Abstract: Method for controlling a sheet feeding device (1) comprising an elevator (2) for a stack of sheets, and an air supply system (3) configured to supply and direct one of more air streams towards an upper region (4) of the sheet feeding device for floating a plurality of upper sheets of the stack of sheets, wherein the elevator comprises a vertically movable support (5) for supporting the stack of sheets from below, wherein the sheet feeding device comprises an optical sensor (6) positioned adjacent the floated sheets for measuring light reflected from the floated sheets at a plurality of different heights, wherein the method comprises the steps of: continuously deriving from the optical sensor a density reading (DR) indicating the density of sheets floated, continuously deriving an average density (AD) based on a plurality of density readings, continuously deriving an upper density limit (UDL) based on the average density multiplied by a predetermined upper density limit factor (UDLF), continuously deriving a l

Abstract: Sheet feeding device (1) comprising an elevator (2) for a stack of sheets, and an air supply system (3) configured to supply and direct one of more air streams towards an upper region (4) of the sheet feeding device (1) for floating a plurality of upper sheets of the stack of sheets, wherein the elevator (2) comprises a vertically movable support (5) for supporting the stack of sheets from below, wherein the sheet feeding device (1) comprises a first side support member (6) and a second side support member (7) configured to sideways support respective opposite sides of the stack of sheets, wherein the sheet feeding device (1) further comprises a vacuum belt feeder (8) provided above the elevator (2) and configured to grab and feed an uppermost sheet of the floated sheets away from the floated sheets, and wherein an upper portion of each side support member (6, 7) is provided with at least one respective cam (9) comprising a respective guide surface extending obliquely upwards-inwards from the respective side

Abstract: Method for controlling a sheet feeding device (1) comprising an elevator (2) for a stack of sheets, and an air supply system (3) configured to supply and direct one of more air streams towards an upper region (4) of the sheet feeding device for floating a plurality of upper sheets of the stack of sheets, wherein the elevator comprises a vertically movable support (5) for supporting the stack of sheets from below, wherein the sheet feeding device comprises an optical sensor (6) positioned adjacent the floated sheets pot for measuring light reflected from the floated sheets at a plurality of different heights, wherein the method comprises the steps of: continuously deriving from the optical sensor a density reading (DR) indicating the density of sheets floated, continuously deriving an average density (AD) based on a plurality of density readings, continuously deriving an upper density limit (UDL) based on the average density multiplied by a predetermined upper density limit factor (UDLF), continuously deriving

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 device further comprises a sensor arrangement (22) arranged to determine where the upper paper sheets in the stack of papers (12) start to separate from the rest of the paper sheets, the sensor arrangement (22) comprising a plurality of infrared reflective sensors (22a).

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

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 device further comprises a sensor arrangement (22) arranged to determine where the upper paper sheets in the stack of papers (12) start to separate from the rest of the paper sheets, the sensor arrangement (22) comprising a plurality of infrared reflective sensors (22a).

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?).

Abstract: A paper feeding device comprises a storage surface for a stack of papers and being adapted to be move vertically between a first, lower end position and a second, upper end position, and a feeding roll for feeding papers from their position on the storage surface and imparting an uppermost sheet of paper a horizontal displacement. A first mounting device comprises a first vertically movable, preferably pivotable housing adapted to mount or suspend a first end of the feeding roll, and a second mounting device comprises a second vertically movable, preferably pivotable housing adapted to mount or suspend a second end of the feeding roll opposite to the first end of the feeding roll. By providing the first and second housings pivotable independently of each other and an intermediate axle, the feeding roll adapts to a non-uniform stack of papers, improving the reliability of the feeding.

Abstract: A method for feeding sheets of paper comprises the following steps: providing a stack of papers on a storage surface of a paper feeding device; providing a flow of air for separating an uppermost sheet of paper from the rest of the stack of papers; determining the vertical position of the uppermost sheet of paper; adjusting the flow of air in dependence on the determined vertical position of the uppermost sheet of paper; and repeating the steps of determining the vertical position of the uppermost sheet of paper and adjusting the flow of air in dependence on the determined vertical position of the uppermost sheet of paper. During continuous operation, the flow of air is controlled in cycles with one part of the cycle, preferably the first part of the cycle, with a higher flow of air, and one part of the cycle, preferably the second part of the cycle, with a lower flow of air.

Abstract: A paper feeding device comprises a storage surface for a stack of papers and being adapted to be move vertically between a first, lower end position and a second, upper end position, and a feeding roll for feeding papers from their position on the storage surface and imparting an uppermost sheet of paper a horizontal displacement. A first mounting device comprises a first vertically movable, preferably pivotable housing adapted to mount or suspend a first end of the feeding roll, and a second mounting device comprises a second vertically movable, preferably pivotable housing adapted to mount or suspend a second end of the feeding roll opposite to the first end of the feeding roll. By providing the first and second housings pivotable independently of each other and an intermediate axle, the feeding roll adapts to a non-uniform stack of papers, improving the reliability of the feeding.

Abstract: A method for feeding sheets of paper comprises the following steps: providing a stack of papers on a storage surface of a paper feeding device, providing a flow of air for separating an uppermost sheet of paper from the rest of the stack of papers; determining the vertical position of the uppermost sheet of paper; adjusting the flow of air in dependence on the determined vertical position of the uppermost sheet of paper; and repeating the steps of determining the vertical position of the uppermost sheet of paper and adjusting the flow of air in dependence on the determined vertical position of the uppermost sheet of paper. During continuous operation, the flow of air is controlled in cycles with one part of the cycle, preferably the first part of the cycle, with a higher flow of air, and one part of the cycle, preferably the second part of the cycle, with a lower flow of air.