Patent Publication Number: US-10780546-B2

Title: Variable radius sanding block

Description:
CROSS REFERENCE TO RELATED APPLICATION 
     This application claims the benefit of U.S. Provisional Application No. 62/489,819 filed on Apr. 25, 2017. The above identified patent application is herein incorporated by reference in its entirety to provide continuity of disclosure. 
    
    
     BACKGROUND OF THE INVENTION 
     The present invention relates to the sanding of wood, musical instruments, and other rounded surfaces. 
     Sanding blocks conventionally are provided having a fixed curvature that is only intended to be used to sand objects of a corresponding curvature. In order for most wood workshops to be able to sand a wide range of surfaces they have to maintain several sanding blocks, where each one has a different curvature. For this reason, multiple sanding blocks in many wood workshops tend to take up substantial amounts of space. In order to address these concerns, the present invention provides a sanding block having a curved surface whose curvature can be changed to match the curvature of the curved surface that needs sanding. 
     SUMMARY OF THE INVENTION 
     In view of the foregoing disadvantages inherent in the known types of sanding blocks now present in the prior art, the present invention provides a variable radius sanding block wherein the same can be utilized for providing convenience for the user when sanding of wood, musical instruments, and other rounded surfaces. 
     It is therefore an object of the present invention to provide a new and improved means of sanding rounded surfaces that has all of the advantages of the known art and none of the disadvantages. 
     It is another object of the present invention to provide a variable radius sanding block assembly having a base member and a plurality of insertable radius patches of varying width and curvature, such that when one of the radius patches is inserted into the base member they combine to form a single structure having a rounded surface at one end. 
     Another object of the present invention is to provide a base member having a flexible folded internal structure and two flexible arms, such that the arms define an opening to receive a radius patch and for the folded internal structure to expand and contract so that the size of the opening defined by the flexible arms can be increased or decreased. 
     Yet another object of the present invention is to provide a base member and radius patch each having a pair of grooves and protruding lips, such that the grooves and protruding lips interlock with one another so that the base member securely retains the radius patch once inserted therein. 
     An additional object of the present invention is for radius patches of differing size to have correspondingly different colors in order to be more easily recognizable. 
     Another object of the present invention is to provide a variable radius sanding block that may be readily fabricated from materials that permit relative economy and are commensurate with durability. 
     Other objects, features and advantages of the present invention will become apparent from the following detailed description taken in conjunction with the accompanying drawings. 
    
    
     
