Abstract: A spray gun for applying a film to a workpiece has a spray head provided with an annular nozzle designed to discharge material which is to undergo pneumatic atomization. A second annular nozzle surrounds the pneumatic material discharge nozzle and is designed to discharge atomizing air for pneumatic atomization of the material issuing from the pneumatic material discharge nozzle. The spray head is further provided with an additional material discharge nozzle designed to discharge material which is to undergo hydrostatic atomization. The hydrostatic material discharge nozzle is disposed centrally of, and is surrounded by, the pneumatic material discharge nozzle. The hydrostatic material discharge nozzle forms a first spray of hydrostatically atomized material while the annular nozzles form a hollow conical second spray which surrounds the first spray when both sprays are on simultaneously.

Abstract: Electrostatic spraying apparatus according to the present invention has two opposed electrodes in a housing adjacent to the path of a spray from a spray nozzle and a barrier adjacent to each electrode. The barrier includes pointed protuberances arranged so that the liquid collecting on them is discharged electrostatically. Each housing is secured to the barrier by a support extending from a recess within the housing.

Abstract: In a fluid spray gun, the fluid nozzle is threadedly attached to the gun body and is covered by an air cap and threaded retaining ring. A latching mechanism is placed in the gun body and removably latches the toothed nozzle in place to prevent rotation due to friction from the air cap and retaining ring. The latch is held in place by the air cap and/or retaining ring but is easily disengaged when the air cap and retaining ring are removed.

Abstract: Electrostatic painting apparatus comprises a support moveable at high speed along a slide. On this support is a pneumatically controlled paint sprayer producing an electrostatically charged jet of paint. A paint feed assembly comprising a pressure regulator and a discharge valve is juxatposed with the sprayer. Sprayer control devices are disposed on a chassis connected to the feed assembly by a harness. These control means comprise three gas pressure regulators supplying the sprayer and controlling the paint pressure regulator and a high DC voltage generator. The position of the chassis relative to the slide is determined such that the harness is as short as possible, so as to reduce to a minimum the command transmission time. This arrangement makes it possible to reduce the weight carried by the support. The units carried by the chassis are remotely controlled by a microprocessor-based unit over a remote control line.

Abstract: A hydraulic system, suitably an ink supply system for an ink jet printer, wherein a first pump conveys ink under pressure from a reservoir to a work head and a gear pump returns unused liquid from a collector at the work head to the reservoir. A bleed line connects an outlet from the first pump to an inlet to the gear pump. Accordingly, there is a flow of liquid via the bleed line such that the gear pump applies sufficient suction to the collector to draw air or a mixture of air and unused liquid therefrom. The flow is also sufficient to ensure adequate lubrication of the gear pump. The first pump may also be a gear pump, in which case the two pumps are formed as a double-ended pump.

Abstract: An electrostatic spray gun having an electrode for applying an electrostatic charge to coating material. A lever is provided for controlling both the flow of material from the spray gun as well as the position of a first magnet. The first magnet, in turn, controls a first magnetically actuatable electric switch for connecting and disconnecting a high voltage to the electrode. A second magnetically actuatable electric switch, controlled by the position of a second magnet, is electrically connected in series with the first switch, so that the high voltage can be disconnected from the electrode regardless of the position of the actuating lever. The spray gun can therefore be operated with or without the application of an electrostatic charge to the coating material.

Abstract: An agricultural sprayer (10) comprises a mobile frame (12) supporting a spray system (90) in which the water and chemical concentrate are stored in separate tanks (92, 94, 96 and 98) for mixture in the desired ratio as needed responsive to travel of the sprayer so as to facilitate application at the proper rate. The frame (12) preferably comprises a main frame section (14) with outboard pairs of pivotal frame sections (16, 18) which are individually supported by adjustable gauge wheels (34, 54) movable between raised and lowered positions relative to the ground by actuator assemblies (60). The spray system (90) includes a water tank (92) and a plurality of chemical tanks (94, 96 and 98) connected through individual shut-off valves, adjustable, positive displacement pumps, and an electrostatic water treater, to a plurality of spray heads.

Abstract: A spray gun for airless atomization and electrostatic deposition of a coating material upon a substrate, including a gun nozzle tip element serving to prevent arcing from the gun nozzle tip to an adjacent electrical ground. As disclosed, the airless spray gun includes a metallic nozzle tip from which atomized liquid coating material is emitted, and the thus-emitted coating material is charged by an electrode mounted on the nozzle which is electrically isolated from the metallic tip. During use of the spray gun, the metallic tip becomes charged via electrical charge conduction through the emitted atomized coating material. To prevent arcing from the charged tip to an electrical ground, a pair of resistive threads are secured in bores in the spray gun nozzle, each having a first end electrically connected to the conductive tip and a second end extending slightly beyond the nozzle.

