Abstract:
A wire pulling tool for threading a wire through a wall or partition includes an elongate shank having a threaded end adapted to engage the end of a wire such as a cable or other type of electrical wire and a tapered end having a head ending in a point. The tool is especially adapted for structures having inner and outer walls. Once the wire is engaged the tool is pushed through a hole in the wall to the other side. The wire may then be pulled through the wall by pulling on the tool.

Description:
This application is a continuation of patent application Ser. No. 60/117,282 filed Jan. 26, 1999. 
    
    
     BACKGROUND OF THE INVENTION 
     The present invention relates to a tool for threading wire through walls. 
     Telephone and cable television installers must frequently thread cables through walls where holes have been drilled to accommodate electrical cables. Often the walls are double walls, that is, the cable must be threaded through a first or interior wall partition and a second or exterior wall partition. Frequently, insulation is stuffed into the space between the wall partitions. This presents a problem, especially with cables that have little tensile strength, as the cables bend and cannot be forced through the space between the wall partitions. Sometimes the holes must be drilled separately because of the insulation residing between the walls. The problem is also encountered in floors where there is subflooring with insulation beneath it and in ceilings where insulation has been piled in the attic on top of the ceiling. 
     Many complicated devices have been developed for drilling holes and installing wires or cables therethrough. Two examples of such devices are disclosed in Pope, U.S. Pat. No. 3,697,188, and Flener, U.S. Pat. No. 5,529,433. Both of these devices are relatively complicated. Further, as holes are often already bored, such as in the case of a reinstallation of a faulty wire or where a second telephone line is to be added, drilling is often unnecessary. Perkins, U.S. Pat. No. 5,310,294, discloses another device in which a cutting element bores a hole through a wall. Then, before removing the cutting element, a wire attachment apparatus is coupled to the cutting element. The wire cutting element, with the attached wire attachment apparatus and wire, is then pulled through the hole. Again, if the holes are already bored, this device is overly complicated and the cutting apparatus is unnecessary. 
     Other devices have been developed to catch a loose or hooked end of a cable within a narrow structure such as a wall. Caracofe et al., U.S. Pat. No. 5,458,317 and Comroe, U.S. Pat. No. 4,230,305, disclose devices that can catch, grab, or otherwise receive a pre-threaded cable. These devices are necessary when the cable is being threaded long distances through walls. These devices are particularly suited to situations where the first hole is above the second hole. However, because these devices require relatively large openings in the wall in order to insert their catching ends, they should only be used when absolutely necessary. 
     The device described in Stegall, U.S. Pat. No. 4,386,800, is used for pulling wire through pre-drilled holes. This device, however, includes multiple parts including cable grasping fingers. These parts, particularly the cable grasping fingers, could easily break, could easily be bent, or could easily become lost. Also, because the cable must be inserted into the sleeve, the size (outer diameter) of the cable to be pulled through the wall is strictly limited by the inner diameter of the sleeve. 
     What is needed then is a simple device that is capable of threading wire or cable through pre-drilled holes in a wall, ceiling, or flooring. The device should be sturdy and adaptable to multiple types and sizes of wire and cable. 
    
