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...http://www.google.se/patents/US4228961?utm_source=gb-gplus-sharePatent US4228961 - Electrostatic power painting head
