Abstract:
A device for sharpening crayons, wax pencils, and the like is provided. This device includes: a multi-blade removable and replaceable crayon sharpening cartridge; an electric motor mechanically coupled to the blade cartridge for axially rotating the blade cartridge around a crayon that has been inserted into the blade cartridge; a base for supporting the electric motor; a contoured receptacle positionable on the base beneath the blade cartridge for capturing crayon debris; and a contoured exterior housing for enclosing the electric motor and the blade cartridge.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
       [0001]    This patent application claims the benefit of U.S. Provisional Patent Application Ser. No. 60/820,375 filed on Jul. 26, 2006 and entitled “Powered Sharpener for Crayons,” the disclosure of which is incorporated by reference as if fully rewritten herein. 
     
     BACKGROUND OF THE INVENTION 
       [0002]    The described invention relates in general to systems and devices for sharpening writing instruments, and more specifically to an electric crayon sharpener that replicates the general appearance of a factory molded crayon prior to the use thereof. 
         [0003]    Devices for sharpening writing instruments such as crayons typically include a cone-shaped tapered channel for receiving a unsharpened crayon. The inner wall of this tapered interior channel usually includes a sharpening edge, which may be formed in the wall of the channel or may be provided as a protruding blade that extends from the opening of the channel to the terminal apex thereof. With regard to manual sharpeners, the sharpening edge engages and shaves the exterior surface of the crayon as the crayon is manually rotated in the tapered channel. With regard to powered sharpeners, the sharpening edge is rotated by mechanical means around the crayon. In both cases, the result is that the tip of the crayon is gradually shaved layer by layer into a conical form, tapering more or less to a point. 
         [0004]    While being generally effective for their intended purpose, currently available crayon sharpeners suffer from certain performance-related shortcomings. For example, currently available devices are not typically capable of replicating the factory molded tip found on newly purchased crayons. The tips of crayons that have been sharpened to a point with prior art devices quickly deteriorate with use into an undesirable and disappointing dull shape. Also, most art prior devices require that the paper jacket surrounding an unsharpened crayon be removed prior to sharpening. If this paper is not removed, the crayon may not be sharpened at all or the sharpening edges of the sharpener may be quickly dulled. Finally, when the sharpening edges found in most prior art devices wear and become dull, the sharpening edges and/or blades cannot be easily sharpened or replaced. Thus, there is a continuing need for a crayon sharpener that produces an acceptable sharpened tip, while simultaneously and automatically removing the paper sleeve and that has a blade assembly that can be easily and economically replaced to extend the life of the sharpener. 
       SUMMARY OF THE INVENTION 
       [0005]    The following provides a summary of certain exemplary embodiments of the present invention. This summary is not an extensive overview and is not intended to identify key or critical aspects or elements of the present invention or to delineate its scope. 
         [0006]    In accordance with one aspect of the present invention, a system for sharpening crayons is provided. This system includes a blade cartridge and mechanical or manual means for either axially rotating the blade cartridge around a crayon that has been inserted into the blade cartridge for sharpening or axially rotating a crayon that has been inserted into the cone-shaped axial bore within the bore. The blade cartridge further includes: (i) a body, wherein the body further includes: a) a first portion having a partially cone-shaped (i.e., a portion of the bore is cylindrical and a portion of the bore is cone-shaped) axial bore passing at least partially through the length thereof; and b) a second portion formed substantially perpendicular to the first portion at one end thereof, and (ii) a first rotary blade mounted on the second portion of the body, wherein the first rotary blade further includes a plurality of chopping teeth formed thereon, and wherein a portion of the first rotary blade extends into the axial bore; (iii) a second rotary blade mounted on the second portion of the body, wherein the second rotary blade further includes a smooth cutting edge formed thereon, and wherein a portion of the second rotary blade extends into the axial bore; (iv) a first planar blade mounted on the first portion of the body substantially parallel to the center axis of the body, wherein at least a portion of the first planar blade extends into the axial bore; and (v) a second planar blade mounted on the first portion of the body at an angle relative to the center axis of the body, wherein at least a portion of the second planar blade extends into the axial bore. Both a front loading and a top loading version of the crayon sharpener of the present invention are described herein. 
         [0007]    In accordance with another aspect of the present invention, a mechanical device for sharpening crayons is provided. This device includes: (a) a blade cartridge having the features previously described; (b) an electric motor mechanically coupled to the blade cartridge for axially rotating the blade cartridge around a crayon that has been inserted into the cone-shaped axial bore; (c) a base for supporting the electric motor; (d) a receptacle positionable on the base beneath the blade cartridge; (e) an exterior housing for enclosing the electric motor and the blade cartridge, wherein the exterior housing is adapted both to receive the receptacle and to receive a crayon; and (f) at least one source of electric power. 
