Patent Abstract:
A device for preventing a slip-down of sheets of paper contained in an automatic sheet feeding section obliquely mounted in an ink jet printer is provided. The device includes a buckler body having a plate in contact with a bottom of sheets loaded in the automatic sheet feeding section, a guide projection formed at one side of an upper surface of the buckler body for jumping up a sheet located at the top of the loaded sheets, and at least one or more jack buckler having a plurality of teeth each having a slide side and a threshold side, the slide side guiding the sheet located at the top loaded sheets while the threshold side holds remaining sheets beneath the sheet guided by the slide side.

Full Description:
[0001]    This application makes reference to, incorporates the same herein, and claims all benefits accruing under 35 U.S.C. §119 from my application PREVENTING DEVICE FROM SLIP-DOWN OF PAPER IN INK JET PRINTER filed with the Korean Industrial Property Office on May 12, 2000 and there duly assigned Serial No. 2000-25323.  
         BACKGROUND OF THE INVENTION  
         [0002]    1. Field of the Invention  
           [0003]    The present invention relates to a sheet separator mounted on an automatic sheet feeding device of a printer, and more particularly, to a sheet separator having an improved buckler mounted on the automatic sheet feeding device in the printer.  
           [0004]    2. Description of the Related Art  
           [0005]    An automatic sheet feeding device including a sheet separator has been used in an ink jet printer. The automatic sheet feeding device is obliquely installed on a side of a printing device in the ink jet printer that horizontally rests on a table. Sheets of paper are loaded in the automatic sheet feeding device and are slanted with respect to the side of the printing device. The sheet separator is mounted on a lower portion of the automatic sheet feeding device and disposed to contact the lower ends of the sheets loaded in the automatic sheet feeding device. The sheets are separated by the sheet separator and supplied one by one to the side of the printing device of the printer by a pick-up roller disposed adjacent to the automatic sheet feeding device. The sheet separator, however, can neither separate and supply the sheets one by one from the automatic sheet feeding device to the printing device nor support remaining sheets of paper loaded within the automatic sheet feeding device while supplying of one of the sheets to the printing device.  
           [0006]    In efforts to improve the sheet separator, U.S. Pat. No. 5,895,040 entitled Sheet Separator to Oleksa et al and U.S. Pat. No. 5,938,190 entitled Specialty Media Feed Guide Snd Sheet Feeding Apparatus Using Same to Campbell et al disclose two different friction materials and a plurality of friction pads attached to the automatic sheet feeding device. Sheet separating and guiding mechanisms disclosed in these references, however, are not sufficient to separate the sheets one by one, support the sheets stacked in the automatic sheet feeding device diagonally mounted on the printing device, and guide the sheets one by one from the automatic sheet feeding device to the printing device in a horizontal direction.  
           [0007]    The automatic sheet feeding device having the conventional sheet separator fails to separate a single sheet from the sheets stacked in a tray of the automatic sheet feeding device. Moreover, a plurality of sheets will slip down to the sheet separator due to vibration generated in the course of picking-up a sheet from the sheet stacked in the tray, and the plurality of the sheets are picked up simultaneously and fed to the printing device when a particular type of sheets, such as an over head projection medium or coated papers, are used, or when the printer is used in high temperature and high humidity condition.  
         SUMMARY OF THE INVENTION  
         [0008]    It is an object of the present invention to provide an improved sheet separator mounted on an automatic sheet feeding device diagonally installed in an ink jet printer.  
           [0009]    It is another object to provide a sheet separator able to effectively support sheets of paper within an automatic sheet feeding device diagonally installed in an ink jet printer.  
           [0010]    It is yet another object to provide a sheet separator able separate sheets one by one from an automatic sheet feeding device diagonally installed in an ink jet printer.  
           [0011]    It is still yet another object to provide a sheet separator able to hold remaining sheets stacked within an automatic sheet feeding device diagonally installed in an ink jet printer.  
           [0012]    It is also an object to provide a sheet separator able to prevent a slip down of sheets stacked within an automatic sheet feeding device diagonally installed in an ink jet printer during picking up a sheet located on a top of the sheet.  
           [0013]    It is further object to provide a sheet separator able to prevent a plurality of sheets from being picked up from an automatic sheet feeding device diagonally installed in an ink jet printer simultaneously.  