Abstract: A spray gun for airless atomization for electrostatic deposition of a coating material upon a substrate includes a novel dual electrode element having a spring loop portion. The two electrodes are the respective end portions of a single electrode wire, which has its major portion between the electrodes formed into a spiral spring. A tip resistor is provided with a conductive fitting that presents a broad and sturdy bearing surface which abuts the electrode spring portion to thereby directly connect the electrode with a high voltage charging circuit. The electrode spring accommodates spacing variations between the electrode and tip resistor, and provides a continuous electrical connection regardless of the rotational position of the electrode relative to the tip resistor. The dual electrode spring further serves to secure a number of otherwise loose parts of the gun nozzle assembly together, and prevents the parts from falling out and getting lost when the nozzle assembly is removed from the spray gun.

Abstract: Spray combination of two liquids is advantageously accomplished by applying a high potential of one polarity to a first liquid thereby converting the first liquid into finely divided ionized particles, spraying a second liquid through a porous member and applying thereto a high potential of the other polarity thereby converting the second liquid into finely divided ionized particles, and combining the two masses of finely divided particles of the two liquids electrostatically with each other.

Abstract: Apparatus is disclosed for resistively damping capacitively stored energy in electrostatic spray guns, wherein a fluid spray valve incorporates an electrode for carrying high electrostatic voltage, the electrode terminating in the spray valve and the spray valve having a conductor contacting the electrode and extending externally thereof. A resistive element at least partially encloses the spray valve and electrically contacts the conductor, permitting electrical conductivity while also permitting axial sliding movement of the spray valve inside of the resistive element.

Abstract: Oil is delivered by a single pumping means to an application header which extends across the path of movement of an electrically grounded metal strip requiring oiling. A perforated plate within the header divides it into two chambers and forms a diffuser between the two chambers to assure an even distribution of oil in the chamber which receives its oil by passage through the diffuser. The perforated plate also forms a charging electrode for oil filling the header and serves a third purpose in that it is a final filter for the oil passing through the header. The header has oil delivery orifices or a continuous delivery slot leading from the chamber of the header which faces the metal strip. Oil is attracted in small discrete streams onto the surface of the grounded strip traveling in near proximity to the header and the strip is uniformly coated with oil across its full width. Excess oil is recovered and returned to the pumping means for recycling in the system.

Abstract: An air atomizing nozzle assembly for electrostatic spray guns is disclosed. The nozzle assembly is made of plastic parts and includes an air cap having a central bore which surrounds a fluid nozzle tip. The nozzle has a nut formed on its forward end to facilitate threading of the rearward end of the nozzle tip into a threaded bore of the gun body. Formed on the front part of the nozzle, either as a part of the nut or a cylindrical surface adjacent the nut, is an accurately machined surface engageable in press fit relationship with a mating accurately machined bore of the air cap. These mating press fit surfaces center the bore of the air cap relative to the nozzle tip so as to leave an annular, evenly dimensioned air flow passage surrounding the nozzle tip and defined between the nozzle tip and the bore of the air cap. The air cap is retained in a one-piece resilient retaining ring by snapping the air cap into an annular lip of the retaining ring.

Abstract: An electrostatic spray gun is provided with electrostatic power circuitry for supplying high voltage power to an electrode with a switch for enabling and disabling the circuitry, the switch being operated by movement of a trigger controlling flow of a coating fluid through the spray pistol. The switch is a magnetic switch normally open, but closeable by a magnet positioned adjacent the switch, the trigger having means to shunt the magnetic field allowing the switch to open when the trigger is closed and allowing the switch to close when the trigger is open. A second magnet is provided movable towards and away from the first magnet whereby the second magnet effectively shunts the magnetic force of the first magnet when moved adjacent thereto to prevent closure of the switch independent of movement of the trigger.

Abstract: Disclosed is a spray gun having a gas nozzle and a fluid nozzle, each of said nozzles being in cooperative spatial relationship with the other to cause a fluid stream issuing from the fluid nozzle to be atomized and sprayed as fluid particles by gas issuing from the gas nozzle. In a preferred embodiment the fluid nozzle orifice has therein an axially disposed rod to increase surface area from which said fluid particles can be formed, said rod being electrically grounded at least during fluid issue from the nozzle. The spray gun additionally has an induction charging electrode disposed adjacent the gas and fluid nozzles, said electrode defining a charging zone wherein an electrostatic charge is imparted to atomized electrically-chargeable fluid particles.

Abstract: An airless electrostatic spray gun for atomizing and electrostatically depositing liquid coating materials onto substrates. The gun is characterized by a low capacitance which enables the electrode of the gun to be shorted to a grounded object without the resulting spark having sufficient energy content to ignite the surrounding atmosphere.