         [0008]    In yet another aspect of this invention, a method for sharpening a crayon is provided. This method includes (a) providing a blade cartridge having the features previously described; (b) inserting the tip of an unsharpened crayon into the cone-shaped axial bore, wherein the crayon is at least partially wrapped in paper; (c) applying force to the crayon in a direction toward and into the blade cartridge; and (d) rotating the blade cartridge around the crayon while force is being applied thereto, wherein rotating the blade cartridge causes the chopping teeth of first rotary blade to score the paper wrapped around the crayon at multiple points; wherein rotating the blade cartridge causes the smooth cutting edge of the second rotary blade to circumferentially score the paper wrapped around the crayon, wherein rotating the blade cartridge causes the first planar blade to remove the paper wrapped around the crayon from the crayon to form a paperless collar on the crayon, and wherein rotating the blade cartridge causes the second planar blade to shave the end of the crayon into a cone, and wherein the surface of the cone is inset relative to the unsharpened portion of the crayon. 
         [0009]    Additional features and aspects of the present invention will become apparent to those of ordinary skill in the art upon reading and understanding the following detailed description of the exemplary embodiments. As will be appreciated by the skilled artisan, further embodiments of the invention are possible without departing from the scope and spirit of the invention. Accordingly, the drawings and associated descriptions are to be regarded as illustrative and not restrictive in nature. 
     
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0010]    The accompanying drawings, which are incorporated into and form a part of the specification, schematically illustrate one or more exemplary embodiments of the invention and, together with the general description given above and detailed description given below, serve to explain the principles of the invention, and wherein: 
           [0011]      FIG. 1A  is a perspective view of an assembled crayon sharpener in accordance with a first exemplary embodiment of the present invention. 
           [0012]      FIG. 1B  is an exploded view of the crayon sharpener of  FIG. 1A . 
           [0013]      FIG. 1C  is a side perspective view of the crayon sharpener of  FIG. 1A , wherein the exterior housing has been removed. 
           [0014]      FIG. 1D  is a side view of the crayon sharpener of  FIG. 1A , wherein the exterior housing has been removed. 
           [0015]      FIG. 1E  is a bottom perspective view of the crayon sharpener of  FIG. 1A , wherein the exterior housing has been removed. 
           [0016]      FIG. 1F  provides a side perspective view of the adapter and blade cartridge components of the crayon sharpener of  FIG. 1A . 
           [0017]      FIGS. 1G-I  are multiple views of the adapter and blade cartridge components of the crayon sharpener of  FIGS. 1A and 1F , wherein the blade cartridge has been properly inserted into the adapter. 
           [0018]      FIGS. 1J-K  are two rear perspective views of the blade cartridge component of the crayon sharpener of  FIG. 1A  showing the relative positions of the blades. 
           [0019]      FIG. 1L  is a rear cutaway view of the blade cartridge component of the crayon sharpener of  FIG. 1A , wherein a crayon has been inserted into the axial bore of the cartridge. 
           [0020]      FIG. 1M  is a perspective view of the crayon sharpener cleaning device of the present invention. 
           [0021]      FIG. 2A  is a perspective view of an assembled crayon sharpener in accordance with a second exemplary embodiment of the present invention. 
           [0022]      FIG. 2B  is an exploded view of the crayon sharpener of  FIG. 2A . 
           [0023]      FIG. 2C  is a side perspective view of the crayon sharpener of  FIG. 2A , wherein the exterior housing has been removed. 
           [0024]      FIG. 2D  is a bottom perspective view of the crayon sharpener of  FIG. 2A , wherein the receptacle has been removed. 
           [0025]      FIG. 3  is a side perspective view of a crayon being sharpened with the crayon sharpener of the present invention. 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       [0026]    Exemplary embodiments of the present invention are now described with reference to the Figures. Reference numerals are used throughout the detailed description to refer to the various elements and structures. In other instances, well-known structures and devices are shown in block diagram form for purposes of simplifying the description. Although the following detailed description contains many specifics for the purposes of illustration, a person of ordinary skill in the art will appreciate that many variations and alterations to the following details are within the scope of the invention. Accordingly, the following embodiments of the invention are set forth without any loss of generality to, and without imposing limitations upon, the claimed invention. 
