Voltage block system for electrostatic coating with conductive materials

Abstract

The disclosure relates to a voltage block system for delivering conductive coating materials continuously to electrically charged electrostatic paint spray devices from a primary paint supply system which is at ground potential. In a preferred form, the system utilizes cooperatively associated coating material transfer and inventory vessels. The inventory vessel is connected to the electrostatically charged spray devices and continuously supplies coating material thereto. The transfer vessel is alternatively coupled to the primary paint supply, in order to be replenished thereby, and with the inventory tank, in order to refill the inventory tank prior to its exhaustion. The inventory tank is maintained under a positive gas pressure both during refilling operations and at other times, so that coating material is always supplied to the spray devices under pressure. At all times, the primary paint supply is isolated from the high voltage. In a simplified, special purpose version, a single inventory tank is refilled during intervals between the arrival of successive workpieces on a continuously moving conveyor. In this version, the high voltage is turned off during refilling operations. The system lends itself well to production lines, where there is frequent need for changing from one color of coating material to another.

Dependencies are inferred from the claim text.