Abstract:
A reaming tool has a generally planar base with a base opening. A stand is coupled to the base and extends away from the base, the stand having at least one cross member. A guide opening extends through the cross member. An elongate reamer has a longitudinal axis, a first end and a second, opposing end. The reamer extends through the guide opening and the base opening, with the second end of the reamer being proximal to the base opening. A set of reaming flutes are formed in the reamer proximate its second end. The reamer is slidable and rotatable in the guide opening and the base opening, and the orientation of the longitudinal axis of the reamer with respect to the base and the stand is fixed by the guide opening.

Description:
FIELD 
       [0001]    The present invention relates generally to fabrication tooling, in particular to a reaming tool for the repair of fabrication tooling. 
       BACKGROUND 
       [0002]    Fabrication tooling, such as welding fixtures, are often used in conjunction with a surface plate. A surface plate is a solid, flat plate used as a horizontal reference plane for precision inspection, layout, and tooling setup. The surface plate is often used as a reference plane for measurement of a workpiece placed upon or affixed to the surface plate. Consequently, a primary surface of the surface plate is a very flat planar surface, its planarity being closely controlled to facilitate accurate measurement of the workpiece. 
         [0003]    Surface plates often include one or more datum pin holes. The datum pin holes are usually laid out in an accurate and precise geometric pattern or grid to facilitate the installation of removable attach points or supports for the tooling. For example, a welding fixture may be removably attached to a surface plate by means of a set of supports extending between the welding fixture and the surface plate. 
         [0004]    A common problem with surface plates used in conjunction with fabrication tooling is that welding material and other debris can accumulate in the datum pin holes, rendering them unusable. Hand tools such as drills and screwdrivers may be used to repair the datum pin holes by removing the debris, but such tools are not efficient for this task. Furthermore, the datum pin holes are subject to damage by these hand tools, necessitating repair or replacement of the surface plate. 
       SUMMARY 
       [0005]    A reaming tool is disclosed according to an embodiment of the present invention. The reaming tool includes a reamer that is slidably and rotatably coupled to a stand. A base supports the stand, orienting the reamer in an upright position. A biasing element biases the reamer away from the base when not in use. A handle is coupled to an upper end of the reamer. In use, the handle is grasped and the reamer is urged downwardly against the force of the biasing element, into a datum pin hole that is blocked with debris. The handle is rotated with the reamer in the datum pin hole, thereby dislodging debris therein. The reamer is sized and shaped to closely fit the datum pin hole to efficiently remove the debris. The size and shape of the reamer also reduces the risk of damage to the datum pinhole by the action of the reamer. Compressed air may also be used to urge the dislodged debris away from the datum pin hole, if desired. 
         [0006]    In one embodiment of the present invention a reaming tool has a generally planar base with a base opening. A stand is coupled to the base and extends away from the base, the stand having at least one cross member. A guide opening extends through the cross member. An elongate reamer has a longitudinal axis, a first end and a second, opposing end. The reamer extends through the guide opening and the base opening, with the second end of the reamer being proximal to the base opening. A set of reaming flutes are formed in the reamer proximate its second end. The reamer is slidable and rotatable in the guide opening and the base opening, and the orientation of the longitudinal axis of the reamer with respect to the base and the stand is fixed by the guide opening. 
         [0007]    The present invention also provides a method for clearing debris from a cavity of a tool. The method includes the steps of providing a generally planar base having a base opening therethrough, and coupling a stand to the base, the stand extending away from the base and having at least one cross member. A guide opening is formed in the cross member, the guide opening extending through the cross member. An elongate reamer is provided, the reamer having a longitudinal axis, a first end and a second, opposing end. The reamer extends through the guide opening and the base opening, with the second end of the reamer being proximal to the base opening. A set of reaming flutes are also formed in the reamer proximate its second end. The reamer is slidable and rotatable in the guide opening, the base opening and the cavity to clear debris from the cavity. Furthermore, the orientation of the longitudinal axis of the reamer with respect to the base and the stand is fixed by the guide opening. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0008]    Further features of the inventive embodiments will become apparent to those skilled in the art to which the embodiments relate from reading the specification and claims with reference to the accompanying drawings, in which: 
           [0009]      FIG. 1  is a perspective view of a reaming tool according to an embodiment of the present invention; 
           [0010]      FIG. 2  is a perspective view of a reaming tool according to another embodiment of the present invention; 
           [0011]      FIG. 3A  is a first schematic diagram showing the reaming tools of  FIGS. 1 and 2  in a stowed condition; 
           [0012]      FIG. 3B  is a second schematic diagram showing the reaming tools of  FIGS. 1 and 2  in use; and 
           [0013]      FIG. 4  is a perspective view of a reaming tool according to yet another embodiment of the present invention; 
       
    
    
     DETAILED DESCRIPTION 
       [0014]    In the discussion that follows, like reference numerals are used to refer to like structures in the various embodiments and figures. 