         [0027]    The present invention relates to systems, devices, and methods for sharpening writing implements such as crayons, wax pencils, and the like. As previously indicated, a first general embodiment of this invention provides a system for sharpening a crayon, wax pencil, or similar item; a second general embodiment of this invention provides a powered or manual device for sharpening a crayon; and a third general embodiment of this invention provides a method for sharpening a crayon that has the general appearance of a new, factory-molded crayon. With reference now to the Figures, one or more specific embodiments of this invention shall be described in greater detail. 
         [0028]      FIGS. 1A-M  provide various illustrative views of a first embodiment of the present invention including and include detailed views of certain components thereof. This “front-loading” embodiment is designed to be a heavy-use or high-volume device for schools, businesses, or other institutions. As best shown in  FIG. 1A , an assembled sharpener  100  includes a contoured external housing  102  that further includes front portion  104  and bottom portion  108 . Aperture  106  is formed in front portion  104  for receiving crayon  300  and bottom portion  108  is shaped to accommodate receptacle  170 , which holds crayon shavings and paper fragments. External housing  102  is attached to base  190  and encloses internal components, which include an electric motor, two activation/deactivation safety switches, an adapter, and a removable and replaceable blade cartridge which is mounted on the adapter. A plurality of non-skid (e.g., rubberized or suction cup) feet is typically attached to the bottom surface of base  190  for securing the crayon sharpener on a surface such as a tabletop or desktop. 
         [0029]      FIG. 1B  provides an exploded view of the first exemplary embodiment of this invention and illustrates the various external and internal components thereof. As shown in  FIG. 1B , crayon sharpener  100  includes internal support  120 , which is mounted on base  190 . Internal support  120  includes center aperture  122 , internal housing mounting apertures  124 , motor mounts  126  and drawer switch aperture  128 . Motor  130 , which is typically electric, rests on base  190  and is connected to internal support  120  by mounting screws  132 , which are inserted into motor mounts  126 . Motor  130  includes drive shaft  134 , upon which first drive gear  136  is mounted. First drive gear  136  is mechanically coupled to second drive gear  138  for transferring mechanical force to adapter  140 . Adapter  140  includes finger wheel  141  for manually rotating the adapter, cylindrical body  142 , channel  144 , adapter shaft  146 , and button  148 , which further includes an engagement member  149  formed thereon. Button  148  is typically a separately moveable device that is mounted within body  142  such that engagement member  149  extends into channel  144 . Adapter shaft  146  extends through aperture  122  in internal support  120  and aperture  139  in second drive gear  138 , and is secured thereto by a spring clip, pin, or other mechanical coupling means (see  FIGS. 1B-1E ). 
         [0030]    Blade cartridge  150  includes stem  155 , which further includes notch  156  (see  FIGS. 1F-K ). Blade cartridge  150  may be attached to adapter  140  by moving button  148  to a disengaged position wherein engagement member  149  is recessed partially into body  142 , inserting stem  155  into channel  144  such that notch  156  contacts engagement member  149 , pulling blade cartridge  150  toward finger wheel  141 , using finger wheel  141  to rotate adapter  140  roughly 180°, and depressing button  148  to move engagement member  149  fully into channel  144  and into locking engagement with notch  156 . Blade cartridge  150  may be removed from adapter  140  by simply depressing button  148  to disengage notch  156  and engagement member  149  from one another. Other locking means are possible, such as, for example, magnetic locking means or rotate-and-lock means, which typically include interlocking structures or features formed both on the blade carrier and on the adapter. 
         [0031]      FIGS. 1J-K  provide several views of blade cartridge  150 , which includes horizontal body portion  151  and vertical body portion  152 . A centrally located, partially cone-shaped axial bore  153  is formed in horizontal portion  151  for receiving a crayon in need of sharpening. As shown in  FIG. 1G , the outer portion of axial bore  153  is cylindrical in shape and the inner portion of axial bore  153  is substantially cone-shaped. The cone-shaped portion of axial bore  153  terminates in planar stop surface  161 , which imparts a flattened nose or tip to a crayon being sharpened with the present invention. A cylindrical collar or lip  154  is formed around the opening of axial bore  153  for insertion into aperture  112  (see below). Rotary paper chopping blade  157  and rotary paper cutting blade  159  are mounted on vertical body portion  152  as shown in  FIGS. 1J-K , and planar crayon shaping blade  158  and planar paper peeling blade  160  are mounted on horizontal body portion  151  as shown in  FIGS. 1J-K . The rotary blades rotate freely around a central axis when in use and the planar blades remain in a fixed position. A portion of each of the four blades extends into axial bore  153  for making contact with a crayon that has been inserted into axial bore  153 . Although the term “blade” is used with reference to the exemplary embodiments, it should be understood that the term “blade” as used herein refers to metal blades as well as any other structure or feature, metal or otherwise, that may operate as a cutting, scoring, chopping, and/or peeling device. 
