Abstract:
A bit ( 20 ) for a tool is provided. The bit includes a housing ( 22 ) having a cutting portion ( 24 ) and a shank ( 26 ). The bit also includes a post ( 40 ) disposed within the housing and positioned to assist in anchoring the bit to a workpiece ( 52 ) during use.

Description:
CROSS-REFERENCE TO RELATED APPLICATION  
       [0001]     This application is a continuation of application Ser. No. 11/282,309, filed Nov. 17, 2005, which is a Continuation-In-Part of application Ser. No. 10/835,894, filed Apr. 30, 2004, which claims the benefit of Provisional Application No. 60/467,269, filed Apr. 30, 2003, the disclosures of which are hereby expressly incorporated by reference. 
     
    
     FIELD OF THE INVENTION  
       [0002]     The present invention relates generally to wood working tools and, in particular, to plug cutters.  
       BACKGROUND OF THE INVENTION  
       [0003]     Wooden plugs are often used to fill holes in a workpiece to conceal fasteners and screws that have been set below the surface of the workpiece. Typically, a wooden plug having a length greater than the depth of the cavity in which the fastener is seated is cut from a section of wood. The plug is then glued within the cavity and the section of the plug extending from the workpiece is trimmed and sanded, such that the plug is flush with the workpiece to conceal the fastener.  
         [0004]     In the past, such wooden plugs have been cut using a plug cutter attachable to a drill press. Certain plug cutters include a plurality of cutting surfaces adapted to cut a shaped plug from wood. The plug cutter is pressed against a piece of wood and drilled to form the shaped plug. The plug is then removed from the piece of wood by chipping or cutting wood away from the base of the plug. Although such plug cutters are effective at cutting wooden plugs, they are not without their problems.  
         [0005]     As a non-limiting example, existing plug cutters, when initially cutting wood to form a plug, may spin along the surface of the wood before the cutting prongs are set within the wood. This is also true if a tool operator uses a hand drill to drive the plug cutter. As a result, and regardless of whether a drill press or a hand drill is used to drive the plug cutter, existing plug cutters are potentially dangerous to the tool operator as the plug cutter may slide across the surface of the wood until and unless the plug cutter is set within the wood. Also, such sliding motion damages the surface of the wood, thereby resulting in waste wood product.  
         [0006]     Thus, although existing plug cutters are effective at cutting wood plugs, there exists a need for improved plug cutters that assist in retaining the plug cutter in a localized area of the wood during initial cutting of the plug.  
       SUMMARY OF THE INVENTION  
       [0007]     In accordance with one embodiment of the present invention, a bit for a tool is provided. The bit includes a housing having a cutting portion and a shank. The bit also includes a post disposed within the housing for at least rotational movement within the housing, wherein the post is positioned to assist in anchoring the bit to a workpiece during use. In accordance with further aspects of this embodiment, the bit includes a biasing member disposed within the housing and positioned to urge the post into an extended position.  
         [0008]     In accordance with another embodiment of the present invention, a bit for a tool is provided. The bit includes a housing having a cutting portion and a shank, and a post. The post is slidably disposed within the housing and configured for rotational movement within the housing, wherein the post is positioned to assist in retaining the bit in a localized area of a workpiece during use. In yet another embodiment, the bit further includes a biasing member disposed within the housing and configured for rotational movement within the housing, wherein the post is positioned to reciprocate the post between an extended position and a retracted position in response to a drilling pressure applied to the bit.  
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0009]     The foregoing aspects and many of the attendant advantages of this invention will become better understood by reference to the following detailed description, when taken in conjunction with the accompanying drawings, wherein:  
         [0010]      FIG. 1  is an isometric view of a bit for a tool formed in accordance with one embodiment of the present invention;  
         [0011]      FIG. 2  is an exploded, isometric view of the bit of  FIG. 1 ;  
         [0012]      FIG. 3  is a cross-sectional, side planar view of the bit of  FIG. 1  showing the post in an extended position;  
         [0013]      FIG. 4  is a cross-sectional, side planar view of the bit of  FIG. 3 , showing the post in a retracted position; and  
         [0014]      FIG. 5  is an isometric view of a bit for a tool formed in accordance with a second embodiment of the present invention. 
     
