Apparatus for dispensing conductive coating materials including color changing capability

A method of supplying electrically conductive coating material of two or more colors to coating dispensers, comprising:

• transferring coating material of a first color from a first supply to first and second reservoirs;
• transferring said first color of coating material from said first and second reservoirs to a first flow control valve;
• transferring coating material of a second color from a second supply to third and fourth reservoirs;
• transferring said second color of coating material from said third and fourth reservoirs to a second flow control valve;
• transferring said first color of coating material from said first or second reservoirs through said first flow control valve to a color change manifold;
• transferring said second color of coating material from said third or fourth reservoirs through said second flow control valve to said color change manifold;
• operating said color change manifold to send said first or second color of coating material therethrough to said coating dispensers;
• electrically isolating from their respective first or second supplies whichever of said first, second, third, or fourth reservoirs is supplying coating material to said color change manifold;
• and
• electrostatically charging the coating material sprayed from said coating dispensers.

The method of transmitting electrically conductive coating material to at least one electrostatic coating dispenser, comprising:

• supplying coating material to a first holding means from a first transfer unit which is connected to the source of coating material and to the coating dispenser, said transfer unit maintaining the first holding means electrically isolated from the coating dispenser which coating material is supplied to the first holding means;
• supplying a second holding means with coating material from a second transfer unit which is connected to the source of coating material and to the coating dispenser, said transfer unit maintaining the second holding means electrically isolated from the coating dispenser while coating material is supplied to the second holding means;
• transferring coating material from one of the first and second holding means to the coating dispenser while maintaining said one holding means electrically isolated from the source;
• and
• switching the flow of coating material transferred to the coating dispenser to the other of the first and second holding means when said one holding means is depleted of coating material.

The method of transmitting electrically conductive coating material to at least one electrostatic coating dispenser, comprising:

• supplying coating material to a first pump from a source of coating material while maintaining the first pump electrically isolated from the coating dispenser, the first pump having a reservoir and a piston movable within the reservoir;
• supplying a second pump with coating material from the source while maintaining the second pump electrically isolated from the coating dispenser, the second pump having a reservoir and a piston movable within the reservoir;
• transferring coating material from one of the first and second pumps to the coating dispenser while maintaining said one pump electrically isolated from the source;
• switching the flow of coating material transferred to the coating dispenser to the other of the first and second pumps when said one pump is depleted of coating material;
• terminating the supply of coating material to each of the first and second pumps, and the transmitting a flushing fluid to the first and second pumps;
• and
• alternately moving the piston of each of the first and second pumps in one direction and then in the opposite direction while flushing fluid is present within the reservoirs thereof to clean coating material from the reservoirs.

The method of transmitting electrically conductive coating material to at least one electrostatic coating dispenser, comprising:

• supplying coating material to a first holding means from a source of coating material while maintaining the first holding means electrically isolated from the coating dispenser;
• supplying a second holding means with coating material from the source while maintaining the second holding means electrically isolated from the coating dispenser;
• transferring coating material from one of the first and second holding means to the coating dispenser while maintaining said one holding means electrically isolated from the source;
• switching the flow of coating material transferred to the coating dispenser to the other of the first and second holding means when said one holding means is depleted of coating material;
• and
• circulating coating material through the first and second holding means to and from the source when the coating material is not being discharged from the coating dispensers.

Apparatus for transmitting electrically conductive coating material to at least one electrostatic coating dispenser, comprising:

• first and second pumps each having a reservoir formed with an inlet and an outlet;
• first transfer means for supplying coating material to said first pump, said first transfer means including:
• (i) a filling station adapted to be connected to a source of coating material;
• (ii) a discharge station spaced from said filling station;
• and
• (iii) a first shuttle movable between said filling station and said discharge station, said first shuttle being connected to said inlet and outlet of said first pump and being releasably couplable to each of said filling and discharge stations, said shuttle being effective to permit the transfer of coating material into said reservoir of said first pump when coupled to said filling station and to permit the transfer of coating material from said pump reservoir when coupled to said discharge station;
• second transfer means for supplying coating material to said second pump, said second transfer means including:
• (i) a filling station adapted to be connected to a source of coating material;
• (ii) a discharge station spaced from said filling station;
• (iii) a second shuttle movable between said filling station and said discharge station, said second shuttle being connected to said inlet and outlet of said second pump and being releasably couplable to each of said filling and discharge stations, said shuttle being effective to permit the transfer of coating material into said reservoir of said second pump when coupled to said filling station and to permit the transfer of coating material from said pump reservoir when coupled to said discharge station;
• flow control means, connected to said discharge station of each of said first and second transfer means, for sequentially transmitting coating material supplied from said first pump and said second pump through their associated discharge stations to at least one coating dispenser.

