Including Electrostatic Charging Patents (Class 239/3)
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Patent number: 5975426Abstract: A durable electrospray needle uses a capillary having a substantially large outside diameter. Provision of a porous bead at the spray tip advantageously allows a fine electrospray to be formed without the need for finely machining a needle tip and orifice, which allows for economical construction. Further, because the bead itself may serve as the anode in an electrospray field circuit, costs associated with electrode placement are eliminated.Type: GrantFiled: May 14, 1998Date of Patent: November 2, 1999Assignee: Waters Investments LimitedInventor: Peter Myers
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Patent number: 5947377Abstract: An electrostatic, liquid spray, rotary atomizer has an atomizer housing, a power supply within the housing and an atomizer cup at a front end of the housing. The atomizer cup, which is formed of a non-conductive material, has several elongate conductive pathways embedded in the body of the cup. Each conductive pathway has one end exiting an outer surface at a rear end of the cup for receiving the charge from the power supply and another end exiting an inner surface at a front end of the cup for conveying an electrical charge from the power supply to the liquid (paint) particles passing through the atomizer cup. An electrode is provided for maintaining a small voltage at the access hole.Type: GrantFiled: August 28, 1997Date of Patent: September 7, 1999Assignee: Nordson CorporationInventors: Michael P. Hansinger, Jeffrey A. Conrad, Woodie Francis, Harold Beam, Joseph Jerome Karbowniczek, Ronald Schroeder
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Patent number: 5924631Abstract: This invention relates to a triboelectric projector of pulverulent coating product, comprising a channel for charging the coating product, a supply conduit connecting a source of coating product to said projector, a mixture of air and of coating product circulating in said conduit, an injector of air for dilution and/or acceleration of said mixture of air and coating product, characterized in that the outlet orifice of said injector is disposed on the path of said mixture of air and coating product in an inner chamber of the projector, downstream of the admission of said conduit in said projector and upstream of the inlet of the charging channel. The invention also relates to a process for controlling such a projector, consisting in measuring the charge obtained in the charging channel and in servo-controlling by this charge the instantaneous flowrate of air injected by the injector.Type: GrantFiled: July 8, 1997Date of Patent: July 20, 1999Assignee: Sames SAInventors: Jose Rodrigues, Daniel Belmain, Thierry Barlet
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Patent number: 5915621Abstract: An electrostatic powder coating gun for dispersing aggregate powder onto substrates. The gun includes swirling air passage outlets to form a vortex of air inside the spray gun tip to reduce powder adhesion and assist in pulverizing the powder material. The coating gun employs a powder supply unit having a fluidized bed that includes temperature and humidity controls to adjust the temperature and humidity of the compressed air supplied to the spray gun and a mixer to agitate the powder in the container.Type: GrantFiled: October 16, 1997Date of Patent: June 29, 1999Assignees: Nippon Paint Co., Ltd., Nihon Parkerizing Co., Ltd.Inventors: Kenzo Yanagida, Masahiro Yamamoto, Mituyosi Kumata, Koichi Tsutsui, Shannon Libke
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Patent number: 5904294Abstract: An apparatus for use in directing a flow of air with particles entrained therein toward a workpiece includes a nozzle and a deflector. The nozzle has a passage with a noncircular cross sectional configuration. The deflector has an outer side surface with a circular cross sectional configuration. A flow of air with particles of powder entrained therein is conducted along outer surface areas on the deflector at a first volumetric flow rate. A flow of air with particles of powder entrained therein is conducted along outer surface areas on the deflector at a second volumetric flow rate which is greater than the first flow rate. The deflector includes a porous member which is releasably connected with a main portion of the deflector to facilitate cleaning and provide access to the interior of the deflector. Seal members are provided between an electrode sheet, the porous member, and the main portion of the deflector.Type: GrantFiled: September 13, 1996Date of Patent: May 18, 1999Assignee: Nordson CorporationInventors: Alan J. Knobbe, Terrence M. Fulkerson
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Patent number: 5894989Abstract: A plurality of linear elements or meshed elements are arranged in a powder paint transportation path in an electrostatic powder coating gun. The materials of the linear elements and meshed elements are capable of charging the powder paint by static electricity generated by friction between the powder paint and the elements.Type: GrantFiled: April 22, 1997Date of Patent: April 20, 1999Assignee: Kao CorporationInventors: Shinichiro Yasuda, Masayuki Maruta, Yukiya Sato
