Abstract:
An automatic pencil sharpener includes a pencil sharpening mechanism and a sharpening switch within a central receiver configured to receive a pencil through an access opening. The pencil sharpening mechanism and sharpening switch are operatively connected to a sharpener control unit. When a pencil actuates the sharpening switch, the sharpening control unit powers the pencil sharpening mechanism and the notification light illuminates in a first color. At a subsequent event or time when the pencil is substantially fully sharpened, the notification light illuminates in a second color. The illumination is preferably produced by at least one green LED and one red LED.

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
       [0001]    This application claims the priority of U.S. Provisional Patent Application No. 62/132,795 filed on Mar. 13, 2015, the entirety of which is incorporated by reference. 
     
    
     BACKGROUND 
       [0002]    The present disclosure relates generally to pencil sharpeners, and more particularly, to automatic pencil sharpeners that operate on electrical power. 
         [0003]    Conventional automatic pencil sharpeners typically sharpen a pencil that is inserted and removed at the user&#39;s discretion. It is common for a user to leave the pencil in the sharpener longer than necessary. As a result, the pencil continues to sharpen and the pencil sharpener removes material beyond what is necessary, shortening the life of the pencil and putting unnecessary wear on the pencil sharpener. It would be advantageous to provide an automatic pencil sharpener that provides a notification to the user when the pencil reaches a desired sharpness. 
       SUMMARY 
       [0004]    Briefly stated, the present invention is directed to an automatic pencil sharpener having a notification light that informs a user when a pencil reaches a predetermined sharpness. The preferred pencil sharpener is a type which contains a pencil sharpener mechanism responsive to a sharpening switch accessible within a receiver of the pencil sharpener. The pencil sharpener mechanism contains a rotary blade assembly. The rotary blade assembly automatically sharpens a received pencil to a desired sharpness. 
         [0005]    A sharpening switch is disposed within a pencil sharpening housing and is activatable by a pencil that is inserted through an access opening into the receiver. When the pencil activates the switch, the pencil sharpener mechanism starts operating and the notification light is activated. The notification light emits a dramatic illumination in a first frequency or color. Upon a subsequent operational event, the notification light is fully illuminated at a second frequency or color to indicate to the user that the pencil is completely sharpened. The illuminations can be a constant state, or flashed or pulsed in various patterns. In one embodiment, the notification light employs LEDs that illuminate in green and then illuminate in red. 
         [0006]    In one embodiment, the pencil sharpener comprises a housing assembly having a pencil receiver extending from a first end at an exterior access opening to a second end. The access opening accommodates a pencil. A pencil sharpening mechanism is disposed in the housing assembly proximate the second end. A sharpening switch is disposed in the housing assembly and positioned to detect the presence of a pencil in the receiver. A notification light module is disposed in the housing assembly and, upon illumination, is configured to emit light visible exteriorly from the housing assembly. A control unit is operably connected to the sharpening mechanism, the sharpening switch and the notification light module, wherein when a pencil is inserted into the receiver and engages the sharpening switch, the control unit powers the pencil sharpening mechanism and causes the notification light module to illuminate. 
         [0007]    The notification light module comprises an LED and the housing assembly has a light transmissive portion wherein light emitted from the LED is transmitted through the portion. The notification light module is preferably disposed for emitting light in the vicinity of the access opening. The pencil sharpener also comprises a switch which is activatable upon sharpening the pencil at a second position indicative of a substantially completely sharpened pencil. The notification light module comprises at least two LEDs, one LED being illuminated upon activation of the first sharpening switch and a second LED being illuminated upon activation of the second switch. The first LED emits at a first frequency which is preferably in the green range, and the second LED emits at a second frequency which is preferably in the red range. The first LED may be pulsed and the second LED may emit radiation at a steady state. The illumination from the first LED and the illumination from the second LED are generally disposed for transmission about the access opening. 
         [0008]    The pencil sharpener may further comprise a blade guard having an upper portion, and LEDs are mounted to the circuit board disposed at an upper portion of the blade guard assembly. The blade guard assembly further includes an axial conduit which extends from the lower portion to the upper portion. A wire extends through the conduit for connecting an LED circuit board assembly to a second circuit board assembly disposed in the housing assembly. 