           [0014]    These and other objects of the present invention may be achieved by providing an improved sheet separator for preventing a slip-down of sheets stacked in an automatic sheet feeding device diagonally installed in a main body of a printing device of an ink jet printer. The sheet separator includes a friction dam disposed to contact lower edges of sheets loaded in the sheet feeding device, a buckler body disposed on the friction dam and between the friction dam and the lower edges of the sheets, a guide projection formed on an upper side of the buckler body for jumping up a top sheet located on a top of the sheets from the automatic sheet feeding device toward the printing device of the ink jet printer, and at least one or more jack bucklers having a plurality of inclined projections having a slide side and a threshold side, the slide side allowing a lower edge of the sheet located on the top of the sheets to be jumped toward the main body of the printing device while the threshold side prevents lower edges of the remaining sheets from moving toward the slide side. 
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0015]    A more complete appreciation of the invention, and many of the attendant advantages, thereof, will be readily apparent as the same becomes better understood by reference to the following detailed description when considered in conjunction with the accompanying drawings in which like reference symbols indicate the same or similar components, and wherein:  
         [0016]    [0016]FIG. 1 is a perspective view of a sheet separating feeder of an ink jet printer constructed by the principle of the present invention;  
         [0017]    [0017]FIG. 2 is a perspective view of a second embodiment of a sheet separator mounted on an ink jet printer constructed by the present invention;  
         [0018]    [0018]FIG. 3 is a perspective view of a jack buckler of FIG. 2;  
         [0019]    [0019]FIG. 4 is a side view illustrating a jack buckler coupled on a automatic sheet feeding device slantingly mounted on a main body of a printing device in an ink jet printer constructed by the principle of the present invention; and  
         [0020]    [0020]FIG. 5 is a partially enlarged sectional view of jack buckler indicated by A in FIG. 4. 
     
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT  
       [0021]    Referring now to the drawings, FIG. 1 shows a perspective view of a sheet separating feeder diagonally mounted on a side of a printing device in an ink jet printer which is not shown in FIG. 1. An automatic sheet feeding section  100  includes a frame  110  slantingly installed on the side of the ink jet printer. Sheets of paper are loaded within frame  110 . A lower edge of a sheet is separated from the sheets loaded in frame  110  and fed toward the printing device through an opening formed on the side of the printing device. The sheets loaded in the automatic sheet feeding device are inclined with respect to a horizontal line of the printing device. The sheet is fed obliquely, downwardly, and horizontally to the printing device of the ink jet printer. A pickup unit  120  is rotatably mounted on a rotary pivot connected to the frame  110  of the of automatic sheet feeding section  100  transfers the loaded sheets to the printing device in the ink jet printer. A friction dam  130  is located on a passageway of the sheets, and includes a plurality of dam grooves  132  and a paper guide  140  installed in one of dam groove  132  for guiding a picked-up sheet to the printing device in a horizontal direction. Automatic sheet feeding section  100  separates and supplies the sheets to the printing device one by one.  
         [0022]    A buckler bracket  150  is installed in one of dam grooves  132  and includes friction surfaces  151  in an upper surface thereof, and a friction bracket  152  is mounted on the upper surface of buckler bracket  150  for separating each sheet from the sheets. Friction bracket  152  is made of a soft material, such as a rubber material, and may be attached to one of dam grooves  132  without being mounted on the upper surface of buckler bracket  150 . If friction bracket  152  is disposed between one of dam grooves  132  and buckler bracket  150  placed on the one of dam grooves  132 , then teeth  153  protrude through an elongated opening  160  formed on a longitudinal surface of a center portion of buckler bracket  150 . A lower edge of the sheet contacts either one of teeth  153  and friction surface  151  formed on both sides of the elongated opening  160 . Each one of teeth  153  has a threshold side and a sliding side having an angle with the threshold side.  
         [0023]    Referring to FIGS.  2  to  4 , an automatic sheet feeding section  200  in an ink jet printer includes a frame  210  diagonally installed in a side of a printing device in an ink jet printer for accommodating loading of sheets P, a pick-up unit  220  installed on a rotary pivot of frame  210 , a friction dam  230  disposed to contact lower edges of sheets and including a plurality of dam grooves  232  and a sheet guide  240  installed in one of dam grooves  232  for guiding a picked-up sheet P to be fed to the printing device in a horizontal direction. The picked up sheet is picked up obliquely and downwardly, passes over friction dam  230  horizontally, and is fed toward the printing device horizontally. The printing device includes an ink cartridge  410 , a sheet feeder  400 , and a sheet controller  420 . A sheet separated from frame  210  passes over jack buckler  300  and is fed horizontally between ink cartridge  410  and sheet feeder  400  while sheet controller  420  adjusts the sheet to be located on a position for printing an image on the sheet by ink cartridge  410 .  
