Device for feeding papers

Abstract

Disclosed is a paper feeding device (10) comprising a storage surface (14) for a stack of papers (12), with a leading edge (14a), a trailing edge (14b), and a first and a second side edge (14c, 14d). The surface (14) is adapted to be moved vertically. The device further comprises a vacuum feeder (16) for feeding papers from their position on the storage surface (14) and imparting on an uppermost sheet of paper (12a) a horizontal displacement, and a blower arrangement (18, 20) adapted to provide a curtain of air separating the uppermost sheet of paper (12a) from the rest of the stack of papers. The blower arrangement comprises a front blower unit (20) having air openings with a first portion (20a) adapted to create first air cones (20a′) and second portions (20b) adapted to create second air cones (20b′), wherein the first air cones (20a) are different from the second air cones (20b′).

1 . A paper feeding device ( 10 ) comprising:
 a storage surface ( 14 ) for a stack of papers ( 12 ), the storage surface having a leading edge ( 14   a ), a trailing edge ( 14   b ), and a first and a second side edge ( 14   c,    14   d ) (and being adapted to be move vertically between a first, lower end position and a second, upper end position,)   a vacuum feeder ( 16 ) for feeding papers from their position on the storage surface ( 14 ) and imparting an uppermost sheet of paper ( 12   a ) a horizontal displacement,   a blower arrangement ( 18 ,  20 ) adapted to provide a curtain of air separating the uppermost sheet of paper ( 12   a ) from the rest of the stack of papers,   
       characterized in that 
       the blower arrangement comprises a front blower unit ( 20 ) provided along the leading edge ( 14   a ) of the storage surface ( 14 ), the front blower unit having air openings comprising a first portion ( 20   a ) adapted to create first air cones ( 20   a ′) and a second portion ( 20   b ) adapted to create second air cones ( 20   b ′), wherein the first air cones ( 20   a ) are different from the second air cones ( 20   b ′). 
     
     
         2 . The paper feeding device according to  claim 1 , wherein the first air cones are created in a first direction, and wherein the second air cones ( 20   b ′) are created in a second direction, wherein the second direction is different from the first direction. 
     
     
         3 . The paper feeding device according to any one of  claim 1  or  2 , wherein the first portion ( 20   a ) is vertically displaced approximately 5 mm in relation to the second air opening ( 20   b ). 
     
     
         4 . The paper feeding device according to any one of  claims 1  to  3 , wherein the front blower unit ( 20 ) provides four air flows. 
     
     
         5 . The paper feeding device according to any one of the previous claims, wherein the width of each air opening is between 20 and 40 mm, more preferably between 25 and 35 mm, and most preferably about 28 mm. 
     
     
         6 . The paper feeding device according to any one of the previous claims, wherein the height of each air opening is between 10 and 20 mm, and most preferably about 14 mm. 
     
     
         7 . The paper feeding device according to any one of the previous claims, wherein the first air cone ( 20   a ′) comprises approximately 60% of the air, and the second air cone ( 20   b ′) comprises approximately 40% of the air. 
     
     
         8 . The paper feeding device according to any one of the previous claims, wherein the first and second air cones have the same shape. 
     
     
         9 . The paper feeding device according to any one of the previous claims, wherein the first and second air cones have a similar shape. 
     
     
         10 . A paper processing machine comprising a paper feeding device ( 10 ) according to any one of  claims 1 - 9 .