         [0009]    In another embodiment, the pencil sharpener comprises a housing assembly having a receiver adjacent a first end at an exterior access opening and extending to a second end. The access opening accommodates a pencil. The housing assembly has a notification light which, upon activation, is visible exteriorly of the housing assembly. A pencil sharpener mechanism is mounted to the assembly proximate the second end. A sharpener control circuit is operatively connected to a sharpening switch and the sharpening mechanism. When a pencil is inserted in the receiver and the sharpening switch is activated, the sharpening control unit powers the pencil sharpener mechanism to sharpen a pencil and illuminates the notification light in a first color and at a subsequent time when the pencil sharpener mechanism is operating and the pencil is substantially completely sharpened, the sharpening control unit illuminates the notification light in a second color. 
         [0010]    The notification light is preferably disposed adjacent the access opening. When the pencil is withdrawn from the receiver, the notification light ceases illumination. 
         [0011]    In various embodiments, the notification light can sequentially illuminate two distinct frequencies or colors, can illuminate an arcuate section and effectively rotate the section along the circumference of the notification light over time, and can fully illuminate at a pre-established event or time. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0012]      FIG. 1  is a perspective view, partly in schematic, of a pencil sharpener incorporating a notification light; 
           [0013]      FIG. 2  is a front elevational view of the pencil sharpener of  FIG. 1 ; 
           [0014]      FIG. 3  is a rear elevational view of the pencil sharpener of  FIG. 1 ; 
           [0015]      FIG. 4  is a top plan view of the pencil sharpener of  FIG. 1 ; 
           [0016]      FIG. 5  is a perspective view, partly in schematic, of the pencil sharpener of  FIG. 1  with the cover removed; 
           [0017]      FIG. 6  is a perspective view of the pencil sharpener of  FIG. 1  with the cover removed and partially exploded; 
           [0018]      FIG. 7  is a schematic circuit diagram for a control circuit for the pencil sharpener of  FIG. 1 ; 
           [0019]      FIG. 8  is a schematic circuit diagram for a second embodiment of a control circuit for the pencil sharpener of  FIGS. 1 ; and 
           [0020]      FIG. 9  is an enlarged sectional view, partly in schematic and portions removed, of an interior portion of the pencil sharpener of  FIG. 1 . 
       
    
    
     DETAILED DESCRIPTION 
       [0021]    Referring to  FIGS. 1-4 , wherein like numerals indicate like elements throughout, there is shown a representative embodiment of an automatic pencil sharpener  10 . The pencil sharpener  10 , in accordance with the present disclosure, automatically sharpens a pencil  12  to a predetermined sharpness and illuminates a notification light (schematically illustrated in  FIGS. 1 and 5 ) at a pre-established operational time to inform the user that the pencil is at the predetermined sharpness. The pencil sharpener is preferably adapted to be positioned on a desktop or other horizontal surface in an upright orientation for use as needed. 
         [0022]    Referring to  FIG. 1 , an embodiment of the pencil sharpener  10  includes an upright housing assembly  20  with a removable cover  21 . The housing assembly  20  has a generally vertical central receiver  22  having a first end  24  and a tapered second end  26 . The receiver  22  receives a pencil to be sharpened. The receiver  22  is configured to receive a pencil  12  through access opening  28  at the first end  26 . The housing assembly  12  contains a pencil sharpener mechanism  30  with a rotatable blade assembly  32  having at least one rotatable helical blade driven by a motor  34  operatively responsive to a sharpening switch  36  ( FIGS. 4, 8 and 9 ). The pencil sharpener mechanism  30  is disposed for operation at the second end  26  of the receiver  22  and is configured to sharpen the pencil to a desired sharpness. An illuminatable notification light module  40  is disposed at an upper location. Power for the pencil sharpener is preferably supplied by a wall socket-mounted, power supply cord connecting at socket  29 . 
         [0023]    The rotary blade assembly  32  has a plurality of cutting surfaces, which may be straight or curved. The rotary blade assembly  32  is supported at an angle obliquely oriented relative to the central axis of receiver  22  and functions to produce the sharpened point configurations of the pencil. The central axis of the receiver  22  is vertical in the disclosed embodiment, but may have a different orientation in other embodiments. In one embodiment, the pencil sharpener mechanism  30  is supported by a safety spring (not depicted) to prevent damage to the pencil sharpener  10  due to excessive or improper use. 
         [0024]    With reference to  FIGS. 5 and 6 , the cover  21  which retains the shavings from the sharpened pencils has been removed to reveal the blade assembly  32  and certain features of the notification light module  40 . A platform  42  supports a stepped cylindrical case  44  which encloses at least some portions of the motor  34  and the linkage/mechanical connections with the blade assembly  32 . A blade housing  50  which has angularly spaced, inverted U-shaped openings  52  is supported on the top edge  46  of the case. The top of the housing has an integral quasi-cylindrical coupler neck  60 . A light transmissive cap  70 , which may be translucent and/or transparent, includes a central opening defining access opening  28  for the pencil access to the receiver  22 . The light transmissive cap  70  includes a reduced generally cylindrical side  72  with a resilient snap tab  74 . The snap tab  74  is received in a complementary recess  64  at the interior of the coupler neck  60  to secure the cap  70  to the blade housing  50 . In some embodiments, the cap  70  may be partially or completely transparent. 
