Abstract: A spray gun includes a material inlet and an air inlet. A reciprocating hydraulic motor is connected to and drives a reciprocating hydraulic pump which pumps material from a material reservoir to the pump outlet. A first air piloted hydraulic valve is connected to the pump outlet and the first valve is connected to and is operable to transmit pumped material to either the material inlet of the gun or to the material reservoir. A second motor is connected to and drives a second hydraulic pump which is connected to and supplies hydraulic fluid from a hydraulic reservoir to the reciprocating hydraulic motor. A second air-piloted hydraulic valve is connected between the second hydraulic pump and reciprocating hydraulic motor and is operable to transmit pumped hydraulic fluid to either the reciprocating hydraulic motor or to the hydraulic fluid reservoir. An air control valve is connected to an air supply and is connected to the first and second valves.

Abstract: A pneumatic system is disclosed for regulating the acceleration and running speed of an air turbine and alternator used in electrostatic spray apparatus having a self-contained electrical power supply. The air turbine includes a rotor which is arranged to be biased in a first direction of rotation by a flow of impinging drive air and in a second opposite direction by a flow of impinging brake air. The flows of air cooperatively result in rotation of the turbine in a desired direction of operation and enable a minimized period of acceleration for a predetermined running speed.

Abstract: A hand-manipulable electrostatic spray gun is disclosed which is one requiring no electric cable attached to it. Within the hand-manipulable spray gun an air turbine is driven at high speed in the order of 60,000 rpm and drives directly an alternator to generate an alternating voltage in the order of 50 volts at about 1000 Hz. The output of this alternator is supplied to a step-up transformer to achieve a secondary voltage in the order of 2500 volts. From here, it is supplied to a long chain series voltage multiplier to increase the voltage thereof to one in the order of 55-80 kilovolts. The combination of a relatively small transformer and small capacitance establishes a direct voltage output from the voltage multiplier which has an alternating voltage ripple in excess of fifteen percent.

Abstract: A safety airless spray tip is disclosed having an integral guard extending from the forward end thereof to prevent accidental human injection by the liquid being sprayed. The guard comprises U-shaped wire members located on opposite sides of the spray opening to cooperatively define a protected three-dimensional space through which the emitted spray fan passes, the protected space being of sufficient dimension to prevent the injection of human skin pressed against the guard.

Abstract: An electrostatic spray gun apparatus for coating systems having an entirely self-contained light weight electrical power supply adapted to convert the kinetic energy available in a moving air stream into the required high d.c. potential and which dispenses with external electrical supply connections thereto.

Abstract: An improved energy converting and electric power generating system for electrostatic spray apparatus for coating systems adapted to convert the kinetic energy available in a moving air stream into electrical power.