Abstract:
A rotary sheet flipper may not properly flip certain types of sheets, for example sheets with a low beam strength. The invention relates to devices and methods for flipping a sheet with blowing assistance. According to various aspects of the invention, devices and methods for flipping a sheet are provided comprising receiving an end of the sheet, flipping the end with the sheet otherwise unrestrained; and blowing the sheet to assist flipping the sheet. Numerous variations and modifications are evident in light of the description provided herein.

Description:
CROSS REFERENCE TO RELATED APPLICATIONS  
       [0001]     This is a 111A application of Provisional Application Ser. No. 60/581,548, filed Jun. 21, 2004, entitled DEVICES AND METHODS FOR FLIPPING A SHEET WITH BLOWING ASSISTANCE by David J. Laluk, et al. 
     
    
     BACKGROUND OF THE INVENTION  
       [0002]     A rotary sheet flipper may not properly flip certain types of sheets, for example sheets with a low beam strength. The invention relates to devices and methods for flipping a sheet with blowing assistance.  
       SUMMARY OF THE INVENTION  
       [0003]     According to various aspects of the invention, devices and methods for flipping a sheet are provided comprising receiving an end of the sheet, flipping the end with the sheet otherwise unrestrained; and blowing the sheet to assist flipping the sheet. Numerous variations and modifications are evident in light of the description provided herein. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0004]      FIG. 1  presents a schematic side view of an apparatus according to one aspect of the invention.  
         [0005]      FIG. 2  presents a partial cross-sectional view taken along line  2 - 2  of  FIG. 1 .  
         [0006]      FIG. 3  presents a partial cross-sectional view of the apparatus  100  taken along line  3 - 3  of  FIG. 1 .  
         [0007]      FIG. 4  presents a partial cross-sectional view of the apparatus  100  is provided taken along line  4 - 4  of  FIG. 2 .  
         [0008]      FIGS. 5-8  present the same partial cross-section as  FIG. 4 , but at different stages of operation so certain components are in different positions depending upon the stage of the sequence.  
         [0009]      FIGS. 9 and 10  present a schematic end view and a schematic front view, respectively, of one embodiment of a blowing source and mount.  
         [0010]      FIGS. 11 and 12  present a schematic end view and a schematic front view, respectively, of another embodiment of a blowing source and mount.  
         [0011]      FIG. 13  presents a exemplary blower output curve for a blower that may be implemented in the practice of the invention.  
         [0012]      FIG. 14  presents a top view of one embodiment of a tamper, side plate, and stack, with portions broken away. 
     
    
     DETAILED DESCRIPTION OF THE INVENTION  
       [0013]     Various aspects of the invention are now described with reference to the drawings, which are not drawn to any particular scale, and wherein like components in the numerous views are numbered alike. Referring now specifically to  FIGS. 1 and 2 , a sheet processing apparatus  100  is presented according to one aspect of the invention.  FIG. 1  presents a schematic side view of the apparatus  100 , and  FIG. 2  presents a partial cross-sectional view taken along line  2 - 2  of  FIG. 1 . Apparatus  100  comprises a sheet handling device  102  for flipping a sheet  104 . The sheet  104  has an end  106 . The sheet handling device  102  comprises a rotary sheet flipper  108  that comprises a sheet holder  110  that receives the sheet end  106  and flips the sheet end  106  with the sheet  104  otherwise unrestrained. A blowing source  112  is oriented to assist flipping the sheet  104 .  
         [0014]     The apparatus  100  of  FIG. 1  is a stacker, for purposes of illustration, but the invention is not limited to use in a stacker. If configured as stacker, the apparatus  100  places the sheet  104  on a stack of sheets  105 . The apparatus  100  comprises a sheet transport path  114  that implements driven nips (not shown), for example, to move the sheet  104  along the transport path  114 , as indicated by arrow  116 . An example of a driven nip is a pair of opposing rollers, one of the rollers being driven. Such mechanisms are very well known in the sheet transport art.  
         [0015]     Apparatus  100  also comprises a diverter  118  that alternatively directs the sheet  104  to transport path  120 , or transport path  122 , depending upon the position of the diverter  118 . In  FIG. 1 , the diverter is positioned to direct the sheet  104  to the transport path  122 . Transport path  122  is directed to the rotary sheet flipper  108 , and transport path  120  is directed to exit the right side of the apparatus, for further sheet processing by another apparatus for example. The sheet  104  may be directed to the transport path  120  by rotating the diverter  118  counter-clockwise around a pivot  124 . The transport path may be provided with driven nips  126  and  128 .  
