Patent Abstract:
A tool for engaging a nut, the nut being configured for engaging an abuting surface and having at least one laterally-extending projection. The tool comprises a base and a plurality of upstanding axially projecting tangs extending from the base for alternatively engaging opposing sides of the laterally-extending projection.

Full Description:
FIELD OF THE INVENTION  
         [0001]    The invention is generally related to apparatus for engaging a fitting. More particularly, the invention relates to wrench-likes tools for engaging a locknut such as employed with electrical connectors.  
         BACKGROUND OF THE INVENTION  
         [0002]    Locknuts are typically screwed against the end of a pipe fitting or other conduit to hold the latter securely so as to provide an electrical ground. They commonly take the form of a collar having internal threads and may be constructed of various materials (e.g., metal, plastic) and come in a variety of shapes (e.g., hexagonal, square, round) and sizes.  
           [0003]    One common application of locknuts is the securing of sections of electrical connectors within electrical junction boxes. A junction box thereby serves to join different runs of raceway or cable and provides space for the connection and branching of the enclosed conductors.  
           [0004]    Locknuts used in association with electrical conduit are typically annular metal rings. The locknut includes a threaded inner surface for engaging a complementary threaded outer surface on the electrical connector. A series of projections known as lugs, commonly six or eight, extend radially from the ring. Between the lugs are rounded openings or scallops.  
           [0005]    Conventional methods of tightening and loosening or removing locknuts include placing a screwdriver or similar device against one of the lugs and hitting the screwdriver with a hammer. This method, while effective, does not guarantee a tight fitting and has some inherent safety concerns.  
           [0006]    One tool for engaging a locknut is disclosed in U.S. Pat. No. 2,522,038, issued to Houghton. Houghten discloses a wrench having a cage connected to a shank with a suitable handle thereon. An annular member is secured to the cage. A plurality of lug extensions extend therefore in spanner wrench fashion. The position of the extensions is such that they fit into the spaces between a pair of lugs of the locknut.  
           [0007]    U.S. Pat. No. 2,575,779, issued to Young, discloses an electrician&#39;s wrench and reamer having a tool head which includes a pair of spaced prongs that are set apart so as to readily straddle a nut and fit the scallops. Each prong is configured to fit between a pair of adjacent lugs.  
           [0008]    U.S. Pat. No. 5,524,511, issued to Taka&#39;s, discloses a locknut tool having a C-shaped handle. The handle includes a pair of shoulders that engage a lug when the wrench is fitted over a locknut. The position of the shoulders is such that they fit into the spaces between a pair of lugs of the locknut.  
           [0009]    Because they result in only a limited amount of torque, these prior art tools are limited in their ability to tighten or remove a locknut. The need exists for a simple, efficient tool for tightening and removing locknuts.  
         SUMMARY OF THE INVENTION  
         [0010]    One aspect of the invention provides a tool and method for engaging a nut, the nut being configured for engaging an abuting surface and having at least one laterally-extending projection. The tool comprises a base and a plurality of upstanding axially projecting tangs extending from the base for alternatively engaging opposing sides of the laterally-extending projection.  
           [0011]    In one embodiment, the base is carried by a wrench. The base can be configured for releasable attachment to a socket wrench. The socket wrench can permit the apparatus to engage the nut in a ratcheting fashion.  
           [0012]    Another aspect of the invention provides a tool and method for engaging a nut, the nut being configured for engaging an abuting surface and having at least one laterally-extending projection. The tool comprises a handle and a head carried by the handle and having a plurality of upstanding axially projecting tangs for alternatively engaging opposing sides of the projection.  
           [0013]    According to yet another aspect of the invention, a second head is carried by the handle and has a plurality of upstanding axially projecting tangs for alternatively engaging opposing sides of the projection. The first and second heads may be of the same or of different size and configuration. Further, the first and second heads may have the same or different number of upstanding axially projecting tangs. 
       
