Xerographic fuser roller

Claim 1

XEROGRAPHIC FUSING APPARATUS, COMPRISING: A RELATIVELY RIGID GENERALLY CONCAVE HOLLOW CYLINDRICAL FUSER ROLLER MOUNTED FOR ROTATION ABOUT THE LONGITUDINAL AXIS THEREOF, THE DIAMETER OF SAID ROLLER BEING LINEARLY AND SYMMETRICALLY TAPERED ALONG SAID AXIS WITH RESPECT TO THE CENTER THEREOF, FROM A MAXIMUM VALUE AT EACH END TO A MINIMUM VALUE AT THE CENTER, SAID FUSER ROLLER COMPRISING A METAL CYLINDER HAVING AN OUTER LAYER COMPRISING POLYTETRAFLUOROETHYLENE DISPOSED THEREON; A RADIANT HEATING ELEMENT DISPOSED ALONG SAID LONGITUDINAL AXIS WITHIN THE INTERIOR OF SAID FUSER ROLLER FOR HEATING SAID FUSER ROLLER TO A DESIRED XEROGRAPHIC TONER FUSING TEMPERATURE; A CYLINDRICAL PRESSURE ROLLER COMPRISING A METAL CORE SURROUNDED BY A CYLINDER COMPRISING ELASTOMERIC MATERIAL, AND AN OUTER LAYER COMPRISING POLYTETRAFLUOROETHYLENE DISPOSED THEREON, SAID PRESSURE ROLLER BEING DISPOSED IN JUXTAPOSITION WITH SAID FUSER ROLLER, SAID PRESSURE ROLLER BEING MOUNTED FOR ROTATION ABOUT THE LONGITUDINAL AXIS THEREOF, SAID LONGITUDINAL AXES BEING MUTUALLY PARALLEL AND SPACED APART A GIVEN DISTANCE SUCH THAT THE PERIPHERIES OF SAID ROLLERS ENGAGE EACH OTHER ALONG THE ENTIRE LENGTH OF THE LINE OF CONTACT THEREOF, SAID FUSER ROLLER HAVING A TAPER FROM THE CENTER TO EACH AND THEREOF SUCH THAT THE DIAMETER OF SAID FUSER ROLLER INCREASES ON THE ORDER OF 0.001 INCH PER INCH OF LENGTH THEREOF; AND TRANSPORT MEANS FOR FEEDING PAPER SHEETS HAVING XEROGRAPHIC TONER THEREON BETWEEN SAID ROLLERS.