         [0016]      FIG. 3  presents a partial cross-sectional view of the apparatus  100  taken along line  3 - 3  of  FIG. 1 . An air source  130  is in fluid communication with the blowing source  112  via a hose or tube  132 . The air source  130  may be any device suitable for developing air movement, for example a blower, fan, or a compressed air source (a compressor). One, two, or more blowing sources  112  may be provided, and more than one hose  132  may be provided to supply multiple blowing sources. A wye-connection  134  may be provided to split the output from the air source  130  between two blowing sources  112 . Other plumbing arrangements may also be implemented, such as one or more manifolds. A regulator  136  may be provided to adjust the flow and/or pressure applied to the blowing source  112 , for example a bleed valve that vents some of the flow to ambient. The regulator  136  may be adjustable to permit tuning the blowing source  112  for sheets having particular properties. Alternatively, the air source motor may be regulated to provide a desired flow, for example by regulating DC voltage supply to a DC air source motor. The air source  130  and/or regulator  136  may be mounted anywhere on the apparatus  100  where convenient, particularly where access is available to adjust the regulator  136 . The air source  130  is shown mounted on a side panel of the apparatus  100 . A more convenient location may be on the back of the apparatus. The air source  130  maybe mounted immediately adjacent the blowing source  112 , in the area of the rotary sheet flipper  108  for example, thereby eliminating most or all of the interconnecting hose.  
         [0017]     Referring again to  FIGS. 1 and 2 , the sheet holder  110  is configured as a wheel mounted on a shaft  138 , the wheel comprising a tongue  140  that defines a slot  142  that receives the sheet end  106 . The exemplary rotary sheet flipper  108  presented in the drawings comprises two sheet holders  110  each configured as a wheel and each having two tongues  140  diametrically opposed on each wheel.  
         [0018]      FIG. 4  presents a partial cross-sectional view of the apparatus  100  taken along line  4 - 4  of  FIG. 2 . Referring now to  FIGS. 2 and 4 , the sheet handling device  102  comprises a tamper  144  that traps the sheet end  106  after flipping, and a side plate  214 . The sheet holder  110  comprises a cam  146 . The tamper  144  comprises a tamper shaft  148 , a tamper arm  150  mounted to the tamper shaft  148  that engages the sheet end  106 , and a cam arm  152  mounted to the tamper shaft  148  that interacts with the cam  146 .  
         [0019]     According to a further aspect of the invention, a sheet flipping method is provided comprising receiving the sheet end  106 , flipping the sheet end  106  with the sheet  104  otherwise unrestrained, and blowing the sheet  104  to assist flipping the sheet  104 . The method may comprise placing the sheet  104  on a stack of sheets  105 . The blowing may also be oriented and re-oriented in order to adjust the sheet handling device  102  for processing of sheets  104  having different characteristics. The sheet end  106  may be trapped after flipping. The method may comprise placing the sheet  104  on a stack of sheets  105  and trapping the sheet end  106  on the stack of sheets  105  after flipping.  
         [0020]      FIGS. 5-8  present the same partial cross-section as  FIG. 4 , but at different stages of operation of the sheet handling device  102  so certain components are in different positions depending upon the stage of the sequence. Operation of the sheet handling device  102  will now be discussed in more detail with reference to  FIGS. 4-8 . Blowing, as indicated by arrows  154  may be initiated by powering the air source  130  at the same time the main drive for the apparatus is powered. Referring now specifically to  FIG. 4 , the sheet  104  is driven by the nip  128  as indicated by arrow  156  so that the sheet  104 , and more specifically the sheet end  106  is received by the sheet holder  110  within the slot ( 142  of  FIG. 1 ) defined by the tongue  140 . Referring now to  FIG. 5 , a counter-clockwise rotation of the sheet holder  110  is initiated by a motor as the nip  128  continues to drive the sheet  104 . One of the cams  146  interacts with the cam arm  152 , which causes the tamper  144  to rotate clockwise and lift the tamper arm  150  from the stack of sheets  105 . At this point of the rotation of the sheet holder  110 , the sheet  104  is approximately aligned with the right edge of the stack  105 , and the sheet end  106  is positioned beneath the tamper arm  150 . Rotation of the sheet holder  110  continues until the cam  146  passes the end of the cam arm  152  thus releasing the tamper  144  to rotate counter-clockwise under a spring load, or other force such as a solenoid or the force of gravity for example, until the tamper arm  150  rests on the sheet end  106  so that the sheet end  106  is gripped