Abstract:
A scraper in combination with a sharpener provides consistent sharpening of the scraper blade. The scraper has a scraper blade, blade holder, and bearing surface. The sharpener has a sharpening element and a guide generally parallel to the sharpening element. The bearing surface of the scraper fits the guide of the sharpener and the scraper blade contacts the sharpening element. The scraper can be drawn along the guide to draw the blade along the sharpening element. The bearing surface and guide keep the blade in consistent and correct relation to the sharpening element to provide proper sharpening of the scraper blade. Adaptors may be used to sharpen additional types of blades or tools on the sharpener and different types of sharpening elements may be used in the sharpener.

Description:
RELATED U.S. APPLICATION DATA 
     This application claims priority from U.S. provisional application No. 61/238,838, filed on Sep. 1, 2009. The entire disclosure contained in U.S. provisional application 61/238,838, including the attachments thereto are incorporated herein by reference. 
    
    
     FIELD OF THE INVENTION 
     This invention relates to blade sharpeners and more particularly to scrapers and scraper blade sharpeners. 
     BACKGROUND 
     Scrapers are utilized in removing paint, finish and fine layers of wood among other things in areas that motorized tools are unable to operate. Typically, scraper blades are sharpened freehand with a file after being attached to a blade holder or handle by some means. It takes considerable practice, skill, and attention to the task to sharpen a blade by freehand methods and obtain a straight and sharp edge. A blade being freehand sharpened with a file usually results in the center hollowed, edges rounded or a combination of both, resulting in a gouged or uneven work surface when the defectively sharpened blade is used on the work surface. In addition to quality issues, the typical method of sharpening a blade, for example, a scraper blade, presents safety issues. In the sharpening process, pressure is applied to the blade with a file while moving the file across the blade. Workers sometimes slip off the blade edge with the file while moving the hand holding the file towards the blade, which can result in injury, such as a cut to the hand that is holding the file. 
     Understanding the dynamics to sharpen the blade does not always result in the ability to apply that knowledge. It takes time and experience. Many workers never achieve this skill, even after considerable effort. The several embodiments of the present apparatus and method eliminate the need to acquire the skill and provide a willing, but untrained, individual the ability to sharpen a blade in a safe, effective, and expeditious manner. 
     RELEVANT ART 
     U.S. Pat. No. 523,908 by Sly is for a “Machine for Sharpening Shears.” In Sly, an arm is attached one of the shear halves. The shear half is placed on a sharpening stone while the other end of the arm is placed in a guide. The arm keeps the shear blade at the correct angle while it is being moved on the stone. 
     U.S. Pat. No. 1,359,271 by Plummer is for a “Universal Tool Sharpener”. In Plummer, an abrading block rests on a base. A cylindrical guide bar fixed at each end spans above the abrading block. A carrier is fitted over the end of the guide rod to mount it on the guide rod. Tools can be fixed in the carrier and arranged so that their point or blade contacts the abrading block. Sliding the carrier along the guide rod moves the tools point or blade along the abrading block to sharpen the tool. 
     U.S. Pat. No. 1,675,981 by Lees is for a “Graver Sharpener and Facet Cutting Machine.” In Lees, a wet stone rests on a panel with a block running along an edge of the wet stone and support guide block support one end of each of two arcuate guide rods. The other ends of the guide rods are on support posts. A straight guide bar has nuts with apertures at each of its ends and spans the arcuate guide rods and can slide along the arcuate guide rods. A block for holding a graver is slid over the end of the straight guide bar to assemble it to the guide bar. The block can pivot about the straight guide, and it can slide along the straight guide. A graver held by the block can be put in contact with the wet stone and moved along it to sharpen it, while being maintained at a desired angle. 
     SUMMARY 
     One embodiment of the present invention is a bladed tool and sharpener combination with the means to abrade the blade edge square to its face at an angle resulting in the blade being sharpened. The sharpener has a sharpening element and a guide such as a guide rod. The bladed tool has a bearing surface on it matching the guide. By placing the bearing surface of the bladed tool on the guide rod of the sharpener, the blade of the bladed tool can be maintained in contact with the sharpening element in correct orientation while being moved back and forth. In one embodiment the bladed tool is a scraper. Alternative embodiments include adapters that can be substituted into the combination tool and used to sharpen other bladed tools such as chisels. These adapters do not need to be permanently mounted as part of the combination tool to be used. Among other things, this provides a means of sharpening a larger variety of blades and bladed tools. 
     As discussed above, the article and method of the present invention overcomes the disadvantages inherent in prior art methods and prior art devices. In this respect, before explaining at least one embodiment of the invention in detail, it is to be understood that the invention is not limited in its application to the details of construction and/or to the arrangement of the support structure set forth in the following description or illustrated in the drawings. The invention is capable of other embodiments and of being practiced and carried out in various and diverse ways. Also, it is to be understood that the phraseology and terminology employed herein are for the purposes of description and should not be regarded as limiting. 
