APPAREIL DESTINE A COMMANDE LE FONCTIONNEMENT D'UN PISTOLET DE PULVERISATION

摘要

A spray gun for spraying articles such as automobile bodies fed in succession is automatically controlled by a selectively operable valve having a plurality of liquid delivery ports and gun purging ports. The liquid delivery ports are connected one each to sources of liquid of different colors and the gun purging ports to a source of compressed gas and a source of solvent. A single hollow arm connected by a feed hose to the gun is movable relative to the ports of the valve under control of a program unit and a timer in a manner such that when the program unit signals the requirement for a change of color the timer causes the hollow arm to be moved from the current liquid delivery port first to the compressed gas gun purging port so that a slug of air is delivered into the hollow arm and then to the solvent gun purging port so that solvent is delivered to complete the emission of colored liquid from the arm, the feed hose, and the gun and to effect cleansing of these parts preparatory to the delivery of liquid of a different color. The compressed gas and solvent is fed at a pressure sufficient to maintain the feeding pressure of liquid remaining in the arm, the feed hose, and the gun until the liquid is emitted from the gun.