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Patent number: 5885661Abstract: An apparatus and method are provided for efficiently and effectively coating a substantially flat surface, i.e., a substrate, with a high-viscosity chemical such as photoresist. The chemical is dispensed through a piezo electrically controlled droplet jet cartridge on to the surface. The thickness of the chemical coating is controlled by controlling the rate at which chemical is dispensed through the droplet jet cartridge. A number of droplet jet cartridges are aligned such that gaps in chemical dispensed by one droplet jet cartridge are filled by chemical dispensed by other droplet jet cartridges. An array of droplet jet cartridges which spans the width of the surface moves across the surface to coat the surface with chemical in a single pass. To coat a circular surface, the surface is spun while a droplet jet cartridge is moved from the center of the surface to the outer edge of the surface. Chemical is dispensed on to the surface in a helical pattern.Type: GrantFiled: July 26, 1995Date of Patent: March 23, 1999Assignee: Semiconductor Systems, Inc.Inventor: William T. Batchelder
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Patent number: 5882591Abstract: Biological fluids, e.g. bodily fluids such as plasma/serum, semen, milk or blood, can be treated efficiently with ozone to inactivate certain viruses, bacteria, fungi etc. To effect and enhance the contact of such fluids with ozone, or another disinfecting or deactivating gas, the fluids are thoroughly nebulized, or atomized, i.e. dispersed into minute droplets. Nebulization has been found to afford a faster O.sub.3 -fluid reaction rate than other known methods. It is proposed to create a fine "rain" of droplets to fall through a controlled atmosphere of O.sub.3 /O.sub.2 and/or O.sub.3 /inert gas mixture. Electric and magnetic fields are superimposed over the space through which the droplets are passed.Three types of nebulizers/atomizers are described: compressed gas (O.sub.3 /O.sub.2 mixture) atomizer, ultrasonic nebulizer, and rotary nebulizer.The invention was tested on coliphage MS2 which is safe, easy to handle, and more resistant to chemical disinfections than viruses such as HIV. More than 7 log.sub.Type: GrantFiled: August 6, 1997Date of Patent: March 16, 1999Inventor: Mladen M. Kekez
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Patent number: 5873523Abstract: An electrospray apparatus incorporating the invention includes a capillary with an exit for ejecting a fluid, and an electrode positioned downstream from the exit. A gas source is used to establish a region of gas, at least immediately about the exit. A voltage supply creates a potential difference between the capillary exit and the electrode, the potential difference being sufficient to both establish a cone jet mode of operation at the exit of the capillary, to ionize the region of gas about the exit and create a current flow between the exit and the electrode. The current flow exhibits an increased value upon the gas becoming ionized, thus enabling detection of the establishment of a corona. This action creates a corona-assisted cone jet mode of electrospray operation which enables the fluid to disperse into highly uniform sized particles. The preferred gas is carbon dioxide.Type: GrantFiled: February 28, 1997Date of Patent: February 23, 1999Assignee: Yale UniversityInventors: Alessandro Gomez, Juan Fernandez de la Mora, Keqi Tang
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Patent number: 5762775Abstract: A method for use in electrically forming dispersions of a nonconducting fluid in a conductive medium that minimizes power consumption, gas generation, and sparking between the electrode of the nozzle and the conductive medium. The method utilizes a nozzle having a passageway, the wall of which serves as the nozzle electrode, for the transport of the nonconducting fluid into the conductive medium. A second passageway provides for the transport of a flowing low conductivity buffer fluid which results in a region of the low conductivity buffer fluid immediately adjacent the outlet from the first passageway to create the necessary protection from high current drain and sparking. An electrical potential difference applied between the nozzle electrode and an electrode in contact with the conductive medium causes formation of small droplets or bubbles of the nonconducting fluid within the conductive medium.Type: GrantFiled: November 15, 1996Date of Patent: June 9, 1998Assignee: Lockheed Martin Energy Systems, Inc.Inventors: David W. DePaoli, Constantinos Tsouris, James Q. Feng
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Patent number: 5725151Abstract: An electrospray adapted fuel injection valve includes an anode and cathode to inject monopolar electric charge into electrically insulating fuel. On exiting the injector, the charge containing fuel atomizes and disperses to reduce electrostatic energy. Additional electrodes with an appropriate method of biasing extend the range of applicability of the process by adjusting space charge distribution within the injector to compensate for variability in component manufacture and variability in the electrical conductivity of the fuel.Type: GrantFiled: October 3, 1996Date of Patent: March 10, 1998Assignee: Ford Global Technologies, Inc.Inventors: Robert Eugene Hetrick, Michael Howard Parsons
