Patent Publication Number: US-6663479-B2

Title: Contouring hand sander tool

Description:
This application claims the benefit of U.S. Provisional Application No. 60/292,442 filed on May 21, 2001. 
     This invention relates to a hand held tool for holding and using a continuous sanding belt for sanding and smoothing operations, and for producing more uniform rounding of edges and corners of work surfaces. 
    
    
     BACKGROUND 
     Although sanding blocks and the like have long provided certain advantages over the unsupported use of sand paper, rigid flat blocks while good for use on flat surfaces are often less than ideal when used to create rounded edges and corners of work objects. 
     A review of the hand held devices available today indicates that a more accommodating tool for such rounding operations would be useful to craftsmen. 
     OBJECTIVES 
     Consequently, the major objective of this invention has been to devise such a tool using continuous sanding belts that, in addition to sanding and smoothing flat surfaces, can provide a way to more uniformly round edges and corners of work pieces. 
     A second and useful objective of this invention has been to incorporate into the tool&#39;s design a unique but simple way to quickly place and remove a continuous sanding belt from the tool. 
     Further objects and advantages of my invention will become apparent from consideration of the drawings and ensuing descriptions. 
    
    
     LISTING OF FIGURES 
     FIG. 1 shows a side view of this invention minus the belt. 
     FIG. 2 shows a top view of tool minus the belt. 
     FIG. 3 shows a sectional view of a deep channel in the tool taken along line  3 — 3  of FIG.  1 . 
     FIG. 4 shows a perspective view of the tool with its base plate rotated to the open position, and a belt in position to be mounted. 
     FIG. 5 shows a perspective view of the tool with belt loosely mounted having its base plate partially rotated back toward a closed, longitudinally aligned position with the sander housing. 
     FIG. 6 shows a perspective view of the tool with its base plate closed, such that it is fully aligned with the sander housing. Also, the sanding belt is shown creased down into the channel of the housing. 
     FIG. 7 is a perspective view of the tool in action, rounding the edge of a work Piece. 
     
       
         
           
               
             
               
                   
               
               
                 DRAWING REFERENCE NUMBERS: 
               
               
                   
               
             
            
               
                   
               
            
           
           
               
               
            
               
                   
                 20 sander housing; 
               
               
                   
                 22 base plate; 
               
               
                   
                 24 rotational coupling means; 
               
               
                   
                 26 continuous sanding belt; 
               
               
                   
                 28 deep channel; 
               
               
                   
                 30 rounded ends; 
               
               
                   
                 32 rounded profile. 
               
               
                   
                   
               
            
           
         
       
     
    
    
     DESCRIPTION 
     Referring to the figures a hand operated sanding tool is shown which may be grasped partly around its girth with one hand. It is composed of two parts, a single piece sander housing  20 , and a rigid flat bottom base plate  22 . The sander housing is made from a compressible, resilient, material. 
     When viewed from the side, as shown in FIG. 1, the sander housing has a rounded profile  32 , over its length tapering down at both ends to meet the base plate whose overall dimensions are generally the same as the housing, where they contact each other. However, they do differ in that the base plate has rounded ends  30 . Along the rounded profile of the top of the sander housing is a deep channel  28 , centrally aligned, having its trough run parallel to the flat bottom of the housing. 
     Along the housings length both sidewalls are slightly tilted in toward each other, being closer together at the top of the housing, as shown in FIG. 3, thereby enhancing an easy grip of the tool. 
     The two parts of the sander are held closely together with a single, centrally located bolt, or equivalent,  24 , passing up through both pieces and tightened so as to allow the base plate to be easily rotated. 
     Operation 
     Positioning and holding a continuous sanding belt on a sanding tool so it won&#39;t slip when being used requires some kind of a tensioning mechanism to be incorporated in the tools design. The following describes a simple but effective way to do this. 
     The bottom base plate of the tool, which is free to turn, is rotated about ninety degrees with respect to the upper sander housing portion, as seen in FIG.  4 . When in this position a side view of the tool reveals that its overall circumferential distance, around which the belt contacts, is minimized. A belt may then be placed over the tool and tensioned by rotating the base plate back toward its original inline alignment with the upper housing, as seen in FIG.  5 . When fully aligned, as seen in FIG. 6, the distance around the tool, in contact with the belt, will be maximized as will be the tension on the belt because the compressible resilient material of the housing, around which the belt is placed, is squeezed and in such a compressed state applies pressure to expand the belt thus creating a tension. 
     When the tool is used for rounding edges, as shown in FIG. 7, the action is to move the sander back and forth in a longitudinal direction. No careful sideways motions or sanding techniques are required, as with typical flat faced sanding devices. 
     Conclusions 
     In addition to flat surface sanding, the tool may be used to obtain more uniformly rounded edges offering an advantage over existing block sanders. 
     The belt tensioning mechanism is very simple. It only requires the use of the housing and the swiveling base plate to place and remove sanding belts. 
     While the base plate must be made of rigid material, the sander housing is made from a resilient, compressible material, such as lightweight foam whose exceptional lightweight makes it especially desirable when used for overhead work. 
     Although the preferred embodiment of the invention has been presented in the above descriptions these should not be construed as limitations on the scope of the invention, but rather, as an exemplification of one preferred embodiment thereof. Other variations are possible, for example, the shape and extent of the channel in the sander housing or, the location of the rotational coupling means. Accordingly, the scope of the invention should be determined, not by the embodiment(s) illustrated, but by the appended claims and their legal equivalents.