Method for the uniform electroplating of sheet and strip

Claim 1

IN THE METHOD FOR THE CONTINUOUS ELECTROPLATING OF A PRINICIPALLY METALLIC COATING ONTO A METAL STRIP, WHICH INCLUDES A. THROUGH A PLATING ELECTROLYTE, PASSING THE STRIP IN PARALLEL RELATION TO A GENERALLY RECTANGULAR FACE OF AN ANODE FROM HAVING A LENGTH L AND A WITH WA, WHEREIN WA IS APPROXIMATELY EQUAL TO THE WIDTH OF SAID STRIP, AND B. APPLYING A CURRENT DENSITY BETWEEN SAID ANODE FROM AND SAID STRIP, AT A MAGNITUDE AND FOR A TIME, SUFFICIENT TO EFFECT THE DEPOSITION OF A SUBSTANTIALLY UNIFORM DESIRED COATING WEIGHT ALONG A WIDTH OF SAID STRIP, SAID COATING EXHIBITING AN EDGE EFFECT, THE IMPROVEMENT FOR SUBSTANTIALLY ELIMINATING SAID EDGE EFFECT, WHICH COMPRISES EMPLOYING AN ANODE CONFIGURATION COMPOSED OF TWO TANDEMLY ALIGNED FRACTIONS: THE FIRST FRACTION HAVING A FIRST WHICH IS GENERALLY RECTANGULAR, SAID FIRST FRACTION FACE HAVING A WIDTH, WA, AMD A LENGTH VARYING FROM ABOUT L/3 TO 2L/3, THE SECOND FRACTION HAVING A FACE WHICH IS GENERALLY TRAPEZOIDAL, SAID SECOND FRACTION FACE HAVING A CORRESPONDING LENGTH OF 2L/3 TO L/3 RESPECTIVELY, AND A WIDTH TAPERING APPROXIMATELY LINEARLY AND DECREASING FROM A WIDTH WA TO A WIDTH WB, WHEREIN WB IS APPROXIMATELY EQUAL TO THE PREDETERMINED WIDTH OF UNIFORM COATING WEIGHT PRODUCED BY SAID RECTANGULAR ANODE FORM.