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Patent number: 5725150Abstract: A method and system for supplying electrically conductive coating materials to an electrostatic dispenser with a parallel arrangement of subsystems selectably coupled to the dispenser by a four-port system voltage blocking valve, which electrically isolates the subsystems. The subsystems each include first and second piston cylinders that alternatingly receive a selected coating material from a corresponding manifold and supply the coating material to the dispenser by a subsystem voltage blocking valve, which isolates the dispenser from the manifold, when coupled to the dispenser. The first and second piston cylinders of each subsystem also alternatingly receive a solvent from the corresponding manifold and direct the solvent to a waste receptacle by a corresponding subsystem voltage blocking valve when the subsystem is not coupled to the dispenser.Type: GrantFiled: May 15, 1996Date of Patent: March 10, 1998Assignee: Illinois Tool Works Inc.Inventors: Harold T. Allen, Edward T. Feldman, Varce E. Howe, Ghaffar Kazkaz, Jerry L. McPherson, Jr., James Scharfenberger
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Patent number: 5704977Abstract: For a rapid and simple assembly, the rotary atomizer of the coating arrangement described has a fastening pin (34) arranged on a valve unit (12). The fastening pin is inserted into a matching opening of a mounting flange (70) and is retained therein by a clamping device that exerts a force pressing the valve unit (12) against the flange (70). The atomizer is composed of individual modules (2,4,6,10,12) connected by screw connections and additionally comprises a rigid light guide rod for the transmission of optical rpm measuring signals, which remains in the valve unit (12) during disassembly of the atomizer.Type: GrantFiled: August 10, 1995Date of Patent: January 6, 1998Assignee: Behr Systems, Inc.Inventors: Michael Baumann, Harry Krumma, Frank Rupertus, Rolf Schneider, Kurt Vetter
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Patent number: 5685482Abstract: Induction charging apparatus for HVLP spray guns and air-assisted airless spray guns includes an air cap having a central orifice for receiving a spray gun nozzle. The cap includes one or more charging electrodes adjacent the orifice and carrying a voltage sufficiently large to induce on the spray droplets charges of a polarity opposite to that on the electrodes. A rotatable electrical connector enables the cap to rotate 360.degree. while maintaining electrical connections between the electrodes and a power supply. The spray gun nozzle is an airless nozzle receiving liquid at a pressure of about 1,000 psi and having a spray tip from which liquid is sprayed along a flow path coaxial with the electrodes. Air at less than about 10 psi is directed along the flow path to assist in the atomization of the liquid from the airless nozzle.Type: GrantFiled: April 20, 1995Date of Patent: November 11, 1997Inventor: James E. Sickles
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Patent number: 5655517Abstract: A device for dispensing a comminuted liquid to the upper respiratory tract, which comprises an electrohydrodynamic comminution means and a means for supplying a liquid to the comminution means. And a device for comminuting a liquid, the comminution site sit of which is provided by fibres projecting from an end surface or edge, the edge or surface being composed substantially of fibres.Type: GrantFiled: June 1, 1995Date of Patent: August 12, 1997Assignee: Electrosols, Ltd.Inventor: Ronald Alan Coffee
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Patent number: 5622313Abstract: In a triboelectric powder spray gun in which a charge is imparted to the powder triboelectrically by repeated impacts of the powder with contact surfaces, the charging effectiveness of the gun is enhanced by using an electrode to produce corona treatment of the contact surfaces. The corona treatments discharge the contact surfaces and eliminate the need for adjacent grounds with the powder flow path.Type: GrantFiled: March 3, 1995Date of Patent: April 22, 1997Assignee: Nordson CorporationInventors: Harry J. Lader, William R. Rehman, James W. Messerly
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Patent number: 5620138Abstract: Apparatus and methods for pumping a uniform flow of air entrained powder at low flow settings to a diffuser of an electrostatic spray gun which disperses the powder and cools the spray gun. A single or double stage pump with a bleed port design draws powder into the pump from a powder container when compressed air directed into the pump is above a predetermined pressure. In another embodiment, a pump delivers a constant velocity of air entrained powder to the spray gun.Type: GrantFiled: November 9, 1994Date of Patent: April 15, 1997Assignee: Nordson CorporationInventor: Gerald W. Crum
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Patent number: 5582347Abstract: A particle spray apparatus includes a spray gun having a deflector connected with a housing assembly. An electrode arrangement extends from the housing assembly into the deflector and is exposed to the flow of air with particles entrained therein to electrostatically charge the particles. The electrode arrangement is exposed to a flow of fluid to remove contaminants which may accumulate around components of the electrode arrangement. Accumulation of particles on an end surface of the deflector is discouraged by a flow of fluid from a chamber in the deflector through a porous member. The flow of fluid from the chamber is also conducted through a porous electrode sheet which extends along the porous member. Due to the relatively high voltage conducted through the electrode arrangement, an arc may tend to form in a passage along which fluid is conducted to the electrode arrangement. To prevent this from occurring, the passage through which fluid is conducted to the electrode arrangement is relatively long.Type: GrantFiled: October 11, 1994Date of Patent: December 10, 1996Assignee: Nordson CorporationInventors: Alan J. Knobbe, Terrence M. Fulkerson, Curtis B. Haller, John B. Wolanin
