| 摘要 |
802,929. Electroplating with copper. SYLVANIA ELECTRIC PRODUCTS, Inc. Feb. 27, 1956 [March 2, 1955], No. 6080/56. Class 41. [Also in Group XL (a)] The turns of a molybdenum or tungsten wire helix 22 of a travelling - wave tube (see Group XL (a)) are fixed in position in relation to supporting edges formed in a surrounding vitreous support 16 by means of an electroplated layer of copper which increases the outer diameter of the helix in relation to the bore in the support. Three copper wire anodes 36a, 36b and 36c are supported by external clamps and placed under tension by spring-loading to prevent shorting against the helix 22 serving as the cathode. A high-speed plating solution employed comprises essentially copper cyanide, potassium thiocyanate, potassium hydroxide and free potassium cyanate. The temperature is maintained at 80‹ C. and the current density at 100 amps./ sq. ft. A plating time of 15 to 20 minutes is sufficient to build up the necessary layer. |