    
     BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING 
     FIG. 1 is a simplified side view of a preferred embodiment of the wire threading tool of the present invention. 
     FIG. 2 is an enlarged cross-sectional side view of a preferred embodiment of a wire connecting end of the wire threading tool of the present invention. 
     FIG. 3 is a simplified side view of a preferred embodiment of the threading tool of the present invention interconnected with a wire and being threaded through a wall. 
     FIG. 4 is a reduced facsimile copy of a preferred embodiment of the wire threading tool. 
     FIG. 5 is an enlarged facsimile copy of the wire connecting end of the wire threading tool of FIG.  4 . 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
     FIGS. 1 and 4 show a preferred embodiment of the wire threading tool  10  of the present invention. The wire threading tool  10  is preferably a slender rod  12  having a threading end  14  and a wire connecting end  16 . As will be described in detail below in connection with FIG. 3, the wire connecting end  16  of the wire threading tool  10  connects to a wire, cable, or other flexible device (indicated generally as  18 ) that can also be bored so as to be attached to the wire connecting end  16 . The wire threading end  14  of the wire threading tool  10  guides the tool through a wall, partition, ceiling, flooring, or other solid surface (indicated generally as  20 ) that may include insulation  22 . By pulling or pushing the wire threading tool  10  through the wall  20 , the attached wire  18  follows and is thereby threaded through the wall  20 . 
     The rod  12  is shown as a {fraction (3/16)}″ steel rod. However, the rod may be made from any relatively stiff material including, but not limited to, copper, plastic, or ceramic. Further, the width of the rod may be adapted to suit the intended use of the rod. For example, larger widths may be used for heavier cable and narrower widths may be used for lighter cable. It should be noted, however, that a single size can accommodate a great variety of wire sizes. The length of the rod may also be adapted for its intended use. For example, 10″-12″ lengths have been shown suitable for use in outside walls or partitions between levels of a building. 24″ lengths have been shown as useful for interior walls and floors of manufactured homes. 
     The threading end  14  of the wire threading tool  10  is shown as tapered or ground to a blunt point. A sharper point may be used for applications in which there is significant or particularly thick insulation present or if a thin membrane (such as those used in manufactured homes) is present. If the rod  12  is made from an alternate material, the threading end  14  may be molded into a pointed form or may be attached as a separate piece. 
     The shown embodiment of the wire connecting end  16 , shown in detail in FIGS. 2 and 5, preferably has a flat surface  24  on the wire connecting end  16  of the rod  12 . The flat end  24  has a bore hole  26  therein. A screw apparatus  28  is inserted into the bore hole  26 . The screw apparatus  28  may be a drywall screw with its head removed. Alternatively, the screw apparatus  28  may be any screw-type device suitable for coupling with the end of a wire  18 . The screw apparatus  28  is brazed (shown as  30 ), welded, glued, or otherwise securely interconnected within the bore hole  26 . The screw apparatus  28  may also be formed integrally with the rod  12 . 
     FIG. 3 shows the wire connecting tool  10  threading a wire  18  through a wall  20 . In this figure the wire connecting end  16  is securely connected to a wire  18 . The wire threading end  14  is inserted through a first or inside partition  32 , insulation  22 , and a second or outside partition  34  of a wall  20 . By pulling or pushing the wire threading tool  10  through the wall  20 , the attached wire  18  follows and is thereby threaded through the wall  20 . 
     One preferred method for creating the wire threading tool  10  includes the step of cutting a rod  12  to a desired length. One end, the wire threading end  14 , of the rod  12  is then tapered or ground to a blunt point. The wire connecting end  16  is then created by grinding or otherwise creating the flat surface  24 , drilling or boring the bore hole  26 , inserting the screw apparatus  28 , and then securing the screw apparatus  28  within the bore hole  26 . The screw apparatus  28  may be secured by brazing, welding, gluing, or performing any securing step to securely interconnect the screw apparatus  28  within the bore hole  26 . An alternate preferred method for creating the wire threading tool  10  is to mold the tool  10  as a single integral unit. 
     One preferred method of using the wire threading tool  10  includes connecting the wire connecting end  16  to an untrimmed end of a wire  18 , preferably by screwing the screw apparatus  28  into the end of the wire. Next, the threading end  14  is inserted into a preferably pre-bored hole  36  (shown in phantom in FIG. 3) of a first partition  32  of a wall  20 , through any insulation  22  present, and through the second partition  34  of the wall  20 . The tapered threading end  14  may be used as a guide, may be used to find a hole in the second partition  34 , or may be used to puncture a thin membrane (not shown). The tool  10  may either be pulled through the wall  20  by locating the distal end of the tool and pulling it, or may be pushed through by feeding the wire  18  by hand. Once through the wall  20 , the attached wire  18  follows the tool  10  and is thereby threaded through the wall  20 . The wire  18  may then be trimmed and used for its intended purpose. 
     The wire threading tool  10 , as described above, is useful for threading most types of wires and cables  18  through walls  20 , ceilings, and floors of existing buildings. For example, the wire threading tool  10  may be used in the installation or maintenance of telephone wires, cable television cables, and electrical wires. Also, because of the weight of the tool  10 , a wire  18  fed through an exterior wall  20  from within the structure will be pulled by gravity downward after the wire connecting end  16  clears the exterior wall  20 . By feeding the cable by hand from within the structure, no ladder is necessary for installation on multi-level structures. 
     The terms and expressions which have been employed in the foregoing specification are used therein as terms of description and not of limitation, and there is no intention, in the use of such terms and expressions, of excluding equivalents of the features shown and described or portions thereof, it being recognized that the scope of the invention is defined and limited only by the claims which follow.