Electrostatic coating method and apparatus

Claim 1

A METHOD OF COATING AN EXTERIOR SURFACE OF A HOLLOW ARTICLE OF NON-CONDUCTIVE MATERIAL WHICH COMPRISES THE STEPS OF CREATING IN SPACED RELATION FROM AND SUBSTANTIALLY WITHIN THE BOUNDARIES OF THE INTERIOR SURFACE OF SAID ARTICLE A LOCALIZED ZONE OF CORONA DISCHARGE OF PREDETERMINED POLORITY TO ESTABLISH INTERNALLY OF THE ARTICLE AND SUBSTANTIALLY THROUGHOUT ITS CONFINES A CLOUD OF CHARGE ATMOSPHERIC PARTICLES, SIMULTANEOUSLY CREATING IN SPACED RELATION FROM THE EXTERIOR SURFACE OF THE ARTICLE AN IONIZING ZONE OF CORONA DISCHARGE OF OPPOSITE POLOARITY TO THAT OF THE ATMOSPHERIC PARTICLES WITHIN SAID ARTICLE, INTRODUCING A GASEOUS DISPERSION OF PARTICLED COATING MATERIAL INTO THE IONIZING ZONE EXTERIOR OF SAID ARTICLE TO FORM A CLOUD OF COATING MATERIAL PARTICLES CHARGED OPPOSITELY TO THE INTERNAL ATMOSPHERIC PARTICLES, AND ESTABLISHING ACROSS THE NONCONDUCTING WALLS OF THE ARTICLE AN ELECTRIC FIELD WHEREBY THE INTERNAL ATMOSPHERIC PARTICLES WILL BE ATTRACTED TO THE INTERNAL SURFACES OF THE WALL AND THE EXTERNAL COATING MATERIAL PARTICLES WILL BE ATTRACTED TO THE EXTERNAL SURFACES OF THE WALL.