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT  
       [0015]      FIG. 1  illustrates a plug cutter  20  formed in accordance with one embodiment of the present invention. The plug cutter  20  includes a housing  22  having a cutting portion  24  formed at one end and a shank  26  formed at the other end of the housing  22 . The cutting portion  24  includes a plurality of cutting tines  30   a - 30   d . The cutting tines  30   a - 30   d  are suitably disposed around a perimeter of the housing  22 .  
         [0016]     The shank  26  is suitably integrally formed with the housing  22  and is sized and constructed in a well-known shape, such as a hex shank, for coupling to a hand drill (not shown) or table mounted drill press (not shown). Although the shank  26  is geometrically illustrated as a hex-shaped shank, other geometries are also within the scope of the present invention. For example, the geometry of the shank  26  could be flat, round, tri-flat, square, polygonal, or splined. As a result, such geometrically shaped shanks are also within the scope of the present invention. Further, although the housing  22  is illustrated and described as having an integrally formed shank  26 , other types of housing, such as a multi-piece housing, are also within the scope of the present invention.  
         [0017]     As may be best seen by referring to  FIG. 2 , the plug cutter  20  includes a post  40  slidably disposed within a cavity  21  of the housing  22  on a biasing member  42 , such as a helical spring. The post  40  is configured within the cavity  21  of the housing  22  for at least rotational movement, as described in greater detail below.  
         [0018]     Although the biasing member  42  is illustrated as a helical spring, it should be apparent that other types of biasing members are also within the scope of the present invention. As an example, an elastomeric spring or a plurality of springs, are also within the scope of equivalent structures for a biasing member of the present invention. Accordingly, other types of biasing members, and their structural equivalents, are also within the scope of the present invention.  
         [0019]     The cavity  21  extends partially through the longitudinal direction of the housing  22 . The cavity  21  is sized and geometrically shaped to receive the post  40  therein.  
         [0020]     The post  40  is retained within the housing  22  by a retaining collar  44 , a round spring  46 , and a washer  48 . In one embodiment, the washer  48  acts as a bushing. The post  40  includes a pointed retaining end  50  for assisting in restraining or centering the plug cutter  20  relative to a workpiece during use, as is described in greater detail below.  
         [0021]     As may be best seen by referring to  FIGS. 3 and 4 , the post  40  is slidably or reciprocally mounted within the cavity  21  of the housing  22  on the biasing member  42 . The washer  48  is disposed between one end of the biasing member  42  and a face of a shoulder  51  extending around the perimeter of one end of the post  40 . The retaining collar  44  is slidably received and seated against a stepped annular shoulder  53  integrally formed within the cavity  21 . The retaining collar  44  is thus positioned to retain the post  40  within the housing  22  during use and illustrated in  FIG. 3 . The retaining collar  44  is suitably retained within the cavity  21  by the round spring  46 . As disposed within the cavity  21 , the post  40  is slidably received within the cavity  21 , and the biasing member  42  assists in reciprocating the post  40  between an extended and retracted position.  
         [0022]     The post  40  is received within the cavity  21  for rotational movement. In that regard, the post  40  is disposed within the cavity  21  for rotational movement in response to operational conditions. Specifically, the washer  48  acts as a busing to permit 360-degree rotation, in either direction, of the post  40  about an axis extending through a longitudinal direction of the cavity  21 .  
         [0023]     Operation of the plug cutter  20  may be best understood by referring to  FIGS. 3 and 4 . As seen in  FIG. 3 , the plug cutter  20  is shown in the extended position, wherein the retaining end  50  of the post  40  is partially received within a workpiece  52 , such as a section of wood. As received within the workpiece  52 , the post  40  assists in retaining and/or centering the plug cutter  20  relative to the workpiece  52  during initial and continued drilling of the plug cutter  20  into the workpiece  52 .  
         [0024]     During use, the plug  40  is displaced into a retracted position ( FIG. 4 ) within the cavity  21  of the housing  22  in response to a drilling pressure applied to the plug cutter  20 . Because of the interference of the retaining end  50  of the plug  40  with the workpiece  52  during drilling operation of the plug cutter  20 , the post  40  assists in retaining and/or centering the plug cutter  20  relative to the workpiece  52  to minimize the risk of injury to a drill operator.  
         [0025]     As the plug cutter  20  operates, the post  40  may encounter resistance in the workpiece  52 , such as a knot, sap, nail, or any other typical resistance encountered in a workpiece. As the post  40  encounters such resistance, the post  40  may slow or even stop its rotational movement relative to the cutting portion  24 . In this situation, the post  40  of the present disclosure is configured to allow rotational movement relative to the cutting portion  24  if resistance is encountered. Such rotational movement of the post  40  permits the cutting portion  24  to operate in its intended fashion Such rotational movement also minimizes the risk of damage to the biasing member  42 .  
         [0026]     As may be best seen by referring to  FIG. 5 , a plug cutter  120  formed in accordance with a second embodiment of the present invention will now be described in greater detail. The plug cutter  120  is identical in materials and operation to the embodiments described above with the exception that the plurality of cutting tines  30   a - 30   d  formed with the housing  22  have been replaced with a single, radially-shaped cutting surface  130 . Such a cutting surface is well known in the art.  
         [0027]     While the preferred embodiment of the invention has been illustrated and described, it will be appreciated that various changes can be made therein without departing from the spirit and scope of the invention.  
         [0028]     The embodiments of the invention in which an exclusive property or privilege is claimed are defined as follows: