Abstract:
A bushing for a hole in a structural member includes a flange with an aperture there through. A plurality of tabs are hinged to the flange at locations around the aperture. During installation of the bushing, the plurality of tabs are inserted into the hole with the flange being located on one side of the structural member. The plurality of tabs then are flared outward on the opposite side of the structural member to prevent the bushing from being extracted from the hole. A plurality of latches retain the tabs in the flared position.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     Not Applicable 
     STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT 
     Not Applicable 
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to bushings for insertion into holes in a structural member, such as a metal wall stud, to protect electrical wires that pass through that hole. 
     2. Description of the Related Art 
     In many instances, metal studs are being used in the walls of buildings instead of conventional wooden studs. The metal studs are fabricated by bending sheet metal to form an elongated member having a “C” shaped cross section. Holes are punched in the wide side of the metal stud to allow wires and pipes to be run within the wall. The relatively thin edge of these holes can abrade and cut the insulation of the wires and cables being pulled through the studs during installation and in several cases damage to the metal conductors of the cable can occur. As a consequence, electricians have to exert extreme care when installing wires through metal studs. 
     As a solution to this problem, bushings have been devised which are placed into the respective openings in the metal studs and then the wires and cables are run through the bushing. Such bushings are fabricated of rubber or plastic and have surfaces against which the wires may rub with negligible abrasion. As a consequence, the bushings protect the wires both during installation and thereafter. 
     It is desirable that such bushings be easy and quick so that the labor required to install electrical wires and cables is not increased significantly. In this regard, it is therefore desirable that the bushing be fabricated as a single piece to eliminate the need for the electrician to locate multiple components and then assemble them in the hole of the stud. For example, U.S. Pat. No. 5,596,177 discloses a single piece bushing in which a backing flange is attached to a mating face flange by a strap. However, this type of bushing requires that the aperture in the stud be large enough to enable the backing flange to pass there through so that the face and backing flange ultimately are at opposite sides of the stud aperture when the bushing is fully assembled. 
     SUMMARY OF THE INVENTION 
     A bushing for a hole in a structural member, such as a metal stud, includes a flange which is larger in at least one dimension than the hole. The flange has an aperture there through and a plurality of tabs are connected to the flange at locations around the aperture. The tabs are bendable between a first position in which the plurality of tabs is able to enter the hole in the structural member and a second position in which the plurality of tabs retains the bushing in the hole. 
     When the bushing is installed, the plurality of tabs are inserted into the hole with the flange abutting a surface on one side of the structural member. The plurality of tabs are then bent to flare outward on the opposite side of the structural member. In the preferred embodiment, the bushing has a latching mechanism attached to the flange which maintains the plurality of tabs in the bent second position. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is an isometric view of a bushing according to the present invention; 
     FIG. 2 is top view of the bushing in FIG. 1; 
     FIG. 3 is a cross-sectional view of the bushing in an intermediate stage of installation on a metal stud; and 
     FIG. 4 is a cross-sectional view of the bushing completely installed on the metal stud. 
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     With initial reference to FIGS. 1 and 2, a bushing  10  has a planar, annular flange  12  with a central, circular aperture  14  extending there through. Four tabs  16  project from one surface  15  of the flange  12  and are equidistantly spaced around the central aperture  14 . The tabs  16  are curved with a radius that conforms to the radius of the central aperture  14 . Thus, the four tabs  16  in a first position, as illustrated, form a generally cylindrical, tubular structure projecting from the one surface  15  of the flange  12 . As will be described, this tubular structure is able to enter an opening in a structural member, such as a metal stud for example. 
     Each of the tabs  161  as body  18  from which two legs  20  extend and which are connected to the flange  12 . Each of the legs  20  has a transverse notch  22  which reduces the thickness of the leg. The notches  22  form hinge portions in each leg that enable the respective tab  16  to bend downward approximately 90 degrees into a second position in which the body  18  is substantially parallel to the flange  12 . Because of the curvature of the tabs, one will appreciate that in the second position each tab is not exactly parallel to the plane of the flange  12 . As will be described, the bushing is placed into this second position upon being installed on a structural member. 
