Apparatus for electropolishing tubes

Claim 1

Apparatus for electropolishing the inner surface of a metallic tube comprising: a metallic lance adapted to be inserted in the tube; at least two electrically insulating spacer elements mounted on said lance in longitudinally spaced relation therealong, with the exposed surface of said lance between said elements constituting a metal cathode, said elements being of an overall dimension about the same as that of the interior diameter of the tube so that said elements serve to center said lance, and particularly said cathode, within said tube, the forward one of said elements being constructed to provide passageways therethrough for the out flow of electrolyte from the annular space between said cathode and the tube, and the rearward one of said elements and said lance being provided with passageways therethrough for flow of electrolyte from within said lance through said passageways and out of said rearward element forwardly toward said forward spacer element; means connected to said lance rearwardly of said rearward element for supplying said lance passageway with liquid electrolyte a cell for containing liquid electrolyte with said lance projecting through a tube exit opening in the side wall of said cell with said rearward spacer element located substantially within said opening in closely spaced relation therewith; a tubular structure projecting from said wall interiorly of said cell forwardly of said rearward spacer element whereby the flow of liquid electrolyte therefrom minimizes or prevents flow of electrolyte out of said cell through said exit opening when no tube is present; means defining a tube entrance opening in the side wall of said cell opposite said exit opening; and means for minimizing or preventing flow of electrolyte out of said entrance opening when no tube is present comprising means for directing a jet-like flow of electrolyte into said entrance opening.