Sheet flattening method
AssigneeThe Mead Corporation
InventorsGary D. Cason, John E. Dobson, Francis P. Gunter, Svetislav Mitrovich, Suresh C. Paranjpe
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Abstract
A method and apparatus for flattening curled ones of a plurality of moving paper sheets subsequent to the printing and at least partial drying thereof is disclosed. The sheets are transported sequentially along a transport path, and the selected sheets are heated to a plasticizing temperature. The selected sheets are then stretched in both a longitudinal and a lateral direction with respect to the transport direction of the sheets.
Claims2
A method for operating upon selected ones of a plurality of moving paper sheets for flattening of the selected sheets subsequent to the printing thereon with a liquid ink, comprising the steps of:
- transporting the sheets sequentially along a transport path;
- heating the selected sheets during transportation thereof along said transport path;
- applying a stretching force to the selected sheets in a longitudinal direction with respect to the sheets during transportation thereof along said transport path;
- and
- applying a stretching force to the selected sheets in a
- lateral direction with respect to the sheets during transportation thereof along said transport path;
- said heating of the selected sheets being performed at a first predetermined location along said transport path;
- said heating of the selected sheets further being performed by a heater selectively movable between a first position remote from said transport path and a second position adjacent said first predetermined location and said transport path, and wherein said heating step includes:
- moving said heater from said first position to said second position prior to transporation of a selected sheet past said first predetermined location;
- in the event the next succeeding sheet of the moving sheets is a selected sheet, retaining said heater in said second position;
- and
- in the event the next succeeding sheet of the moving sheets is not a selected sheet, moving said heater from said second position to said first position.
A method for operating upon selected ones of a plurality of moving paper sheets for flattening of the selected sheets subsequent to the printing thereon with a liquid ink, comprising the steps of:
- transporting the sheets sequentially along a transport path;
- heating the selected sheets during transportation thereof along said transport path;
- applying a stretching force to the selected sheets in a longitudinal direction with respect to the sheets during transportation thereof along said transport path;
- and
- applying a stretching force to the selected sheets in a lateral direction with respect to the sheets during transportation thereof along said transport path;
- said heating of the selected sheets being performed at a first predetermined location along said transport path;
- said application of said longitudinal stretching force and said lateral stretching force being performed on the selected sheets simultaneously and at a second predetermined location along said transport path;
- said application of said lateral stretching force to the selected sheets being performed by:
- applying compressive force to the selected sheets at said second predetermined location along said transport path, and
- converting said compressive force to said lateral stretching force;
- said application of said compressive force to selected sheets being performed by a pair of oppositely-driven rollers disposed in selectively compressive mutual contact for movement of sheets therebetween along said transport path;
- said application of said compressive force to selected sheets including:
- mutually compressing said rollers to produce said compressive force therebetween prior to transportation of a selected sheet past said second predetermined location;
- in the event the next succeeding sheet of the moving sheets is a selected sheet, maintaining said rollers in compression to produce said compressive force;
- and
- in the event the next succeeding sheet of the moving sheets is not a selected sheet, relieving compression between said rollers at least partially to produce at least substantially less than said compressive force between said rollers.
Dependencies are inferred from the claim text.