Abstract:
The drywall tapering device has a drive roller and two idler rollers extending from the front face of a frame in a triangular configuration with the drive roller above the idler rollers. The drive roller has an annular groove defined around its base and tapers in diameter from wide to narrow as the roller extends from the base to its free end. The butt end of a drywall panel is supported against an elongate track. The frame is clamped over the butt end and the track, a spring-biased adjustment screw assembly being used to clamp the drive roller against the butt end with the track engaging the groove. A drill grips a mandrel extending from the drive roller and causes the drive roller to rotate and ride along the track, forming a tapered recess in the butt end of the drywall, the idler rollers following below the track.

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
     This application claims under 35 U.S.C. §119 priority to and the benefit of U.S. Provisional Patent Application Ser. No. 61/855,631, filed May 20, 2013 in the United States, and is incorporated herein by reference in its entirety. 
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to building construction, and particularly to a drywall tapering device for tapering the ends of drywall sheets so that butt joints can be covered by paper tape and joint compound, eliminating unsightly butt joints. 
     2. Description of the Related Art 
     Drywall has largely replaced plaster and lath in the construction and remodeling of homes and offices, such as in the construction of interior walls or ceilings. Sheets or panels of drywall, conventionally supplied as 4′×8′ or 4′×16′ sheets, are fastened to the wall studs or ceiling joists, either vertically or horizontally, by drywall nails or screws. The elongated 8′ or 16′ sides are formed with tapered edges so that paper tape can be placed in the tapered recesses of adjoining panels and secured with joint compound to form a smooth joint that is hardly noticeable when painted. However, when the wall or ceiling is longer than eight feet, it can be necessary to place two or more panels end-to-end, forming a butt joint. The ends of drywall panels are either tapered or not tapered. Typically, butt joints are simply covered with joint compound and smoothed by sanding. Over time, however, the joint can spread slightly as the studs and joists expand and contract in response to thermal stress, resulting in ridges or gaps forming along the seam of the butt joint. 
     Thus, a drywall tapering device addressing the aforementioned problems is desired. 
     SUMMARY OF THE INVENTION 
     The drywall tapering device has a drive roller and two idler rollers extending from the front face of a frame in a triangular configuration with the drive roller above the idler rollers. The drive roller has an annular groove defined around its base and tapers in diameter from wide to narrow as the roller extends from the base to its free end. The butt end of a drywall panel is supported against an elongate track. The frame is clamped over the butt end and the track, a spring-biased adjustment screw assembly being used to clamp the drive roller against the butt end with the track engaging the groove. A drill grips a mandrel extending from the drive roller and causes the drive roller to rotate and ride along the track, forming a tapered recess in the butt end of the drywall, the idler rollers following below the track. 
     Two drywall panels having tapered recesses formed in this manner can be placed end-to-end and taped with drywall tape and joint compound to form a smooth, secure seam. 
     The drive roller is rotatably mounted in a mounting tube that is vertically slidable in a slot defined in the frame. The mounting tube has front and rear annular disks disposed against the front and rear faces of the frame to constrain the tube to slide in the slot. A stud having a compression spring coaxially disposed around its shank is positioned below the rear annular disk. A threaded bolt extends through the top of the frame, and a knob is mounted on the free end of the threaded bolt. The opposite end of the threaded bolt bears against the rear annular disk, pressing the rear annular disk against the compression spring to fix the height of the drive roller. The height of the drive roller can be adjusted by using the knob to screw the threaded bolt into and out of the frame, thereby clamping the drive roller against drywall panels, such as of a conventional thickness, e.g., ½ inch, ⅝ inch, etc. 
     These and other features of the present invention will become readily apparent upon further review of the following specification and drawings. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a perspective view of an embodiment of a drywall tapering device according to the present invention. 
         FIG. 2  is a side view of the drywall tapering device shown in  FIG. 1 . 
         FIG. 3  is a rear view of the drywall tapering device shown in  FIG. 1 . 
         FIG. 4  is a front view of the drywall tapering device shown in  FIG. 1 . 
         FIG. 5A  is a perspective view of a system for tapering drywall according to the present invention. 
