Electrostatic spray gun construction

Claim 1

A spray gun for use in the electrostatic spray coating of fluids wherein grounded articles are coated by having charged atomized spray particles electrostatically attracted toward and deposited thereon comprising means for atomizing liquid coating material and projecting the atomized coating mAterial towards an article to be spray coated, first conduit means for directing liquid coating material under pressure to said atomizing means including normally closed valve means for supplying the liquid coating material to said atomizing means when in open position, said valve means including seating surface means and closure means adapted to be displaced out of engagement therewith by a force having a magnitude at least as large as a preselected value whereby said valve will be opened, electrogasdynamic power generating means, second conduit means for directing a stream of pressurized air to said electrogasdynamic generating means for passage therethrough for charging the atomized spray particles and for maintaining an electrostatic depositing field having one terminus adjacent to locus of atomization, trigger means for controlling the flow of pressurized air to said electrogasdynamic generating means, pressure sensitive means operatively engaging said closure means and responsive to the trigger controlled flow of pressurized air having a pressure proximate thereto exceeding a predetermined value for applying a force at least as large as said preselected force to said valve closure means for opening said valve means said electrogasdynamic generating means having a minimum flow diameter selected to maintain a pressure proximate to said pressure sensitive means at least as large as said predetermined value, and third conduit means for exhausting the air discharged from said electrogasdynamic generating means from said spraying apparatus.