     Accordingly, those skilled in the art will appreciate that the concept upon which this invention is based may readily be utilized as a basis for the design of other structures, methods, and systems for carrying out the purposes of the present invention. It is important, therefore, that the claims be regarded as including such equivalent constructions insofar as they do not depart from the spirit and scope of the present invention. 
     Furthermore, the purpose of the foregoing Abstract is to enable the U.S. Patent and Trademark Office and the public generally, and especially including the practitioners of the art who are not familiar with patent or legal terms or phraseology, to determine quickly from a cursory inspection, the nature and essence of the technical disclosure of the application. The Abstract is neither intended to define the invention of the application, nor is it intended to be limiting to the scope of the invention in any respect. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Additional utility and features of this invention will become more fully apparent to those skilled in the art by reference to the following drawings, wherein all components are designated by like numerals and described more specifically. 
         FIG. 1  is a perspective view of a first embodiment of a scraper tool in position on a first embodiment of a sharpener. 
         FIG. 2  is the same view as  FIG. 1 , but with the scraper tool having moved to a second position on the sharpener. 
         FIG. 3  is a side section view taken through the sharpener of  FIG. 1  at the plane indicated. 
         FIG. 4  is a front perspective view of the embodiment of  FIG. 1 . 
         FIG. 5  is a perspective view of the scraper tool of  FIG. 1  apart from the sharpener. 
         FIG. 5A  is an exploded perspective view of the scraper tool of  FIG. 5 , including the blade holder, bushing, blade, and clamp screw. 
         FIG. 6  is a perspective view of the sharpener of  FIG. 1  with an adaptor for sharpening other tools. 
         FIG. 7  is an exploded perspective view of  FIG. 6 , which is intended for use in sharpening a chisel. 
         FIG. 7A  is a perspective view of an alternate adaptor having a cap on the open bearing which can be put in place to enclose a guide after the bearing is placed on a guide. 
         FIG. 7B  is an exploded perspective view of the embodiment of an adaptor of  FIG. 7A , which shows the cap removed. 
         FIG. 7C  is a perspective view of an embodiment of an adaptor, which has a clip attached near an open bearing. 
         FIG. 8A  is a side view of the partially closed bearing of  FIG. 5A . 
         FIG. 8B  is an example of an alternate bushing, with a fully open bearing. 
         FIG. 8C  is an example of another alternate bushing, without surface reducing groves in the bearing surface. 
     
    
    
     DETAILED DESCRIPTION OF EMBODIMENTS 
       FIGS. 1 ,  2 ,  3 , and  4  illustrate a first embodiment of a scraper kit, which includes a scraper tool and a sharpener, while  FIGS. 5 and 5A  illustrate a scraper apart from sharpener. 
     The embodiment of the scraper tool shown in  FIGS. 1-5A  includes blade holder  105 , scraper blade  107 , bushing  109 , and clamp screw  108 . Referring now to  FIGS. 5 and 5A , it can be seen that bushing  109  is removable and provides a slide bearing  114  at least partially open with a slot along its length and a blade mount surface  115 . Slide bearing  114  is sized to fit a guide rod  101  such as shown in  FIGS. 1-4 . To sharpen blade  107  while mounted in bladed holder  105 , slide bearing  114  is placed over guide rod  101 , blade holder  105  is rotated to bring blade  107  into contact with the sharpening surface  116  of sharpening element  102 , and blade holder  105  is slid back and forth on guide rod  101  while maintaining contact between blades  107  and sharpening surface  116 . 
     The sliding of blade holder  105  back and forth on guide rod  101  produces wear on slide bearing  114  and over time bearing  114  may become worn beyond effectiveness. Because of this, in the embodiment shown in  FIGS. 1-5A , bearing  114  is made as part of removable bushing  109  which also incorporates blade mount surface  115 . As shown in  FIG. 5A , both blade mount surface  115  of bushing  109  and blade  107  have apertures, blade mount surface aperture  117  and blade aperture  118 , respectively. Blade holder  105  has an aperture, or hole  119 , which may be threaded. Clamp screw  108  passes through blade aperture  118  of blade  107  and bushing aperture  117  of bushing  109  and threads into hole  119  in blade holder  105  to clamp blade  107  and bushing  109  to blade holder  105 . The blade  107  typically is made of metal, such as steel. The bushing  109  may be made of metal, plastic or other desired material. 
