GB141733A - Improvements relating to electrolytic apparatus - Google Patents

Abstract

141,733. Merritt, M. M. April 15, 1919, [Convention date]. Roller-conveyer apparatus; electrolytes, circulating and trcating non-chemically; cells; supporting electrodes; preparing surfaces; treating after deposition; moulds; metals, depositing.-In coating a wire or forming a tube, the steel wire or other cathode passes around sheaves 21, 22, Fig. 2, so as to traverse the depositing apparatus repeatedly in opposite directions, while the circulating electrolyte falls from the cell into a tank and is thus aerated. The depositing apparatus may consist of a pair of open-ended troughs 18, sloping downwards from the middle, where the electrolyte enters, to the ends. To facilitate threading of a new wire, the troughs can be raised and lowered between rollers and sliding guides by racks and pinions 27 and a handle 29, a pawl 30 normally arresting the pinions. Within the troughs the parallel lengths of wire may be guided by horizontal glass rollers, supported by a fixed frame independent of the troughs. Anodes may consist of copper sheets or copper scrap held by perforated leaden plates. The tank 19 receiving the falling electrolyte is large enough to allow of the separation of impurities, and may have a heating device to promote the disengagement of hydrogen. Iron or steel wire, before being plated in the troughs 18, may be led through a cleaning tank 9, Fig. 1, containing hydrochloric acid and tin chloride. After being washed by jets 10, the wire is lightly plated in a copper-cyanide bath 11, and is then washed by passage through a glass tube 14, supplied with water by a branch 15. According to the Specification as open to inspection under Sect. 91 (3) (a), a current density exceeding 50 amperes, say 1000 amperes, per sq. ft. may be employed in the main depositing apparatus. Aluminium, before plating with copper, may be freed from oxide and provided with a protecting coating for instance of tin from a solution of hydrochloric acid and tin chloride. This treatment may be effected in the tube 14. which then contains a sponge to prevent rapid flow; the other preliminary operations above described are omitted. In the manufacture of tubes, there is used a cathode of fusible metal such as tin, or tin-lead alloy, or other conductive or conductivelycoated material. No preliminary treatment is essential, but if the cathode contains tin or the like, and is first treated in the cyanide bath, a part of the tin or the like adheres during the subsequent melting out so that a tube tinned &c. internally is obtained. The melting out may be effected in a vertical furnace after the tube has been coiled to a helix, air pressure being applied at the upper end of the tube. The Claims also mention the cleaning of cathodes by steam after deposition. This subject-matter does not appear in the Specification as accepted.