GB178067A - Improvements in or relating to apparatus for electrical etching - Google Patents

Abstract

178,067. Weeks Photo-Engraving Co., Inc., (Assignees of Weeks, R. M.). April 2, 1921, [Convention date]. Void [Published under Sect. 91 of the Act]. Electrodes; metals, removing.-In etching by electrolysis the plate to be etched is suspended in a bath of electrolyte in which is submerged a cathode formed from a material, preferably silver, which is resistant to etching and electrolytic action and which will minimize the generation of hydrogen. Special means are described for suspending the plate. As shown, the plate v is supported in an inverted position in a tank a containing an electrolyte by forked supports k, Fig. 5, provided with notches l to receive the plate and adjustably bolted to hangers g connected by a bar i and hooked over a rod f adjustably secured to positive bus-bars c. A negative bus-bar e encircles the tank. Resting on the bottom of the tank is a wooden frame n supporting a number of carbon plates o electrically connected together by loops of silver wire. Spaced above the plates o is a silver plate q having its edges turned over the frame and being connected by silver wires r to the plates o and by silver wires s to the negative bus-bar e. The plates q and o form the cathode and any hydrogen bubbles formed on the plates o are prevented from rising by the plate q. The carbon plates o are provided to expedite the etching, but they may be omitted, the silver plate q alone forming the cathode. Further, to expedite the etching, carbon plates t connected to the leads s may be hung round the sides of the tank. The rod f, hangers g, and bar i are made of copper and the supports k of silver.