     Although the embodiment of  FIGS. 1-5A  has bearing  114  as a part of removable bushing  109 , that is not a requirement. Other embodiments may have bearing  114  made integral to the scraper, either from the same material as the rest of the scraper, or as an insert resistant to wear, such as a metal insert. Similarly, other embodiments may have a blade mount surface integral to the scraper as opposed to being part of removable bushing  109 . In the embodiments shown in  FIGS. 1-5A , having blade aperture  118  and bushing aperture  109  arranged concentrically over holes  119  when blade  107  and bushing  109  are mounted on blade holder  105 , allows a single clamp screw  108  to clamp both items onto blade holder  105 . An alternative mechanism could be used for clamping instead of a screw, if desired. It is conceivable that, in other embodiments, blade  107  could be made permanent in blade holder  105 , but that is unlikely, since blade  107  wears from use and sharpening, and once a permanent blade is worn, its whole scraper would have to be thrown away. Additionally, in some embodiments, slide bearing  125  may be recessed in a notch in blade holder  126  with surfaces of the notch leading back to terminate at the bearing surface. The walls of the notch facilitate keeping the scraper engaged. Also, while the bearing surface is shown as cylindrical, it could also be comprised of tow or more flat surfaces. 
     Handle  120  extends from blade holder  105 . Where handle  105  joins blade holder  105  there is a broad, curved, indented design element, or hand rest  106 , in the top surface of the scraper to fit the heel of a person&#39;s palm to aid in applying pressure to the blade and or work surface. Hand rest  106  is most fully seen in  FIG. 4  and may be seen in profile in  FIG. 3 . There are several manners in which hand rest  106  may be used. One manner includes pressing into hand rest  106  with the heel of the palm of one hand to apply pressure. 
     At the end of handle  120  distal from blade holder  105  is ring  121 . Ring  121  is large enough that at least one finger may be inserted through it to pull the scraper. This provides a strong, positive grip for pulling the scraper while it is in use. The combination of hand rest  106  and ring  121  on the scraper allows a user to both apply pressure to the scraper and pull steadily notwithstanding the pressure being applied. As a grip, ring  121  allows the scraper to be used easily at a wide range of angles. 
     In the embodiments shown in  FIGS. 1 ,  2  and  6 , the sharpening tool includes a frame  100 , a guide rod  101 , a sharpening element  102 . Guide rod  101  in this embodiment has a cylindrical shape and can be made of solid or hollow material of most any kind that would be rigid enough and strong enough to resist deflection. Guide rod  101  is held between two parallel uprights  122  extending from base  123  of frame  100 , which could be made of most any material. The presence of two uprights in the embodiments shown allows guide rod  101  to be securely supported at each end which provides a level of rigidity and limits the sliding motion of a blade holder. However, other embodiments may have frames with other configurations and two uprights are not a requirement. Frame  100  may be made by casting, molding, or by other means. Sharpening element  102  in this embodiment is a mill bastard file. Other embodiments may employ other sharpening elements such as files of other grades, a diamond abrasion tool, a honing stone, etc. 
     In the embodiments shown in  FIGS. 1-5A , the position of sharpening element  102  may be adjusted, and sharpening element  102  may even be removed and replaced. Sharpening element  102  is clamped into place between base  123  and the bottom of uprights  122  by tensioning screw  104  and nut  103 . Nut  103  is positioned over slot  124  and tensioning screw  104  is turned through nut  103  until its end contacts the bottom of sharpening element  102  and generates enough force to securely hold sharpening element  102  in place. Slots  124  allow tensioning screws  104  and nut  103  and each end of sharpening element  102  to be moved so that they are centered on sharpening element  102  as well as allowing the overall position of sharpening element  102  to be adjusted. Sharpening element  102  may be removed by sufficiently relaxing the hold of tensioning screws  104 . 
       FIGS. 6 and 7  show the same sharpening tool of  FIG. 1  being used with an alternative blade holder  110 , for use in holding a different tool to be sharpened, such as a chisel. In this case, a chisel toe plate  111  is secured to the blade holder  110  by means of clamping screws  112 . The toe plate  111  has a recess for receiving the blade of the chisel, as shown in phantom in  FIG. 6 . There also is a set screw  113 , which clamps the chisel blade against the toe plate  111 . Blade holder  110  has a slide bearing  125  partially opened along its length which engages the guide rod  101  in the same manner as the previously described bearing  114 . Other shapes of toe plates and/or tool holders could be used instead of the toe plate  111  and blade holder  110  for holding other tools. 
     Referring now to  FIG. 7A , another embodiment of a blade holder  126  is shown. In that embodiment, bearing cap  127  allows partially open slide bearing  128  on blade holder  126  to be closed around a guide rod after it has been positioned on the guide rod. Although the bearing cap  127  in  FIG. 7A  provides a 360 degree enclosure of the rod, other embodiments of bearing cap  127  may create a wrapping of less than 360 degrees about the guide rod. The extent of wrapping about the guide rod deemed necessary is determined by the application and the loads generated by the application. 
