Apparatus for developing electrostatic images

Claim 1

IN A MEANS FOR DEVELOPING LATENT ELECTROSTATIC IMAGES ON SHEETS WITH LOW VISCOSITY DEVLOPER LIQUIDS WHICH MEANS INCLUDES A TANK FOR HOLDING THE LIQUID, A PAIR OF PARALLEL ADJACENT ROLLERS POSITIONED IN SAID TANK IN CLOSE PROXIMITY TO EACH OTHER SO AS TO FORM A TROUGH BETWEN THEM AND AT SUCH A LEVEL AS TO HAVE AT LEAST ONE OF THEIR LOWER SURFACES DIPPING INTO THE DEVELOPER LIQUID IN SAID TANK, BUT WITH THE UPPER SURFACES OF BOTH ROLLERS PROJECTING SUBSTANTIALLY ABOVE THE LIQUID LEVEL IN THE SAID TANK, MEANS SUPPORTING SAID ROLLERS IN SAID TANK FOR ROTARY MOTION THERIN, MEANS FOR SO DRIVING SAID ROLLERS IN OPPOSITE DIRECTIONS AS TO HAVE THE UPPER SURFACES OF SAID ROLLERS APPROACHING EACH OTHER AND MOVING DEVELOPER LIQUID FROM SAID TANK AND INTO SAID TROUGH TO FORM A STANDING WAVE OF DEVELOPER, LIQUID THEREIN, AND MEANS FOR MOVING AN ELECTROSTATICALLY IMAGED SHEET TO BE DEVELOPED ACROSS THE SURFACE OF THE STANDING WAVE OF DEVELOPER LIQUID; THE IMPROVEMENT WHICH COMPRISES A CORE MAMBER ARRANGED IN AND EXTENDING LENGTHWISE OF THE TROUGH AND SUBMERGED IN SAID STANDING WAVE TO PROVIDE A STABILIZING MEANS THEREFOR.