         FIG. 5B  is a detailed side view of the drywall tapering device and the track in the system for tapering drywall shown in  FIG. 5A . 
         FIG. 6A  is a top view of a butt joint. 
         FIG. 6B  is a top view of a seam joint formed by a factory tapered butt end and a tapered butt end created by a drywall tapering device and a system for tapering drywall according to the present invention. 
     
    
    
     Unless otherwise indicated, similar reference characters denote corresponding features consistently throughout the attached drawings. 
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     Referring to  FIGS. 1-5B , a drywall tapering device  100  is shown. The drywall tapering device  100  includes a frame  102  and channel or slot  104  defined on the frame  102 . As shown in  FIGS. 1-4 , the slot  104  can extend through the frame  102  to form a cut-out region. Communicating with the slot  104  of the frame  102  is a drive roller  112 . The drive roller  112  includes an annular groove  114  defined around its base. The annular groove  114  is situated around the perimeter of the drive roller  112  and is adapted to receive a lip  202  of a track  200 , as shown in  FIG. 5B . By receiving the lip  202 , the drive roller  112  and the frame  102  of the drywall tapering device  100  can be moved linearly along the track  200  in a controlled manner. In addition to the annular groove  114 , the drive roller  112  has a shape that includes a circumferential taper  116  extending from the annular groove  114  towards a front edge  118  at the distal end of the drive roller  112 . The taper  116  is formed by a decrease in diameter along the length of the drive roller  112  from wide at the base to narrow at the distal end. As shown in  FIGS. 1-513 , the taper  116  of the drive roller  112  forms a generally frustoconical shape or any suitable shape that fits the user&#39;s needs. This taper  116  of the drive roller  112  can allow for a corresponding tapered butt end, such as the tapered edge  606   b  shown in  FIG. 6B , to be formed on an end of a sheet, panel, board, or web  208  when the sheet  208  is placed beneath the drive roller  112  and the frame  102  of the drywall tapering device  100  is moved along the edge of the sheet of material  208 . 
     In order to facilitate movement of the drywall tapering device  100 , the drywall tapering device includes a drive attachment  122  extending from the rear  120  of the drive roller  112  as shown in  FIGS. 2 and 3 . The drive attachment  122  assists in moving the frame  102  across the track  200  by communicating with a drive mechanism  124 . In this embodiment, the drive attachment  122  can be an elongate mandrel for selective coupling with the drive mechanism  124 , the drive mechanism  124  selectively gripping the mandrel  122  and rotating the drive roller  112 . Desirably, the drive mechanism  124  can be a cordless power drill, such as having a ½ inch bit, as exemplarily shown in  FIG. 5A . Other examples of drive mechanisms include, but are not limited thereto, power tools, pneumatic tools, manual tools, or any instrument that can be selectively coupled to the drive attachment  122  and rotate the same. Rotation of the drive roller  112  facilitates concurrent movement of the drive roller  112  and the frame  102  of the drywall tapering device  100  along the track  200  while the drive roller  112  forms a tapered edge on the desired butt end of the sheet  208 . 
     The drive roller  112  can be adjustably positioned along the slot  104  of the frame  102  by a controller  106  in order accommodate various thicknesses of sheets  208 . The drive roller  112  is rotatably mounted in a mounting housing  111  configured to vertically slide inside the slot  104 . In this instance, the mounting housing  111  is constructed as a mounting tube with the drive attachment  122  extending outwardly from the back of the mounting housing  111 . Desirably, the diameter of the mounting housing  111  is about the same as the width of the slot  104  so that the mounting housing  111  can be received in the slot  104  with minimal tolerances which can help to minimize undesirable rotation of the mounting housing  111  within the slot  104 . Also, the diameter of the mounting housing  111  can be constructed with a diameter larger than the width of the slot  104  so that diametric opposing sides can be ground, milled, or molded to form guide faces or surfaces  111   a  of the mounting housing  111 . The guide faces  111   a  can permit the mounting housing  111  to fit and slide within the slot  104  and can provide an abutment surface to assist in preventing relative rotation of the mounting housing  111  therein. 