    
    
     DESCRIPTION OF THE DRAWINGS  
       [0014]    [0014]FIG. 1 is a perspective view of an electrical junction box.  
         [0015]    [0015]FIG. 2 is a perspective view of a locknut commonly used with electrical connectors.  
         [0016]    [0016]FIG. 3 is a perspective view of a tool embodying features of the invention.  
         [0017]    [0017]FIG. 4 is a top view of the tool shown in FIG. 3.  
         [0018]    [0018]FIG. 5 is a side view of the tool shown in FIG. 3.  
         [0019]    [0019]FIG. 6 is a perspective view of an alternative embodiment of a tool embodying features of the invention.  
         [0020]    [0020]FIG. 7 is a top view of an alternative embodiment of a tool embodying features of the invention.  
         [0021]    [0021]FIG. 8 is a top view of an alternative embodiment of a tool embodying features of the invention.  
         [0022]    [0022]FIG. 9 is a perspective view illustrating use of the tool shown in FIG. 8 to engage a locknut on a connector within an electrical junction box.  
         [0023]    [0023]FIG. 10 is a perspective view of an alternative embodiment of a tool embodying features of the invention.  
         [0024]    [0024]FIG. 11 is a top view of the tool shown in FIG. 10.  
         [0025]    [0025]FIG. 12 is a side view of the tool shown in FIG. 10.  
         [0026]    [0026]FIG. 13 is a perspective view illustrating use of the tool shown in FIG. 12 to engage a locknut on a connector within an electrical junction box. 
     
