Abstract: The invention relates to a level detecting system for a powder container of a powder-coating apparatus. It contains an inductive proximity sensor (22) and an electrically insulating membrane (28) which is displaceable to-and-fro the proximity sensor and which is fitted on its inside surface opposite the proximity sensor with a metallic element (32) affixed to it and affecting the magnetic properties of the proximity sensor. The level detecting system operates regardless of any powder particles adhering to it.

Abstract: Powder spray coating injector device consisting generally of three tubes nested coaxially. Fluidized powder is carried through an inner one of the tubes and compressed air is carried through annular passages between the inner tube and an intermediate tube and between the intermediate tube and an outer tube. The compressed air is used by a fluidizer to fluidize the powder coating material and by an injector to convey the fluidized powder coating material to a conventional powder spray applicator. Upstream ends of the tubes, relative to the direction of powder feeding, are connected via an adapter to an end section. The end section is provided with at least one fluidizer and the injector through which fluidized power is sucked. Any residual powder is easily cleaned from the injector device by positioning a cap over the fluidizer and injector and by delivering compressed air to the cap while fluidizing and injector air is supplied to the device.

Abstract: A powder spray coating device which includes an injector air flow controller having two alternate air flow paths for delivering feed air to an injector which delivers powder to a spray device. Optionally, the air flow controller also may have two alternate air flow paths for delivering supplemental air to the injector or downstream from the injector. In a first setting of a mode selector, feed air is delivered through a manually adjusted air valve and in a second setting of the mode selector the feed air is delivered through an automatically adjusted air valve. When supplemental air is provided, the supplemental air passes through a manually adjusted air valve in the first mode selector setting and through an automatically adjusted air valve in the second mode selector setting. A controller may detect articles to be coated and set the automatically adjusted feed air and supplemental air valves.

Abstract: A coating powder feed device supplies a plurality of flows of coating powder from a container to, for example, a plurality of powder coating devices or a plurality of containers. A plurality of individual powder feed devices are mounted in a housing which is sealed against entry of coating powder. Only the exterior housing surfaces, intake heads at lower ends of the individual powder feed devices which include powder suction inlets, and the internal fluidized powder flow channels are exposed to the coating powder, thus facilitating cleaning when changing powders. The individual powder feed devices are simultaneously lowered into a powder supply container during use.

Abstract: A powder barrier with a filter element of microporous material for use with an air injector in a powder feeder in a powder coating system. The microporous material is permeable to air, but not to the coating powder. The powder barrier prevents a penetration of coating powder into the air feed path in a direction opposite to the air flow direction. The powder barrier permits a quick color change without the need to disassemble the air injector for cleaning.

Abstract: An air injector for a powder feeder in a powder coating system having a powder barrier with a filter element of microporous material. The microporous material is permeable to air, but not to the coating powder. The powder barrier prevents a penetration of coating powder into the air feed path in a direction opposite to the air flow direction. The powder barrier permits a quick color change without the need to disassemble the air injector for cleaning.

Abstract: A spray disk (4) rotating at high speed and connected to high voltage surrounds a guide rod (30) and can be reciprocated up and down along said guide rod, the latter being of a stationary arrangement. This permits the use of drive means (34, 50) which extend along the guide rod (30) so that for the up and down motion of the spray disk (4) there are no carrier rods required which protrude beyond the stroke of the spray disk beyond the device.

Abstract: Spraying unit for spray coating articles with powdered or liquid material contains a spray head fastened to a front end of a tubular inner and axially extending support and an outer protective tube disposed concentrically about the inner support. The inner support and the outer protective tube are electrically insulative. One or more high-voltage generators are spacedly disposed about the inner support, axially rearward of the spray head, and within an elevated pressure chamber defined between the protective tube and the inner support. The arrangement is such that it produces a constant outwardly bound flow of gas from the elevated pressure chamber which flow prevents soilage of the internal parts by coating material.

Abstract: An electrostatic spray coating device in which a coating material passes through a tube in a body and is electrostatically charged by electrodes as it exits the body. In the body is mounted a bar transformer for providing a high voltage to the electrodes. A magnetic conductor bar, such as a ferrite core, is also mounted in the body outside the bar transformer for conducting magnetic flux between its ends, thus providing a flux circuit within the body. If more than one conductor bar is used, the bars are spaced to facilitate heat discharge. A multiplying and rectifying circuit such as a Greinacher circuit may also be mounted in the body between the transformer and the electrodes, with its components distributed around the tube.