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Patent number: 5564628Abstract: A process and apparatus for controlling high vegetative and brush growth along a narrow, continuous strip of land along the sides of a roadway or other right-of-way comprising preparing a dilute aqueous herbicidal solution, particulating said solution into coarse or large droplets and imparting an electrostatic charge to the droplets of herbicidal solution, and spraying the particulated and electrostatically charged droplets of said solution upon a narrow, continuous strip of land along the side of a roadway with minimal encroachment of the spray upon the environmental land adjacent said strip, and apparatus for effectively and accurately performing such operations.Type: GrantFiled: November 25, 1991Date of Patent: October 15, 1996Assignee: Agro Statics, Inc.Inventors: Sue A. Hall, Donald J. Gardner
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Patent number: 5538186Abstract: An apparatus for transferring electrically conductive coating material comprises a filling station having a first coupling element connected to a source of the coating material and a shuttle carrying a second coupling element which is movable with respect to the filling station between a paint transfer position in which the coupling elements engage and a neutral position physically spaced from the filling station. The shuttle, in turn, is connected to the reservoir of a piston pump which communicates with one or more air operated or air assist spray guns. A high-voltage power supply is connected to the metal body of the piston pump to charge the electrically conductive coating material immediately before it is supplied to the spray gun.Type: GrantFiled: June 6, 1994Date of Patent: July 23, 1996Assignee: Nordson CorporationInventor: Ronald D. Konieczynski
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Patent number: 5529246Abstract: An outer tube 5 is integrally rotated with a rotating disk 17. A powder supply passage 16 for supply of powder particles is formed between an inner tube 15 and the outer tube 5. A lower end of the inner tube 15 is secured to a sub-disk 23, and a distributing passage 25 is formed as a space between the sub-disk 23 and the rotating disk 17. Air including powder particles introduced into a separation passage 41 is separated into air and powder in the separation passage 41, and the particles are fed to the distributing passage 25 through the powder supply passage 16. The powder particles falling in the powder supply passage 16 undergo a swirling motion in accordance with the rotation of the outer tube 5, and owing to the swirling motion, the powder particles in the powder supply passage 16 are distributed uniformly in the circumferential direction.Type: GrantFiled: January 21, 1994Date of Patent: June 25, 1996Assignee: Ransburg Industrial Finishing K.K.Inventors: Eiji Saito, Takao Murakami
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Patent number: 5520735Abstract: An apparatus is operable to sequentially spray powder onto each workpiece of a plurality of workpieces. The powder flows from an improved nozzle assembly as a series of pulses. Accumulation of powder on surfaces in the nozzle assembly is retarded by conducting a flow of fluid (air) from a source of fluid pressure through openings in the surfaces in the nozzle assembly. Thus, a plurality of openings are formed in a side wall of the nozzle assembly to enable fluid to flow through the openings in the side wall into the flow path of air and powder through the nozzle assembly to retard accumulation of powder on an inner side surface of the side wall. An inner deflector has an end surface which faces toward the workpiece and on which powder tends to accumulate. A flow of fluid is conducted through openings in the end surface of the inner deflector to retard the accumulation of powder on the end surface of the inner deflector.Type: GrantFiled: September 20, 1994Date of Patent: May 28, 1996Assignee: Nordson CorporationInventor: Douglas C. Mulder
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Patent number: 5409162Abstract: Induction charging apparatus for HVLP spray guns includes an air cap having a central fluid exit orifice for receiving the spray gun nozzle. The cap includes one or more charging electrodes surrounding the orifice and carrying a voltage sufficiently large to induce on the spray droplets charges of a polarity opposite to that on the electrodes. The cap includes a rotatable electrical connector to enable the cap to rotate 360.degree., while maintaining electrical connections between the electrodes and a power supply.Type: GrantFiled: August 9, 1993Date of Patent: April 25, 1995Inventor: James E. Sickles
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Patent number: 5402945Abstract: An improved method for row crop spraying whereby a solution is atomized by high speed air, imparted with an electrical charge, slowed with more high speed air, and deposited over crops including a nozzle for practicing such a technique. Such charged droplets are attracted to oppositely charged crops and are, therefore, more likely to adhere to crops than fall to the ground or to be swept away by the wind. Since a larger percentage of solution adheres to the plant, less solution can be applied thereby addressing both environmental and pecuniary concerns.Type: GrantFiled: January 22, 1993Date of Patent: April 4, 1995Assignee: Gervan Company InternationalInventor: Wallace A. Swanson, Jr.
