Patent ID: 8365659

Claim:
An apparatus for screen printing on a convex surface, the apparatus comprising: a stamp head having a cylindrical wall that defines a stamp chamber and a covering surface that closes a first end of the stamp chamber; a tampon for containing stamp ink, disposed within the stamp head, having a convex-curved pressure surface; a removable, replaceable convex-curved, small screen printing plate that is releasably fastened on the stamp head and stretched across the tampon pressure surface so as to close off a second end of the stamp chamber; and a small screen printing plate mounting that is structured and arranged in the form of an annular wall and having a radially inwardly directed pressure surface that removably attaches the small screen printing plate to the stamp head and stretches the small screen printing plate across the tampon pressure surface, wherein the small screen printing plate is adapted to invert from a convex-curved shape to a concave-curved shape so that some portion of the small screen printing plate is introduced into the stamp chamber when said small screen printing plate contacts the surface of the convex surface, wherein inversion of the small screen printing plate from a convex-curved shape to a concave-curved shape causes compression of the tampon housed within the stamp head and the stamp ink contained therein to pass through the small screen printing plate and onto the convex surface, and wherein the stretch imparted on the small screen printing plate by the mounting constrains the concave-curved shape of the small screen printing plate to optimize the printing of the stamp ink onto the convex surface.