         [0015]    The general arrangement of a reaming tool  10  is shown in  FIG. 1  according to an embodiment of the present invention. Reaming tool  10  includes a base  12 , a stand  14 , a reamer  16  and a handle  18 . A biasing element  20  is retained between stand  14  and a stop  22  coupled to reamer  16 , biasing the reamer upwardly and away from base  12 . 
         [0016]    Base  12  is generally planar with a generally flat lower surface  24  and a base opening  26 . Base  12  may be made from any type of material suitable for the expected use and environment including, without limitation, metal, plastic and composites. In addition, base  12  may be formed in any conventional manner including, but not limited to, casting, machining, forming, molding and stamping. Furthermore, base  12  may be finished in any conventional manner, such as painting, coating, plating, molded-in colors and decorative features, or may be left unfinished. Although base  12  is shown with a generally round shape in  FIG. 1  it is understood that the base may be any suitable geometric shape including, without limitation, polygonal, square, triangular, rectangular, pentagonal and octagonal within the scope of the invention. 
         [0017]    Stand  14  is made of a unitary piece and extends upwardly and away from base  12 , providing a support structure for reamer  16 . A pair of generally horizontal cross members  28  extend between a pair of spaced-apart upright members  30 . Cross members  28  each include a guide opening  32 , the guide openings being aligned over one another. Stand  14  may be made from any type of material suitable for the expected use and environment including, without limitation, metal, plastic and composites. In addition, stand  14  may be formed in any conventional manner including, but not limited to, casting, machining, forming, molding and stamping. Furthermore, stand  14  may be finished in any conventional manner, such as painting, coating, plating, molded-in colors and decorative features, or may be left unfinished. Although stand  14  is shown with two cross members  28  and two upright members  30  in  FIGS. 1 and 2  it is understood that a lesser or greater number of either or both the cross members and the upright members may be provided within the scope of the invention. 
         [0018]    Reamer  16  comprises a generally cylindrical body having a shank portion  34  and a plurality of reamer flutes  36 . Shank portion  34  of reamer  16  extends upwardly through guide openings  32  and beyond stand  14 , handle  18  being attached to a first end  38  of the reamer. A second, opposing end  40  of reamer  16  extends to base opening  26 , reamer flutes  36  being formed proximate the second end. Flutes  36  may include of a set of parallel straight or helical cutting edges extending upwardly from second end  40  along the length of the body of reamer  16 , each cutting edge being ground at a slight angle and with a slight undercut below the cutting edge. Second end  40  may also include a tapered portion  42  to produce a self centering action of reamer  16  as it enters a datum pin hole, as discussed in more detail below. If reamer flutes  36  are helical the spiral of the helixes may be either clockwise or counter-clockwise. 
         [0019]    Reamer  16  may be made from any suitable material including, without limitation, unalloyed or alloyed steel, “high speed steel” (HSS), carbide, cobalt and tungsten carbide. Reamer  16  may be hardened or heat treated, and may also be coated with materials including, but not limited to, titanium nitride, chemical vapor deposition of diamonds, or titanium carbon nitride to increase the usable life and durability of reamer flutes  36 . In some embodiments reamer  16  is made from a unitary piece of material. Alternatively, shank portion  34  and reamer flutes  36  may be made of different materials and joined together. 
         [0020]    Handle  18  is generally rounded and is attached to first end  38  of reamer  16  with a first set screw  44 , adhesive or welding. Handle  18  may be made from any type of material suitable for the expected use and environment including, without limitation, metal, plastic and composites. In addition, handle  18  may be formed in any conventional manner including, but not limited to, casting, machining, forming, molding and stamping. Furthermore, handle  18  may be finished in any conventional manner, such as painting, coating, plating, molded-in colors and decorative features, or may be left unfinished. Although handle  18  is shown with a generally round shape in  FIGS. 1 and 2  it is understood that the base may be any suitable geometric shape that would readily accommodate manual operation including, without limitation, square, rectangular, pentagonal and octagonal within the scope of the invention. In other embodiments handle  18  may be a crank-type handle. 
         [0021]    In the embodiment of  FIG. 1  biasing element  20  is a helical coil compression-type spring. Biasing element  20  is configured with predetermined characteristics including spring constant, spring index, number of coils, and free (i.e., uncompressed) length, the spring characteristics being calculated to urge reamer  16  upwardly and away from base opening  26  when tool  10  is not in use, that is, when no downward force is being applied to handle  18 . Conversely, the characteristics of biasing element  20  are preferably selected such that excessive downward force is not required to urge reamer  16  into and through base opening  26 . Biasing element  20  may be made from any suitable material including, without limitation, music wire, stainless steel, hard-drawn wire, polymers, and plastic. In alternate embodiments biasing element may be an elastomeric material such as foam, natural rubber and synthetic rubber, for example. 
