Apparatus and method for Z-folding sheets
First Claim
1. Apparatus for Z-folding sheets, which has a folding roll pair driven in opposite directions and a transport roller pair for delivering the sheets to the folding rolls of the folding roll pair, said Z-folding apparatus comprising:
- associated with the folding rolls of the folding roll pair, a pressure roller unit positioned, with respect to a transport path of a sheet, between the transport rollers and the folding rolls that in a first position (I) rests against both folding rolls simultaneously and for moving into a second position (II) lifted away from the folding rolls;
a sensor arranged in the transport path of the sheet is associated with the transport roller pair;
a sensor arranged in the transport path of the sheet is associated with the folding rolls;
have transport speed which of the folding rolls is changeable;
the pressure roller unit has a plurality of rollers, arranged next to one another and each independently rotatably mounted;
the pressure roller unit has a first and a second roller group with rollers, of which the rollers of the first roller group are mounted eccentrically, to more positively grip the sheet by a certain amount (x) with respect to the longitudinal axis of the pressure roller unit, and the rollers of the second roller group are mounted eccentrically with respect to the longitudinal axis of the pressure roller unit by said certain amount in the opposite direction from the rollers of the first roller group; and
the rollers of said pressure roller unit are arranged in such a way that of each two of said rollers arranged next to one another, one is associated with the first roller group and one with the second; and
with the pressure roller unit in the first position (I), the rollers of the first roller group are in nonpositive contact against the one folding roll, and the rollers of the second roller group against the other folding roll.
3 Assignments
0 Petitions
Accused Products
Abstract
A pivotedly mounted pressure roller unit, associated with which is a folding roller pair, is arranged on the transport path of a sheet to be folded. The pressure roller unit has a first and a second roller group, having rollers offset alternatingly eccentrically with respect to one another and mounted in independently rotatable fashion, which coact with the folding rolls in such a way that simultaneously, the rollers of the first roller group can be laid nonpositively against the one folding roller, and the rollers of the other roller group against the other folding roller. The transport speed (v2) of the folding rolls can be reduced to a lower transport speed (v1), thus causing a transport roller pair driven at an unchanging transport speed to bulge the sheet into an arc prior to entry into the folding rolls. By pivoting the pressure roller unit against the folding rolls, the arc and the trailing end of the sheet are transported simultaneously by the pressure roller unit. Once the folding rolls have grasped the trailing sheet end, the pressure roller unit is pivoted away and the folds in the sheet are made.
25 Citations
10 Claims
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1. Apparatus for Z-folding sheets, which has a folding roll pair driven in opposite directions and a transport roller pair for delivering the sheets to the folding rolls of the folding roll pair, said Z-folding apparatus comprising:
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associated with the folding rolls of the folding roll pair, a pressure roller unit positioned, with respect to a transport path of a sheet, between the transport rollers and the folding rolls that in a first position (I) rests against both folding rolls simultaneously and for moving into a second position (II) lifted away from the folding rolls; a sensor arranged in the transport path of the sheet is associated with the transport roller pair; a sensor arranged in the transport path of the sheet is associated with the folding rolls; have transport speed which of the folding rolls is changeable; the pressure roller unit has a plurality of rollers, arranged next to one another and each independently rotatably mounted; the pressure roller unit has a first and a second roller group with rollers, of which the rollers of the first roller group are mounted eccentrically, to more positively grip the sheet by a certain amount (x) with respect to the longitudinal axis of the pressure roller unit, and the rollers of the second roller group are mounted eccentrically with respect to the longitudinal axis of the pressure roller unit by said certain amount in the opposite direction from the rollers of the first roller group; and the rollers of said pressure roller unit are arranged in such a way that of each two of said rollers arranged next to one another, one is associated with the first roller group and one with the second; and
with the pressure roller unit in the first position (I), the rollers of the first roller group are in nonpositive contact against the one folding roll, and the rollers of the second roller group against the other folding roll. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10)
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Specification