         [0024]    Automatic sheet feeding section  200  separating a sheet from a stack of sheets includes a buckler bracket  250 , as a sheet separator, installed in one of dam grooves  232  with a friction bracket  252 , as a sheet separator, at a top thereof. Jack buckler  300 , as a sheet separator, may be installed in one of dam grooves  232  without a friction bracket  252  while friction bracket  252  is installed in the other one of dam grooves  232 . Jack buckler  300  is installed in one of dam grooves  232  of friction dam  230  together with sheet guide  240  and buckler bracket  250  to prevent a slip-down of sheets P as well as to separate a sheet from a stack of sheets P. Friction buckler  252  may be referred to friction buckler  152  of FIG. 1 while buckler bracket  250  may be referred to buckler bracket  150  of FIG. 1. A hook  340  is formed on each one of sheet guide  240 , buckler bracket  250 , and jack buckler  300  so that sheet guide  240 , buckler bracket  250 , and jack buckler  300  are detachably attached to opening  260  formed on dam grooves  232  of friction dam is  230  and are easily replaced with a new one after used for a predetermined period of time.  
         [0025]    Jack buckler  300  molded by a injection molding of a plastic material includes a buckler body  310 , a guide projection  320 , a plurality of teeth  330 , and hook  340 . The injection molding of the plastic material provides jack buckler  300  with superior characteristics of a uniform shape and an accurate size as well as a high abrasion resistance. Buckler body  310  of jack buckler  300  has an upper surface of a flat rectangular shape. Each corner of an upper portion of buckler body  310  is rounded so as not to prevent the lower end of sheets P form moving toward the printing device from frame  210 .  
         [0026]    Guide projection  320  is an initial portion L of buckler body  310  where a sheet located on a top of the stack of sheets is allowed to jump up and fed over friction dam  230  toward the printing body. Guide projection  320  has upwardly and downwardly inclined sides  322 ,  324  . As the sheet located on the top of the stack of sheets is jumped up by guide projection  320  due to a friction with a pick-up roller, the sheet may be directly picked up without contacting downwardly inclined side  324  of guide projection  320 .  
         [0027]    Teeth  330  having a threshold side  332  and a sliding side  334  prevent a plurality of the Halosheets from being picked up simultaneously due to a slip-down of the plurality of the sheets from guide projection  320 . A plurality of teeth  330  are formed on a top surface of buckler body  310  adjacent to guide projection  320 . Two different groups of teeth  330  are formed on the top surface of buckler body  310  in a series adjacent to guide projection  320 . A first group of teeth  330  is located in a first portion M of the top surface of buckler body  310  while a second group of teeth  330  is located in a second portion N of the top surface of buckler body  310 . As shown in FIG. 5, threshold side  332  of first portion M has an angle a with a first plane perpendicular to a second plane of the surface of the buckler body  310  while threshold side  332  of second portion N has an angle β with the first plane perpendicular to the second plane of the surface of the buckler body  310 . Angle a of threshold side  332  of teeth  330  formed in first portion M is greater than angle β of threshold side  332  of teeth  330  formed in second interval N. When a sheet is jumped up while passing through guide projection  320 , and when remaining sheets slide along guide projection  320  and are located in first portion M and second portion N of teeth  330  due to vibration, respective ends of the sheets are remained between thresholds side  332  and sliding side  334  of teeth  330 . The Sheets remained between thresholds side  332  and sliding side  334  of teeth  330  is picked up one by one and separated by threshold side  332  of teeth  330 .  
         [0028]    Hook  340  is extended downwardly from a side of buckler body  310  and has an outwardly-cut shape to be inserted into opening  260  formed on dam grooves  232  and detachably attached to dam grooves  232  so that buckler body  310  may not be separated when installed in dam groove  232  of friction dam  230 .  
         [0029]    As described above, the sheet separating device constructed by the principle of the present invention prevents a slip-down of sheets in an ink jet printer and enhances reliability in an pickup operation of sheets one by one in the ink jet printer. The plurality of sheets are prevented to be picked up simultaneously.  
         [0030]    While the invention has been shown and described with reference to a certain preferred embodiment thereof, it will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the invention as defined by the appended claims.

Technology Classification (CPC): 1