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Patent number: 5397605Abstract: In a method of electrostatic painting, the air to be conveyed towards the spraying nozzle (10) of a gun (9) together with the powdered paint, is enriched with at least one additive gaseous fluid consisting of at least one gas supplied from a feeding bottle (136, 137, 138, 139) and/or vapor obtained by submitting the air to bubbling through a working liquid (115). The additive fluid which has a greater electric conductivity than the air, causes an increase in the paint amount coated on the workpiece (11) in relation to the paint amount sprayed from the nozzle (10).Type: GrantFiled: May 18, 1993Date of Patent: March 14, 1995Inventor: Girolamo Barbieri
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Patent number: 5395046Abstract: A hand-held powder spray gun includes a wand type handle that extends from the top of the handle and away from the rear of the gun, which provides for ergonomic operation of the gun. The wand handle can be converted to a pistol handle by removal of the handle from the gun body. The parts of the wand handle and the pistol handle are interchangeable to facilitate conversion and repair. The wand handle can be used with a diffuser having hose connections extending from the rear of the spray gun to make the gun easier to operate when held from above. A diffuser having hose connections at the bottom is also provided for use with a pistol type handle.Type: GrantFiled: October 25, 1993Date of Patent: March 7, 1995Assignee: Nordson CorporationInventors: Alan J. Knobbe, Gerald W. Crum, Curtis B. Haller
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Patent number: 5378957Abstract: Apparatus for dispersing a fluent material such as a liquid includes a device for discharging a stream of the fluent material and a device for providing energetic electrons such that the electrons impinge on the fluent material to provide a net negative charge on the fluent material in the discharged stream. The fluent material discharged is dispersed at least partially under the influence of the net negative charge so imparted. The electron-supply device includes a chamber separated from the fluid passageway by an electron-permeable membrane, and may also include an electron gun for generating a beam of energetic electrons such that the electron beam passes through the window and impinges on the fluent material. The electrons may impinge on the fluent material as the fluent material is discharged from the device so that the fluid flow carries the charged portions of the fluent material away from the device. The apparatus may be used to atomize liquids even where the liquids are electrically conductive.Type: GrantFiled: June 11, 1992Date of Patent: January 3, 1995Assignee: Charged Injection CorporationInventor: Arnold J. Kelly
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Patent number: 5341989Abstract: An electrostatic powder spray gun includes a hose purge adapter connected in the hose line that supplies powder to the gun. The hose purge adapter is connected to a supply of purge gas and allows the powder flow path in the hose line and the powder flow path in the gun to be quickly and conveniently purged of accumulations of powder. By facilitating purging of the powder flow path, the purge adapter prevents accumulations of powder that may tend to come loose as a soft lump of powder, usually different in color, and cause an imperfection on the surface of the object being coated. The purge adapter also reduces the collections of powder in the flow path in the hose line which facilitate a grounding path by the powder, resulting in possible shocks to the operator and in a high current draw into the gun which can result in poor transfer efficiency.Type: GrantFiled: February 16, 1993Date of Patent: August 30, 1994Assignee: Nordson CorporationInventors: Terrence M. Fulkerson, Robert R. Pallante
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Patent number: 5341990Abstract: An apparatus for transferring electrically conductive coating material comprises a filling station having a first coupling element connected to a source of the coating material and a shuttle carrying a second coupling element which is movable with respect to the filling station between a paint transfer position in which the coupling elements engage and a neutral position physically spaced from the filling station. The shuttle, in turn, is connected to the reservoir of a piston pump which communicates with one or more air operated or air assist spray guns. A high-voltage power supply is connected to the metal body of the piston pump to charge the electrically conductive coating material immediately before it is supplied to the spray gun.Type: GrantFiled: June 11, 1993Date of Patent: August 30, 1994Assignee: Nordson CorporationInventor: Ronald D. Konieczynski
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Patent number: 5332154Abstract: An electrostatic spray nozzle that is positioned at an angle above horizontal and less than vertical having a body with an upper fluid emitting end and a lower bottom end. The body having an interior cavity therein. Within the cavity is a shim capable of conducting electricity that defines an opening at the fluid emitting end and a channel that joins the fluid emitting end opening to a supply of flowable material. The body has an enclosed electrode external adjacent to and below the emitting end. Both the shim and the electrode are electrically connected to a voltage source. The nozzle, in operation, bends the field adjacent the emitting end upwardly in accordance with the method of the invention.Type: GrantFiled: February 28, 1992Date of Patent: July 26, 1994Assignee: Lundy and AssociatesInventors: Barry G. Maier, Bruce A. Hunnicutt
