Abstract:
A wire gripping assembly for securing an electrical box or light fixture to a support. The wire gripping assembly includes a wire gripping device having a body with open channels and a through bore, a clip member having legs for sliding engagement within the channels, a cable having an end connector thereon, and a thumbscrew for adjusting the clip member with respect to the body. The thumbscrew includes a head having an outer circumference with serrations to enable hand tightening and an end with a slot for engagement by a screwdriver or similar tool. The wire gripping assembly eases installation of an electrical device to an overhead support by enabling a two-step connection including initial hand tightening using the serrated outer surface of the thumbscrew and subsequent secure tightening by engaging the slot of the thumbscrew with a screwdriver or similar tool.

Description:
This application is a Continuation-In-Part of U.S. patent application Ser. No. 29/460,462 filed Jul. 11, 2013 and still pending, which is incorporated herein in its entirety by reference thereto. 
    
    
     FIELD OF THE INVENTION 
     The present invention relates to devices for the installation of electrical outlet or junction boxes and more particularly to a wire gripping assembly useful for the suspension of electrical outlet boxes or light fixtures from above as might be required in suspended ceiling installations and the like. 
     BACKGROUND OF THE INVENTION 
     Commonly owned parent application Serial No. 29/460,462 disclosed the ornamental design for a wire gripping device with a knurled thumbscrew. The wire gripping device is used for the adjustable suspension of electrical boxes or light fixtures from above as might be required in suspended ceiling installations and the like. 
     Although many overhead support devices have been proposed for the support of electrical boxes or light fixtures, the devices are usually cumbersome to operate as the installer must typically support the electrical box or light fixture while at the same time manipulating a tool, such as a screwdriver, to complete the installation. 
     What is needed is an improved overhead support device that eases the installation task by enabling the installer to at first hand tighten the electrical box or light fixture to the overhead support to hold it in place, and afterwards to complete the installation by tightening the connections with a screwdriver. Providing a hand tightening capability to the overhead support device enables the installer to quickly connect the suspended device to an overhead support while also freeing the installer&#39;s hands to subsequently complete the installation by tightening the connections with a screwdriver. 
     SUMMARY OF THE INVENTION 
     According to the present invention, there is provided a wire gripping assembly for enabling an installer to secure an electrical box or light fixture to a support in two steps, including initially hand tightening the wire gripper and subsequently securely tightening with a screwdriver. The wire gripping assembly positively locks a wire or cable in place between an overhead support and a suspended load such that it can support the suspended load and maintain tension on the wire. The wire gripping assembly includes a wire gripping device and a cable for supporting an electrical box or light fixture. The wire gripping device includes a knurled thumbscrew that enables initial hand tightening connection of an electrical device to an overhead support. After initial hand tightening, an installer&#39;s hands are freed to complete the installation by tightening with a screwdriver or similar tool. The cable may include a loop or one or more hooks for effecting a quick and secure attachment of an electrical device to an overhead support. 
     OBJECTS AND ADVANTAGES 
     Several advantages are achieved with the wire gripping assembly of the present invention, including:
         (1) The wire gripping assembly can be used to rapidly suspend an electrical box, light fixture, or similar load from a support.   (2) The wire gripping assembly eliminates the need for tools to effectively suspend an electrical box, light fixture, or similar load from a support.   (3) The wire gripping assembly will maintain tension on the suspended load while supporting it in place.   (4) The wire gripping assembly includes all of the components required for an installer to suspend an electrical box or light fixture from an overhead support.   (5) The wire gripping assembly will work in conjunction with conventional support wires of several diameters including 0.062-inch, 0.080-inch, and 0.093-inch diameter wires.   (6) The wire gripping assembly will support a maximum static load of 100 pounds for electrical boxes and a maximum static load of 75 pounds for light fixtures.       

     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  an isometric view of a preferred embodiment of a wire gripper assembly according to the present invention. 
