GB344024A - Improvements in or relating to methods of and apparatus for plating objects, such as wires - Google Patents

Abstract

344,024. Electrolysis. WORLD BESTOS CORPORATION, 52, Courtland Street, Paterson, New Jersey, U.S.A.- (Assignees of Brockway, C. P.; 217, Lincoln Avenue, Ridgewood, New Jersey, U.S.A.) Nov. 28, 1929, No. 36483. Convention date, Nov. 28, 1928. [Class 41.] Electrodes; preparing surfaces; treating after electrolysis; metals, pickling; chromium, depositing.- A wire 5, Fig. 4, tobe plated is passed through a passage formed by coincident grooves 41 in the engaging surfaces of two insulators 40, 44, which are enclosed in a box-shaped anode 31 provided with holes 39 for the passage of the wire. The wire is connected as cathode by a plunger 46 inserted through a passage in the upper insulator 44. The grooves 41 are enlarged at the ends 43 so that the wire does not touch the insulators at a point near the effective part of the anode. A number of electrode assemblies of the kind described may be mounted on a rod in the bath and the wire passed through them in succession. A laminated coating of chromium of flexible character may be deposited by this means. The wire may be first treated as an anode and immediately afterwards given an initial coating before entering the main bath by the apparatus shown in Fig. 2. This comprises a glass tube 20 divided mid-way by an insulator 21 having a small axial hole through which the wire passes. Cylindrical electrodes 22, 23 having inturned flanges at the base are secured by clips 24, 25 in the two compartments of the tube, the electrode 23 being connected to the positive terminal of the plating generator, and the electrode 22 to the negative terminal of an independent generator to the positive of which the wire is connected. The wire may first be passed through alkali and acid cleaning baths and rinsing baths. After the main plating the wire is rinsed and then subjected to electrical bombardment in a vacuum to free it from occluded hydrogen. For this purpose the wire is passed over pulleys through a mercury well 52, Fig. 6, and up a tube 54 into the vacuum chamber 49 from which it passes out by a tube 55 and mercury well 53. A source of high tension current is connected to the base 50 and to an electrode 601 surrounded by an insulating tube 61 sealed in the base. The wire may also be subjected to vacuum bombardment before plating, A suitable bath for chromium plating consists of 80 lbs. chromic acid, 2 lbs. chromic sulphate, 1À6 Ibs. boric acid, and 250 lbs. water.