Cathode head

Claim 1

A cathode head for holding a flat record matrix of a first diameter during electroforming of a replica of a second diameter on the surface of the matrix, said cathode head comprising in combination: a disc shaped support member, a cathode plate, and a lock ring member, said support member being made of a dielectric material and being of a diameter at least as large as said first diameter and having a circular cavity defined in a face thereof having a diameter of at least the second diameter but less than the diameter of the support member, said cathode plate being a disc-shaped member comprised of an electrically conductive material selected from the group consisting of stainless steel, nickel, and titanium and being of a thickness sufficient to reduce the current density during electroforming a replica on the matrix so as to prevent burn outs of said matrix during electroforming, said cathode plate further having a flat face portion and a configuration which mates with the configuration of said cavity, said cathode plate being positioned within said cavity with the flat face portion positioned so as to receive said matrix; said lock ring member being made of a dielectric material and having means for engaging and locking in a liquid-tight seal on the outer edge of said disc-shaped member and having an inner diameter of said second diameter whereby when a matrix is placed on the flat faced portion of the cathode plate and the lock ring member is engaged and tightened on the disc-shaped member the matrix is forced into liquid-tight electrical contact with the cathode plate.