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Patent number: 5328093Abstract: The invention includes an electrically isolated electrically less-conductive component fluid-flow course and an electrically-grounded electrically more-conductive component fluid-flow course. The electrically more-conductive component fluid-flow course may be additionally electrically isolated at the preference of an operator. The invention includes an electrostatic spray gun a mixer positioned proximal to the electrostatic spray gun, and a first conduit which holds alternating segments of electrically more-conductive component and electrically less-conductive component. The alternating segments function in series to additively provide a combined resistance which electrically blocks the high-voltage potential generated at the electrostatic spray gun.Type: GrantFiled: July 28, 1993Date of Patent: July 12, 1994Assignee: Graco Inc.Inventor: Ann Feitel
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Patent number: 5326031Abstract: An apparatus for transferring electrically conductive coating materials, such as water-based paint, from at least one source to one or more coating dispensers or spray guns for discharge onto a substrate includes two "parallel" flow paths, each having a large reservoir pump, which transmit coating material to a common valve which, in turn, switches flow to the coating dispensers from one flow path to the other. Each parallel flow path provides a voltage block between one or more sources of coating material and the electrostatically charged coating material discharged from the spray guns to ensure that there is never a completed electrical path between the source of conductive coating material and the charged coating material during a coating operation. Additionally, a rapid and efficient color change capability is provided for the entire system which permits different colored coating materials to be dispensed from the apparatus herein with minimum downtime of the coating operation.Type: GrantFiled: October 15, 1992Date of Patent: July 5, 1994Assignee: Nordson CorporationInventor: Ronald D. Konieczynski
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Patent number: 5322684Abstract: A potent cosmetically active material such as a perfume is delivered to the body by electrostatic spraying. The active material can be sprayed at ultra-low flow rates, preferably in neat or substantially neat form.Type: GrantFiled: July 9, 1992Date of Patent: June 21, 1994Assignee: Elizabeth Arden Co., Division of Conopco, Inc.Inventors: Philip J. Barnett, Michael R. Lowry
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Patent number: 5316800Abstract: A coating is applied to a substrate by conveying the substrate past a number of liquid spraying nozzles (32) to which high voltage is applied to produce spray in the form of liquid ligaments which deposit as such, or in the form of droplets, on the substrate to form generally parallel tracks which merge with each other to produce a substantially uniform thickness coating. The nozzles (32) are operable in two modes: a normal spraying mode and a deflect mode in which the ligaments are deflected away from the substrate and towards a collector electrode (34). Operation of the nozzles (32) may be co-ordinated so that different formulations are deposited as separate panels in succession lengthwise of the substrate. The coating system is particularly suitable for coating multicoloured dyesheets for use in thermal transfer printing.Type: GrantFiled: August 9, 1991Date of Patent: May 31, 1994Assignee: Imperial Chemical Industries PLCInventors: Timothey J. Noakes, Ian D. Pavey, Christopher S. Jeffs
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Patent number: 5292067Abstract: Relatively low resistivity liquids are formed into sprays under the influence of an applied electric field acting between a nozzle and the nozzle surroundings which may be at earth potential. The liquid issues from the nozzle as a ligament which undergoes necking to a diameter smaller than that of the nozzle orifice, thereby producing droplets with a volume median diameter less than the orifice diameter.Type: GrantFiled: March 2, 1992Date of Patent: March 8, 1994Assignee: Imperial Chemical Industries PLCInventors: Andrew Jeffries, Michael L. Green, Timothy J. Noakes
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Patent number: 5288525Abstract: A system for coupling a grounded color changer to an electrostatic coating material sprayer electrically isolates the color changer from a high voltage at the sprayer. The system has a fluid path extending from the color changer to the sprayer and a reservoir is coupled to the fluid path at a connection point intermediate the color changer and sprayer. To fill the system with coating material to be sprayed, the fluid path to the sprayer is first filled with coating material from the color changer, following which the remaining coating material to be sprayed during the coating operation is flowed from the connection point into the reservoir. At least a portion of the fluid path between the connection point and the color changer is then cleaned of coating material to electrically isolate the reservoir and the sprayer from the color changer. Coating material is then delivered from the reservoir to the sprayer for being subjected to a high voltage and emitted in an electrostatically charged atomized spray.Type: GrantFiled: March 24, 1992Date of Patent: February 22, 1994Assignee: Binks Manufacturing CompanyInventor: Michael J. Diana
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Patent number: 5271569Abstract: An apparatus is provided for transferring electrically conductive coating materials, such as water-based paint, from at least one source to one or more coating dispensers for discharge onto a substrate. One voltage block is provided to avoid the creation of an electrical path between one or more sources of coating material and the coating material which is electrostatically charged during a coating operation, and a secondary voltage block is provided between each of a number of individual spray guns and the charged coating material so that each spray gun can be electrically isolated from the charged coating material when not in use. The apparatus is optionally provided with a color changer, and/or a heater which is electrically isolated from the charged coating material and is effective to elevate the temperature of the coating material prior to discharge from the spray guns.Type: GrantFiled: October 9, 1992Date of Patent: December 21, 1993Assignee: Nordson CorporationInventors: Ronald D. Konieczynski, Bruce C. Hills, Kenneth J. Coeling