Apparatus for transmitting electrically conductive coating material to at least one electrostatic coating dispenser, comprising:

• first and second pumps each having a reservoir formed with an inlet and an outlet;
• a first transfer unit for supplying coating material to said first pump, said first transfer unit including:
• (i) a filling station connected to a source of coating material;
• (ii) a discharge station spaced from said filling station;
• and
• (iii) a first shuttle releasably couplable to said filling station and to said discharge station, said shuttle being connected to said inlet and to said outlet of said first pump;
• a second transfer unit for supplying coating material to said second pump,
• (i) a filling station connected to the source of coating material;
• (ii) a discharge station spaced from said filling station;
• and
• (iii) a second shuttle releasably couplable to said filling station and to said discharge station, said second shuttle being connected to said inlet and to said outlet of said second pump;
• filling control means, associated with each of said first and second transfer means, for moving said shuttle of each of said first and second transfer means to their respective filling stations in response to depletion of coating material from said reservoir of said first and second pumps, respectively;
• discharge control means, associated with each of said first and second transfer means, for moving said shuttle of each of said first and second transfer means to their respective discharge stations in response to filling of said reservoir of said first and second pumps, respectively, with coating material;
• flow control means, connected to said discharge station of each of said first and second transfer means and to at least one coating dispenser, for sequentially transmitting coating material to the coating dispenser from said reservoir of said first pump through said discharge station of said first transfer means, and then to the coating dispenser from said reservoir of said second pump through said discharge station of said second transfer means.

Apparatus for supplying electrically conductive coating material, comprising:

• a first reservoir and a second reservoir each adapted to connect to a source of electrically conductive coating material;
• flow control means for connecting said first and second reservoirs to at least one coating dispenser;
• means for alternatively transmitting coating material from said first reservoir and from said second reservoir through said flow control means to the coating dispenser for discharge onto a substrate;
• means for charging the coating material discharged from the coating dispenser;
• first means movable to a first position for electrically isolating said first reservoir from the source of electrically conductive coating material when said first reservoir is receiving coating material from the source, and second means movable to a second position for electrically isolating said second reservoir from the source of electrically conductive coating material when said second reservoir is receiving coating material from the source.

Apparatus for transmitting electrically conductive coating material to at least one electrostatic coating dispenser, comprising:

• first and second pumps each having a reservoir formed with an inlet and an outlet;
• a first transfer unit for supplying coating material to said first pump, said first transfer unit including:
• (i) a filling station connected to a source of coating material;
• (ii) a discharge station spaced from said filling station;
• and
• (iii) a first shuttle releasably couplable to said filling station and to said discharge station, said shuttle being connected to said inlet and to said outlet of said first pump;
• a second transfer unit for supplying coating material to said second pump, said second transfer unit including:
• (i) a filling station connected to the source of coating material;
• (ii) a discharge station spaced from said filling station;
• and
• (iii) a second shuttle releasably couplable to said filling station and to said discharge station, said second shuttle being connected to said inlet and to said outlet of said second pump;
• flow control means, connected to said discharge station of each of said first and second transfer units and to a coating dispenser, for sequentially supplying coating material from said first pump and then from said second pump to said coating dispenser for deposition onto a substrate;
• circulation means for circulating coating material from the source of coating material, through each of said first and second transfer units, and back to said source, when said coating dispenser is not dispensing coating material.

Apparatus for supplying electrically conductive coating material to at least one coating dispenser, comprising:

• a color changer connected to at least one coating dispenser;
• a number of parallel, voltage block systems each connected to said color changer and to a separate source of electrically conductive coating material, each of said voltage block systems including:
• (i) a first reservoir and a second reservoir each adapted to connect to a source of electrically conductive coating material;
• (ii) flow control means for connecting said first and second reservoirs to at least one coating dispenser;
• (iii) means for alternatively transmitting coating material from said first reservoir and said second reservoir through said flow control means to the coating dispenser for discharge onto a substrate;
• (iv) means for charging the coating material discharged from the coating dispenser;
• and
• (v) means for electrically isolating said first reservoir from the source of electrically conductive coating material when said first reservoir is supplying coating material through said flow control means to the coating dispenser, and means for electrically isolating said second reservoir from the source of electrically conductive coating material when said second reservoir is supplying coating material through said flow control means to the coating dispenser.