       BRIEF DESCRIPTIONS OF THE DRAWINGS 
       Although the characteristic features of this invention will be particularly pointed out in the claims, the invention itself and manner in which it may be made and used may be better understood after a review of the following description, taken in connection with the accompanying drawings wherein like numeral annotations are provided throughout. 
         FIG. 1  shows a perspective view of an embodiment of a fully assembled variable radius sanding block. 
         FIG. 2A  shows a perspective view of the base member of the variable radius sanding block in a resting position. 
         FIG. 2B  shows a perspective view of the base member of the variable radius sanding block in a flexed position. 
         FIG. 3  shows a cross-sectional view of the base member of the variable radius sanding block. 
         FIG. 4  shows a perspective view of a radius patch of the variable radius sanding block. 
         FIG. 5  shows a perspective view of a radius patch partially inserted into the base member of the variable radius sanding block. 
         FIG. 6  shows a perspective view of an embodiment of the fully assembled variable radius sanding Block alongside additional radius patches of varying size. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     Reference is made herein to the attached drawings. Like reference numerals are used throughout the drawings to depict like or similar elements of the variable radius sanding block. The figures are intended for representative purposes only and should not be considered to be limiting in any respect. 
     Referring now to  FIG. 1 , there is shown a perspective view of an assembled variable radius sanding block. The variable radius sanding block  1000  comprises a base member  100  and a plurality of variably sized radius patches  200 . In the illustrated embodiment, assembly of the variable radius sanding block requires insertion of one of the radius patches  200  into the base member  100 . In the illustrated embodiment, both the base member  100  and the radius patch  200  are made of an extruded plastic, such that the base member  100  is flexible and can be easily manipulated while the radius patch  200  is rigid and resistant to manipulation. 
     Referring now to  FIGS. 2A and 2B  there is shown a perspective view of the base member of the variable radius sanding block in a resting position and a flexed position, respectively. The base member  100  includes a top end  110  and a bottom end  120 , such that the top end  110  includes a left flexible arm  111  and a right flexible arm  112 . Together the two arms  111 , 112  form an incomplete arch  115  and define an opening  116 . The opening  116  is sized and proportioned to allow any of the variably sized radius patches  200  to be inserted into the base member  100 , thereby completing the arch  115  to form a continuous upper surface, as seen in  FIG. 1 . The radius of the arch  115  being adjustable based on the width and size of the radius patch  200  that is inserted. The flexible arms  111 , 112  are configured to collapse inward to make the opening  116  smaller or expand outwards to make the opening  116  larger depending on the size of the radius patch  200  to be inserted. Furthermore, each flexible arm  111 ,  112  of the base member  100  includes a protruding lip  113  on the left arm and  114  on the right arm. Each protruding lip  113 ,  114  is configured to secure any of the variably sized radius patches  200  in place once inserted into the base member  100 . 
     In the illustrated embodiment, the bottom end  120  of the base member  100  also includes a folded spring  123  having a plurality of expandable segments  124  that operably connect an outermost left side  151  to an outermost right side  152 , such that each expandable segment  124  can expand or contract to control the position of the two flexible arras  111 ,  112  in the top end  110 , and when combined the expandable segments  124  define a smooth upper surface  121  configured to receive the radius patches  200  when inserted, such that a bottom end  220  of radius patch  200  (see  FIG. 4 ) is flush against the smooth upper surface  121  when inserted. Additionally, the folded spring  123  that connects the outermost left side  151  to the outermost right side  152  across the entire length of the base member  100  between the two opposing faces  131 ,  132 . 
     In use, when a radius patch  200  is inserted into the base member  100  the expandable segments  124  of the folded spring  123  are configured to flex or spread apart to form a concave curve at a lower surface of the folded spring  123  and a convex curve at an upper surface thereof (see  FIG. 2B ) so that the flexible arms  111 ,  112  in the top end  110  of the base member  100  are able to collapse inward and expand outward. The lateral sides of the radius patch bear against the flexible arms and exert force thereto. More specifically, when the expandable segments  124  of the folded spring  123  move to a flexed position to form the convex curve, the flexible left arm  111  is forced to flare outward because the left arm  111  forms the upper portion of the outermost left side  151  that is operably connected to the folded spring  123  by means of a left connecting joint  141 . The flexible right arm  112  is similarly forced to flare outward because the right arm  112  also forms the upper portion of the outermost right side  152  that is operably connected to the folded spring  123  by means of a right connecting joint  142 . 