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Patent number: 5229171Abstract: An apparatus and method including a droplet coating generator for generating a stream of electrically charged coating droplets within an evacuable chamber towards a substrate positioned within the evacuable chamber. A piezoelectric vibrator and orifice plate coupled thereto generate the stream of coating droplets. The coating droplets are urged to move in a sweeping motion across the substrate by at least one pair of opposing spaced apart electrodes powered by an electrical power supply. A uniform coating is thus produced while the evacuable chamber is maintained at subatmospheric pressure as required during typical semiconductor processing. Multiple applications of a photoresist coating may be applied by the coating apparatus without requiring that the evacuable chamber be repeatedly vented and pumped down to subatmospheric pressure.Type: GrantFiled: December 23, 1991Date of Patent: July 20, 1993Assignee: Research Triangle InstituteInventors: Robert P. Donovan, Ravindran Periasamy, Anthony C. Clayton, David S. Ensor
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Patent number: 5222664Abstract: An electrostatic spraying device in which liquid emerging from an outlet (24) of the device nozzle (12) is subjected to an electrical field sufficiently high for the liquid to be drawn from the outlet as one or more ligaments which break up into charged droplets to form the spray. In order to provide shock suppression, the electrical field is produced by means of high voltage circuitry having a bi-polar output with a frequency no greater than 10 Hz.Type: GrantFiled: July 25, 1991Date of Patent: June 29, 1993Assignee: Imperial Chemical Industries PLCInventors: Timothy J. Noakes, Brian Reed, John J. Chambers
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Patent number: 5222663Abstract: An electrostatic spraying device in which liquid emerging from an outlet of the device nozzle (12) is subjected to an electrical field sufficiently high for the liquid to be drawn from the outlet as one or more ligaments which break up into charged droplets to form the spray. The device is adapted for the spraying of targets which are conventionally difficult to coat electrostatically, eg. targets of insulating material. This is achieved by the use of circuitry (18, 20, 22, 24) which generates a bi-polar high voltage output having a frequency such that successive clouds of particles are charged with opposite polarity but do not discharge each other in flight. In this way, the charge applied to the particles is effective to assist seeking of the target without leading to build-up of charge on the target.Type: GrantFiled: July 25, 1991Date of Patent: June 29, 1993Assignee: Imperial Chemical Industries PLCInventors: Timothy J. Noakes, Brian A. Reed, John J. Chambers
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Patent number: 5219690Abstract: A process for coating a substrate such as a photoreceptor is performed by delivering at least two fluid streams to a bell of a rotary atomizer, combining the fluid streams substantially at the bell of the rotary atomizer such that the bell atomizes and mixes the fluid streams into a substantially homogenous atomized mixture, and depositing the mixture onto the substrate in the form of a layer on the substrate. The process is useful for depositing a plurality of different substances, such as two charge generating pigments, on the surface of a substrate such as a photoreceptor. Because the substances are combined substantially at the bell of the rotary atomizer and subsequently dried or polymerized, different substances can be incorporated into a single layer on the substrate that would normally not be combinable due to interaction between the plurality of substances such as agglomeration.Type: GrantFiled: April 12, 1991Date of Patent: June 15, 1993Assignee: Xerox CorporationInventor: John M. Hammond
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Patent number: 5208078Abstract: Disclosed herein is a method of paint application. This method has the following advantageous effects. More specifically, when different paint is used, desired paint is alternately supplied to a first paint feeder and a second paint feeder from a paint feed source thereby to enable efficient painting of a workpiece by a spray gun. On the other hand, when the same paint is used, the paint is supplied only to the first paint feeder without using the second paint feeder, thereby making it possible to reduce wastefully-discharged paint and to efficiently carry out any cleaning work.Type: GrantFiled: June 27, 1991Date of Patent: May 4, 1993Assignee: Honda Giken Kogyo Kabushiki KaishaInventors: Ichirou Ishibashi, Yoshio Tomioka, Toshio Kubota, Niichi Toyama
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Patent number: 5188291Abstract: The invention relates to a fluid distribution device in the form of a sprayer. A preferred embodiment of the sprayer uses a rotating fluid conduit which makes use of centrifugal force to break up fluid emerging from the conduit into fine droplets. Air flow though the preferred embodiment may shear the fluid droplets and assist in carrying them to the desired target. An apparatus for placing an electrostatic charge on the droplets may also be used.Type: GrantFiled: May 29, 1990Date of Patent: February 23, 1993Assignee: Her Majesty the Queen in right of New ZealandInventor: David J. Cross
