FIELD OF THE INVENTION 
       [0001]    The present invention relates to a drywall sander, and more particularly to a hand-held manually-operated drywall sander that can be used advantageously for sanding dry wall and other surfaces. 
       BACKGROUND OF THE INVENTION 
       [0002]    Abrasive sheets, such as conventional sandpaper, are commonly used to hand sand or finish a work surface. In hand sanding, a user holds the sandpaper directly in his or her hand to move the sandpaper across the work surface. Sanding by hand can be an arduous task. To facilitate the hand sanding process it has been common to hold the sandpaper on a sanding block. For example, U.S. Pat. No. 5,168,672 discloses a sanding block with a handle and a base to which an abrasive paper sheet may be attached. This type of sanding block and other known sanding blocks suffer from one or more drawbacks. 
         [0003]    For example, tensioning the sandpaper is a desirable feature of sanding blocks, but it is often difficult to load the sandpaper and get it tight. If the sandpaper is not tight, it may wrinkle, and the wrinkles may snag on the work surface and cause the abrasive media to tear or the work surface to be damaged or sanded unevenly. Further, users may experience difficulty in installing sandpaper on a sanding block, as some sanding blocks require both ends of the abrasive sheet to be installed on the sanding block simultaneously. Sanding blocks also tend to be difficult and/or expensive to manufacture. 
         [0004]    With respect to sanding dry wall, sanding blocks reveal additional shortcomings. In particular, sanding blocks present difficulties when sanding corners and other areas where two or more panels of dry wall meet. In trying to reach tight spots with a sanding block, users may have to repeatedly reposition themselves and/or readjust their grip on the sanding block. Constant repositioning by the user and constant reconfiguring of the sanding tool can lead to decreased efficiency and uneven sanding. Further, sanding block users are subjected to contact between their fingers and the sidewalls, which may result in injury or cause a user to go to great pains to avoid such contact, which again may result in uneven sanding. 
         [0005]    Some sanding devices in the prior art have offered solutions to one or more of these concerns. For example, some devices have included a hand grip with a sanding tool. Other sanding tools have been created with elongated constructions such that corners are more easily reached. However, while these devices may address one or more of the above-described concerns, such devices fail to address all of these concerns. 
         [0006]    It is an object of this invention to simultaneously address all of the above-described concerns, namely to increase sanding efficiency, to minimize sanding injury and/or user fatigue, to more readily sand access corners, and to assure consistent and high quality sanding, and to do so at relatively low expense. 
       SUMMARY OF THE INVENTION 
       [0007]    Generally, the present invention achieves the above-stated objects with a drywall sander, i.e., a sanding tool, having a substantially rigid blade with a first face and a second face, a top edge, and a bottom side, and a substantially elongated handle extending from the bottom side. The sanding tool includes an abrasive layer which covers a first portion on the first face of the blade, extends over the top edge, and covers a second portion on the second face of the blade. The sanding tool may include a substantially thin backing layer that is positioned between the blade and the abrasive layer. The backing layer may include or actually may be a buffer layer. According to an aspect of the invention, the rigid blade has a non-uniform thickness, being thicker near the handle and thinner near the edge, so as to have a triangular shape when viewed from the side. 
         [0008]    According to one aspect of the invention, the abrasive layer removably attaches to the drywall sander on the first and second faces, and has a substantially central fold, and serves as part of a sanding attachment. In the most simple and straightforward understanding of the invention, the sanding attachment comprises sandpaper, with the backing layer being the paper backing of the sandpaper and the abrasive layer being the abrasive front surface of the sandpaper. Preferably, the sanding attachment attaches to the blade by any structural manner which permits ready attachment and detachment, such as being hoop and loop fasteners (i.e., Velcro fastener), secured to the first and second faces and to the backside of the backing layer, i.e., the back of the sandpaper. 
         [0009]    Thus, the sanding attachment is positioned over the rigid blade so as to extend over the top edge and to cover some or all of the first and second faces. Then the attachment is attached to the first and second surfaces with the abrasive layer exposed on opposite sides of the blade. 
         [0010]    Various exemplary embodiments of the present invention include a method for using the sanding tool described above. 
         [0011]    These and other features of the invention will be more readily understood in view of the following drawings. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0012]      FIG. 1  is a perspective view of a drywall sander according to a first preferred embodiment of the present invention. 