between the tamper arm  150  and the sheet stack  105 , as is shown in  FIG. 6 . The tamper  144  may be damped by a damper, particularly if the tamper arm  150  tends to bounce. A quick gripping of the sheet end  106  after the sheet holder  110  releases it is desirable so that the blowing source  112  does not have an opportunity to blow the entire sheet  104  away. Gripping in the range of 15-60 milliseconds from the time the leading edge of the sheet  104  first strikes the side plate  214  ( FIG. 6 ) is believed to be satisfactory. All or part of the tongue  140 , for example about one-third of it, may be disposed between the sheet end  106  and the stack of sheets  105  when the tamper first contacts the sheet end  106  and traps it. Rotation of the sheet holder  110  continues until the tongue  140  is removed, and then stops. Referring now to  FIG. 7 , the nip  128  continues to drive the sheet  104 , which forms a loop moving to the left as indicated by arrow  158 . Eventually the end of the sheet  104  opposite the sheet end  106  exits the nip  128  and the transport  122 , as shown in  FIG. 8 . The blowing provided by the blowing source  112  urges continuing movement of the balance of the sheet, as indicated by arrow  156 , so that ultimately the sheet lies flat on the stack  105 . The sheet holder  110  maybe rotated into the position shown in  FIG. 4 , at an appropriate time, in order to repeat the cycle for another sheet.  
         [0021]     Without the blowing provided by the blowing source  112 , sheets having certain properties, particularly sheets having a low beam strength, tend to remain in the looped position on the top of the stack  105 . Stated differently, the motion indicated in  FIG. 8  does not occur the sheet remains looped and does not open. The next sheet is deposited and several sheets may be deposited in this condition. The looped sheet is damaged and the stack is altered in an undesirable manner that may render the stacker inoperable until the looped sheet (or sheets) is cleared.  
         [0022]     Referring again to  FIG. 1 , the sheet stack  105  rests on a tray  160 . The tray may be removable, and may be provided with wheels (not shown) to facilitate transporting it from one location to another on a shop floor. The elevation of the tray is controlled by multiple chain drives  162 , or other suitable mechanism for controlling the elevation of a tray in a stacker. In one embodiment, four chain drives  162  are provided, one at each corner of the tray  160 . Each chain drive  162  comprises a sprocket  164  and a chain  166 . The chain drives are controlled so that the tray  160  lowers as sheets are added to the sheet stack  105  such that the top of the sheet stack  105  remains at an approximately constant location.  
         [0023]     Referring now to  FIGS. 9 and 10 , a schematic end view and a schematic front view, respectively, of the blowing source  112  and mount  113  are presented. Mount  113  comprises a bracket  168 . A clamp  170  holds a tube  172  in place and is mounted to the bracket  168  by a fastener  174 . Another fastener  176  mounts the bracket  168  in place within the apparatus  100 , as shown in  FIGS. 2 and 4 - 8 . The tube.  172  is connected to the hose  132  of  FIGS. 1 and 3 . Referring again to  FIGS. 9 and 10 , and according to one aspect of the invention, the blowing source  112  may be oriented by moving it in a first direction  178 , a second direction  180 , and/or at least a third direction  182  (an additional direction  184  is also indicated). The blowing source  112  may also be oriented by rotating it, for example, about fastener axis  186  or fastener axis  188 . The blowing source may be oriented by translating it and rotating it. The mount  113  may be made adjustable to permit orienting and re-orientating the blowing source  112 .  
         [0024]     Referring now to  FIGS. 11 and 12 , a schematic side view and a schematic front view, respectively, of a blowing source  190  and mount  192  are presented according to another embodiment of the invention. Mount  192 . comprises a bracket  198 . The blowing source  190  comprises a tube  194  perforated with an array of holes  196 . The tube  172  is connected to the hose of  FIGS. 1 and 3 . Referring again to  FIGS. 11 and 12 , a clamp  200  holds the tube  194  in place and is mounted to the bracket  198  by the fastener  174 . The fastener  176  mounts the bracket  168  in place within the apparatus  100 . The blowing source  190  and mount  192  of  FIGS. 11 and 12  may be a direct substitute for the blowing source  112  and mount  113  of  FIGS. 9 and 10 . A mirror image arrangement may be substituted on the other side of the rotary sheet flipper  108  (on the left in  FIG. 2 ). As shown in  FIG. 2 , the rotary sheet flipper  108  is rotatable about an axis of rotation  202 . Referring again to  FIGS. 11 and 12 , the tube  194  has a longitudinal axis  204 , and may be parallel to the axis of rotation  202  of the rotary sheet flipper  108 .  