     Although a circular central aperture  14  and correspondingly curved tabs  16  are shown in the illustrated embodiment of the exemplary bushing  10 , a rectangular aperture could be provided with straight tabs along each side of the aperture. This variation of the bushing would be particularly useful with rectangular apertures often found in metal studs. In addition, the flange also could have a different geometric shape appropriate to the shape of the central aperture. Similarly, other geometrically shaped central apertures and flanges can be designed to correspond to the shape of the stud aperture in which the bushing is to be used. 
     A separate latch  24  is located in a notch of each tab  16  that is formed between the pair of legs  20 . The tab  16  extends upward from the surface of the flange  12 . Each latch  24  has a tapered upper surface  26  which extends downward to a flat hook edge  28 . Thus, there are four latches  24 , each associated with a different one of the plurality of tabs  16 . 
     Four short walls  30  extend upwardly from the surface of the flange  12  with each wall  30  being located in the notch between a pair of adjacent tabs  16 . Each wall is curved to conform to the circumference of the central circular aperture  14  in the flange. As will be described, these walls aid in centering the flange in the opening of the stud, and also shield wires passing through the stud from the edges of the stud aperture adjacent the corresponding locations of the bushing. 
     Referring to FIG. 3 the bushing  10  is used by inserting the generally cylindrical configuration of the four tabs  16  through a hole  42  in a metal stud  40 . The stud typically is manufactured with such holes  42  that have standard size and shapes. Alternatively, an electrician may use a hole cutting tool to create custom sized holes at desired locations in the stud. As seen in the illustration, the bushing  10  is sized so that the tabs  16  and latches  24  will ass easily through the stud hole  42  when the tabs are in the first position illustrated. The stud hole  42  can be smaller than that illustrated so that the latches  24  bend and snap over the edges of that hole. The geometric shape of the stud hole  42  does not limit the use of the bushing  10 . That is, although the exemplary version of the bushing  10  is illustrated with the four tabs  16  located in a circular configuration, that bushing can be used with rectangular or other shaped stud holes as long as the assembly of tabs  16  can pass through the hole and the flange  12  is large enough to preclude the entire bushing from passing through the hole. The flange has to be larger than the hole, but does not have to entirely cover the hole. For example the corners of a square stud hole the may be slightly exposed, yet the flange may have a diameter that is greater than the length of each side of the square and still is considered to be larger than the hole. The key characteristic is that the size of the flange preclude the entire bushing from passing through the hole when completely installed. 
     Once the tabs have been inserted through the hole, the flange  12  is held against one surface of the stud  40 . The installer then bends each of the four tabs  16  outward, flaring them away from the central aperture  14  and against the opposite surface of the stud  40  as shown in FIG.  4 . In doing so, each of the tabs  16  bends about the hinge notch  22  in the legs  20  of the tab. As this bending occurs, an edge  32  which is between the two legs  20  of each tab  16 , rubs along the tapered surface  26  of the corresponding latch  24 . This engagement forces the latch  24  to bend slightly allowing the tab edge  32  to pass over the tip  34  of the latch after which the latch springs back into its original position wherein latch surface  38  engages the tab  16  to hold the tab in a bent second position against the stud  40 . When all four of the tabs  16  are so positioned and latched in place, the bushing  10  is captivated in the hole  42  of the stud wherein the stud  40  is held between the flange  12  and each of the four tabs  16 . 
     After installation, wires and cables can be passed through the central aperture  14  in the bushing  10 , with the interior surfaces of the tabs  16 , latches  24  and walls  30  shielding the wires and cables from contact with the edge of the aperture  42  in the metal stud  40 . Thus, the relatively smooth, soft plastic surfaces of the bushings  10  virtually eliminate abrasion of the wire and cables as they are pulled through the bushing. 
     The foregoing description was primarily directed to a preferred embodiments of the invention. Although some attention was given to various alternatives within the scope of the invention, it is anticipated that one skilled in the art will likely realize additional alternatives that are now apparent from disclosure of embodiments of the invention. Accordingly, the scope of the invention should be determined from the following claims and not limited by the above disclosure.