Abstract: An electrostatic spray coating apparatus having a spray nozzle which has a spray orifice for atomizing coating material. The nozzle orifice may be round or, preferably, is in the form of a slot to impart a flat shape to the atomized material. The spray nozzle is mounted to be rotated on a body of the spray gun so that the atomized material particles are driven radially outwards in addition to the forward direction and are thereby distributed uniformly in the cloud of sprayed material. A brake may be provided to slow down the rotation when greater penetration into cavities in the article being painted is desired. In invention may be used in either power spray coating apparatus or liquid spray coating apparatus.

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 spray coating device for the electrostatic spray coating of articles. The device includes a spray appliance which is carried by an elongated tubular support housing through which all connecting conduits for the spray appliance extend. The tubular support can be supported by a carrier device, such as a reciprocator, located outside of a spray booth and can extend through a side wall opening in the spray booth for positioning the spray appliance in the spray booth. The spray appliance may be a powder coating material applicator. Preferably, the top surfaces of the spray appliance and the tubular carrier are substantially continuous and without significant steps and of the smallest possible size in order to minimize the deposit of coating material and dust.

Abstract: Electrostatic spray coating system which accurately determines the actual value of a high voltage present on at least one high voltage electrode as coating material is electrostatically charge. A control or input voltage is measured on the input of a voltage transformer and multiplier circuit and is multiplied by the voltage multiplication factor of the voltage transformer and multiplier circuit, thereby calculating the theoretical or no load value of the voltage on the high voltage electrode. This theoretical value deviates from the actual value of the electrode voltage by the amount of the internal voltage drop across the voltage transformer and multiplier circuit when a current flows in it. The internal voltage drop is determined as a function of the electrode current and is subtracted from the theoretical value in order to generate a signal voltage corresponding to the actual value of the electrode high voltage.

Abstract: Electrostatic spray device for coating powder or liquid with at least one charging electrode for electrostatic charging the coating material. The device has at least one, and preferably a plurality, of counter electrodes for the electrostatic removal of free charges (electrons or ions) from the stream of sprayed coating material adjacent a coating material discharge nozzle on the device. The counter electrodes are carrier by a ring which is slipped onto a body of the device. A sleeve screwed onto the body holds the ring in an axial direction on the body. An electrical line for discharging the free charges from the counter electrodes is secured to the ring. The electrical line passes through and is confined in a bore in the body to prevent rotation and axial movement of the ring on the body. When the sleeve is removed from the body, the counter electrode ring and attached electrical line can be withdrawn from the body in the axial direction as a unit.

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: A powder feed device, especially for powder coating material, with an injector (2), in which a partial vacuum is created by a feed air stream according to the principle of a Venturi pipe and powder is drawn out of a powder container (10) and transported. An additional air stream can also be added to the feed air stream. In a computer (24), a plurality of predetermined powder feed rates (m) is stored in memory, on a calibration diagram (50), along a first diagram axis, and a plurality of feed air rates (FV) is stored in memory along a second diagram axis, for predetermined total air rates (GV) (feed air and added additional air, if needed).

Abstract: A spray booth for use in the spray coating of articles with coating powder. The spray booth forms a coating space which at a bottom is bounded by powder collection means. The powder collection means is divided into an inner collection means and a surrounding outer collection means for the separate collection of surplus powder and the separate removal of the entire surplus powder from the booth. The outer collection means collects surplus coating powder dropping off the inside surfaces of the booth walls. Since this powder may be contaminated with different color or different types of powder from previous spraying operations, it is discarded as waste. The inner collection means collects pure surplus powder which has not touched the booth wall surfaces. This pure surplus powder is recycled.

Abstract: A spray device and method for the coating of objects with powder coating material. A high voltage electrode or several electrodes are located on only one side of the coating material stream in the vicinity of a spray orifice for electrostatically charging the coating material. A first flow of compressed air is directed over the electrodes to keep the coating material from accumulating on the electrode and to shape the envelope of the sprayed coating material. A second stream of compressed air is directed at the stream of coating material to counteract the deflection of the stream by the first flow and by the effects of the high voltage. Better coating efficiency (reduced loss of sprayed powder) is achieved than with electrodes arranged on both sides of the coating material stream.

