Electroplating method and apparatus

Claim 2

MOTHOD FOR SIMULTANEOUSLY ELECTROPLATING THE INTERIORS OF EACH OF A PLURALITY OF HOLLOW METAL WHICH COMPRISES, POSITIONING AN ANODE CENTRALLY WITHIN EACH OF THE HOLLOW OBJECTS BEING ELECTROPLATED, ELECTROCALLY CONNECTING SAID ANODES AND THE OBJECTS BEINGS BEING ELECTROPLATED IN SERIES WITH EACH OTHER AND WITH A SOURCE OF AN ELECTROLYZING CURRENT, CONTINUOUSLY SUPPLYING AN ELECTRICALLY CONDUCTIVE ELECTROLYTE SOLUTION FORM A COMMON SOURCE OF SUPPLY OF SAID SOLUTION TO THE INTERIOR OF EACH OF THE HOLLOW OBJECTS BEING ELECTROPLATED AND CONTINUOUSLY WITHDRAWING AND EQUIVALENT QUANTITY OF SAID SELECTROLYTE SOLUTION FROM EACH OF SAID OBJECTS AND RETURNING SAID SOLUTION TO SAID COMMON SOURCE OF SUPPLY, PASSING AN ELECTROLYZING CURRENT THROUGH THE SERIES OF ANODE AND ELECTROLYTE-CONTAINING OBJECTS, AND

Claim 3

The method according to claim 1 in which the solution inlet and solution outlet passageways connected to the objects being electroplated each comprises a separate length of non-conductive tubing, each of said lengths of tubing having a cross-sectional area and being of a length such that the resistance to the flow of an electrical current through the electrolyte solution contained in each length of tubing is sufficiently great that the magnitude of stray electrolyzing current flowing from any of said objects through the solution contained in said tubing is reduced to a value that will not significantly affect the electroplating operation taking place in other objects in the series.

Claim 4

The method according to claim 1 in which the required minimum ohmic value of the resistance to the flow of an electric current through the electrolyte solution contained in each passageway is determined by first determining the maximum variation in the thickness of the layer of electrodeposited metal that can be tolerated, by determining the amperage of stray currents required to plate or deplate a layer of metal equal in thickness to a layer of the prescribed tolerance, and by determining the minimum ohmic value required to prevent the amperage of the stray currents from exceeding tHe maximum amperage permitted.

Claim 5

Apparatus for simultaneously electroplating the interior surfaces of each of a plurality of hollow metal objects with a uniform layer of an electrodeposited metal which comprises: a plurality of serially disposed substantially identical hollow metal objects to be electroplated, a non-consumable anode centrally disposed within each of the hollow metal objects in the series, power supply means for supplying an electrolyzing current, and electrical conductor means electrically connecting the hollow metal objects and the anodes disposed therein in series with each other and with the electrolyzing current power supply means, a vessel adapted to contain a supply of electrolyte solution, an electrolyte solution supply conduit connected to the electrolyte solution supply vessel and to each of the hollow metal objects for supplying electrolyte solution to the interior of each of said hollow metal objects, and an electrolyte solution discharge conduit connected to each of the hollow metal objects and to the electrolyte solution supply vessel for withdrawing electrolyte solution from each of said objects and returning said solution to said supply vessel, the electrolyte solution supply conduit and discharge conduit connected to each hollow metal object comprising a length of tubing of electrically insulating material, said tubing having a cross-sectional area and having sufficient length such as to cause the resistance to the flow of an electric current through the elctrolyte solution contained in each of said lengths of tubing to be sufficiently great to reduce the magnitude of the electrolyzing current flowing therethrough from any of the objects being electroplated to a value that will not significantly affect the electroplating operation taking place in other objects in the series.

Claim 6

Apparatus for simultaneously electroplating the interior surfaces of each of a plurality of hollow metal objects with a uniform layer of an electrodeposited metal which comprises: a plurality of serially disposed substantially identical hollow metal objects to be electroplated, a non-consumable anode centrally disposed within each of the hollow metal objects in the series, power supply means for supplying an electrolyzing current, and electrical conductor means electrically connecting the hollow metal objects and the anodes disposed therein in series with each other and with the electrolyzing current power supply means, a vessel adapted to contain a supply of electrolyte solution, an electrolyte solution supply conduit connected to the electrolyte solution supply vessel and to each of the hollow metal objects for supplying electrolyte solution to the interior of each of said hollow metal objects, and an electrolyte solution discharge conduit connected to each of the hollow metal objects and to the electrolyte solution supply vessel for withdrawing electrolyte solution from each of said objects and returning said solution to said supply vessel, the electrolyte solution supply conduit and discharge conduit connected to each hollow metal object comprising a length of tubing of electrically insulating material, said tubing having a cross-sectional area and having sufficient length such as to cause the resistance to the flow of an electric current through the elctrolyte solution contained in each of said lengths of tubing to be sufficiently great to reduce the magnitude of the electrolyzing current flowing therethrough from any of the objects being electroplated to a value that will not significantly affect the electroplating operation taking place in other objects in the series.