Abstract: A method and apparatus are disclosed for the spraycoating of the interior of a hollow body, one region of which, e.g. a seam, must receive a heavier coating than the remainder of the surface to be sprayed. A single spray coating operation is performed, in which a relatively heavy spray jet is concentrated on the seam and a relatively thin cloud of coating material is used to coat the entire interior surface of the body. Preferably, a cloud of electrostatically charged coating material is formed by an atomizer fed by a feed conduit from which a certain amount of coating material is diverted to be formed into the relatively highly concentrated spray jet directed at the seam. The relatively high-velocity particles of material of the spray jet which is concentrated onto the seam and the relatively low-velocity particles of material of the coating cloud together produce on the seam a thinner layer of material than would normally suffice and which, nonetheless, adheres well.

Abstract: A jet device for depositing fluid drops upon a moving fluid receiving medium, such as a fabric web, includes a coating head defining a fluid receiving reservoir and including an orifice plate defining a row of orifices which communicate with the fluid receiving reservoir. Fluid is supplied to the reservoir under pressure such that the fluid flows through each of the orifices and emerges therefrom as a fluid filament. The fluid filaments are stimulated to break up into jet drop streams. A charging plate of electrically conductive material defining a charging slot for charging drops formed from the fluid filaments is mounted adjacent and aligned with the coating head means such that the fluid filaments extend into the charging slot of the charging plate and break up of each of the filaments occurs within the slot.

Abstract: This invention is in an improvement in electrostatic spraying apparatus for coating objects with electrostatic powder, or dust. The apparatus includes a housing or body member having a discharge nozzle at one end and internal flow passages for conducting compressed gas supplied from an external source to the discharge nozzle and a deflector element coaxially disposed adjacent the discharge end of the nozzle. A source of powder or dust is provided and is mixed with the compressed gas to produce a powder gas mixture which is fed to the flow passage. Electrodes connected to a high voltage source are provided within the flow passage and at the discharge end of the nozzle to ionize the powder gas mixture. The invention provides a hollow oval shaped charging chamber within the nozzle communicating with the flow passage so that the powder gas mixture passes therethrough and is ionized therein.

Abstract: An electrostatic powder painting gun head in which a needle electrode is provided at a central portion in the proximity of a cylindrical powder ejection port made of insulator, an annular strip electrode is disposed outside of the powder ejection port, also a gas injection port for forming a gas flow layer along the surface of the annular strip electrode is provided, and further there is provided a high voltage power supply for applying a predetermined voltage between the needle electrode and the annular strip electrode.

Abstract: The disclosed gun is of the type having a housing with a nozzle and a deflecting plate spaced from the muzzle and mounted on a rod axially guided in the muzzle, the annular channel formed between the muzzle and the rod serving as a powder channel. Electrodes extend into the powder channel and are connected to a high voltage source. A stepping motor is connected to the rod to change its axial position, and control means are connected to the motor. Digital circuits inside the housing and manually operable switches permit automatic control or manual control from the gun of the deflecting plate spacing, the voltage, and the powder feed. Indicating means on the gun display the values of the controlled parameters.

Abstract: An electrostatic spray gun for powdered material in which separate connecns for supplying powder and compressed air are provided together with a spray tube and spray nozzle. A charging device charges the powder electrostatically. The connections for the powder and compressed gas supply are held in a common housing portion. A gun barrel, together with spray nozzle, constitute nested hollow members fastened to the front of the housing. A barrel head on an outer end of the gun barrel holds the spray nozzle to the outer end of the spray tube which is fastened axially and radially to the housing by an exterior barrel tube. A spacer which encloses the spray tube is held on both ends and is fixed to rotate with housing and barrel head.

Abstract: In this arrangement a circuit is provided for generating deflection voltges for the coloring material marking the insulation of electrical conductors as the electrical conductors are extruded which compensate for distortions in the shape of color ring insulation markings when large ring spaces or high conductor extrusion speeds are employed. Two spaced spray nozzles to provide two steams of color material. These nozzles are disposed on oposite sides of the extruded electrical conductor, each of the spray nozzles provide one half of the color rings. The deflection voltage consists of a rectangular waveform with a semicircular top portion. A high resistance potentiometer is connected between the two spray nozzles with the wiper of the potentiometer connected to a high DC voltage source. Adjustment of the wiper renders the amplitudes of the two streams of color material equal.