Abstract: A paint spraying apparatus on which a number of paint applicator units of different types can be selectively and replaceably mounted depending upon conditions of a paint coating operation required. A color changing valve assembly is provided in a valve casing which serves as a common base assembly for a number of paint applicator units to be chosen from, including rotary atomizing head type electrostatic paint applicator units and spray gun type electrostatic paint applicator units. Accordingly, depending upon conditions of coating operation, such as shape of a coating surface, nature of paint, properties of solvent etc., a suitable paint applicator unit, selected from the paint applicator units, can be easily and replaceably mounted in position on the valve casing. The color changing valve assembly which is provided within the valve casing can be shared as a common mount base by a plural number of paint applicator units of different types.

Abstract: A rotary atomizing head assembly employing a main body and a hub member which can be easily disassembled and reassembled whenever necessary. A ring engaging surface is provided on the inner peripheral side of a recessed hub socket on the main body, while a ring fitting groove is provided on the outer peripheral side of a cylindrical body portion of the hub member. With an O-ring set in the ring fitting groove, the cylindrical body portion of the hub member is fitted into the recessed hub socket, whereupon the hub member is resiliently retained on the main body of the rotary atomizing head by resilient retaining force of the O-ring. In this instance, the O-ring is pressed against the ring engaging surface to prevent dislocation of the hub member. On the other hand, the hub member can be disassembled from the main body by pulling the hub member in the axial direction to such a degree as to cause elastic deformation to the O-ring.

Abstract: A rotary atomizing head assembly of the present invention is capable of washing off paint deposits from outer peripheral surface of a bell cup in a reliable manner. A paint reservoir (15) which is provided on a bell cup (11) is communicated with the outer peripheral surface of the bell cup (11) through solvent passages (16), and an annular guide (17) is provided around the outer peripheral side of the bell cup (11). Therefore, at the time washing the rotary atomizing head assembly (10), a thinner which is spouted out from a nozzle (6) is introduced into a solvent diffusing chamber (18) which is formed between the bell cup (11) and a enlarged front portion (17B) of the annular guide (17), through the paint reservoir (15) and solvent passages (16).

Abstract: In a rotary atomizing head type coating machine, paint mist is prevented from depositing on a shaping air ring and synthetic resin cover. Shaping air ring includes an inner ring of a metallic material, an outer ring of an insulating synthetic resin material, and a shaping air outlet hole provided at the fore ends of the two rings. The inner ring has its base end electrically connected to an air motor, and provides an annular repulsion electrode at its fore end. This annular repulsion electrode induces strong positive discharges, thereby attracting clouds of negative ions, and preventing paint deposition on and contamination of the shaping air ring by a phenomenon of homopolar repulsions between clouds of negative ions and negatively charged paint particles.

Abstract: A spray gun type electrostatic paint coating machine which is capable of improving quality of coated surfaces, the coating machine including an air nozzle (8) and a paint nozzle (21) respectively provided at the fore end of a spray gun body (6). The spray gun body (6) and the air nozzle (8) are made of an electrically insulating material, while the paint nozzle (21) is made of a metallic material including a paint spouting orifice (21C) which is projected on the front side through the air nozzle (8). The paint spouting orifice (21C) is connected to ground through a paint supply passage (10) to serve as a grounding electrode. Sprayed paint particles are at the earth potential, so that they are less susceptible to influences of dielectric polarization and negatively charged quickly by the high negative voltage of the external electrode.