     Referring now to  FIG. 3 , there is shown a cross-sectional view of the base member of the variable radius sanding block. In the illustrated embodiment, the expandable segments  124  of the folded spring  123  form a plurality of overlapping folds, wherein each expandable segment  124  comprises a gap  301  having a triangular cross section when in the resting position. The gaps  301  each include an open end  302  and a closed end  303 , wherein each end  302 ,  303  alternate in orientation between adjacent expandable segments  124 . The expandable segments  124  are biased to remaining in a closed position such that the open end  302  of the gap  301  remains closed when the base member  100  is disposed in a resting position. In operation, when the base member  100  is flexed in order to receive the radius patch  200  and form the desired curvature, the open ends  302  of the gaps  301  are configured to open relative to the size of the radius patch  200  received by the base member  100 . 
     In the illustrated embodiment, outermost openings  122  are formed between the bottom of the base member and the connected joints  141 ,  142 . These outermost openings  122  provide additional ability for the folded spring  123  to flex. Further the outermost openings  122  and expandable segments  124  extend entirely through the base member  100 , between the two opposing faces. 
     Referring now to  FIG. 4 , there is shown a perspective view of radius patch. In the illustrated embodiment, the radius patch comprises a top end  210 , a bottom end  220 , a left side wall  213 , a right side wall  214 , and a plurality of chambers  240  defined by partitions  241  that run along the length of the radius patch  200  between the two opposing faces  231 ,  232 . In the illustrated embodiment, the bottom end  220  of each patch  200  includes a smooth surface configured to rest flush on top of the upper surface  121  of the folded spring  123  of the base member  100  (see  FIG. 2A ) when positioned therein. 
     In the illustrated embodiment, the top end  210  of each radius patch  200  includes a pair of grooves  211 ,  212  on the left side and on the right side, both being sized and proportioned to allow the protruding lips  113 ,  114  of the flexible arms  111 ,  112  of the top end  110  of the base member  100  to pass through upon insertion. Additionally, in the illustrated embodiment, the grooves  211 ,  212  and the protruding lips  113 ,  114  of the flexible arms  111 ,  112  are used as the primary means of securing the radius patch  200  to the base member  100  upon insertion. 
     Furthermore, the illustrated embodiment allows for a push clip installation method for inserting the radius patch  200  into the base member  100 . In using the push clip installation method, the radius patch  200  is first placed in the opening  116  such that the flexible arms  111 ,  112  of the base member  100  rest against the side walls  213 ,  214 . Next while firmly pressing downward on the radius patch  200  in the opening  116 , squeeze the flexible arms  111  and  112  inward toward one another. Finally, upon exerting sufficient force the protruding lips  113 ,  114  of the base member  100  will snap into the grooves  211 ,  212  of the radius patch  200 . After the radius patch is inserted and the sanding block  1000  is assembled the bottom end  120  of the base member is covered by sand paper and used to sand a curved surface. In the illustrated embodiment, sandpaper is adhesively fastened to the surface of the bottom end  120 . 
     Referring now to  FIG. 5 , there is shown a perspective view of a radius patch partially inserted into the base member of the variable radius sanding block. In the illustrated embodiment the smooth surface of the bottom end  220  of the radius patch  200  is shown sliding along the smooth upper surface  121  of the folded spring  123  of the base member  100 . Also, the flexible arras  111 ,  112  of the top end  110  of the base member  100  are shown moving through the grooves  211 ,  212  of the radius patch. 
     Referring now to  FIG. 6 , there is shown a perspective view of fully assembled variable radius sanding block alongside additional radius patches of varying size. In the illustrated embodiment each radius patch  200  has a width corresponding to a different radius, such that wood workshops would be able to sand a wide range of surfaces with a single base member  100  in combination with radius patches  200  of varying size, and a sheet of sand paper. In other embodiments the size of each patch  200  also corresponds to a specific color according to a color coding system. 
     It is therefore submitted that the instant invention has been shown and described in what is considered to be the most practical and preferred embodiments. It is recognized, however, that departures may be made within the scope of the invention and that obvious modifications will occur to a person skilled in the art. With respect to the above description then, it is to be realized that the optimum dimensional relationships for the parts of the invention, to include variations in size, materials, shape, form, function and manner of operation, assembly and use, are deemed readily apparent and obvious to one skilled in the art, and all equivalent relationships to those illustrated in the drawings and described in the specification are intended to be encompassed by the present invention. 
     Therefore, the foregoing is considered as illustrative only of the principles of the invention. Further, since numerous modifications and changes will readily occur to those skilled in the art, it is not desired to limit the invention to the exact construction and operation shown and described, and accordingly, all suitable modifications and equivalents may be resorted to, falling within the scope of the invention.