Work holder for electrochemical abrading machine

Claim 1

A work-holder device for use with an electro-chemical apparatus comprising: rotatable base means including a plate-like mounting portion of electrically conductive material, said mounting portion having a substantially horizontal and upwardly directed support surface thereon adapted to have at least one work-holding fixture mounted thereon for permitting the mounting of a workpiece on said base means; post means fixedly connected to and extending vertically upwardly from the central portion of said base means for conducting current thereto, said post means including a first annular member fixedly secured to said electrically conductive mounting portion and extending upwardly from said support surface, said first member having a first contact surface positioned adjacent the upper end thereof and facing upwardly, said first contact surface being positioned a substantial vertical distance above said support surface; said post means also including a second member, at least a lower portion of which is cylindrical, positioned above said first member and having a downwardly directed second contact surface adjacent the lower end thereof and disposed in rotatable slidable bearing engagement with said first contact surface, said first and second members being of electrically conductive material whereby electrical current supplied to said second member is conducted therefrom through said first member to said electrically conductive mounting portion; resilient holding means coacting between said first and second members for axially securing said first and second meMbers together while permitting relative rotation therebetween, said resilient holding means normally maintaining said first and second contact surfaces in snug slidable engagement with one another; and protective sleeve means surrounding at least the mutually adjacent ends of said first and second members for preventing electrolyte used in the electro-chemical operation from contacting the first and second contact surfaces, said protective sleeve means including an elongated thin-walled hollow sleeve constructed of nonmetallic material which is substantially chemically inert and nonconductive, an upper portion of said hollow sleeve being snugly and sealingly received in surrounding relationship on said cylindrical portion of said second member, the remaining portion of said hollow sleeve being positioned in surrounding relationship to said first member for permitting said first member to freely rotate within said sleeve, the lower end of said sleeve being disposed closely adjacent the upper surface of said plate-like mounting portion.