Method for applying an internal coating to a cathode ray tube

Abstract

Abstract Apparatus for applying Adquadag coating to the funnel of a cathode ray tube envelope comprises means for supporting the envelope with the sealing land exposed, and means for spraying an Aquadag solution upon the wall of the funnel. A deflector is interposed between the spray means and the edge of the funnel to intercept that portion of the spray directed toward that edge while another member is positioned adjacent the inside wall of the funnel to establish an orifice between that member and that portion of the funnel wall normal to the sealing land. The envelope supporting means is rotated, relative to the spray means, to apply a uniform coat of Aquadag upon the funnel while an air pump establishes a pressure differential between the inside of the envelope and the outside to generate a flow of air across the sealing land of the funnel, up through the orifice and into the funnel to prevent deposit of coating material upon the sealing land. The invention also contemplates a method, utilizing the above described apparatus, for applying an Aquadag material to the funnel section of a cathode ray tube while maintaining the sealing land free of material.

Inventors

• 👤 D Nuehring

Bibliographic Details