GB579941A - Improvements relating to electroplating apparatus - Google Patents

Abstract

579,941. Electroplating. VANDERVELL, G. A. March 20, 1945, No. 6024/44. [Class 41] An electrolytic bath is fitted with auxiliary electrodes in addition to the anode and cathode, in order to control the distribution of the plating on the cathode, the auxiliary electrodes being maintained at a potential different from that of the cathode. As applied to the plating of the internal surface of bearing shells, the apparatus consists of sides 1, base 2, and ends 4, which are fastened together by screws 23. The bath has two contact rails 3 upon which the bearing. shell S rests. These rails are connected at their ends by supports 8 and have vertical terminal rods 10 fixed into their ends. Rods 10 pass through an insulating carrier 6, strengthened by frame 5, carrying the anode 24, which at its centre has a connection passing through carrier 6 to the socket 20. On either side of the anode 24, longitudinal strips of rubber 26 are let into the face of carrier 6, making contact with the edges of shell S. Guard rails 7, 7 acting as the auxiliary electrodes, are fixed to supports 14, which are bent over at their ends to rest on top of the end plates 4, and may be adjusted to the work by placing packing 16 between the ends of sup-, ports 14 and the plates 4. A wire 22 is placed in a central groove running along the base 2 and is connected through support 15 to rods 14. After the plating is completed, carrier 6 may be removed by handles 17 and placed on a tilted draining board, on which the rails 3 and the bearing can likewise be placed, Fig. 5 (not shown). The negative of the source is divided into two paths, Fig. 6, one supplying the rails 3 and the other the electrodes 7, 22. Resistance R1 is adjusted to give the correct voltage between anode and cathode for the plating process and R2 is adjusted to give the correct potential to such of the auxiliary electrodes as may be required. Where a superposed A.C. or pulsating D.C. are employed in the main circuit it is possible to use similar potentials between the cathode and auxiliary electrode. Specifications 419,764 and 573,635 are referred to.