Electrostatic coating apparatus

Claim 1

IN AN ELECTROSTATIC COATING APPARATUS, A SUPPORT FOR AN ARTICLE TO BE COATED, CONVEYOR MEANS FOR MOVING SAID SUPPORT AND AN ARTICLE SUPPORTED THEREBY ALONG A PREDETERMINED PATH THROUGH A COATING ZONE, MEANS FOR CREATING IN THE COATING ZONE A SPRAY OF COATING-MATERIAL PARTICLES BEARING ELECTRICAL CHARGES OF THE SAME POLARITY, SAID SUPPORT HAVING AN ARTICLE ENGAGING PORTION AND BEING ELECTROCONDUCTIVE TO MAINTAIN A SUPPORTED ARTICLE AT A PARTICLEATTRACTING POTENTIAL, SAID SUPPORT BEING PROVIDED WITH A PERMANENT SHEATH OF INSULATING MATERIAL ENCASING ALL PORTIONS OF THE SUPPORT EXPOSED TO THE COATING ZONE EXCEPT THAT SUPPORT-PORTION ENGAGED BY THE ARTICLE, AND MEANS INCLUDING A DISCHARGE ELECTRODE DISPOSED AT ONE SIDE OF SAID PATH AND AT A POINT THEREALONG ANTERIOR TO THE COATING ZONE FOR IMPRESSING ON EACH OF SAID SHEATHS PRIOR TO ITS ENTRY INTO THE COATING ZONE AN ELECTRICAL SURFACE CHARGE OF THE SAME POLARITY AS THAT BORNE BY THE COATING-MATERIAL PARTICLES, SAID SHEATH BEING SUFFICIENTLY NON-CONDUCTIVE TO MAINTAIN SUCH IMPRESSED SURFACE CHARGE FOR THE DURATION OF ITS PASSAGE TO AND THROUGH THE COATING ZONE, WHEREBY THE CHARGED PARTICLES OF COATING MATERIAL WILL BE ELECTROSTATICALLY REPELLED FROM THE SHEATH.