Abstract: Contained in the feed gas line (4) and in the dosing gas line (24) of an injector (2) is a pressure setting instrument (6, 26) each which is adjustable with regard to its outlet pressure. A gas flow instrument (46) displays the entire amount of feed air and dosing air flowing per unit of time. This makes it possible to change the pressures of the feed air and the dosing air while nonetheless keeping the entire gas quantity in the powder/gas flow in a simple way at a desired value.

Abstract: The gun grip (18) and the gun barrel (2) are two bodies that are detachably connected with each other. The fluid line (26) is a stiff tube with two tubular shanks (27, 28) which at said angle extend obliquely to each other. The one tubular shank (28) is removably installed in a channel (25) of the gun grip (18), the other tubular shank (27) in a first channel (10) of the gun barrel (2), each from sides of the gun grip (18) and the gun barrel (2) that border on each other.

Abstract: Fluidized powder in a powder preparation container is treated to impart to it a desired moisture content through the feeding into the fluidized powder of a stream of compressed air whose moisture content and temperature have been carefully regulated. Powder in the preparation container which has attained the desired moisture content is then transferred to a powder holding container and from there to a spraying device by which spraying device the powder is electrostatically charged and sprayed on articles. Further, the powder preparation container is heated along several distinct heating zones which are arranged one above the other along the axis, i.e. height, of the container. The powder in the powder preparation container is stratified with the powder at the bottom of the container being affected only negligibly by the continuous introduction of fresh powder through the top of the container.

Abstract: Consists essentially of a gun barrel (2) and a carrier (18) which can be fitted into a recess (20) on the rear, bottom end of the gun barrel (2), and of a voltage generator module (14). Formed in the gun barrel (2) is a first channel (10) for a fluid and above it, offset axially to the rear, a straight-line second channel (16) for accommodating the voltage generator module (14). A straight-line third channel (24) through the carrier (18) enables the connection of an electrical connector (40) to the primary side of the voltage generator module (14) by a simple plug connection, without disassembly of other parts. A straight-line fourth channel (25) in the carrier (18) communicates with the first channel (10). This makes all of the channels so short that all parts can be made from plastic without manufacturing problems and can be cleaned quickly.

Abstract: An apparatus and method for accurately determining the quantity of powder flowing in a spraying device includes a power density measuring element for measuring the powder density of the powder/gas mixture flowing in the spraying device and a device for measuring the flow rate of the pure gas prior to its mixing with the powder. Signals representative of the powder density and gas flow rate are generated and transmitted to an electronic evaluation device which calculates from these measurements the absolute flow rate of the powder per unit time.

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: A spray-coating device for spraying liquid or powdered coating material on articles includes a transformer for stepping up an alternating voltage and a voltage multiplier circuit for converting the output of the transformer to a high DC output for driving a charging electrode in the spray-coating device. The alternating voltage for the transformer is obtained from a controllable source of alternating voltage which produces a sinusoidal voltage whose frequency is constantly adjusted such that the voltage and current flowing through the transformer are in phase with one another. This assures that the transformer is operated at its resonant frequency.

Abstract: A powder coating apparatus fluidizes coating powder in a powder container and mixes with the fluidized powder an additional substance, such as steam, water or other liquid. The additional substance is delivered into the interior of one or a plurality of enclosed bells which extend across the powder container. Each bell has a respective lower opening deep enough into the powder container to be immersed in the fluidized coating powder. The additional substance is delivered under pressure through a tube passing through the bell, through outlet nozzles in the tube and into the bell and then pressurizes the bell to keep the fluidized powder out of the bell and to deliver the additional substance out of the lower opening into the fluidized powder.

Abstract: A generally rectangularly shaped powder coating booth of a powder spraying apparatus is fomed of two main sections, each of which is constituted of wall and roof elements which are swingably interconnected to one another. The walls and roof of each half of the booth may be straightened out to form a flat, continuous and rectangularly shaped surface from which residues of powder may be removed easily and rapidly. Thus when the two halves of the booth are flattened out the booth is transformed into two parallel and spaced surfaces which can be cleaned by being vacuumed by a respective suction nozzle that is disposed to travel over and vacuum the surfaces automatically.