         [0032]    As shown in  FIG. 1B , adapter  140  and blade cartridge  150  are enclosed within internal housing  110 , which includes center aperture  112 , mounting pegs  113 , mounting tabs  114 , and mounting screws  116 . Lip  154  of blade cartridge  150  extends through aperture  112  when crayon sharpener  100  is assembled for providing stability to blade cartridge  150 . Switch  180  (see below) is mounted on mounting pegs  113 , while mounting screws  116  are inserted through mounting tabs  114  to attach internal housing  110  to internal support  120  at mounting apertures  124 . 
         [0033]    The exemplary embodiment of the present invention shown in  FIGS. 1A-1L  includes two switches that affect the operation of crayon sharpener  100 . First switch  180  is mounted on the front portion of internal housing  110  and includes switch housing  181 , ring  182 , and switch  183 . As a crayon is inserted through ring  182 , switch  183  is depressed, thereby completing the electrical circuit that provides power to motor  130 . If switch  183  is not depressed (as when a crayon is not inserted through ring  182 ) crayon sharpener  100  will not operate. Second switch  184  is mounted on internal support  120  between internal support  120  and motor  130  and includes switch housing  185 , ring  186 , and switch  187 . When receptacle  170  is properly positioned on base  190 , peg  172  extends through aperture  128  and ring  186  and depresses switch  187 , thereby completing the electrical circuit that provides power to motor  130 . If receptacle  170  is removed from base  190 , crayon sharpener  100  will not operate. Thus, for crayon sharpener  100  to function properly, a crayon must be inserted into blade cartridge  150  and receptacle  170  must be properly positioned on base  190 . Although not shown in the Figures, but as will be appreciated by the skilled artisan, a plurality of electrical wires connects the various electrical components of this embodiment of the present invention. 
         [0034]    All embodiments of the present invention may include cleaning brush  196 , which is typically stored underneath base  190 . As shown in  FIGS. 1B ,  1 E, and  1 M, cleaning brush  196  includes tapered end  197  and bristles  198  for removing debris from blade cartridge  150 . In the exemplary embodiment shown in  FIG. 1E , cleaning brush  196  snaps into brush mounts  194 , which are formed in base  190  and may be removed as needed. 
         [0035]      FIGS. 2A-D  provide various illustrative views of a second embodiment of the present invention including and include detailed views of certain components thereof. This “top-loading” embodiment is designed to be a light-use or relatively low-volume device for home use. As best shown in  FIG. 2A , a completely assembled sharpener  200  includes a contoured external housing  202  that further includes top portion  204  and bottom portion  208 . Aperture  206  is formed in top portion  204  for receiving crayon  300  and bottom portion  208  is shaped to accommodate receptacle  270 , which holds crayon shavings and paper fragments. External housing  202  is attached to base  290  at housing mounts  291  and encloses internal components, which include an electric motor, two activation/deactivation switches, and a blade cartridge. A plurality of non-skid (e.g., rubberized or suction cup) feet is typically attached to the bottom surface of base  290  for securing the crayon sharpener on a surface such as a tabletop or desktop. 
         [0036]      FIG. 2B  provides an exploded view of the second exemplary embodiment of this invention and illustrates the external and internal components thereof. As shown in  FIG. 2B , crayon sharpener  200  includes internal housing  210 , motor  230 , and blade cartridge  250 . Motor  230 , which is typically electric, rests on base  290  and includes gear box  232  which houses the gears of drive train  233  (see  FIG. 2C ), and drive shaft  234 , to which blade cartridge  250  is mechanically coupled at stem  255 . In this embodiment, blade cartridge  250  is not removable from crayon sharpener  200 . Blade cartridge  250  includes a first or “horizontal” body portion  251  and a second or “vertical” body portion  252 . A centrally located, partially cone-shaped axial bore  253  is formed in horizontal portion  251  for receiving a crayon in need of sharpening. The outer portion of axial bore  253  is cylindrical in shape and the inner portion of axial bore  253  is substantially cone-shaped. The cone-shaped portion of axial bore  253  terminates in planar stop surface (not shown), which imparts a flattened nose or tip to a crayon that has been sharpened with the present invention. A cylindrical collar or lip  254  is formed around the opening of axial bore  253  for insertion into an aperture (not shown) formed in the top portion of internal housing  210 . Rotary paper chopping blade  257  and a rotary paper cutting blade (not shown) are mounted on vertical body portion  252 , and planar crayon shaping blade  258  and a planar paper peeling blade (not shown) are mounted on horizontal body portion  251  as shown in  FIGS. 2B-D . The rotary blades rotate freely around a central axis when in use and the planar blades remain in a fixed position. A portion of each of the four blades extends into axial bore  253  for making contact with a crayon that has been inserted into axial bore  253 . 