         FIG. 2  is a side view of a wire gripper body that forms a portion of the wire gripper assembly of  FIG. 1 . 
         FIG. 3  is an end view of the wire gripper body. 
         FIG. 4  is a sectional view of the wire gripper body taken along line  4 - 4  of 
         FIG. 2 . 
         FIG. 5  is a sectional view of the wire gripper body taken along line  5 - 5  of  FIG. 3 . 
         FIG. 6  is a top isometric view of the wire gripper body. 
         FIG. 7  is a bottom isometric view of the wire gripper body. 
         FIG. 8  is a side view of a clip member that forms a portion of the wire gripper of  FIG. 1 . 
         FIG. 9  is an end view of the clip member. 
         FIG. 10  is a top view of the clip member. 
         FIG. 11  is an isometric view of the wire gripper. 
         FIG. 12  is a side view of the wire gripper assembly of  FIG. 1 . 
         FIG. 13  is a top view of the wire gripper assembly. 
         FIG. 14  is an end view of the wire gripper assembly. 
         FIG. 15  is bottom view of the wire gripper assembly. 
         FIG. 16  is a sectional view of the wire gripper assembly taken along line  16 - 16  of  FIG. 12 . 
         FIG. 17  is a sectional view of the wire gripper assembly taken along line  17 - 17  of  FIG. 14 . 
         FIG. 18  is a sectional view of the wire gripper assembly taken along line  17 - 17  of  FIG. 14  and including a wire inserted and secured therein. 
         FIG. 19  is an isometric view of the wire gripping assembly of the present invention supporting an electrical box. 
         FIG. 20  is an isometric view of the wire gripping assembly of the present invention supporting a light fixture. 
         FIG. 21  is a plan view of a wire gripping assembly for supporting an electrical box. 
         FIG. 22  is a plan view of a an alternate embodiment of a wire gripping assembly for supporting a light fixture. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     With reference to  FIG. 21  there is shown a preferred embodiment of a wire gripping assembly  30  including a wire gripper  32  and a cable  34  including an end connector thereon  36 . The end connector  36  is a loop on one end of the cable  34 . 
     As shown in  FIG. 1 , the wire gripper  32  is an assembly of several parts including a body  42 , a clip member  44 , and a thumbscrew  46 . Clip member  44  includes legs  48  thereon and body  42  of wire gripper  32  includes channels  50  for accepting slidable movement of the legs  48  of the clip member  44  therein. Thumbscrew  46  includes a large head  52  that engages the clip member  44  and enables adjustment of the clip member  44  with respect to the wire gripper body  42 . The head  52  of thumbscrew  46  includes an end  49  having a slot  51  therein and an outer circumference  53  having serrations  55  thereon. 
     Referring to  FIGS. 2-5 , wire gripper body  42  is preferably constructed of metal and includes a base portion  54  having two ends  56 , a top  58 , a bottom  60 , and two sides  62 . A boss  64  is integral with the base  54  and extends orthogonally from the top  58  of the body  42 . A through bore  66  extends longitudinally through the base  42  to both ends  56 . A threaded bore  68  is centered in and extends through the boss  64  to the through bore  66 . Although through bore  66  is shown herein as a circular bore in the drawings, it should be understood that through bore  66  can be of various shapes, including square, hexagonal, octagonal, oval, and others, without departing from the scope of the invention. 
     As shown particularly in  FIG. 5 , two open channels  50 , provided on either side of the boss  64 , divide the body  42  into end portions  70  at each end  56  of the body  42 . The through bore  66  also extends through the boss  64  thereby creating a ledge  72  in the boss  64  immediately below the through bore  66 . The ledge  72  includes two ends  74  and is in axial alignment with the threaded bore  68 . The various portions of the through bore  66  are in axial alignment along longitudinal axis  76  as shown in  FIG. 5 . 