       FIG. 7B  is an exploded perspective view of the blade holder  126  of  FIG. 7A . In  FIG. 7B  additional screws  129  and matching apertures  130  provide the means of attaching bearing cap  127  to blade holder  126 . Other elements of blade holder  126  shown in  FIGS. 7A and 7B  are similar to the embodiment of blade holder  110  shown in  FIGS. 6 and 7 . 
       FIG. 7C  is a perspective view of an embodiment of blade holder  126  which has clip  131  attached near, or on, open bearing  128 . Clip  131  has a spring quality to it. Once bearing  128  of blade holder  126  is installed on a guide such as guide rod  101  in the sharpener discussed above, clip  131  retains bearing  128  in contact with the guide. Clip  131  may be attached with a screw or any of several possible alternative means of attachment. It may also be located on either side of bearing  128 . 
       FIGS. 8A ,  8 B, and  8 C show several embodiments of slide bearing  125 . In the embodiment shown in  FIG. 8A , the internal surface of slide bearing  125  encloses an angle greater than 180 degrees. In this embodiment slide bearing  125  can “snap” over guide rod  101  and thereafter provide some measure of retention of blade holder  105  without assistance. In order to do this, slide bearing  125  must have sufficient flexibility. This flexibility may be due to the inherent flexibility of the material of bearing  125  or may result as much from the design of bearing  125 . The embodiment of slide bearing  125  in  FIG. 8B  does not have the capability to wrap around guide rod  101 . Because of this, slide bearing  125  of  FIG. 8B  may be made of a more rigid, or harder, material. This may be desirable for wear durability. The embodiment of slide bearing  125  shown in  FIG. 8C  has a smooth bearing surface in contrast to the embodiments of bearing  125  in  FIGS. 8A and 8B , which have surface reducing grooves. 
     OPERATION 
     As illustrated in  FIG. 1 , the blade holder  105  and its attachments are mounted on the guide rod  101  and are positioned to be pulled along the sharpening element  102  to the position shown in  FIG. 2  in order to sharpen the scraper blade  107 . The sharpening element  102  in this embodiment is a file and cuts only in one direction, so after completing a first pass from right to left (from the position shown in  FIG. 1  to the position shown in  FIG. 2 ), the blade holder  105  is placed back in its original position shown in  FIG. 1  and is pulled across the file  102  again for further sharpening. Once the scraper blade  107  has been sharpened, the scraper tool is disengaged from the guide rod  101  as shown in  FIG. 5 , ready for use on a work surface.  FIG. 3  shows how the bushing  109  is received in a recess in blade holder  105 , and how blade  107  is clamped against the flat portion of the bushing  109  and against the blade holder  105  by means of the clamp screw  108 . It also shows how bearing  114  wraps around the guide bar  101 , as discussed above with respect to  FIG. 8A . This bearing  114  has grooves in the curved surface that wraps around the guide bar  101  to reduce the surface area of contact between the bushing  109  and the guide bar  101 . 
     As the scraper blade  107  is sharpened and mass is lost from the blade  107 , the angle between the tip (the sharp edge) of the blade  107  and the sharpening surface  116  of sharpening element  102  is reduced, which results in a smaller angle on the edge, but sharper scraper blade  107 . 
     The arrangement shown in  FIGS. 1 ,  2 ,  3  and  4  is for a right handed person, with the scraper blade  107  positioned on the left side of the guide rod  101 . Alternatively, for sharpening elements  102  that act in only one direction, the sharpening element  102  can be turned 180 degrees and the sharpening motion would be accomplished with a push rather than pull, or if the blade holder is being held by a left handed person, he could turn the sharpener 180 degrees and push the blade holder  105  along the guide rod  101  to sharpen. This enables both left and right handed people to share sharpening tool without changing the set up. As the sharpening element  102  is worn with use, it can easily be repositioned so that fresh and or unworn areas of the sharpening element  102  contact the blade  107  by loosening the tensioning screws  104  and the nut  103  and repositioning the sharpening element  102 . 
     The frame  100  holds the guide rod  101  parallel to the sharpening element  102  and at a height conducive to enable sharpening of the scraper blade  107 . 
       FIG. 6  shows the frame  100  and assembly being utilized to sharpen a chisel. In this arrangement, the chisel is moved across the sharpening element  102  parallel and square to sharpening surface  116 . 
     The above description describes only a few embodiments of the present invention. These are not the only ways the invention could be made. The scope of the invention should be determined by the claims and their legal equivalents and should not be limited to the examples shown and described here.