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: Electrostatic spray appliance for coating material for the spray-coating of articles comprisesa single carrier (4) which carries a plurality of gun barrels (6, 8), so that the carrier (4), together with the gun barrels, forms spray guns. The gun barrels (6, 8) are releasably fastened to the carrier (4). The supply lines (54, 56, 58, 60, 62, 64, 78) are combined to form a line bundle and are led through a movable robot arm (68) in the longitudinal direction of the arm on the side of the carrier (4) facing away from the gun barrels (6, 8). The spray nozzles (12) are preferably slit nozzles having slits arranged obliquely relative to their theoretical connecting line.

Abstract: An injector-conveyor device for the pneumatic conveying of powder, particularly powdered coating material, in order to measure the amount of powder conveyed, measures indirectly the vacuum produced in an injector (4) by having a stream of air measured with respect to its amount of flow or pressure drop in a throttled measurement channel (30) which places the outside atmosphere (32) in fluid communication with the vacuum chamber (10) of the injector (4). In order to avoid errors in measurement due to pressure variations in a powder suction channel (8), an equalization air inlet (56) is provided by means of which a small amount of equalization air is introduced into the powder suction channel (8) in order to make the pressure variations occurring therein of higher frequency and smaller with respect to the amplitudes of variation.

Abstract: An electrostatic powder spray coating system for car bodies is disclosed. Above the car bodies (14) are moved through the cabin and from which the spray organs (94) are supplied with powder. The powder container (92) is supplied with fresh powder and recycled powder from a supply container (36). Short paths between the powder container and spray organs allow precise metering and therefore a good coating quality. The spray coating is applied within an arrangement of inner and outer cabins which allows pressurizing of space between the cabins to prevent ingress of atmospheric air into and egress of powder out of the system.

Abstract: The cabin walls (30) and preferably also the cabin floor (34) and/or the cabin ceiling (36) each consist of a double-walled construction with an inner wall (40), an outer wall (44), and spacer elements (46) which keep the two walls spaced apart. Each wall consists of several layers (1 to 9), in sandwich construction, where the layer (1), which delimits the spray space (42) of the cabin, consists of polypropylene or of polyvinyl chloride plastic.

Abstract: A pipe arrangement (40) consists of two nested pipes (60, 62) and a nozzle head (68, 76) on their bottom ends. This nozzle head is located within the diameter of the pipe arrangement (40) and does not protrude radially beyond its diameter. The pipe arrangement can thus be slipped through a guide opening (7) of a guide device (1) into a container holding powder or can be pulled out completely of the guide opening (7), without a need for disassembly of parts of the device. The guide device (1) contains preferably a container lid (3) that can be set on the container (6). Provided on the pipe arrangement (40) is a stop (44) that can be fastened on said arrangement at various heights and through the adjustment of which the immersion depth of the pipe arrangement (40) in the container can be adjusted.

Abstract: A filter unit (12) or a cyclone unit (22) can alternately be attached to a cabin (2) to draw powder out of the cabin. The units move on wheels. In an operating position adjacent to the cabin (2), they are automatically aligned with flow connections and can be connected. A common fan (52) for both units is connected with the filter unit (12) via a compressed air cleaning device (42) in terms of flow, if the former is in the operating position, and at the same time it closes off the inlet to a post-filter unit (32), while when the filter unit (12) is removed and the cyclone unit (22) is in the operating position, this cyclone unit (22) is connected with the fan (52) via the post-filter (32), and the cyclone unit (22) closes off a flow inlet of the compressed air cleaning unit (42). In this way, color changes can be carried out in a short period of time, and good exhaust cleaning is achieved by the filter unit (12) during extended operation with the same color, without a color change.

Abstract: A fluidizing and suction withdrawal unit (14) which can be lowered into a container (20) holding a powder (22), in order to fluidize the powder and withdraw the fluidized powder (92) by suction. The fluidizing and suction withdrawal unit (14) is provided with a level sensor (88) which generates a signal, in contingence on the immersion depth (80, 82) to which the fluidizing and suction withdrawal unit (14) is immersed in a powder layer (92) fluidized by it. This assures a consistent feed capacity which also in the case of direct connection of a spray device (76) results in the coating of articles at good coating qualities.