GB644854A - Improvements in or relating to apparatus for and method of electroplating the insides of pipes - Google Patents

Abstract

644,854. Rotating electrodes. BART, S. G. Aug. 6, 1946, No. 23244. [Class 41] The inside of a pipe is electroplated, e.g. with nickel, by rotating an anode element within and insulated from the pipe which constitutes the cathode and the container for the electrolyte, both the cathodic pipe and anode element having a surface of substantially cylindrical form and being mounted for rotary movement, each about its own axis and inter-driven to turn in unison, and the axes being horizontal and thus parallel one above the other. As shown, a pipe P is provided with temporary end closures 23 and contains electrolyte 17 to such level as to form a closed gas receiving chamber above it. The pipe is mounted horizontally, e.g. on a cradle, for rotary movement, and a cylindrical anode 45 is supported by insulating means on the interior surface of the pipe in slightly space relationship therefrom. The cradle may be formed by a set of four rollers, one of which at least is power-driven. Each end closure comprises an end-plate 23 temporarily secured in place on the pipe and a fixed plate 34 in which the end-plate 23 is journalled for rotary movement. These two plates are provided, in off-set relation to the centre, with fluid conduits 33, 36 respectively, and in addition the end-plate 23 has a circular groove 32 co-operating with the conduits to provide a circuit for electrolyte which is forced through pipe 35 under regulated pressure. An anode flexible conductor 29 passes into the pipe through openings in plates 34 and 23 of one end of the pipe for connection to the anode 45. This anode comprises a hollow perforated shell 46 of insulating material and a body 47 of loose anode-forming particles, e.g. of nickel, contained within a fabric bag in the shell, which is closed by end-plates 48, 49. The anode may be reciprocated axially of the cathode pipe in sliding contact therewith as the pipe rotates, thereby in turn rotating the anode. Alternatively separate drives may be provided for rotating the pipe and anode, this latter by the application of power to the cable 29. The anode may alternatively be formed by a set of anode bars which replace the body 47 of loose metal particles, the bars being circumferentially distributed within the shell 46. In another form, the anode may comprise an outer nickel shell on a copper cylinder provided at one end with a closure head in the centre of which projects a nipple to receive the end of the anode cable 29 and insulating rings encircle adjacent opposite ends of the anode. The pipe p may be supported on the anode which is power-driven, the pipe is then without end closures and is accommodated in an open bath.