An electrostatic spray gun (10) for the spray application of electrically conductive materials includes a shield (24) to prevent the build-up of electrically conductive flash deposits on preselected non-conductive surface areas (26) of the gun (10). By prohibiting the build-up of electrically conductive flash on preselected areas of the gun surface, the shield (24) is effective in preventing the completion of an electrical circuit between a charged electrode (18) and an electrically grounded gun support member (22). The gun of the present invention is particularly effective in the high volume spray deposition of electrically conductive paints.
A tip guard is provided for protecting an airless spray tip and preventing accumulation of paint on the tip guard. The tip guard has two pair of vanes extending forwardly and radially outwardly from a base, each a pair of vanes being joined by a crossbar. A pointed edge faces radially inwardly from each of the vanes and the crossbar and, generally, planar sides are provided to each plane, thereby allowing air flow through the side of the tip guard and preventing buildup of paint on the surface of the tip guard.
An apparatus for transferring electrically conductive coating materials such as water-based paint from a source to an electrostatically charged dispenser includes first and second shuttle devices and two large reservoir, piston pumps. The first shuttle device is movable between a neutral position wherein the first shuttle is electrically isolated from the filling station, and a transfer position wherein coating material is transmitted from the source to one of the piston pumps through a coupling device which connects the filling station and first shuttle. The second shuttle device is movable with respect to a discharge station between an neutral position wherein the second shuttle is spaced from the discharge station, and a transfer position wherein coating material is transmitted from the filled piston pump, through another coupling device which connects the second shuttle and discharge station and then to the second piston pump for transmission to one or more electrostatic coating dispensers. Movement of the shuttle is controlled to maintain one of the shuttles in the neutral position while the other is at the transfer position.
An apparatus for transferring electrically conductive coating materials such as water-based paint from a source to an electrostatically charged dispenser includes first and second shuttle devices and two large reservoir, piston pumps each having structure for preventing contamination of the coating material and pressure build-up at their piston heads. The first shuttle device is movable between a neutral position wherein it is electrically isolated from a filling station connected to the coating material source, and a transfer position wherein coating material is transmitted to one of the piston pumps through a coupling device which connects the filling station and first shuttle. The second shuttle device is movable with respect to a discharge station between a neutral position wherein the second shuttle is spaced from the discharge station, and a transfer position wherein coating material is transmitted from the filled piston pump, through another coupling device which connects the second shuttle and discharge station and then to the second piston pump for transmission to one or more electrostatic coating dispensers. Movement of the shuttle is controlled to maintain one of the shuttles in the neutral position while the other is at the transfer position.
An apparatus is provided for transferring electrically conductive coating materials, such as water-based paint, from at least one source to one or more coating dispensers for discharge onto a substrate. One voltage block is provided to avoid the creation of an electrical path between one or more sources of coating material and the coating material which is electrostatically charged during a coating operation, and a secondary voltage block is provided between each of a number of individual spray guns and the charged coating material so that each spray gun can be electrically isolated from the charged coating material when not is use. The apparatus is optionally provided with a color changer, and/or a heater which is electrically isolated from the charged coating material and is effective to elevate the temperature of the coating material prior to discharge from the spray guns.
An electrostatic spray gun for spraying solid particulate powder materials while entrained in a gas medium, including an electrically non-conductive housing having an electrode extending forwardly therefrom and a straight electrically non-conductive powder transport tube adjustably and replaceably mounted within the housing so as to enable the discharge end of the tube to be positionably adjusted relative to the electrode or to be replaced with a tube of differing internal diameter so as to vary the transport velocity at which the powder is emitted from the discharge end of the tube.