Abstract: An electrostatic hand-held spray gun with a body consisting of a barrel affixed at a selected angle to a handle. The barrel has a boring which terminates at an atomizer. The handle contains a boring which at a lower end terminates in a hose connection and at an upper end at a control valve. A second end of the barrel boring also terminates at the valve. The control valve is operable by a trigger rotatably affixed to the handle and controls the flow of color material through the boring in the barrel. A spray electrode is located adjacent the atomizer. A tubular trigger guard structure is located near the second end of the barrel in front of the trigger and is oriented at a selected angle with respect to the barrel. A high voltage cascade multiplier module and a step-up transformer module are removably mounted within the trigger guard. A low voltage cable brought into a lower end of the trigger guard provides power to drive the step-up transformer.

Abstract: A hand-held manually operable deposition gun for projecting electrostatically charged particles. The gun includes at its front end means for discharging the particles, which may be either liquid or solid, and an electrode for electrostatically charging the particles. The electrode is maintained at a high unidirectional voltage of several tens of kilovolts by connection to a piezoelectric generator through a voltage integrating device, both mounted at the rear of the gun. The piezoelectric generator is actuated by a motor-driven impulse means also located at the rear of the gun. A trigger mounted on the gun activates both the motor and the flow of particles from the gun.

Abstract: Method and apparatus for providing an electrostatically charged, airless, round vortex spray of liquid in which spray pattern irregularities may be eliminated. In addition to a central nozzle for forming the round vortex spray there is provided an annular nozzle for forming an auxiliary air vortex which is imparted with whirling motion in a direction opposite to that of the round spray of liquid. The air flow rate for the auxiliary air vortex is set above a value at which spray pattern irregularities disappear. The hydrostatic pressure for the round spray ranges between 25 and 75 bars and the air pressure for the auxiliary air vortex ranges between three and one bar.

Abstract: A machine is provided for destroying plants with electricity comprising a tank adapted to hold electrically conductive liquid, an electrode for placing the electrically conductive liquid in the tank at high electrical potential, including a high voltage source of electricity; nozzles for spraying the electrically conductive liquid on plants to be destroyed; and a structure for grounding the high voltage source. Air pressure provided over the liquid in the tank provides the motive force for spraying, and pneumatically operated valves in line with the nozzles are provided for selectively supplying liquid to the nozzles. In this way, there are no moving parts which are electrically charged. Condition-responsive structures, responsive to plant position, are provided for controlling operation of the pneumatic valves, such as air limit proximity switches.

Abstract: Electrostatic coating guns are described wherein a conduit for coating material extends from a handle part, and a high-tension electrostatic generator, constructed as a block or unit, may be replaceably mounted on the handle part. The high-tension generator consists of an electrostatic cascade device wholly embedded in an insulating moulded composition and arranged to apply full high tension to the muzzle end of the gun, this high tension decreasing towards the handle part. The conduit may be a bore moulded in the insulating composition, or it may be a rigid tube, on which the bore in the generator is a sliding fit, or on which the generator may be clamped. In another alternative, the generator is detachably located in the handle part.

Abstract: An apparatus for controlling a color change sequence of automatic paint spray equipment. The apparatus controls the performance of various cleaning functions when it is desired to convert the spray equipment from spraying one color of paint to spraying of another color of paint. The apparatus includes a fluid motor coupled through a reducing transmission to a drum-type programmer. The drum-type programmer includes a set of program sections, each section being divided into a plurality of sectors and each sector adapted to receive a cam plug. Each section is programmed by inserting cam plugs in selected sectors thereof. Fluid switches are mounted adjacent the drum programmer, at least one switch being associated with each of the sections of the drum programmer and responsive to the presence and absence of cam plugs from various ones of the sectors in its respective section of the drum programmer to control a color change function.

Abstract: A printing device in which solvent dissolved toner is applied to a recording carrier to produce a symbol or image wherein a printing head is received interior of a housing with toner particles circulated in the housing in a gas stream. Solvent ejectors within the print head are positioned adjacent a slot opening of the housing and direct a toner-solvent stream against a recording carrier exterior of the housing.

Abstract: Safety device for an electrostatic painting plant using liquid coating products which are very electrically conductive, such as hydrosoluble paints or liquid enamel. An electrically insulating enclosure surrounds the container for the liquid coating material and has a latching device enabling the opening of the enclosure cover to be carried out only in a predetermined sequence, the first step of which causes the grounding of the paint container. The arrangement is such that the container can be disconnected from the ground only after the insulating enclosure cover has been replaced.

Abstract: In a hand held electrostatic type spray coating gun a removable cartridge lengthens the paint supply conduit between the base of the grounded handle and the barrel so that the gun can be used to spray paints which have moderate electrical conductivities such as those containing metallic particles. The cartridge includes a Teflon tube in the form of an elongated spiral. Fluid connections at each end of the cartridge allow the cartridge to be easily removed and stored, and a straight conduit substituted for it when it is not needed, for example when the gun is to be used for nonconductive paints. The location of the cartridge facilitates removal, and combines with the gun to provide a well balanced device for hand held operation.