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 device for coating powder has a powder channel, the downstream end of which has a spray opening for the spraying of the coating powder. At least one gas channel with at least one gas outlet opening is arranged substantially in the radial center of the powder channel upstream of its spray opening, the gas outlet discharging axially in the direction toward the spray opening. At least one electrode, around which gas from the gas channel flows, is located in the gas outlet opening, the downstream electrode end of the electrode terminating substantially at the downstream end thereof. Within the powder channel, directly in front of its spray opening, a funnel-shaped powder channel section is provided for compacting the powder concentration. The gas stream injects electric charges into this section, which the stream of gas has taken up from the electrode. The spray opening preferably has the shape of a slot.

Abstract: A spraying device for spraying powdered material on an article includes an axially extending powder channel formed in the body of the spraying device which has an upstream region and a downstream end. The material flows out through a spraying opening located at the downstream end. A support extends from the spraying opening, upstream into the powder channel. The support defines a gas channel therein. A plurality of gas outlet orifices, located near the spraying opening, connect the gas channel to the powder channel. The orifices are inclined obliquely in the downstream direction. Electrical electrodes, connected to a high voltage, extend into the orifices and reach to or just beyond the orifices, into the powder channel. The axial distance from the tip of the electrodes to the spraying opening should be about equal to the diameter of the powder channel or according to an alternate embodiment about one half the diameter.

Abstract: A powder coating booth has a bottom surface on which powder is collected and from which the powder should be removed. Two scrapers are supported on a transport device which move them together. Each scraper is movable from its respective end of the booth toward a central collection region. Since the scrapers are moved simultaneously, one is moving toward the collection region while the other is moving away. As a scraper moves toward the central collection region, it scrapes powder from the surface and delivers it to the collection region. Each scraper swings into an operating, surface scraping position as it moves from its respective end of the booth toward the collection region, and swings into an upraised, non-scraping position, as each moves from the collection region back to the end region. A cable with scraper engaging flights on it is movable for engaging the scrapers and for moving and for swinging them.

Abstract: A versatile spraying gun includes main tool and several attachment tools any one of which can be inserted in the main tool. Each attachment tool is designed to atomize powder particles that are to be sprayed on an article in accordance with a specific spraying method and atomization principle and method. The main common tool is comprised primarily of a body that defines a powder delivery channel and a coupling piece and discharge electrode located upstream in the delivery channel. The attachment tools have a flow guide member disposed axially within the delivery channel and an attachment piece for attaching the attachment tool to the coupling piece of the main tool. In some attachment tools, the flow guide member also houses a high voltage circuit and appropriate electrodes needed for electrostatic charging of the powder which passes through an electrical field set up between the electrodes.

Abstract: A spraying gun for electrostatic spraying of coating material on an article contains a discharge electrode which is disposed entirely outside the region where the coating material flows. The coating material is accelerated through an annularly shaped and axially extending channel in which the coating material is electrically charged by friction between itself and the insulated walls that define the channel. A gas conduit extends from the discharge electrode and reaches into the annular feed channel of the coating material. Location of the gas conduit between the discharge electrode and the feed channel allows the gas flowing in the gas conduit toward the feed channel to serve the dual purposes of preventing coating material from flowing to and settling on the discharge electrode and providing an electrically conductive path through which undesired electrical charges which develop on the walls of the feed channel discharge to the discharge electrode.

Abstract: A spray gun kit for dispensing coating material, for example paint, includes a common gun body and an assortment of nozzle attachment sets, each of which operates according to a unique atomization process suited for particular applications. The common gun body incorporates as many of the parts which otherwise would be repeated in each nozzle attachment. The arrangement reduces the overall cost, otherwise required, in providing an entirely assembled spray gun for each application and provides greater overall flexibility.

Abstract: A method of and apparatus are disclosed for spraying powder, particularly for the coating of articles, by introducing a spray gas into the powder as the latter is expelled from a spray opening. An additional gas is injected into the stream of powder upstream of the point where the spray gas is introduced, in such a manner as to exert a cyclone effect on the stream of powder, force the powder radially outward and simultaneously drive it in the direction of flow of the powder.

Abstract: A feed channel is provided upstream of a powder-spraying discharge opening in a spray device, with a pipe having an injector which coaxially surrounds such pipe length for the coaxial introduction of accelerating gas. Downstream of the injector an elongated guide member is present in the feed channel. In this way the complete cross-sectional shape of the feed channel is progressively changed along the longitudinal axis of the feed channel to a cross-sectional shape which is annular and has a smaller cross section of flow passage. This results in a further accelerating of the stream of powder. The guide member and the region of the wall of the feed channel which surrounds the guide member at a distance therefrom consists of an insulating material on which powder particles which move past are charged electrically by friction.