GB440183A - Improvements relating to the deposition of metal by electrode dispersion - Google Patents

Abstract

440,183. Depositing metal by electric discharge. CATHODE CORPORATION, Ltd., Great North Road, Barnet, Hertfordshire, WHISTON, H. W., Sutton Grange, near Macclesfield, Cheshire, McIVOR, G. A. B., and THEIN, F. W. N., Great North Road, Barnet, Hertfordshire. April 21, 1934, No. 12066. [Class 41] [See also Group IX] A length of thread to be coated with metal by cathode dispersion is supported on a framework within a vacuum chamber with electrodes mounted inside and outside the frame. In the apparatus shown, the frame consists of a number of notched ribs mounted in slots in upper and lower rings 5. The rings 5 are supported by curved arms 15 united to form a hub 16 keyed to a spindle 14 which is mounted in bearings 19, 21 and passes through a mercury-sealed gland 25. The spindle may be rotated at 10 or 20 revolutions per minute. The frame is provided with a handle 6 whereby it may be withdrawn from the chamber 1 on removal of the coverplate. The external electrodes consist of three upper and three lower arcuate tubes 9 connected by vertical tubes 9a for the circulation of cooling water, which may be supplied by hollow external conductors 7. The internal electrodes consist of semicircular tubes 12 connected by vertical tubes 12<a> and are connected to hollow conductors 10 through which cooling water may also be circulated. Alternatively, the electrodes may consist of thin rods or wires suspended from arcuate members. They may have surfaces of gold, silver or platinum. The thread should be spaced widely on the frame with as little area of contact as possible. After treatment it may be re-wound and re-treated for covering any uncovered parts. Alternatively, auxiliary ribs may be provided on the frame to which the thread is transferred after a time. When alternating current is employed the external electrodes are connected to one pole and the internal electrodes to the other. When direct current is employed all the arcuate electrodes are connected as cathodes, and a short electrode introduced through the bottom below one of the lower tubes 12 is connected as anode ; this electrode may also be water-cooled. Threads of cellulose acetate or other artificial silk or of regenerated viscose may be coated. Threads coated by this method may be twisted to form a multiple thread or may be used for covering a core of hemp or rubber latex.