Abstract: A method and system for supplying electrically conductive coating materials to an electrostatic dispenser with a parallel arrangement of subsystems selectably coupled to the dispenser by a four-port system voltage blocking valve, which electrically isolates the subsystems. The subsystems each include first and second piston cylinders that alternatingly receive a selected coating material from a corresponding manifold and supply the coating material to the dispenser by a subsystem voltage blocking valve, which isolates the dispenser from the manifold, when coupled to the dispenser. The first and second piston cylinders of each subsystem also alternatingly receive a solvent from the corresponding manifold and direct the solvent to a waste receptacle by a corresponding subsystem voltage blocking valve when the subsystem is not coupled to the dispenser.
Type:
Grant
Filed:
May 15, 1996
Date of Patent:
March 10, 1998
Assignee:
Illinois Tool Works Inc.
Inventors:
Harold T. Allen, Edward T. Feldman, Varce E. Howe, Ghaffar Kazkaz, Jerry L. McPherson, Jr., James Scharfenberger