Electrostatic coating guns are described wherein a conduit for coating material extends from a handle part, and a high-tension electrostatic generator, constructed as a block or unit, may be replaceably mounted on the handle part. The high-tension generator consists of an electrostatic cascade device wholly embedded in an insulating moulded composition and arranged to apply full high tension to the muzzle end of the gun, this high tension decreasing towards the handle part. The conduit may be a bore moulded in the insulating composition, or it may be a rigid tube, on which the bore in the generator is a sliding fit, or on which the generator may be clamped. In another alternative, the generator is detachably located in the handle part.
REFERENCE TO RELATED APPLICATION
This application is divided from my co-pending application Ser. No. 600,975 filed Aug. 1, 1975, now U.S. Pat. No. 4,033,506.
Priority Data
Aug 06, 1974 [CH] 10761/74 Aug 06, 1974 [CH] 10762/74 Aug 06, 1974 [CH] 10763/74
An electrostatic hand-held spray gun with a body consisting of a barrel affixed at a selected angle to a handle. The barrel has a boring which terminates at an atomizer. The handle contains a boring which at a lower end terminates in a hose connection and at an upper end at a control valve. A second end of the barrel boring also terminates at the valve. The control valve is operable by a trigger rotatably affixed to the handle and controls the flow of color material through the boring in the barrel. A spray electrode is located adjacent the atomizer. A tubular trigger guard structure is located near the second end of the barrel in front of the trigger and is oriented at a selected angle with respect to the barrel. A high voltage cascade multiplier module and a step-up transformer module are removably mounted within the trigger guard. A low voltage cable brought into a lower end of the trigger guard provides power to drive the step-up transformer. The step-up transformer outputs an intermediate voltage, high frequency, signal to drive the high voltage multiplier circuitry. The output of the high voltage multiplier circuitry is connected by a conductor, through a current limiting resistor to the electrode adjacent the atomizer.
A portable electrostatic spray gun for liquid and/or pulverulent materials has a body with a grip and a second portion which carries a detachable barrel and has an inlet for admission of material to be sprayed. The rear side of the grip has a socket for a first unit of the high-voltage generator. A second unit of the generator is installed in a chamber provided in the second portion of the body and being accessible upon separation of the second portion from the grip. The grip contains a proximity switch which is actuatable by the trigger and can be deactivated by rotating it in the grip. The first unit of the generator has a transformer and an oscillator connected to a low-voltage input, and the second unit has a voltage multiplier connected with two high-voltage electrodes, one in the inlet and the other in an air admitting channel which is provided in the second portion of the body and includes a passage in the second unit of the generator.
An improved electrostatic spray gun wherein the power pack for transforming a low voltage electrical signal from an external source to a high voltage signal for application to the gun electrode is wholly contained within the handle of the gun. The gun includes multiple interchangeable barrels for enabling the gun to spray airless atomized liquids, or air spray atomized liquid, or air-entrained solid particulate materials.
An electrostatic spray gun is provided that alternatively houses an end section of a high voltage cable remotely supplied by a high voltage source or an internal voltage multiplier so the electrode of the gun may be alternatively powered by the high voltage output of the end section of the high voltage cable or the internal voltage multiplier. The gun has an internal chamber into which the internal voltage multiplier or end section of the high voltage cable may be alternatively placed. A resistor/electrode assembly is mounted onto the high voltage output of the internal voltage multiplier or end section of the high voltage cable. A retainer secures the internal voltage multiplier or end section of the high voltage cable within the internal chamber and also maintains the electrical contact between the resistor/electrode assembly and the high voltage output housed within the internal chamber. The internal voltage multiplier and end section of the high voltage cable are configured relative the internal chamber to prevent rotation so that electrical contact between the resistor/electrode assembly and the high voltage output housed within the internal chamber is further maintained.