Non-metallic outlet box having a ground strap with plural ground screws

Information

  • Patent Grant
  • 6369323
  • Patent Number
    6,369,323
  • Date Filed
    Monday, June 26, 2000
    24 years ago
  • Date Issued
    Tuesday, April 9, 2002
    22 years ago
Abstract
The electrical outlet box assembly accommodates an electrical termination device. A non-metallic outlet box housing includes a back wall and a perimetrical side wall with an open front face defining a box interior. A metallic ground strap is supported by the housing within the box interior. The ground strap includes an elongate portion including a pair of spaced apart mounting members in electrical continuity through the elongate portion. The mounting members are positioned to accommodate a ground wire of the electrical termination device.
Description




FIELD OF THE INVENTION




The present invention relates generally to an electrical outlet box for housing termination devices such as switches and receptacles. More particularly, the present invention relates to a non-metallic outlet box including a ground strap having a pair of ground screws thereon to accommodate the ground wires in the outlet box.




BACKGROUND OF THE INVENTION




In terminating electrical conductors to termination devices such as switches, receptacles, ground fault circuit interrupters (GFI) and the like, terminations are typically supported within an electrical outlet box. The outlet box supports and encloses the termination device as well as the wires which are to be terminated thereto. All of the devices housed within the outlet box must be grounded. This requires a wire to be attached from the termination to a portion of the box which is attached to a ground conductor of the power wires fed to the box. With metal boxes, grounding may be accomplished by attaching the wire from the termination to the metal box which is itself attached to the ground conductor. With non-metallic plastic boxes however, a metallic ground strap must be provided within the box. The ground strap is connected to the ground conductor of the power wires fed to the box. Ground wires of the termination device may be attached to the ground strap in order to effect ground continuation between the ground wire and the device.




Typically, the ground straps are provided with a single screw. This ground screw would attach both the ground conductor of the power wires and the ground wire of the termination device. In certain situations where multiple termination devices are supported within a box, it is difficult to individually connect plural wires to a single screw. In addition, in certain situations, the power line is continued from one outlet box to another. In order to continue the ground wire from one box to the next, the ground screw must be undone and a new line must be attached to or continue the power to the next location. As may be appreciated, all of the grounding terminations may not be adequately accommodated by a single ground screw. Further, in prior boxes the single ground screw may be located next to the lip of the box making it difficult to terminate plural ground wires thereto.




SUMMARY OF THE INVENTION




It is, therefore, an object of the present invention to provide an electrical outlet box for accommodating termination devices, where the termination devices may be grounded in the box.




It is a further object of the present invention to provide non-metallic outlet box for accommodating a termination device such as a switch or receptacle. The non-metallic box supports a metallic ground strap for permitting ground connection.




It is still further object of the present invention to provide an outlet box for accommodating termination devices such as switches or receptacles which provides a ground strap having a pair spaced apart mounting members for accommodating ground wire of the termination device.




In the efficient attainment of these and other objects, the present invention provides an electrical outlet box for accommodating electrical termination device. The outlet box includes a non-metallic outlet box housing having a back wall and a perimetrical side wall with an open front face defining a box interior. A metallic ground strap is supported by the housing within the box interior. The ground strap has an elongate portion including spaced apart mounting members in electrical continuity through the elongate portion. The mounting members are positioned to accommodate ground wires extending from the electrical termination device.




As more fully described in the preferred embodiment herein, the ground strap is an L-shaped member including a first leg supported on the back wall of the outlet box, and a second leg supported on the sidewall. The first leg of the ground strap includes a pair of spaced apart internally threaded apertures which accommodate ground screws. The outlet box assembly of the present invention permits the wires to be connected to the various ground screws thereby placing the wires in ground continuity without the need to attach the wires to the same ground screw.











BRIEF DESCRIPTION OF DRAWING





FIG. 1

is a front perspective showing of the outlet box assembly of the present invention.





FIG. 2

is a top perspective showing of the outlet box of the assembly of FIG.


1


.





FIG. 3

is a rear perspective showing of the outlet box of FIG.


2


.





FIGS. 4

,


5


and


6


show top, side and rear plan views respectively of the ground strap used in the outlet box assembly used in FIG.


1


.





FIG. 7

is an enlarged showing of a portion of ground strap of FIG.


4


.











DESCRIPTION OF THE PREFERRED EMBODIMENTS




Referring to

FIGS. 1-3

, the present invention includes an outlet box assembly


10


. Assembly


10


includes a generally rectangular non-metallic plastic box


12


which includes a back wall


14


, top and bottom walls


16


and


18


, and opposed side walls


20


and


22


. Box


12


has an open front face


24


defining a box interior


26


. As it is commonly known in the electrical art, electrical terminations (not shown), such as switches and receptacles may be housed within the interior


26


of box


12


.