         [0037]    The exemplary embodiment of the present invention shown in  FIGS. 2A-D  includes two safety switches that affect the operation of crayon sharpener  200 . First switch  280  is mounted on the top portion of internal housing  210  and includes switch housing  281 , ring  282 , a switch (not shown), and a disc-shaped cover  283 . As a crayon is inserted through ring  282 , the switch is depressed, thereby completing the electrical circuit that provides power to motor  230 . If the switch is not depressed (as when a crayon is not inserted through ring  282 ) crayon sharpener  200  will not operate. Second switch  284  is mounted on base  290  and includes switch housing  285  and switch  287 . When receptacle  270  is properly positioned on base  290 , the rear edge thereof depresses switch  287 , thereby completing the electrical circuit that provides power to motor  230 . If receptacle  270  is removed from base  290 , crayon sharpener  200  will not operate. Thus, for crayon sharpener  200  to function properly, a crayon must be inserted into blade cartridge  250  and receptacle  270  must be properly positioned on base  290 . Although not shown in the Figures, but as will be appreciated by the skilled artisan, a plurality of electrical wires connects the various electrical components of this embodiment of the present invention. An AC adapter receptacle  295  is shown in  FIG. 2B . 
         [0038]      FIG. 3  illustrates a crayon  300  that has been sharpened by the present invention to very closely resemble a factory-molded crayon. When this invention is in use, the described four-blade cartridge is axially rotated (usually at relatively high speed) around a crayon that has been inserted into the axial bore of the cartridge. By applying directional (e.g., forward or downward) force to the crayon and rotating the blade cartridge axially around the crayon (which includes a paper wrapping), the multiple chopping teeth of the first rotary blade create a plurality of score lines on the paper wrapping in a direction generally parallel to the body of the crayon, the smooth cutting edge of the second rotary blade creates another score line around the circumference of the crayon generally behind the plurality of parallel score lines, the first planar blade removes the scored paper from around the crayon to create a paperless collar on the body of the crayon, and the second planar blade gradually shaves the end of the crayon into a cone, wherein the outer finished surface of the cone is inset relative to the unsharpened portion of the crayon (see distance A in  FIG. 3 ). As a result of the plurality of score lines formed by the chopping teeth, the paper removed from the crayon tends to break up into smaller fragments as it is removed. As previously described, a planar stop surface at the end of the cone-shaped portion of the axial bore creates a flattened tip or nose on the sharpened crayon. As described, the removed paper and shaved crayon material is deposited in a receptacle from which it may later be removed. 
         [0039]    In an alternate embodiment of the present invention, the rotary blade that scores the paper wrapping around the body of the crayon is replaced with a straight or planar blade or cutting edge that does not rotate around a central axis point. In another embodiment of this invention, the rotary chopping blade is absent from the blade cartridge, thereby resulting in a three-blade design rather than a four-blade design as described above. In still another embodiment, the first planar blade (i.e., the paper peeling blade) is replaced by a different cutting surface such as a relatively blunt edge or corner formed in or on the cartridge or attached thereto. In still another embodiment, the second portion of the body of the blade cartridge (which is typically perpendicular to the first portion of the body of the blade cartridge) is absent and a planar paper scoring blade is simply mounted on the elongated body of the blade cartridge in an orientation which is generally perpendicular to the axial bore. 
         [0040]    While the present invention has been illustrated by the description of exemplary embodiments thereof, and while the embodiments have been described in certain detail, it is not the intention of the Applicant to restrict or in any way limit the scope of the appended claims to such detail. Additional advantages and modifications will readily appear to those skilled in the art. Therefore, the invention in its broader aspects is not limited to any of the specific details, representative devices and methods, and/or illustrative examples shown and described. Accordingly, departures may be made from such details without departing from the spirit or scope of the applicant&#39;s general inventive concept.