     The mounting housing  111  also includes a front annular disk  109   a  and a rear annular disk  109   b  disposed thereon, the front and rear annular disks  109   a ,  109   b  being spaced apart from each other so as to straddle the frame  102  therebetween. When installed, the annular disks  109   a ,  109   b  are disposed on opposite sides of the frame  102  and thereby can assist in preventing undesirable axial movement of the mounting housing  111  with respect to the frame  102 . This arrangement constrains movement of the mounting housing  111  to slide in the slot  104 . The front annular disk  109   a  and the rear annular disk  109   b  can be construed as stabilizing members, since they confine positioning and movement of the drive roller  112 . 
     In the embodiment of  FIGS. 1-5B , as illustrated, the front annular disk  109   a  and the rear annular disk  109   b  have been shown to be of unequal thickness where the rear annular disk  109   b  is thicker than the front annular disk  109   a . The thicker rear annular disk  109   b  can provide a sturdy base for receiving the mounting housing  111 . Moreover, the thicker rear annular disk  109   b  can provide a sturdy structure for interaction with the controller  106 . 
     In order to facilitate the vertical adjustment of the drive roller  112 , the controller  106  includes a biasing mechanism such as a stud  110  having a compression spring  110   a  coaxially disposed around its shank. The stud  110  and the compression spring  110   a  are positioned below the rear annular disk  109   b  in order to vertically support the rear annular disk  109   b . The stud  110  can extend into the rear annular disk  109   b  to an extent as can insure proper alignment of the drive roller  112  and additionally can prevent rotation of the mounting housing  111 . An adjustment mechanism, such as a threaded bolt  108   a , extends through the top of the frame  102 , and a knob  108  is mounted on the free end of the threaded bolt  108   a . The opposite end of the threaded bolt  108   a  bears against the rear annular disk  109   b , pressing the rear annular disk  109   b  against the compression spring to  110   a  to fix the height of the drive roller  112 . The height of the drive roller  112  can be adjusted by using the knob  108  to screw the threaded bolt  108   a  into and out of the frame  102 , thereby clamping the drive roller  112  against one of the butt ends of the sheet  208 . The threaded bolt  108   a  can also extend, at least partially, into the rear annular disk  109   b . As shown in  FIGS. 1-4 , the knob  108  can be a four pronged handle or any other common attachment, such as a wheel or lever that can assist the user in manipulating the controller  106 . 
     The frame  102  also includes a plurality of idler rollers  126  disposed below the drive roller  112  forming a gap  128  where a butt end of the sheet  208  can be inserted between the drive roller  112  and the idler rollers  126 , such as where the butt end of the sheet  208  can be inserted between the drive roller  112  and the track  200  with the idler rollers  126  positioned to an underside  204  of the track  200 , as best seen in  FIGS. 1 ,  2 ,  4  and  5 B. Each idler roller  126  is also desirably provided with an annular groove  124  proximate the base thereof. The annular grooves  124  on the idler rollers  126  function similarly to the annular groove  114  on the drive roller  112 . In that regard, the annular grooves  124  are configured to engage the bottom portion of the lip  202  as best seen in  FIG. 5B . The disposition of the drive roller  112  and the idler rollers  126  form a generally triangular configuration. In use, the plurality of idler rollers  126  can follow, for example, along the underside  204  of the track  200  as best shown in  FIGS. 5A and 5B  when the frame  102  is moved along the track  200  forming the tapered butt end on the sheet  208 . Placement of the plurality of idler rollers  126  along the underside  204  of the track  200  allows for the drywall tapering device  100  to be further secured to the track  200 , and the annular grooves  124  are vertically aligned with the annular groove  114  on the drive roller  112  so that a relatively secure, accurate and properly aligned engagement can be maintained throughout the operation of the drywall tapering device  100 , such as can enhance the efficiency of the process of forming a tapered edge, as for example, on the sheet  208 . Additionally, by placing the plurality of idler rollers  126  along the underside  204  of the track  200 , when downward pressure is applied onto the drive roller  112  which would also be applied onto the sheet of material  208  and onto the track  200 , the plurality of idler rollers  126  will be forced up and can come into further contact with the underside  204  of the track  200 . This can allow the downward pressure applied to the drive roller  112  to be applied along the end of the sheet  208  to be tapered while the drywall tapering device  100  is traveling along the track  200  and across the sheet  208 . This downward force applied by the drive roller  112  onto one of the ends of the sheet  208  allows for the formation of a tapered edge thereon. 
