Electrostatic spray coating apparatus

Claim 2

In the apparatus of claim 1, the second named conductive means comprising a charging needle detachably secured to the stem and extending through the orifice.

Claim 3

In the apparatus of claim 1, the second-named conductive means comprising a combined charging needle and valve member detachably secured to the stem and adapted to be replaced to accommodate variation in valve characteristics and in the event of damage to the charging needle.

Claim 4

In the apparatus of claim 1, said power lead comprising a conductor terminating in an integral insulated probe, a resistor embedded in the insulated probe and connected at one end to the conductor, and quick detachable connection means embedded in the other end of the probe for connection with the first-named conductive means.

Claim 5

In electrostatic spray apparatus having an electrically insulating body including a material passage terminating in an outlet orifice, and a valve for opening and closing said orifice including an electrically insulating stem extending through said passage, the improvement comprising an electrically insulating material inlet communicating with said passage substantially immediately to the rear of said outlet orifice, an electrically conductive bellows in said passage substantially immediately to the rear of said inlet fixed at one end to the body and at its other end to the stem for sealingly closing said passage, electrically conductive stem means secured to said stem and said bellows at said other end of said bellows and extending to and through said orifice, and means for carrying a high electrostatic charge to said bellows and said conductive stem means to charge material passing from said inlet through said outlet.

Claim 6

In electrostatic spray apparatus having an electrically insulating body including a material passage terminating in an outlet orifice, a valve for opening and closing said orifice including an electrically insulating stem through said passage, and an electrically conductive normally grounded stem operating section mounted on said body at the end thereof remote from said orifice, the improvement comprising electrically insulating material inlet means spaced from said grounded section and communicating with said passage substantially immediately to the rear of said outlet orifice, means in said passage substantially immediately to the rear of said inlet for sealingly closing said passage, electrically conductive stem means secured to said stem forwardly of said sealing means and including a charging needle extending to and through said orifice, and means for carrying a high electrostatic charge to said conductive stem means to charge material passing from said inlet means through said outlet, said body and stem being elongate and said body, stem and inlet means being formed of high dielectric material for electrically isolating coating material from said grounded section whereby to accommodate spraying of both nonconductive and conductive coating materials.

Claim 7

In electrostatic spray apparatus having an electrically insulating body including a material passage terminating in an electrically insulating outlet orifice, and a valve for opening and closing said orifice including an electrically insulating stem extending through said passage, the improvement comprising a material inlet communicating with said passage substantially immediately to the rear of said outlet orifice, means in said passage substantially immediately to the rear of said inlet for sealingly closing said passage, electrically conductive stem means detachably secured to said stem forwardly of said sealing means and extending to and through said orifice, and means for carrying a high electrostatic charge to said conductive stem means to charge material passing from said inlet through said outlet, said sealing means comprising an electrically conductive bellows having an electrically conductive fitting at one end detachably but sealingly clamped between said stem and said conductive stem means, said passage including a shoulder, said bellows having a fitting at its other end engaging said shoulder, and means detachably secured in said passage sealingly clamping the second-named fitting to said shoulder, said bellows aiding in the electrical charging of the coating material and being readily replaceable in the event of damage thereto, said conductive stem means comprising a member including a valve for opening and closing said outlet orifice and a charging needle extending through said orifice, said member being detachably mounted on said stem for ready replacement in the event of damage to the charging needle and/or to accommodate variation in valve characteristics.

Claim 8

In electrostatic spray apparatus having a conductor for carrying a high electrostatic charge to the apparatus, an electrically insulating sheath thereabout, an electrically insulated tubular probe fixedly secured at one end thereof to said sheath, said sheath terminating within said probe and said conductor having a terminal portion projecting into said probe beyond said sheath but deeply seated within said probe, and a resistor inserted in the other end of said probe engaging the terminal of said conductor at one end thereof; the improvement comprising a terminal at the other end of said resistor located adjacent the end of but seated entirely within the probe and having therein quick detachable connection means for connection with the apparatus, and an insulating compound potting said resistor within said probe without airgaps.

Claim 9

Electrostatic spray apparatus comprising an electrically conductive normally grounded handle including a valve-operating trigger, an electrically insulating barrel and valve stem projecting forwardly from the upper end of the handle and the trigger, an electrically insulating nozzle assembly on the forward end of the barrel, a material inlet at the forward end of said barrel rearwardly of the nozzle assembly, an electrically insulating material supply tube inclined downwardly and rearwardly from the material inlet toward the lower end of the handle, conductive elements in the material-receiving portion of the barrel between said inlet and said nozzle assembly, means for carrying a high electrostatic charge to said conductive elements including an electrically insulating conductor-receiving tube generally paralleling said material supply tube, and a strap joining the lower ends of the handle and said tubes for physically supporting said tubes, said barrel, stem and material supply tube electrically isolating coating material from said grounded handle to accommodate spraying of both conductive and nonconductive coating materials.

Claim 10

The apparatus of claim 10, including a ground fitting on the lower end of said conductor-receiving tube and a ground sheath of said tube connected to said fitting, said strap being electrically conductive and conductively secured to said fitting and handle.