     With reference to  FIGS. 8-11 , the clip member  44  includes a base  78  with an aperture  80  centered therein. The legs  48  are orthogonal with respect to the base  78 . As shown in  FIG. 8 , the clip  44  includes shoulders  82  connecting the base with the legs  48 . The shoulders  82  extend at an angle of θ1 with respect to the base  78 . Preferably, angle θ1 is between 35 and 55 degrees. Inclusion of shoulders  82  strengthen the legs  48  with respect to the base  78 . As shown in  FIG. 9 , the legs  48  include two sides  84  and leg ends  86 . The leg ends  86  include a concave arcuate surface  88  extending between the two sides  84  of the leg ends. 
     Referring to  FIGS. 12-15 , the wire gripper  32  is an assembly of the body  42 , the clip member  44 , and the thumbscrew  46 . When assembled, the thumbscrew  46  can be tightened to bear against the base  78  of the clip  44  and thereby urge legs  48  of clip  44  into threaded bore  68  (see  FIG. 6 ) in wire gripper body  42 . With thumbscrew  46  extending through aperture  80  in the base  78  of the clip  44  and threaded into threaded bore  68 , legs  48  of clip member  44  extend into the channels  50  of body  42 . As shown in  FIG. 14 , the arcuate surface  88  of each leg  48  of clip  44  is substantially centered in the through bore  66 . Thus as thumbscrew  46  is tightened within threaded bore  68 , the arcuate surfaces  88  at the ends of each leg  48  will advance farther into each channel  50  of wire gripper body  42 . 
     With reference to  FIG. 18 , the wire gripper assembly  30  of the present invention is used to anchor or support a suspended load or electrical device such as an electrical box or light fixture (not shown). To secure a wire or cable  90  within the wire gripper  32 , the thumbscrew  46  is first loosened sufficiently to withdraw legs  48  from channels  50 , thereby opening through bore  66  and enabling the installer to thread the cable  90  through the through bore  66  one or more times. The cable  90  may be doubled up through the through bore  66 . The thumbscrew  46  is first tightened by hand, thereby forcing arcuate surfaces  88  of legs  48  against the cable  90 . As arcuate surfaces  88  of legs  48  press against the cable  90 , the cable is in turn pressed against both ends  74  of ledge  72  and end portions  70  of body  42 . A screw driver (not shown) is then inserted into slot  51  to fully tighten thumbscrew  46  against the cable  90 . With the thumbscrew  46  fully tightened in the wire gripper  32 , six points of contact  92  on the cable  90  are established within the wire gripper  32  including at the arcuate surfaces  88  of each leg  48  of clip member  44 , at each end portion  70  of body  42 , and at each end  74  of the ledge  72 . After the thumbscrew  46  is fully tightened, the wire gripper  32  securely holds the suspended load. In the preferred embodiment of the wire gripper  32 , the diameter D1 of the through bore  66  is at least two and a half times the diameter D2 of the cable  90 . For use with a stranded wire cable  90  having a diameter D2 of 0.080-inch for example, the diameter of the through bore  66  is preferably at least 0.020-inch. 
     Referring to  FIG. 21 , the preferred embodiment of the wire gripping assembly  30  includes the wire gripper  32  and the cable  34  including an end connector  36  thereon. The end connector  36  is a loop on one end of the cable  34 . The wire gripping assembly  30  includes the wire gripper  32  and the cable  34 . For initial tightening, thumbscrew  46  can be tightened against cable  34  within wire gripper assembly  30  by hand. Subsequently a screw driver is used to secure an electrical device to a support using the wire gripping assembly  30 . 
     With reference to  FIG. 22  there is shown a second embodiment of a wire gripping assembly  96  according to the present invention. Wire gripping assembly  96  is for securing an electrical device (not shown) to a support. Wire gripping assembly  96  includes the wire gripper  32 , and the cable  34  including an end connector  36  thereon. The end connector  36  in wire gripping assembly is a snap hook  98 . Most preferably, the end connector  36  includes two snap hooks  98 . Cable  34  includes a first portion  101  and two opposing end portions  103  joined to first portion  101  by a joint  105 . 