     Referring to  FIG. 5A , the system for tapering drywall  500  includes a table  206  where both the track  200  and the table  206  are adapted to receive the sheet  208 . The table  206  can be formed from any common components, including a plurality of horses and a plurality of pipes over welded struts connected together by a plurality of brackets, for example. The track  200  can be secured to the table  206  by any common securing mechanisms, including brackets or braces, among others. By using this type of configuration and components in the system for tapering drywall  500 , the table  206  and track  200  can be assembled and disassembled relatively easy and quickly. This can allow for the system for tapering drywall  500  to be assembled and disassembled by the user at a job site. 
     In use, the user places the sheet  208  onto the table  206  and the track  200 . In this instance, the sheet  208  is a drywall panel of a conventional thickness, e.g., ½ inch, ⅝ inch, etc. It is to be understood that the drywall tapering device  100  can also be used on compressible webs where a taper can be formed. The user aligns the butt end to be tapered by the drywall tapering device  100  onto the track  200  behind the lip  202 , the lip  202  forming a fence for alignment of the butt end of the sheet  208 . In the embodiment shown, the lip  202  is desirably an elongate, vertical bar extending above and below the horizontal portion of the track  200 . This configuration permits the top part of the lip  202  to engage the annular groove  114  of the drive roller  112  while the bottom part of the lip  202  can engage the annular groove  124  on the idler rollers  126 . The user then places the annular groove  114  of the drywall tapering device  100  in communication with the lip  202  of the track  200 , which also facilitates mutual communication between the lip  202  and the annular grooves  124 . The user connects the drive mechanism  124  to the drive attachment  122  of the drywall tapering device  100  to selectively move the drywall tapering device  100  across the butt end of the sheet  208  to be tapered. Movement of the drywall tapering device  100  across the butt end the sheet of material  208  compresses and forms the new tapered edge, such as tapered edge  606   b  shown in  FIG. 6B . Depending on the user&#39;s needs, the user can adjust the vertical position of the drive roller  112  to accept different thicknesses of sheets  208  by manipulating the controller  106  of the drywall tapering device  100  which can selectively position the drive roller  112  along the slot  104  of the drywall tapering device  100 . 
     Referring to  FIGS. 6A and 6B , a butt joint  600   a  and a seam joint  600   b  are shown. The butt joint  600   a  is formed when a factory tapered edge  604   a  is placed adjacent to a non-factory tapered edge  606   a . The butt joint  600   a  can form bulges or unevenness when tape and compound are placed within the butt joint  600   a  and therefore should be avoided as being typically undesirable. In comparison, as shown in  FIG. 6B , a seam joint  600   b  is formed when a factory tapered edge  604   b  is placed adjacent to a tapered edge  606   b  that was reworked or formed by the drywall tapering device  100  and the system for tapering drywall  500 . The seam joint  600   b  can allow for taping and compound to be filled into the seam joint  600   b  without typically leaving a bulge or unevenness in the wall, and thereby can allow for a smooth and even surface in the wall or ceiling, for example. 
     It is to be understood that the present invention encompasses a variety of alternatives. Though the specification describes forming one butt end on a sheet for tapering, the drywall tapering device  100  can be used to form tapered butt ends on any desired one or more sides of the sheet  208 . Additionally, the drywall tapering device  100  can be constructed from any sturdy materials such as steel, plastic, composites, combinations thereof and the like. Furthermore, the drywall tapering device  100  can form tapers without the track  200  where the front face of the frame  102  forms a sufficient alignment surface for the sheet  208  to be tapered and the idler rollers  126  provide sufficient support for the drywall tapering device  100  to travel along the end of the sheet  208  to be tapered. 
     It is to be understood that the present invention is not limited to the embodiments described above, but encompasses any and all embodiments within the scope of the following claims.