Method and apparatus for holding down a sheet on a feed table of a sheet-processing machine
AssigneeHeidelberger Druckmaschinen AG
InventorsDavid Ehrbar, Andreas Mueller
Life of this patent
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Abstract
A method and an apparatus for holding down a sheet on a feed table of a sheet-processing machine include a lowerable smoothing bar which can be driven according to a speed profile in time with the sheet-processing machine, which results in a targeted deflection of the smoothing bar. The deflection is preserved for the purpose of smoothing the sheet from the middle to the side.
Claims14
A method for holding down a sheet on a feed table of a sheet-processing machine, the method comprising the following steps:
- placing a smoothing bar with a middle and ends above the feed table;
- lowering the smoothing bar toward the feed table in a lowering movement, the lowering movement having a lowest position;
- and
- carrying out the lowering movement of the smoothing bar according to a predefinable speed profile;
- exciting the smoothing bar to carry out an oscillation being superimposed on a kinematic movement in time with the sheet-processing machine;
- configuring the speed profile so that, immediately before reaching the lowest position of the lowering movement, the middle of the smoothing bar overshoots just enough to cause the middle of the smoothing bar to reach a middle end position before the ends of the smoothing bar reach an end position of the ends.
An apparatus for holding down a sheet on a feed table of a sheet-processing machine, the apparatus comprising:
- a smoothing bar disposed above the sheet and configured to be lowered in a direction toward the feed table;
- a four-bar linkage receiving said smoothing bar;
- and
- said smoothing bar being mounted to permit movement of said smoothing bar vertically on both sides of the feed table in time with the sheet-processing machine.
Dependencies are inferred from the claim text.