GB786743A - Electro-deposition of metal layers - Google Patents

Abstract

786,743. Electrodeposition of metal. GLACIER METAL CO., Ltd. Aug. 25, 1955 [Sept. 2, 1954], No. 25552/54. Class 41. A method of electrodepositing metal on a conductive body connected as cathode, comprises continuously mechanically stirring the electrolyte between the anode and cathode to promote rapid and uniform interchange of the layer of electrolyte adjacent the anode with the layer of electrolyte adjacent the cathode.: In one example, Fig. 2, where the cathode is a cylinder 10, the anode 13 is mounted on a vertical, rotatable shaft 14 having plates at each end between which are supported insulating vanes 17. A porous screen 73, e.g. of polyvinyl chloride, may be disposed between the vanes 17. In a modification for depositing lead on the inner surfaces of part-cylindrical bearings 22, Fig. 3, a stack 21 of the bearings is clamped in insulating split jigs 23 having soft rubber linings 24 through which passes a flexible cathode connection. The stack 21 is fed at uniform speed downwardly by driven rollers 26, completed jigs being detached from the stack at the bottom of the apparatus. A rotating anode 35 and stirrer 36 having radial vanes 37 are mounted in the stack 21 as before. A fixed diaphragm 27 seals the interior of the stack 21 into which electrolyte is delivered through a pipe 30 by a pump from a reservoir 31, an overflow 29 in the return line maintaining a level 28 in the apparatus. In another modification, Fig. 11, for plating a flange 62 on a bearing 63, the anode 65, which is soluble, is not rotated, but spring-urged upwardly at 68 within an annular space in an insulating block 66. A stirrer 69 is disposed as shown, and may include a porous screen 74 between the vanes 72 as described above. In an other modification, Fig. 8 (not shown), for plating master discs of gramophone records, the discs are suspended horizontally from a bridge in electrolyte above fixed anodes, and a stirrer on a central vertical axis having horizontal vanes rotated between the discs and the anodes. Where the interior of cylinders are being plated, a soluble non-rotating anode may be employed, Fig. 7 (not shown), which comprises superposed sections tapered at their lower ends to engage a recess in the top of the preceding section, the anode sinking as it dissolves. A stirrer of the kind described with reference to Fig. 3 surrounds the anode.