       FIG. 19  illustrates an example of the preferred embodiment of a wire gripping assembly  30  according to the present invention supporting an electrical box  107 . The wire gripping assembly  30  includes the wire gripper  32  and a cable  34  having a free first end  109  and a second end  111  with an end connector  36  thereon. The end connector  36  is a loop on the first end  109  of the cable  34 . To operate the wire gripping assembly  30 , the second end  111  of the cable with end connector  36  is passed around the support  113  and the free first end  109  of the cable  34  is passed through the end connector  36 . The first end  109  of the cable  34  is then run through bore  66  of wire gripper  32 , then through aperture  115  in knockout engagement member  116  of electrical box  107 , and then passed again through bore  66  of wire gripper  32 . The thumbscrew  46  is then tightened by hand to initially secure electrical box  107  to support  113 . Installation is completed by inserting and turning a screwdriver (not shown) within slot  51  of thumbscrew  46 . 
       FIG. 20  illustrates an example of the second embodiment of a wire gripping assembly  96  according to the present invention supporting a light fixture  117 . The wire gripping assembly  96  includes the wire gripper  32  and a cable  34  having a free first end  109  and a second end  111  with an end connector  36  thereon. The end connector  36  is a pair of snap hooks  98 . To operate the wire gripping assembly  96 , the snap hooks  98  of end connector  36  on second end  111  of cable  34  are first secured through apertures  119  of light fixture  117 . The free first end  109  of cable  34  is then passed through the bore  66  of the wire gripper  32 , around the support  113 , and then back through the bore  66  of wire gripper  32 . As the desired tension is applied by hand to the first end  109  of cable  34 , thumbscrew  46  is hand tightened to initially secure light fixture  117  to support  113 . Installation is completed by inserting and turning a screwdriver (not shown) within slot  51  of thumbscrew  46 . xx 
     The wire gripper body  42 , clip  44 , and thumbscrew  46  are all preferably constructed of metal. Preferably, the body  42  is constructed of a die cast alloy. Most preferably, the body  42  is die cast of ZAMAK, a casting alloy comprised mainly of zinc alloyed with aluminum, magnesium, and copper and available from Eastern Alloys of Maybrook, N.Y. Most preferably, the clip  44  is constructed of hot dipped galvanized steel in a thickness of at least 0.093-inch and with a minimum plating thickness of at least 0.0005-inch per side of the clip. It is important that clip  44  have sufficient thickness so that the legs  48  are rigid and therefore bear against an inserted wire or cable when the thumbscrew  46  is fully tightened. Most preferably, the thumbscrew  46  is a No. 10-24×⅝-inch long knurled head tri-drive machine screw with serrations. The wire gripper  32  of the present invention is rated to support a load of 50 pounds with a 0.62-inch diameter wire, 100 pounds with a 0.80-inch diameter wire, and 150 pounds with a 0.93-inch diameter wire. 
     Most preferably, the cable  34  of drop wire kits  30  and  96  is galvanized stranded wire of 7×7 stranded construction having a 0.080-inch (2.0 mm) core diameter, a galvanized zinc plating of at least 0.00015-inch thickness, and a break strength of 500 pounds. Most preferably, at least a 5-foot length of cable is provided for each wire gripper  32  provided in the kit. 
     In addition to the wire gripper  32  and the cable  34 , drop wire kit  30  may also include an electrical box  107 , such as the FBS415 electrical box, available from Arlington Industries, Inc. of Scranton, Pa. 
     Although the description above contains many specific descriptions, materials, and dimensions, these should not be construed as limiting the scope of the invention but as merely providing illustrations of some of the presently preferred embodiments of this invention. Thus the scope of the invention should be determined by the appended claims and their legal equivalents, rather than by the examples given.