         [0025]     The blowing source  190  may be oriented and re-oriented as previously described with reference to blowing source  112 . Further additional directions of adjustment  206 ,  208  and more may be implemented, as desired. The blowing source  190  may be rotated about the longitudinal axis  204 , as indicated by arrows  210 . The array of holes  196  may be deflected toward the stack of sheets  105 , as shown in  FIG. 11 .  
         [0026]     The holes  196  may be aligned in one or more lines. Two rows of holes  196 , for example, may be implemented. One or more rows of holes  196  may be deflected toward the stack of sheets  105 , or just one row out of multiple rows of holes  196  may be deflected toward the stack or sheets  105 . The holes  196  need not be aligned in lines since any pattern that achieves the result described herein may be implemented in the practice of the invention.  
         [0027]     In a certain embodiment, the tube  194  is copper with an outside diameter of 0.60 inches and an inside diameter of 0.57 inches (standard ½″ copper pipe). There are four (4) holes  196 , each hole  196  having a diameter of 0.11 inch, two holes  196  on either side of the mount  192 , aligned in a straight line and deflected toward the stack of sheets  105 , as shown in  FIG. 11 . Two such mirror arrangements were provided, one on either side of a rotary sheet flipper  108 , powered by an Ametek® blower part number 119350-00 that generates the curve shown in  FIG. 13  (according to manufacturer&#39;s specifications), available from Ametek, Kent, Ohio, U.S.A. An adjustable bleed regulator  136  was provided and operated from full close (no bleed) to full open (full bleed) depending upon the tuning desired.  
         [0028]     Referring now to  FIG. 14 , a top view of one embodiment of the tamper  144 , side plate  214  ( FIG. 6 ), and stack  105 , with portions broken away is presented. The tamper  144  may comprise two L-shaped tamper arms  150  disposed on either side of a center T-shaped tamper arm  151 . The tamper arms  150  and  151  are firmly fixed to the tamper shaft  148  of  FIGS. 2 and 3 - 8 .  
         [0029]     Referring again to  FIG. 1 , a controller  212  is provided to control operation of the apparatus  100 . The controller  212  may implement software, hardware, and/or firmware. The controller may be configured according to methods and practices known in the art.  
         [0030]     In view of the wide variety of embodiments to which the principles of the present invention can be applied, it should be understood that the illustrated embodiments are exemplary only, and should not be taken as limiting the scope of the present invention.  
         [0031]     The claims should not be read as limited to the described order or elements unless stated to that effect. In addition, use of the term “means” in any claim is intended to invoke 35 U.S.C. §112, paragraph 6, and any claim without the word “means” is not so intended.  
         [0032]     Although the invention has been described and illustrated with reference to specific illustrative embodiments thereof, it is not intended that the invention be limited to those illustrative embodiments. Those skilled in the art will recognize that variations and modifications can be made without departing from the true scope and spirit of the invention as defined by the claims that follow. It is therefore intended to include within the invention all such variations and modifications as fall within the scope of the appended claims and equivalents thereof.  
       Parts list  
       [0000]    
       
           100  sheet processing apparatus  
           102  sheet handling device  
           104  sheet  
           105  stack of sheets  
           106  end  
           108  rotary sheet flipper  
           110  sheet holder  
           112  blowing source  
           113  mount  
           114  transport path  
           116  arrow  
           118  diverter  
           120  transport path  
           122  transport path  
           124  pivot  
           126  and  128  driven nips  
           130  air source  
           132  hose  
           134  wye-connection  
           136  regulator  
           138  shaft  
           140  tongue  
           142  slot  
           144  tamper  
           146  cam  
           148  tamper shaft  
           150  tamper arm  
           151  t-shaped tamper arm  
           152  cam arm  
           154  arrows  
           156  arrow  
           158  arrow  
           160  tray  
           162  chain drives  
           164  sprocket  
           166  chain  
           168  bracket  
           170  clamp  
           172  tube  
           174  fastener  
           176  fastener  
           178  first direction  
           180  a second direction  
           182  third direction  
           184  additional direction  
           186  fastener axis of rotation  
           188  fastener axis of rotation  
           190  blowing source  
           192  amount  
           194  tube  
           196  array of holes  
           198  bracket  
           200  clamp  
           202  axis of rotation  
           204  longitudinal axis  
           206 ,  208  further directions of adjustment  
           210  arrows  
           212  controller  
           214  side plate