Apparatus and method for dispensing electrically conductive coating material including a pneumatic/mechanical control

Apparatus for supplying and dispensing electrically conductive coating material, comprising:

• a coating dispenser having an actuator which is movable to an operating position to initiate discharge of coating material therefrom, said coating dispenser employing pressurized air in the operation thereof;
• a pneumatic operated pump for receiving coating material, and for transmitting the coating material to said coating dispenser;
• a voltage block, including:
• (i) a first coupling element adapted to be connected to a source of coating material;
• (ii) a second coupling element connected to said pneumatic operated pump and mateable with said first coupling element;
• (iii) a pneumatic actuator operative to move said second coupling element to a transfer position coupled to said first coupling element, and to a neutral position spaced from said first coupling element;
• a high voltage electrostatic power supply means for applying an electrostatic charge to the coating material which is discharged from said coating dispenser;
• a control valve, connected to a source of pressurized air, which is operative in response to movement of said coating dispenser actuator to said operating position, to:
• (i) transmit pressurized air to said coating dispenser;
• (ii) transmit pressurized air to said pneumatic actuator so that said second coupling element is moved to said neutral position;
• and
• (iii) transmit pressurized air to said pneumatic operated pump to cause coating material to be supplied to said coating dispenser.

Apparatus for supplying electrically conductive coating material to a coating dispenser having an actuator movable to an operating position to initiate discharge of the coating material therefrom and employing pressurized air in the operation thereof, said apparatus comprising:

• holding means for receiving coating material, said holding means being adapted to transmit coating material to the coating dispenser;
• voltage block means including a first coupling element movable in response to operation of a pneumatic actuator to a first position at which coating material is transmitted from a source of coating material to said holding means, and to a second position at which said holding means is electrically isolated from the source of coating material;
• a high voltage electrostatic power supply means for applying an electrostatic charge to the coating material;
• a control valve, connected to a source of pressurized air, which is adapted to operate in response to movement of the coating dispenser actuator to the operating position, to:
• (i) transmit pressurized air to the coating dispenser;
• and
• (ii) transmit pressurized air to said pneumatic actuator of said voltage block means to cause said first coupling element thereof to move to said second position.

In an apparatus for supplying electrically conductive coating material from a source, through a voltage block to a coating dispenser, a control valve comprising:

• a valve body formed with a first passageway having an inlet adapted to connect to a source of pressurized air, and an outlet adapted to connect to the coating dispenser;
• said valve body being formed with a second passageway having an inlet connected to said first passageway and an outlet adapted to be connected to the voltage block;
• first means, located in said first passageway, which is movable to an open position in response to actuation of the coating dispenser to permit the flow of pressurized air from the source of pressurized air, through said first passageway and to the coating dispenser;
• second means, located within said second passageway, which is responsive to movement of said first means to said open position to permit a flow of pressurized air from said first passageway, through said second passageway to the voltage block so that the source of coating material is electrically isolated from the coating dispenser.

A method of supplying and dispensing electrically conductive coating material, comprising:

• transmitting coating material from a source, through temporarily connected coupling elements, to a holding means;
• activating a coating dispenser;
• transmitting a first flow of pressurized air in response to actuation of the coating dispenser from a control valve to the coating dispenser;
• emitting a second flow of pressurized air from said control valve, in response to the transmission of said first flow of air therefrom, to cause the coupling elements to temporarily disengage from one another;
• initiating the flow of coating material from the holding means to the coating dispenser;
• and
• applying an electrostatic charge to the coating material discharged from the coating dispenser.