GB419391A - Improvements in or relating to the electro-deposition of metals - Google Patents

Abstract

419,391. Electrodeposition of metal. WILLIAMS, A. I. WYNNE-, 12a, Raleigh House, Larkhall Estate, South Lambeth, London. July 4, 1933, Nos. 19015 and 26773. [Class 41.] Metal is deposited on a slowly rotating mandrel 1 in close proximity to which there are mounted skimming members 7 which are reciprocated circumferentially to disturb the cathode film of electrolyte, the travel being such as to permit the continuous removal of the deposit at 18 as sheet or tape. The skimming members may be perforated rectangular plates of celluloid, the perforations being more numerous at the middle in order to prevent excessive deposit at the edges. They are mounted on baffles disposed parallel to the flat surfaces of the mandrel, the baffles being reciprocated by linkwork. Glass bristles may be mounted on one or both sides of the skimmers so as to scour gently the anode and /or the cathode. In the case of a long mandrel, the skimmers may consist of wires under tension. The anode consists of metal bars 4 supported on a smooth frame 5 down which the bars may slide as they are consumed, fresh bars being added as required at one or both sides ; the frame is provided with a contact strip 6. The anode may be initially built up of bars diminishing in section to one side or the centre ; or the frame may be eccentric to the mandrel and the bars of uniform section. The cathode may be of stainless steel or may be plated thickly with chromium and ground before use. The unsubmerged part of the cathode is maintained wet by circulating electrolyte or by make-up water. When the axis of the mandrel is submerged, contact with it is made by means of a conducting rod projecting into a bore in the shaft and insulated throughout its length except at the bearing end ; good contact is maintained by spring loading or by tilting of the mandrel. In an example for the deposition of copper tape a bath containing 15 per cent of copper sulphate and 10 per cent of sulphuric acid at 120‹ F. is employed with a current density of 180 amps per sq. ft. The mandrel revolves once each hour and the skimmers make 120 oscillations per minute. Specification 8305/15, [Class 41], is referred to.