is such that the threaded fastener  72  is capable of to extending completely through the central bore  40  and reaching substantially to the rear wall  74  of the central bore  40 . The grounding terminal block assembly  20  further includes a first mounting arrangement  76  on the top end  30  of the tubular body  28  for mounting the tubular body  28  directly to the wall of a meter can box (not shown). The first mounting arrangement  76  includes a lock nut  78  for engaging the threaded nose portion  48  of the tubular body  28 . A second mounting arrangement  80  includes fasteners  82  for insertion through apertures  44  in legs  42  for mounting the tubular body  28  to the wall of a structure. 
   As shown in  FIG. 13 , for the operation of the present invention, the grounding terminal block assembly  20  can be secured to a meter can  24  using the first mounting arrangement  76 . A first method of mounting the grounding terminal block assembly  20  includes securing the tubular body  28  to a meter can  24  by extending the threaded nose portion  48  through a knockout or aperture in the meter can  24  and threading the lock nut  78  tightly onto the threaded nose portion  48 . The first mounting arrangement  76  utilizes the lock nut  78  to secure the grounding terminal block assembly  20  to a meter can  24  or similar service box that is mounted on a wall  84 . Ground wire  26  is then routed through the central bore of the tubular body  28  to connect the electrical meter to earth ground through ground rod  86 . Ground wires  88  are then connected by the threaded fasteners  72  to the grounding terminal block assembly  20  and to the cable TV  90 , data  92 , and phone  94  systems thereby satisfying the requirement of the electrical code to ground these systems. 
   With reference to  FIG. 12 , an alternative method for operating the grounding terminal block assembly  20  would involve mounting it directly to a wall (not shown) or similar structure. In this situation the grounding terminal block assembly  20  can be used in a standalone configuration to ground several electrical systems. In this mode of operation, the second mounting arrangement  80  is employed, which includes securing mounting fasteners  82  through apertures  44  in legs  42  into the wall or similar structure. Ground wires (not shown) can then be secured on one end to the grounding terminal block assembly  20  with threaded fasteners  72  and on their opposite ends to the electrical systems (not shown) that require a ground. 
   With reference to  FIG. 14  there is shown a sectional view of the grounding terminal block assembly  20  of the present invention secured to a meter can  24  that is mounted on a wall  84 . A ground wire  26  has been routed through the central bore  40  of the terminal block assembly  20  and secured therein by threaded fasteners  72 . Ground wires  88  from several electrical systems (not shown) are secured to the threaded fasteners  72 . The offset D 1  of the threaded nose portion  48  from the central bore  40  is important as the rear surface  36  of the tubular body  28  is positioned closer to the wall  84  as the grounding terminal block assembly  20  is secured into the knockout hole  96  in the meter can  24 . Positioning the tubular body  28  closer to the wall makes it less likely to be struck mistakenly by personnel, vehicles, etc. 
   As shown in  FIG. 1 , side bores  54  provide a critical feature to the grounding terminal block assembly  20  of the present invention as they enable an inspector to easily and rapidly view the connection between the ground wire  26  and the threaded fasteners  72 . The ability to rapidly check the internal connections within the grounding terminal block assembly  20  is advantageous over many prior art terminal blocks in which the electrical grounding connections are hidden within the assembly and in which it is therefore difficult to check the integrity of the ground wire connections. 
   The tubular body  28  of the grounding terminal block assembly  20  is preferably constructed of an electrically conductive material. Preferably the tubular body  28  is constructed of metal with preferred metals including zinc, aluminum, brass, copper, and zinc alloys including aluminum, magnesium, and copper. Most preferably the elongated tubular body  28  is die cast in one piece from a die-casting alloy. An especially preferred die-casting alloy is Zamak-7. 
   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.