         [0025]    An LED printed circuit board assembly  80  is located at an upper location of the blade housing interior and has a central opening to accommodate the inserted pencil. The circuit board  80  mounts at least one LED. When the cap  70  is snapped in place on the blade housing  50 , the printed circuit board assembly is located under the light transmissive cap  70  so that at least one LED is positioned to emit light through the cap. 
         [0026]    A tunnel-like conduit  56  extends from the interior of the sharpener base axially to the top of the blade housing. Electrical wires  82  connect the main printed circuit board assembly  90  located in the housing base with the LED printed circuit board  80 . The cap  70  has a radially projecting brim  76  which projects to cover the end of the conduit when the cap is snapped into place. 
         [0027]    The LED circuit board assembly  80  preferably includes at least two LEDs  84  and  86  which emit at different frequencies. When the LEDs are energized, they illuminate at preferably different frequencies, such as, for example, in the green range for LED  84  and the red range for LED  86 . The LEDs illuminate through the top of the translucent and/or transparent cap  70  to provide the notification light which is readily visible exteriorly of the pencil sharpener. 
         [0028]    Various LED configurations and illumination patterns may be provided. Three pairs of angularly spaced LEDs may be provided as schematically illustrated in  FIG. 7  for LED circuit board assembly  81 . 
         [0029]    In one embodiment (not illustrated), the three different LEDs are provided; a green LED, a red LED and a yellow LED. In some embodiments, the LEDs illuminate in a steady state illumination pattern. In other embodiments, one or more of the LEDs are pulsed. In other embodiments three angularly spaced pairs of LEDs are provided and a sequential illumination pattern is provided. 
         [0030]    In one preferred operation, a green LED flashes during sharpening as detected by switch  36 . A red LED illuminates in a steady state when the motor keeps rotating and the completed sharpening has been detected by switch  38 . Naturally, other LED frequencies and patterns and sequences may be provided. 
         [0031]    A sharpener control circuit  90  selectively connects via switches  36  and  38  with the motor  34  for the blade assembly  32 . A green LED  84  and a red LED  86  are disposed in parallel. When the first switch  36  is tripped by inserting the pencil into the sharpener, a microprocessor  88  causes the green LED  84  to pulse. When the second switch  38  is tripped by virtue of the pencil being sufficiently sharpened and the motor continues operating, the red LED  86  is illuminated. Upon removal of the sharpened pencil from the sharpener, both the green LED  84  and the red LED  86  cease illumination. 
         [0032]    When the switch  36  is depressed by the tip of a pencil (not depicted), the sharpener control circuit  90  also begins to operate the pencil sharpener mechanism  30  and illuminates the notification light module  40  at the first color. Upon activation of switch  38 , the sharpener control circuit  90  switches the notification light to the second LED color  86 . The pencil sharpener mechanism  32  continues to operate as long as the switch  38  is depressed. When the pencil is removed from contact with the switch  38  the switch  38 , returns to its original “off” position and the notification light module  40  ceases illumination and the pencil sharpening mechanism  30  ceases operating. 
         [0033]    In one embodiment, a notification light module generates an illumination annulus coaxially surrounding the access opening  28  and sequentially illuminates in two distinct colors. Initially, the notification light module partially illuminates a first color along an arcuate section when the pencil engages the pencil sharpener mechanism switch  36 . If the pencil remains engaged with the pencil sharpener mechanism switch, the notification light module continues illuminating the first color, and the arcuate section rotates about the access opening  28  in the circumferential direction over time until the entire annulus of the notification light is illuminated in the first color. At a set time or when switch  38  is activated, the entire annulus of the notification light is illuminated in a second color. Naturally, multiple LEDs are required. 
         [0034]    In the preferred depicted embodiments, the first color is green and the second color is red. The set time may be adjusted by the user to ensure that a desired sharpness of pencil is consistently achieved. In one embodiment, two separate notification lights are used in which each is illuminated in one of the two colors. 
         [0035]    While preferred embodiments have been set forth for purposes of illustration, the foregoing descriptions should not be deemed a limitation of the invention herein. Accordingly, various modifications, adaptations and alternatives may occur to one skilled in the art without departing from the spirit and the scope of the present invention.