Abstract: A process for measuring the thickness of a layer of powder upon the surface of a workpiece comprises depositing a layer of powder on the surface of the workpiece and simultaneously on the surface of an adjacent wire, directing the powder coated wire past a sensor capable of measuring the diameter of the powder coated wire, and comparing the diameter of the powder coated wire to the diameter of the uncoated wire.

Abstract: A paint hose extension to facilitate safe application of metallic paints with a hand held electrostatic spray gun. The hose extension extends between the spray gun and a hose connected to a grounded paint supply. The hose extension provides a predetermined long electrically insulated paint flow path between a high voltage paint charging electrode in the spray gun and the paint supply hose. An electrically conductive layer shields the hose between an electrically grounded handle on the spray gun and a remote metallic connector which attaches to the paint supply hose. The connector electrically connects the conductive layer with the grounded paint column at the connector.

Abstract: A hand held spray gun including a gun body, a barrel and a nozzle assembly attached to the front of the barrel. A tubular retainer passes through a portion of the body and is threaded into a passage in the barrel to connect the barrel to the body. A fluid valve actuator extends from the body through the retainer and into the barrel passage for operating a fluid valve in the nozzle assembly. The retainer also functions as a guide for the valve actuator, holds a radial fluid seal for forming a sliding seal against the valve actuator and serves as a stop for a spring biased fluid seal between the valve actuator and the barrel.

Abstract: A hand held electrostatic spray gun having an electrostatic power supply mounted in the gun. The power supply includes a circuit module mounted in the gun handle which produces heat during operation. The circuit module has a heat conducting housing which is intimately attached to a heat conducting tube extending through the handle. Compressed air delivered through the tube to a nozzle for assisting atomization and/or pattern shaping cools the circuit module.

Abstract: A continuous electrical connection between a high voltage power source and a paint charging electrode in an electrostatic spray gun. The electrode is mounted on a valve needle which is reciprocated by a trigger mechanism as the spray gun is operated. A novel spring establishes and maintains the electrical connection from a stationary contact on the gun barrel to the moving valve needle. The spring may be mounted on a spacer tube mounted coaxially about the valve needle. The spacer tube can move in an axial direction to exert a force on a seal between the barrel and the valve needle without affecting the electrical connection.

Abstract: An improved electrostatic spraying apparatus for robot mounting is disclosed. The electrostatic spraying apparatus has a drive assembly connected to a spray gun assembly. The spray gun assembly has a base and a detachable barrel. The drive assembly acts to rotate the spray gun assembly through a plurality of preselected paths of movement. In addition, all coating contaminated parts can be removed from the apparatus by removing the detachable barrel.

Abstract: The invention relates to an electrostatic spray gun for the deposition of powdered coating material characterized by an improved deposition efficiency and provided with a multi-stage, trigger operated control that permits spraying at a plurality of conditions that may be preselected by the operator. An axially disposed needle charging electrode is used and an axial air flow passage surrounds the same to reduce any troublesome accumulation of powder on the needle under all spraying conditions.