Graco Inc.

Lawrence J Lunzer

Robert J Lind

Stanley G Karwoski

Alexander O Bally

Yamin Ma

Norman N Fender

Dale R Hemming

Carl D Jacobsen

Anthony G Brajdich

A liquid pumping system for transporting conductive liquids to an electrostatic spraying device while maintaining electrical isolation between the spraying device and the liquid source; the system includes sequentially-arranged metering valves and pumps to sequentially transport predetermined and isolated quantities of liquid.

High voltage sealing and isolation via dynamic seals

An electrostatic spray gun for the application of paints and other coatings has a high voltage power supply having a contact at the front end thereof. A flange on the end of the power supply surrounds the contact and a rubber boot seal snaps over the flange. Located within the rubber boot is a conductive rubber pin which contacts with a conductor located in the barrel of the gun. Utilization of this design minimizes capacitance in the front end of the gun and also virtually eliminates air volume in the area which in turn limits the production of harmful ozone.

Electrostatic spray gun power supply connection

An electrostatic spray gun having a self-contained power supply including a high voltage electrostatic voltage and current source, with circuits for monitoring the voltage and current and developing a frequency signal based on the monitored voltage and current, circuits for modulating the frequency signal with a radio frequency carrier and transmitting the modulated-carrier signal to a remote radio receiver, where the signals are demodulated and converted to a digital display representation of the monitored voltage and/or current.

Apparatus for transmitting electrostatic spray gun voltage and current

An electrical isolation system for monitoring liquid flow rate from pumping equipment housed within a confined enclosure, wherein the flow rate signals are developed into optical signals which are conveyed via fiber optic cables from within the enclosure to control modules outside the enclosure. The control for operating the system may thereby be wholly electrically isolated from the pumping equipment.

Electrically neutral flow measurement system

A device and method of determining the voltage and current existing at the electrostatic electrode in a electrostatic spray gun, the spray gun containing a self-contained power supply including a turbine generator operating the air supplied to the gun, the power supply producing a low voltage d.c., and a voltage multiplier changing the voltage to a high potential which is applied to the electrode of the spray gun, a sensing and measuring circuit for determining the return current or ground current from the electrode to the power supply and producing a voltage directly related to the ground current and producing a voltage signal which may be measured directly to indicate the ground current; a circuit establishing a base voltage from the power supply for comparison against the ground current voltage signal and obtaining a differential voltage which may be measured and which is directly proportional to the electrode voltage. Both the ground current voltage signal and the differential voltage being applied into separate optical signal generators, producing optical signals, the frequency of which varies directly with the magnitude of the voltage being applied; fiber-optic cables transmitting the high frequency optical signals to remote locations, converter devices producing electrical signals, the frequency of which is directly porportional to the ground current voltage signal and to the differential voltage and LED displays receiving such high frequency electrical signals and displaying the electrode voltage and the ground contact or return current from the electrode to the power supply.

Electrostatic spray gun voltage and current monitor with remote readout

An electrostatic spray gun is provided with a spraying voltage control. The contol is produced by Hall effect or magnetoresistive circuitry incorporated with the circuitry of the spray gun. A variably positionable magnet is provided so that the operator may selectively adjust the spraying voltage by positioning the magnet relative to the Hall effect circuitry.

Spraying voltage control with hall effect switches and magnet

An electrostatic spray applicator system of the type utilizing pressurized air from an external source to develop the electrical voltage driving conditions within a spray applicator. The electrical operating conditions are represented by electrical signal generating devices within the applicator, and these electrical signals are converted into optical signals within the applicator for transmission to a remote source. The optical signals are received at the remote source and converted back into electrical signals corresponding to the parameters being measured, and are subsequently converted into decimal display values for visualization by an operator.

Electrostatic spray applicator with two-channel optical monitoring system

A device and method of determining the voltage and current existing at the electrostatic electrode in a electrostatic spray gun, the spray gun containing a self-contained power supply including a turbine generator operating the air supplied to the gun, the power supply producing a low voltage d.c., and a voltage multiplier changing the voltage to a high potential which is applied to the electrode of the spray gun, a sensing and measuring circuit for determining the return current or ground current from the electrode to the power supply and producing a voltage directly related to the ground current and producing a voltage signal which may be measured directly to indicate the ground current; a circuit establishing a base voltage from the power supply for comparison against the ground current voltage signal and obtaining a differential voltage which may be measured and which is directly proportional to the electrode voltage.

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St. Louis Park, MN, United States of America

Lawrence J Lunzer