Sheet feeding or delivering – Feeding – Separators
Reexamination Certificate
2001-02-16
2003-01-14
Bollinger, David H. (Department: 3653)
Sheet feeding or delivering
Feeding
Separators
C271S137000, C271S241000, C271S167000, C271S245000, C271S264000
Reexamination Certificate
active
06505826
ABSTRACT:
BACKGROUND OF THE INVENTION
Field of the Invention
The invention relates to a device for separating or singling sheets piled up so as to form a stack, in a feeder of a sheet-processing-machine, having a transport element with a guiding edge.
Heretofore known devices for separating or singling sheets, which have been piled up so as to form a stack, in a feeder of a sheet-processing machine have a transport element which is constructed as a pivotable flap and functions for transporting one or more sheets, by a pivoting movement, from the stack to a feeder roll of the machine. For this purpose, the respective sheet resting on the top of the stack is pushed along the guiding edge onto a guide face of the transport element which, by subsequent pivoting movement thereof, transports the respective sheet by the leading edge thereof to the feeder roll. Disadvantageously, the contour of the topmost sheet on the front side of the stack, as viewed in the sheet transport direction, is not always flat, so that it is possible for disruption to occur during the transport of the respective sheet from the stack to the feeder roll, for example, because the sheet is in a skewed position. Individual, visual averaging out of the different heights (lower edge region, higher center region) of the stack at the front side by an operator, and corresponding positioning of the stack and, in particular, of the sheet resting on the top thereof, in relation to the guide edge of the transport element does not lead to reliable results with regard to secure and reliable sheet transport from the stack to the feeder roll.
In addition, the published German Patent Document DE 34 11 886 A1 discloses a device having a first and a second detector for establishing the respective height of the front and rear region of a sheet stack or pile.
SUMMARY OF THE INVENTION
It is accordingly an object of the invention to provide a device of the type mentioned at the introduction hereto which, in a reliable, exact and repeatable manner, ensures correct separation or singling of sheets piled up to form a stack, in the feeder, and trouble-free transport of the respective sheets from the stack to a feeding roller of a sheet-processing machine.
With the foregoing and other objects in view, there is provided, in accordance with the invention, a device for separating or singling sheets, which have been piled up to form a stack, in a feeder of a sheet-processing machine, having a transport element with a guide edge, comprising a device for matching the shape of the guide edge to the contour of the topmost sheet at a front side of the stack, as viewed in a sheet transport direction.
In accordance with another feature of the invention, the shape-matching device has a transport element which is at least one of elastically and plastically deformable so as to match the shape of the guide edge to the contour of the topmost sheet.
In accordance with a further feature of the invention, the separating device includes a measuring device for determining the contour of the topmost sheet at the front side of the stack.
In accordance with an added feature of the invention, the separating device includes an adjusting device for matching the contour of the guide edge to the contour of the topmost sheet.
In accordance with an additional feature of the invention, the separating device includes a control unit operatively connected to the measuring device and to an adjusting device for matching the contour of the guide edge to the contour of the topmost sheet.
In accordance with yet another feature of the invention, the transport element is formed as an L profile in cross section and, at an end thereof, has a stop crosspiece which is bringable into engagement with the front side of the stack and, at a top thereof, the stop crosspiece has a guide crosspiece formed with a guide face onto which the topmost to sheet is transportable, the guide edge being located at the outside between the stop crosspiece and the guide crosspiece.
In accordance with yet a further feature of the invention, the transport element is formed rigid in the sheet transport direction and, at the stop crosspiece, is provided with a plurality of mutually spaced teeth for assisting in an elastic deformation of the transport element for matching the contour of the guide edge to the contour of the topmost sheet.
In accordance with yet an added feature of the invention, the separating device includes a fixing device for firmly clamping the teeth separately in order to stabilize the contour-matched guide edge.
In accordance with yet an additional feature of the invention, the fixing device is formed with holding openings wherein the teeth are freely positionable and firmly clampable, by deforming the transport element, so as to match the contour of the guide edge to the contour of the topmost sheet.
In accordance with still another feature of the invention, the adjusting device includes a plurality of actuators arranged spaced apart from one another.
In accordance with still a further feature of the invention, the actuators are formed as plungers having a position which is adjustable on a rotatable cam disc.
In accordance with an alternative feature of the invention, the actuators are formed as spindles operatable by a drive.
In accordance with still an added feature of the invention, the transport element is pivotable, between a stop position and a transfer position, about an axis of rotation extending perpendicularly to the sheet transport direction.
In accordance with still an additional feature of the invention, a matching of the contour of the guide edge to the contour of the topmost sheet by the adjusting device is dependent upon a pivoting-angle position thereof relative to the transport element.
In accordance with another feature of the invention, the guide edge is formed so as to be contour-matched to the topmost sheet in the stop position of the transport element and to be straight in the transfer position of the transport element.
In accordance with a further feature of the invention, the transport element is movable selectively counter to and in a respective contour-matching direction by a restoring spring element, respectively, compressible and expandable by the pivoting of the transport element.
In accordance with an added feature of the invention, in the transfer position of the transport element, the restoring spring element is compressed, the transport element is retracted and the contour matching of the guide edge is canceled, while, in the stop position of the transport element, the restoring spring element is expanded, the transport element is extended and the contour of the guide edge is completely matched to the contour of the topmost sheet.
In accordance with a concomitant feature of the invention, the transport element is formed as a continuous, pivotable flap, and the fixing device is formed as a pivoting shaft for the flap.
In order to achieve the objective of the invention, a separating device is proposed having features distinguished by the fact that the shape of the guide edge can be adapted or matched to the contour of the topmost sheet at a front side of the stack, as viewed in the sheet transport direction. This advantageously prevents the leading edge of the topmost sheet, which is generally not straight, but rather, bent downwardly, in particular in the edge regions thereof, from colliding with the guide edge as it is displaced from the stack onto a guide face of the transport element, and becoming skewed in an uncontrolled manner with respect to the sheet transport direction. By adapting or matching the contour of the guide edge to the leading edge of the topmost sheet, correct transport of the respective sheet from the stack to the feeder roll of a sheet-processing machine by the transport element is therefore reliably assured.
It is advantageous, for adapting or matching the contour of the guide edge, that the transport element be elastically and/or plastically deformable. A deformable guide edge is particularly suitable for exact and repeatable adaptation
Gerstenberger Markus
Henn Andreas
Luxem Wolfgang
Möller Tobias
Wolf Thomas
Bollinger David H.
Greenberg Laurence A.
Heidelberger Druckmaschinen AG
Mayback Greogory L.
Stemer Werner H.
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