Developer powder applicator unit having a supply roll with a magnetized working surface

Claim 1

A POWDER APPLICATOR UNIT CORRESPONDING: AN OPEN TROUGH-LIKE RECEPTACLE FOR MAGNETIC DEVLOPER POWDER; A SCRAPER BAR ALONG THE FORWARD EDGE OF SAID OPEN RECEPTACLE; A POWDER SUPPLY ROLL HAVING A MAGNETIZED WORKING SURFACE HAVING A PATTERN OF UNIFORMLY SPACED SMALL SEPARATED ZONES OF HIGH FIELD GRADIENT AND CAPABLE OF ATTRACTING AND RETAINING A THICK DEPOSIT OF A MAGNETIC DEVELOPER POWDER, AND ROLL DIPPING INTO SAID RECEPTACLE AND ROTATABLE WITH ITS SURFACE IN CLOSE UNIFORM PROXIMITY TO SAID SCRAPER BAR; A SOFT COMPRESSIBLE FEED ROLL PARALLEL TO SAID SUPPLY ROLL AND ABOVE THE REARWARD EDGE OF SAID RECEPTACLE; A SMOOTHING BAR BETWEEN SAID SUPPLY ROLL AND SAID FEED ROLL AND WITH ITS FREE SMOOTHING SURFACE DISPOSED TOWARD SAID FEED ROLL FROM THE INTERCONNECTING PLANE OF TANGENCY BETWEEN THE SAID ROLLS; A PLURALITY OF NARROW GUIDE PLATES CLOSELY SPACED FROM SAID FEED ROOL AND EXTENDING FROM SAID SMOOTHING BAR; AND A SOFT FIBROUS-SURFACED EJECTOR ROLL PARALLEL TO AND IN LIGHT SURFACE CONTACT WITH SAID, FEED ROLL, AND EJECTOR ROLL BEING INTERCONNECTED FOR ROLL, FEED ROLL, AND EJECTOR ROLL BEING INTERCONNECTED FOR POSITIVE ROTATION AT RELATIVE SURFACE SPEEDS OF APPROXIMATELY THREE, ONE AND FIVE RESPECTIVELY AND IN A DIRECTION FOR URGING A COPY-SHEET THROUGH SAID UNIT FROM SAID SUPPLY ROLL TO SAID EJECTOR ROLL.