           [0013]      FIG. 2  is an exploded perspective view of the drywall sander shown in  FIG. 1 . 
           [0014]      FIG. 3  is a perspective view of the attachment shown in  FIGS. 1 and 2 . 
           [0015]      FIG. 4  shows a plan view of another preferred embodiment of the drywall sander of this invention. 
           [0016]      FIG. 5  shows a side view of the drywall sander shown in  FIG. 4 . 
       
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
       [0017]    The following list identifies the associated elements of  FIGS. 1-3 . The present application incorporates by references, in its entirety, previously filed (and now expired) U.S. Provisional Patent Application No. 61/357,279, filed Jun. 22, 2010. In that prior provisional, the invention generally refers to a sanding tool. To some extent, that description is carried over here, but this device is also referred to herein as a drywall scraper, or a drywall sander. Such terms are generally deemed equivalent in this context of this specification. 
         [0018]      10  sanding tool 
         [0019]      15  attachment 
         [0020]      20  blade 
         [0021]      21  first face 
         [0022]      23  top edge 
         [0023]      24  bottom side 
         [0024]      25  elongated handle 
         [0025]      30  abrasive layer 
         [0026]      35  backing layer 
         [0027]      40  central fold 
         [0028]      41  first fold side 
         [0029]      42  second fold side 
         [0030]      25  adhesive 
         [0031]    More specifically,  FIG. 1  shows a drywall sander, or a sanding tool  10 , according to a first preferred embodiment of the invention. The sanding tool  10  has a substantially rigid blade  20  with a first face  21 , a second face, a top edge  23 , and a bottom side  24 . In the exemplary first preferred embodiment shown in  FIG. 1 , the first face  21  of the blade  20  and the second face of the blade  20  are substantially identical. The sanding tool  10  also has a substantially elongated handle  25  extending from the bottom side  24  of the blade  20 . 
         [0032]    The sanding tool  10  further includes an abrasive layer  30 . The abrasive layer  30  covers a first portion on the first face of the blade  20 , extends over the top edge  23 , and covers a second portion on the second face of the blade  20 . Thus, the abrasive layer  30  is exposed on opposing sides of the sanding tool  10 . As shown in  FIG. 1 , the sanding tool  10  includes a substantially thin backing layer  35  which is positioned between the blade and the abrasive layer. In an exemplary embodiment of the present invention as shown in  FIG. 1 , the abrasive layer  30  covers a substantial portion, but not the entire backing layer  35 . In one variation of the invention, the backing layer  35  may be a buffer layer of foam. In its simplest foam, the attachment  15  is an appropriately sized piece of sandpaper, with a paper backing layer  35  and an abrasive front surface  30 , and structure for securing the paper backing  35  to the opposing faces of the blade  20 . 
         [0033]    As shown in  FIG. 1 , the top edge  23  is wider than the bottom side  24 . In an exemplary embodiment of the present invention, the blade width decreases from the top edge  23  to the bottom side  24 . Further, in an exemplary embodiment of the present invention, and as shown in  FIG. 1 , the abrasive layer  30  and the backing layer  35  are cut to maintain substantially the same widths as portions of the blade  20  which they cover. 
         [0034]    As shown in  FIGS. 1 and 2 , angles created by the top edge  23  of the blade  20  and sides of the blade  20 , and mirrored by the abrasive layer  30  (and also the backing layer  35 , if included), are acute angles. The acute angles, combined with a relative flatness of the sanding tool, allows for efficient sanding in corners. In particular, the acute angles of the sanding tool  10  allow for increased access into corners and other tight areas. Further, such exemplary embodiments allow a user to more easily avoid hand contact between the sanding tool  10  and nearby walls during sanding. This advantage is not lost when the second preferred embodiment is used, with the blade  120  of non-uniform thickness, which decreases from the bottom side  24  to the top edge  23 . 
         [0035]    As noted above, in a preferred embodiment of the present invention, the abrasive layer  30  and the backing layer  35  are achieved via conventional sandpaper, as an attachment  15  to the tool.  FIGS. 2 and 3  show more details of the attachment  15  for the sanding tool  10 , with  FIG. 2  showing an exploded perspective view of the attachment  15  as it circumscribes the hand tool  10  and particularly the blade  20 , and  FIG. 3  showing the attachment  15  by itself. 
