Abstract: A spray gun or fuel nozzle wherein the underside of the pistol grip handle is formed with a socket for a rotary insert which is connected to two or more supply conduits for flowable materials. The insert has passages which convey flowable materials from the respective conduits to discrete channels in or on the housing of the gun or nozzle. One of the passages can extend from the respective conduit to the inner end face of the insert to admit flowable material into a channel of the handle, and one or more passages can extend from the respective conduit or conduits to annular spaces which are provided in the peripheral surface of the insert and/or in the adjacent internal surface of the handle and each of which communicates with a discrete channel. At least one channel can be provided in a guard in front of the trigger which is actuatable by the hand holding the handle.

Abstract: A fluid flow machine wherein a reciprocating piston type pump for a flowable material which must be subjected to a pronounced pressurizing action is operated by a double-acting pneumatic motor which is disposed at a level above and is spaced apart from the pump. The unit which regulates the admission of compressed air into and the evacuation of spent air from the motor is installed between the motor and the pump at a level immediately above a chamber for a supply of liquid medium serving to lubricate and clean the piston rod which transmits motion from the piston of the motor to the pump piston. A common cylindrical envelope which is permeable to air surrounds the motor and the regulating unit and defines a large expansion chamber for spent air to thus reduce noise when the machine is in use.

Abstract: Apparatus for electrostatic spray coating of plate-like substrates, particularly printed circuit boards, has one or more endless conveyors or one or more conveyors of finite length with one or two pairs of strip-shaped holding elements for the edges of substrates. The holding elements engage a substantial part or the entire edge of the substrate which is transported through one or more spray coating stations. Each holding element is made of or contains an electrically conductive material, and the holding elements are grounded, at least during travel through the coating station or stations. The holding elements can engage the edges of substrates by friction or they are coated with an adhesive so that they adhere to the edges of the substrates.

Abstract: The nozzle assembly of an electrostatic spray gun has an adapter which is made of an electrically insulating material and has a front surface facing in the direction of propagation of material issuing from the orifice of the nozzle. The adapter has a frustoconical extension which surrounds the orifice and whose external surface defines with the front surface of the adapter an annular space for the tips of electrodes which ionize air flowing toward the spray of material that issues from the orifice. The locations of the tips of electrodes (preferably very close to the front surface of the adapter) and the inclination of the external surface of the frustoconical extension determine the location of contact of ionized air with the spray. The tips of the electrodes are shielded from mechanical damage by being located in the annular space.

Abstract: Apparatus for spray coating plate-like or otherwise configurated workpieces has an endless apertured conveyor which transports a series of workpieces along a horizontal path beneath a rotary atomizer which sprays coating material onto the advancing workpieces. The coating material which bypasses the workpices and passes through the apertures of the conveyor impinges upon and gathers on a web of paper or non-woven fibrous material which is advanced at a speed less than the speed of the conveyor so that the web can be used with great economy because it is or can be advanced at a rate such that, or only when, its portion which is in the path of sprayed coating material cannot gather and retain additional coating material.

Abstract: Apparatus for simultaneously pumping two or more different liquids to a spraying device has a pair of discrete diaphragm pumps for each liquid. The pumps of each pair are connected in parallel and operate alternatingly so that one pump delivers a metered quantity of liquid while the pumping chamber of the other pump receives a metered quantity of the same liquid and vice versa. The capacities of pumps of at least one pair are adjustable in a simultaneous operation, and all pumps are operated by a common prime mover.

Abstract: An electrostatic spray gun wherein the barrel is formed by two tubes which define an annular gap for gaseous or pulverulent material. An electrode is installed in the inner tube between the front and rear ends of such tube and has two or more prongs extending outwardly into the gap. The central portion of the electrode has one or more discharging portions in a path for the flow of pulverulent or gaseous material toward a deflector which is releasably mounted at the front end of the inner tube. The electrode is connected with a high-voltage conductor which is mounted in a tubular shield within the inner tube.

Abstract: A portable electrostatic spray gun for liquid and/or pulverulent materials has a body with a grip and a second portion which carries a detachable barrel and has an inlet for admission of material to be sprayed. The rear side of the grip has a socket for a first unit of the high-voltage generator. A second unit of the generator is installed in a chamber provided in the second portion of the body and being accessible upon separation of the second portion from the grip. The grip contains a proximity switch which is actuatable by the trigger and can be deactivated by rotating it in the grip. The first unit of the generator has a transformer and an oscillator connected to a low-voltage input, and the second unit has a voltage multiplier connected with two high-voltage electrodes, one in the inlet and the other in an air admitting channel which is provided in the second portion of the body and includes a passage in the second unit of the generator.

Abstract: The invention relates to a method and apparatus for electrostatic spraying of powder particles on a surface to be coated. The carrying gas powder mixture axially discharged from a nozzle is expanded by a radially discharged control air stream to thereby form the desired spray mist. The electrostatic charging of the powder is achieved by an ionized gas stream which is fed into the carrying gas powder mixture separately from the control air stream. Some of the advantages achieved by the invention are an improved spray pattern and a more uniform coating.