         [0022]    Stop  22  is attached to shank portion  34  of reamer  16  and acts to restrain biasing element  20  between stand  14  and the stop. Although stop  22  is shown positioned between cross members  28  in  FIG. 1 , the stop could also be positioned above the upper cross member and below handle  18 , biasing element  20  being restrained between the stop and the upper cross member. Stop  22  as shown in  FIG. 1  is a collar-type arrangement secured to shank portion  34  at a predetermined position with a second set screw  46 . Alternatively, stop  22  may be a fastener, a rod or a wire inserted through an aperture (not shown) of shank portion  34 , the fastener being of an appropriate size and shape to retain biasing element  20 . 
         [0023]    Reaming tool  10  is assembled by assembling together base  12  and stand  14  with a set of fasteners  48 . Alternatively, both base  12  and stand  14  may be made as a unitary piece. Handle  18  is attached to first end  38  of reamer  16 . Second end  40  of reamer  16  is inserted through guide openings  32 , stop  22  and biasing element  20  as shown in the figures. Stop  22  is slidably moved along shank portion  34  to a predetermined position such that biasing element  20  will urge reamer  16  upwardly and away from opening  26  of base  12 . Second set screw  46  is tightened against shank portion  34  to hold stop  22  at the predetermined position. 
         [0024]    The general arrangement of a reaming tool  100  is shown in  FIG. 2  according to another embodiment of the present invention. In this embodiment base  12 , cross members  28  and upright members  30  are separate components assembled together with any or all of fasteners  48 , adhesive and welds. Reaming tool  100  is otherwise similar to reaming tool  10  and thus will not be detailed further here. 
         [0025]    With reference now to  FIGS. 3A and 3B , in operation a user places reaming tool  10 ,  100  upon a surface plate  50  such that reamer  16  is positioned atop a cavity, also called a datum pin hole  52 , to be cleaned of debris. The user then presses downwardly upon handle  18  with sufficient force to overcome the upward bias of biasing element  20 , urging reaming flutes  36  into datum pin hole  52 . While maintaining the downward force the user rotates or twists handle  18  clockwise or counter-clockwise as shown in  FIG. 3B , causing the flutes to rotate in datum pin hole  52 , thereby clearing debris from the datum pin hole. The dislodged material falls from datum pin hole  52  by gravity. Compressed air may also be used to urge the dislodged debris away from datum pin hole  52 , if desired. 
         [0026]    The general arrangement of a reaming tool  200  is shown in  FIG. 4  according to yet another embodiment of the present invention. In this embodiment reamer  16  further includes either a clockwise or counter-clockwise helical groove  202  slidably coupled to a corresponding helical projection  204  formed in a guide opening  32  of a select cross member  28 . In other configurations helical groove  202  may be formed in a guide opening  32  of a select cross member  28  and helical projection  204  may be formed upon reamer  16 . Alternatively, a helical groove  202  formed in reamer  16  may slidably engage at least one guide pin  206  installed into a select cross member  28  and extending into the guide opening  32  of the cross member. In other configurations at least one guide pin  206  of reamer  16  may slidably engage a helical groove  202  formed in a guide opening  32  of a select cross member  28 . Handle  18  may be rigidly coupled to reamer  16 , or may be made rotatable with respect to the reamer, such as with a bearing  208 . 
         [0027]    In operation, a user places reaming tool  200  upon a surface plate  50  ( FIGS. 3A ,  3 B) such that reamer  16  is positioned atop a datum pin hole  52  to be cleaned of debris. The user then presses downwardly upon handle  18  with sufficient force to overcome the upward bias of biasing element  20 , urging reaming flutes  36  into datum pin hole  52 . As reamer  16  is urged downwardly helical groove  202  and helical projection  204  (or helical groove  202  and pin  206 ) cause the reamer to rotate ( FIG. 4 ), thereby clearing debris from the datum pin hole  52 . The dislodged material falls from datum pin hole  52  by gravity. Compressed air may also be used to urge the dislodged debris away from datum pin hole  52 , if desired. Reaming tool  200  is otherwise similar to reaming tool  10  and thus will not be detailed further here. 
         [0028]    While this invention has been shown and described with respect to a detailed embodiment thereof, it will be understood by those skilled in the art that changes in form and detail thereof may be made without departing from the scope of the claims of the invention.