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Patent number: 5188290Abstract: In an electrostatic compressed air paint spray gun, the overall exit area of the compressed air discharge opening as well as the pressure and the quantity of the supplied compressed air are dimensioned such and matched such to one another that, first, the ratio (V.sub.L) of the air pressure (P.sub.1) prevailing immediately upstream of the compressed air discharge opening to the air pressure (P.sub.2) prevailing downstream of the compressed air discharge opening is less than 2:1 and, second, quantity and flow rate of the compressed air emerging from the compressed air discharge opening and magnitude of the applied high-voltage guarantee an adequate atomization of the paint as well as a conveying of the atomized paint particles to the workpiece with a given paint throughput and given paint viscosity. A high precipitation efficiency and a good paint compass are thus achieved.Type: GrantFiled: February 12, 1991Date of Patent: February 23, 1993Assignee: J. Wagner GmbHInventors: Gerhard Gebauer, Johann Gruber
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Patent number: 5176321Abstract: A device for electrostatically charging and dispensing a high resistivity cutting lubricant to a workpiece includes a source of high resistivity cutting lubricant and a capillary tube having an entrant end in fluid communication with the high resistivity cutting lubricant and a tapered discharge end forming a sharp point. A high voltage power supply is used for generating a high voltage of less than 5,000 volts d.c. The power supply has a positive terminal and a negative terminal. A high voltage electrode has its one end connected to the positive terminal of the power supply and has its other end operatively coupled to the discharge end of the capillary tube. A nearby grounded electrode is disposed in a spaced-apart relationship from the discharge end of the capillary tube so as to create a high electric field therebetween for electrostatically charging the lubricant.Type: GrantFiled: November 12, 1991Date of Patent: January 5, 1993Assignee: Illinois Tool Works Inc.Inventor: James E. Doherty
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Patent number: 5173274Abstract: Method and apparatus are presented for producing liquid aerosol particles of narrow size distribution by dispersing one or more droplet columns and impinging these droplets onto a vibrating cavitation surface to create a high density fountain of aerosol particles. Flash cavitation of these impinging droplets is achieved through controlled disruption on impact of the impinging liquid droplets with a vibrating surface wherein the measured size and frequency of droplets promote complete disruption of the droplets into aerosol particles with substantially no splash disruption or agglomeration thus efficiently producing small liquid aerosol particles having a narrow size dispersion range.Type: GrantFiled: August 16, 1991Date of Patent: December 22, 1992Assignee: Southwest Research InstituteInventor: Thomas E. Owen
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Patent number: 5165601Abstract: In the broader aspects of the invention there is provided an improved nozzle, an improved nozzle assembly and an improved method in which the improved nozzle comprises a protrusion having an distal end and a collar extending backward from the distal end. The collar is surface free of discontinuities. The outer end has an edge and an adjacent point at which the charge is concentrated. The protrusion has a fluid passage. The fluid passage is sealed from the collar surface. The fluid passage has an outlet adjacent the edge. A conductor is disposed in the protrusion. The conductor extends into the passage and is immersed in the fluid being disposed.Type: GrantFiled: April 11, 1990Date of Patent: November 24, 1992Assignee: Terronics Development CorporationInventors: Phillip R. Rodenberger, Bruce A. Hunnicutt
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Patent number: 5115971Abstract: The present invention constitutes a portable neubulizer capable of producing a finely divided aerosol having uniformly sized droplets. The nebulizer includes a source of fluid such as a capillary tube coupled to a fluid reservoir to which a high voltage is applied in order to generate the aerosol by electrical atomization. The nebulizer further includes a piezoelectric crystal and a mechanism for deforming the crystal so as to generate the required voltage. By using electrical atomization to generate the aerosol and by piezoelectrically generating the voltage required for atomization, a nebulizer is provided which may be of small size so as to be suitable for hand held operations yet is capable of producing measured amounts of finely divided aerosols which are substantially monodispersed.Type: GrantFiled: September 23, 1988Date of Patent: May 26, 1992Assignee: Battelle Memorial InstituteInventors: Bernard J. Greenspan, Owen R. Moss
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Patent number: H1691Abstract: Particles of spray solution are given with an electrostatic charge by applying voltage of 300 to 800 V thereon as the solution passes through the tip of the spray nozzle of an electrostatic spray dispenser.Type: GrantFiled: March 4, 1996Date of Patent: November 4, 1997Inventors: Tateo Ono, Susumu Miyashita
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Patent number: RE35883Abstract: An apparatus for transferring electrically conductive coating materials, such as water-based paint, from at least one source to one or more coating dispensers or spray guns for discharge onto a substrate includes two "parallel" flow paths, each having a large reservoir pump, which transmit coating material to a common valve which, in turn, switches flow to the coating dispensers from one flow path to the other. Each parallel flow path provides a voltage block between one or more sources of coating material and the electrostatically charged coating material discharged from the spray guns to ensure that there is never a completed electrical path between the source of conductive coating material and the charged coating material during a coating operation. Additionally, a rapid and efficient color change capability is provided for the entire system which permits different colored coating materials to be dispensed from the apparatus herein with minimum downtime of the coating operation.Type: GrantFiled: July 3, 1996Date of Patent: September 1, 1998Assignee: Nordson CorporationInventor: Ronald D. Konieczynski