In order to facilitate securing the box to a stud, the box assembly


10


further includes extending brackets


25


along side wall


20


. Brackets


25


may be used to attach box


12


to the side of stud by use of fastener such as nails. In that regard, box


12


is referred to as a nail-on box.




Additionally, box


12


may include an extending frame


27


positioned inwardly from and perimetrically about open front face


24


. Frame


27


also assists in mounting box


12


to a wall surface. Also, as well known in the box art, the wall


14


may include openings


29


to facilitate entry of wires into box


12


. The opening


29


may be closed by retaining members


23


which captively receive the wires inserted into the box.




Outlet box assembly


10


further supports a ground strap


30


also shown in more detail in

FIGS. 4 through 7

. The ground strap


30


is generally an L-shaped member formed of conductive metal having a first leg


32


, a second leg


34


extending at a right angle thereto and a hook-shaped end portion


36


. As shown in

FIG. 1

, first leg


32


is centrally positioned against the back wall


14


of box housing


12


. The second leg


34


extends from the back wall towards the open front face


24


of box


12


along the interior surface


16


a of top wall


16


. The hook-shaped member


36


extends around the top wall


16


of box


12


in order to support ground strap


30


within box


12


. As shown in

FIG. 7

, the depending end


36




a


of hook-shaped member


36


may include outwardly projecting barbs


36




b


for locking engagement into appropriate recess


16




b


on the top wall


16


of box


12


(

FIG. 1

) in order to further support ground strap


30


thereto.




As shown in detail in

FIGS. 3 and 4

, first leg


32


of ground strap


30


includes a pair of spaced apart apertures


40


and


41


which are aligned with apertures


42


and


43


in the back wall


14


of box


12


. Apertures


40


,


41


and


42


,


43


permit the accommodation of ground screws


50


thereinto. In that regard, either or both of apertures


40


and


41


may be internally screw threaded so as to engage the threads of ground screws


50


and


51


to support the ground screws thereat. Apertures


42


and


43


may include an outwardly projecting dimple


42




a


,


43




a


which also helps accommodate ground screws


50


and


51


. Ground screws


50


, inserted through one or both of apertures


40


and


41


of ground strap


30


, also extend through apertures


42


and


43


of back wall


14


to help secure ground strap


30


to box housing


12


.




The pair of ground screws


50


and


51


provided on the first leg


32


of ground strap


30


permit ground conductors to be separately accommodated by each of the ground screws. This allows greater freedom in attaching multiple devices within a single box. Ground conductors attached to either of ground screws


50


and


51


are in electrical continuity via ground strap


30


. As an example, the ground conductor of the power wires extending into box


12


through opening


29


may be attached to one ground screw


50


while the ground wire from the termination device such as a switch or receptacle may be attached to the other ground screw


51


. Thus, one of the ground screws need only accommodate a single wire. This is in distinction to the prior art devices having a single ground screw where multiple wires are required to be terminated by the single ground screw.




Various changes in modifications may be made to the invention, and it is intended to include all such changes and modifications as come within the scope of the invention and as set forth in the following claims.



Claims
  • 1. An electrical outlet box for accommodating an electrical termination device comprising: a non-metallic outlet box housing having a back wall, a perimetrical sidewall and an open front end defining a box interior; an L-shaped metallic ground strap supported within said box interior, said ground strap having an elongate first leg supported on said back wall of said outlet box housing and a second leg supported on said sidewall, said elongate first leg including a pair of spaced apart mounting members in electrical continuity therethrough, said mounting members positioned to accommodate a ground wire of said electrical termination device, a distal end of said second leg includes a hook-shaped member positioned adjacent said open front end of said outlet box.
  • 2. An electrical outlet box of claim 1 wherein said mounting member includes a pair of spaced apart apertures, each of which accommodates a ground screw therein which define said mounting members.
  • 3. An electrical outlet box of claim 2 when said apertures are internally screw threaded.
  • 4. An electrical outlet box of claim 1 wherein said perimetrical side wall includes a slot formed on an exterior surface thereof adjacent said open front end for accommodating said hook-shaped member.
  • 5. An electrical outlet box of claim 4 wherein said hook-shaped member includes a barb extending therefrom for engagement with said exterior surface within said slot for securing said ground strap to said box housing.
Parent Case Info

This application claims the benefit of U.S. Provisional Application No. 60/142,286, filed on Jul. 2, 1999.

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Number Date Country
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