Patent Publication Number: US-2005122842-A1

Title: Sunset time device

Description:
This application for patent is submitted by Sean Anderson Barton, resident of Quincy, Fla., citizen of the United States. This application claims benefit of Provisional Application No. 60/527,185 filed Dec. 5, 2003. 
    
    
     BACKGROUND OF THE INVENTION  
      The present invention relates to sunset time device for manually calculating the time of sunrise or sunset for a particular place for a particular date.  
      Sunset time devices or sun angle calculators that can determine the time of sunrise or sunset for a particular date and for a particular place are known in the art. U.S. Pat. No. 4,551,027 to Spruck, U.S. Pat. No. 4,435,640 to Micheletto, and U.S. Pat. No. 3,971,915 to Fletcher et al. are examples of devices that are capable of such a task. However, the problem with these devices is that they are relatively complex in design or relatively complex in operation.  
      Therefore, there is a need in the art for a device that can quickly and accurately determine the time of sunrise or sunset for a particular place for a particular date, such that the device is not unduly complex and is relatively inexpensive to build. Such a device should be relatively simple to operate and should be able to calculate sunrise and sunset times for any day of the year for any location on Earth.  
     BRIEF SUMMARY OF THE INVENTION  
      The sunset time device of the present invention addresses the aforementioned needs in the art. The sunset time device provides for a device that accurately calculates the time of sunrise or sunset for a particular day of the year for a particular location on Earth and is of relatively simple design and construction and is relatively easy to use.  
      The sunset time device is comprised of three disk members adapted to rotate about a common center. The first disk member has in its center a map of the celestial sphere with indicia thereon showing the locations of the sunrise and sunset terminators on particular days of the year and has around its circumference indicia representing the days of the year. The second disk member has in its center a transparent window containing several colored translucent areas designed to highlight some and obscure some of the sunrise and sunset terminator indicia of the first member and has around its circumference indicia representing the hours of the day and has at a point on its circumference an indicator for aligning with the day of the year indicia of the first member. The third disk member has in its center a map of the Earth with indicia thereon representing the countries, cities, rivers, oceans, meridians, and parallels for aligning with the sunrise and sunset terminator indicia of the first member and has around its circumference indicia representing the time zones of the world for aligning with the hour of the day indicia of the second member. 
    
    
     BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING  
       FIG. 1  is a top elevation view of the sunset time device.  
       FIG. 2  is a top elevation view of the first disk member of the sunset time device.  
       FIG. 3  is a top elevation view of the second disk member of the sunset time device.  
       FIG. 4  is a top elevation view of the third disk member of the sunset time device. 
    
    
     DETAILED DESCRIPTION OF THE INVENTION  
      Referring now to the drawings, it is seen that the sunset time device of the present invention, generally denoted by reference numeral  10 , is comprised of a first disk member  12 , a second disk member  14  atop the first disk member  12 , and a third disk member  16  atop the second disk member  14 . The first disk member  12 , the second disk member  14 , and the third disk member  16  are adapted to rotate about a common center  60 . As seen, each disk member  12 ,  14 , and  16  has a generally circular shape.  
      As seen, the first disk member  12  has in its center a map of the celestial sphere  36  with a plurality of first indicia  32  thereon showing the location of the sunrise terminators on particular days of the year and a plurality of second indicia  34  thereon showing the location of the sunset terminators on particular days of the year and has around its circumference a plurality of third indicia  22  representing the days of the year. The second disk member  14  has in its center a transparent window  46  containing a first colored translucent area  42  and a second colored translucent area  44  and has around its circumference a plurality of forth indicia  26  representing the hours of the day and has at a point on its circumference an indicator  24  for aligning with the third indicia  22  of the first disk member. The third disk member  16  is generally transparent and has in its center a map of the Earth  50  with indicia thereon representing the countries, cities, rivers, oceans, meridians, and parallels for aligning with the first indicia  32  and second indicia  34  of the first disk member  12  and has around its circumference a plurality of fifth indicia  28  representing the time zones of the world for aligning with the forth indicia  26  of the second disk member  14 .  
      The plurality of first indicia  32  is of a first color and the plurality of second indicia  34  is of a second color that is different from the first color. The first colored translucent area  42  is of a third color chosen to highlight the first indicia  32  and obscure the second indicia  34 . The second colored translucent area  44  is of a fourth color chosen to obscure the first indicia  32  and highlight the second indicia  34 .  
      In order to use the sunset time device  10  of the present invention, the second disk member  14  is rotated so that the indicator  24  is aligned with the third indicia  22  representing the date of interest. The third disk member  16  is then rotated so that the location on the map of the Earth  50  that is of interest is aligned with the first indicia  32  of the appropriate date to determine the time of sunrise or with the second indicia  34  of the appropriate date to determine the time of sunset. The fifth indicia  28  representing the time zones of the world are now positioned adjacent to the corresponding forth indicia  26  representing the time of day to indicate the time of day in each time zone when the event (sunrise or sunset) occurs.  
      By way of example,  FIG. 1 , illustrates the sunset time for the date of December 8, in Atlanta, Ga.  
      Alternately, the sunset time device  10  may be a series of spheres instead of disks, each of the spheres operating in similar fashion to that of the disks.  
      While the invention has been particularly shown and described with reference to an embodiment thereof, it will be appreciated by those skilled in the art that various changes in form and detail may be made without departing from the spirit and scope of the invention.