Claims
- 1. A method of measuring sheet bending stiffness of sheets of variable bend stiffness comprising:
providing a sheet corrugator having a plurality of different corrugator ribs; providing one or more sheets below the corrugator, wherein a predetermined gap exists between the topmost sheet and at least a substantial portion of the corrugator; providing at least one of a vacuum source, an air knife and a fluffer as pneumatic sheet deflection force sources; applying a pneumatic sheet deflection force between the sheet corrugator and the topmost sheet which is sufficiently large to raise the topmost sheet against at least some of the corrugator ribs of the sheet corrugator so as to deflect and bend the sheet into a variable profile corresponding to different corrugator ribs and the bending stiffness of the topmost sheet; measuring the deflection of the topmost sheet with at least one sheet deflection sensor associated with the sheet corrugator and responsive to the bend profile of the topmost sheet; and adjusting at least one of the vacuum source, the air knife and the fluffer pneumatic sheet deflection sources according to said measured topmost sheet deflection and predetermined rules therefor.
- 2. The method of claim 1 wherein said corrugator ribs are parallel and have different extensions, wherein different sheets of different bending stiffnesses are differently pneumatically corrugated against said plurality of different corrugator ribs of said sheet corrugator.
- 3. The method of claim 1 wherein the predetermined rules comprise a lookup table stored in a system memory.
- 4. The method of claim 1 wherein said at least one sheet deflection sensor comprises at least one analog sensor.
- 5. The method of claim 1 wherein said at least one sheet deflection sensor comprises at least one digital sensor.
- 6. The method of claim 1 wherein said at least one sheet deflection sensor provides a discrete output for each said sensor.
- 7. The method of claim 1 wherein said at least one sheet deflection sensor provides a continuous output.
- 8. The method of claim 1 wherein said applying of a pneumatic sheet deflection force between the sheet corrugator and the topmost sheet, and said measuring of the deflection of the topmost sheet, both occur during a sheet prefeeding operation.
- 9. The method of claim 1 further including:
providing a variable temperature sheet fuser; and adjusting the sheet fuser temperature according to said predetermined rules and said measured deflection of the topmost sheet.
- 10. The method of claim 1 wherein said sheet corrugator is a sheet feedhead.
- 11. The method of claim 1 wherein said measured deflection of the topmost sheet is provided on a real-time basis as part of a sheet separation and feeding operation in a sheet separator/feeder operation for which said sheet corrugator provides the sheet feedhead.
- 12. A pneumatic sheet separating and feeding method including a sheet feedhead for separating and feeding the top sheet from a stack of print substrate sheets of variable sheet beam strengths by pneumatically forcing the top sheet against said sheet feedhead, wherein said sheet feedhead has a plurality of differentially spaced extending ribs of different rib extensions against which different deformation corrugation shapes of the top sheet are pneumatically formed depending on said variable sheet beam strength of the top sheet.
- 13. The pneumatic sheet separating and feeding method of claim 12, wherein said differentially spaced ribs of different rib lengths ribs of said sheet feedhead are substantially parallel to one another.
- 14. The pneumatic sheet separating and feeding system of claim 12, wherein said sheet feedhead further includes sheet deformation sensing of said different deformation corrugation shapes of the top sheet against said sheet feedhead depending on said variable sheet beam strength of the top sheet to provide an estimate of the sheet beam strength of that top sheet.
- 15. The pneumatic sheet separating and feeding system of claim 14, wherein said estimation of the sheet beam strength of that top sheet is utilized to control the pneumatic sheet separating and feeding pneumatic force level.
Parent Case Info
[0001] This is a divisional of U.S. appln. Ser. No. 10/041,047 filed Jan. 7, 2002 by the same inventors, and claims priority therefrom. This divisional application is being filed in response to a three-way restriction requirement in that parent application and contains rewritten and additional claims to the restricted-out subject matter of original claims 1-8.
Divisions (1)
|
Number |
Date |
Country |
Parent |
10041047 |
Jan 2002 |
US |
Child |
10440696 |
May 2003 |
US |