    
     DETAILED DESCRIPTION  
       [0027]    Although the disclosure hereof is detailed and exact to enable those skilled in the art to practice the invention, the physical embodiments herein disclosed merely exemplify the invention which may be embodied in other specific structure. While the preferred embodiment has been described, the details may be changed without departing from the invention, which is defined by the claims.  
         [0028]    I. Tool for Engaging a Locknut  
         [0029]    [0029]FIG. 1 shows a conventional electrical junction box  10  having a bottom wall  12  and four side walls  14 . The box  10  includes a series of scored knock-out sections  16  that are well known in the art. Removal of a knock-out  16 , e.g., by striking the section with a hammer, results in an opening  18  that permits passage of an electrical connector  20 . The number, placement, and configuration of the knock-outs may be varied to accommodate specific needs.  
         [0030]    Conventional connectors  20  include a threaded end region  22  sized and configured for passage through the opening  18 . Connectors  20  are available in a variety of sizes, e.g., ½ inch diameter, 1 inch diameter.  
         [0031]    The connector  20  is typically secured within the junction box  10  by a locknut  24 . As seen in FIG. 2, a conventional locknut  24  used for electrical connectors  20  is typically an annular metal ring  26  having a threaded inner surface  28  sized and, configured to mate with the threaded end region  22  of the connector  20  within the junction box  10 . Extending from the outer periphery of the ring  26  is a series of projections, or lugs  30 . The areas between adjacent lugs  30  define a series of rounded openings, or scallops  32 . Locknuts  24  employed with electrical connectors  20  typically have either six lugs  30  (as FIG. 2 illustrates) or eight lugs  30  (not shown) and come in a range of various sizes to accommodate the various sizes of connectors  20 , e.g., ½ inch diameter, 1 inch diameter, etc.  
         [0032]    It is often difficult to position a pliers or other tool so as to engage the lugs  30  of a locknut  24  sufficiently to tighten or loosen the locknut  24 . This is particularly the case in instances in which it is necessary to secure a connector  20  in an opening  18  that is located in a corner of the box  10 , as shown in FIG. 1.  
         [0033]    [0033]FIG. 3 shows a wrench tool  34  for engaging a locknut  24 . The tool  34  is particularly well suited for engaging a locknut  24  such as that used to secure an electrical connector  20 , and thus will be described in accordance with such use. However, uses of the tool  34  to engage and secure other fittings are contemplated and will be apparent to those skilled in the art that read this disclosure.  
         [0034]    The tool  34  comprises a handle  36  carrying at least one head  38 A or  38 B. If a preferred embodiment, as seen in FIG. 3, the tool  34  has a first head  38 A and a second head  38 B extending from opposing ends of the handle  36 . The heads  38 A and  38 B are annular rings  39  sized and configured to have an inner diameter slightly larger than the outer diameter of the ring  26  of a complementary locknut  24 . As FIGS.  3 - 5  show, the first and second heads  38 A and  38 B may be of different diameters, e.g., the first ring  39 A may be of a ½ inch diameter and second ring  39 B may by of a 1 inch diameter. It is contemplated, however, that the head  38 A or  38 B may take forms other than a ring  39 , e.g., C-shape crescent wrench configuration or hexagonal (not shown). In one alternative embodiment, shown in FIG. 6, the ring  39  includes an opening or notch  40 . The notch  40  permits electrical wires to pass through the head  38 A or  38 B. It is to be understood that the first and second heads  38 A and  38 B may be of the same of different configurations, e.g., first head  38 A is of a ring configuration and second head  38 B is of a hexagonal configuration.  
         [0035]    Extending from the ring is a series of projections or tangs  42 . The tangs  42  can be arranged in pairs and configured to rest in adjacent scallops  32  to engage opposing sides of a lug  30 . In this arrangement, movement of the head  38 A or  38 B in a first direction (e.g., clockwise) applies force to one side of the lug  30  to move the locknut  24  in a first direction (e.g., tightens the locknut  24 ). Movement of the head  38 A or  38 B in the reverse direction (e.g., counterclockwise) applies force to the opposite side of the same lug  30  to move the locknut  24  in a second direction (e.g., loosens the locknut  24 ). Desirably, there is at least two pair of tangs  42 . The pairs can be variously spaced from one another to accommodate locknuts  24  having varying number of lugs  30 . In the embodiment illustrated in FIGS.  3 - 5 , the pairs are spaced 180° apart, thereby accommodating a locknut  24  having either six or eight lugs  30 .  
         [0036]    In an alternative embodiment, tangs  42  extend circumferentially around the heads  38 A and  38 B, thereby providing a greater amount of torque. The number and configuration of the tangs  42  can be varied to accommodate varying number of lugs  30 . For example, FIG. 7 illustrates an embodiment in which the first head  38 A includes six tangs  42  configured to engage a locknut  24  having six lugs  30  and the second head  38 B includes eight tangs  42  configured to engage a locknut  24  having eight lugs  30 .  
         [0037]    As previously noted, the first and second heads  38 A and  38 B may be of the same diameter or size or of different diameters or sizes. FIG. 8 illustrates an arrangement in which the first and second heads  38 A and  38 B both include six tangs  42 , but the first head  38 A is of one diameter (e.g., ½ inch) and the second head  38 B is of a different diameter (e.g., 1 inch). It is to be understood that by varying the size and configuration of the heads  38 A and  38 B and the number of tangs  42 , the tool  34  can be customized to accommodate virtually any locknut  24 .  
         [0038]    The tool  34  may be made of steel, a combination of steel and plastic, or other suitable materials and formed by mold, die, or machining.  
         [0039]    In use, a connector  20  is placed within an opening  18  in a junction box  10 . A locknut  24  is placed on the threaded end region  22  of the connector  20 . As illustrated in FIG. 9, a tool  34  having a head  38 A or  38 B that is complementary to the locknut  24  (i.e., in diameter of the head  38 A or  38 B and number of tangs  42 ) is then positioned to engage the locknut  24 . The handle  36  is then manipulated to rotate the locknut  24  in a first direction (e.g., clockwise) to tighten the locknut  24 . The locknut  24  may then be rotated in the opposite direction (e.g., counterclockwise) to loosen and remove the locknut  24 .  
         [0040]    II. Alternative Embodiment  
         [0041]    FIGS.  10 - 12  illustrate a socket tool  46  embodying features of the invention. Similar to the embodiment of FIGS.  3 - 5 , the socket  46  may be variously sized and configured and includes a plurality of tangs  42  configured to rest in adjacent scallops  32  to engage opposing sides of a lug  30 . The socket  46  is sized and configured to couple to a conventional socket wrench  48 , as shown in FIG. 13. The tool  46  may be made of steel or other suitable materials and formed by mold, die, or machining.  
         [0042]    This arrangement permits the socket tool  46  to be rotated in a ratcheting fashion. The ratchet motion is particularly desirable in a junction box, where space for manipulating a wrench handle is limited.  
         [0043]    With continued reference to FIG. 13, the connector  20  is placed within an opening  18  of the junction box  10  and a locknut  24  is placed on the connector  20 , as previously described. A socket tool  46  that is sized and configured complementary to the locknut  24  is coupled to the socket wrench  48 . It is to be understood that by varying the size of the configuration of the socket  46 , as well as the number and position of tangs  42 , the tool  46  can be customized to accommodate virtually any locknut  24 . The tool  46  is then placed over the locknut  24  with the tangs  42  positioned to engage the locknut  24 . The wrench  48  is then manipulated to rotate the locknut  24  to tighten or loosen the locknut  24 , as also previously described.  
         [0044]    The foregoing is considered as illustrative only of the principles of the invention. Furthermore, since numerous modifications and changes will readily occur to those skilled in the art, it is not desired to limit the invention to the exact construction and operation shown and described. While the preferred embodiment has been described, the details may be changed without departing from the invention, which is defined by the claims.

Technology Classification (CPC): 1