         [0036]    According to one variation of the present invention, the backing layer may include, or may be a buffer layer of foam. In the embodiment which uses the buffer layer, the sanding tool allows a user to more easily control a force applied to an area to be sanded. In particular, by absorbing some of the force a user applies to the sanding tool  10 , the buffer layer provides flexibility in a range of forces a user can apply to the sanding tool  10 . 
         [0037]    The attachment  15  includes a substantially central fold  40  which establishes a first fold side  41  and a second fold side  42 . In a preferred embodiment of the present invention, the abrasive layer  30  is applied to the backing layer  35  after the central fold  40  is established in the backing layer  35 , so that the abrasive layer  30  will be less susceptible to cracking. 
         [0038]    The attachment  15  is positioned on the substantially flat and substantially rigid first face  21 , second face, and a top edge  23  of the blade  20 . More specifically, the first fold side  41  is positioned over a first portion of the first face  21 , the second fold side  42  is positioned over a second portion of the second face, and the fold  40  is positioned substantially over the top edge  23 . The attachment  15  is positioned such that the backing layer is releasably attached to the blade  20  by an attaching structure which may be selected from the following group: adhesives  45 , hooks and fasteners, snaps, buckles, and hooks. As shown in  FIGS. 2 and 3 , once the attachment  15  is mounted, the abrasive layer is substantially exposed on opposite sides of the blade  20  to which it is attached. The attachment  15  and its corresponding abrasive layers can thereafter be removed from the blade  20  and replaced with a new abrasive layer, at a user&#39;s preference. This will typically occur due to wear. 
         [0039]    The present invention also relates to a method for using a sanding tool, and also the method of preparing a sanding tool for use, in the manner described herein. More specifically, the method for using a sanding tool comprises the steps of applying the abrasive layer of the sanding tool to an area designated for sanding. Because the abrasive layer is exposed on opposing sides of the blade  20  of the sanding tool  10 , the user may use either side of the device. With the ability to use either side, a user can avoid the need for constant repositioning while sanding, and thus can be more efficient. Similarly, the shape of the handle  25 ,  125  (i.e., preferably rounded, as shown in  FIGS. 4 and 5 ) and the shape of the blade  20 ,  120  help to reduce injury and user fatigue, while also providing access to corners, all of which help to assure consistent and high quality sanding. Moreover, the device  10 ,  110  is relatively inexpensive. 
         [0040]      FIGS. 4 and 5  show another preferred embodiment of the invention, which for the most part uses the same reference numbers as  FIGS. 1-3 , but with the number “1” appended at the first end, to indicate the numbers between 100 and 200. More specifically, the drywall sander  110  of  FIGS. 4 and 5  includes a rounded handle  125  and an arcuately shaped blade  120  (when viewed in a first direction). The thickness of the blade  120  (when considered in a second direction, perpendicular to the first) increases from a top edge  123  to a bottom side  124 . As shown in  FIG. 5 , the blade  120  appears triangular in side view. This variation in the thickness of the blade  120  facilitates sanding in certain circumstances, because the user has more leverage. 
         [0041]      FIG. 4  shows a darkened zone  126  which designates a portion of the surface to which an attaching structure  115  may be attached, such as by using a hook and loop attaching structure. With this arrangement, the removable attachment  115 , in this case sandpaper, can be specifically shaped to cover specifically desired shapes of the opposing sides of the scraper  120 . 
         [0042]    While this invention has been described in conjunction with the specific embodiments outlined above, it is evident that a number of alternatives, modifications and variations will be apparent to those skilled in the art. Accordingly, the preferred embodiments of the invention as set forth above are intended to be illustrative, not limiting. Various changes may be made without departing from the spirit and scope of the invention.
A sanding tool including a blade and a handle, the blade having first and second opposing faces. An attachment layer removably secures to the sanding tool at the opposing faces, thereby to provide opposing abrasive layers on opposing sides of the blade. The shape of the blade, with a wider yet thinner top end, and a reduced thickness from a bottom side thereof to a top edge thereof, reduces hand strain when sanding drywall, and also helps to assure uniform sanding and avoidance of hand injury when sanding corners, in a cost-effective manner.