US3895262A - Apparatus for coating articles by means of electrostatically charged articles - Google Patents

Apparatus for coating articles by means of electrostatically charged articles Download PDF

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Publication number
US3895262A
US3895262A US501707A US50170774A US3895262A US 3895262 A US3895262 A US 3895262A US 501707 A US501707 A US 501707A US 50170774 A US50170774 A US 50170774A US 3895262 A US3895262 A US 3895262A
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US
United States
Prior art keywords
electrodes
voltage
articles
voltage generator
circuit arrangement
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired - Lifetime
Application number
US501707A
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English (en)
Inventor
Peter Ribnitz
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Gema Switzerland GmbH
Original Assignee
Gema AG
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Publication date
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Publication of US3895262A publication Critical patent/US3895262A/en
Assigned to RANSBURG-GEMA AG, A SWISS CORP. reassignment RANSBURG-GEMA AG, A SWISS CORP. ASSIGNMENT OF ASSIGNORS INTEREST. Assignors: GEMA AG APPARATEBAU, A SWISS CORP.
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

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Classifications

    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02M—APPARATUS FOR CONVERSION BETWEEN AC AND AC, BETWEEN AC AND DC, OR BETWEEN DC AND DC, AND FOR USE WITH MAINS OR SIMILAR POWER SUPPLY SYSTEMS; CONVERSION OF DC OR AC INPUT POWER INTO SURGE OUTPUT POWER; CONTROL OR REGULATION THEREOF
    • H02M7/00—Conversion of ac power input into dc power output; Conversion of dc power input into ac power output
    • H02M7/02—Conversion of ac power input into dc power output without possibility of reversal
    • H02M7/04—Conversion of ac power input into dc power output without possibility of reversal by static converters
    • H02M7/06—Conversion of ac power input into dc power output without possibility of reversal by static converters using discharge tubes without control electrode or semiconductor devices without control electrode
    • H02M7/10—Conversion of ac power input into dc power output without possibility of reversal by static converters using discharge tubes without control electrode or semiconductor devices without control electrode arranged for operation in series, e.g. for multiplication of voltage
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B05—SPRAYING OR ATOMISING IN GENERAL; APPLYING FLUENT MATERIALS TO SURFACES, IN GENERAL
    • B05B—SPRAYING APPARATUS; ATOMISING APPARATUS; NOZZLES
    • B05B5/00—Electrostatic spraying apparatus; Spraying apparatus with means for charging the spray electrically; Apparatus for spraying liquids or other fluent materials by other electric means
    • B05B5/08—Plant for applying liquids or other fluent materials to objects
    • B05B5/10—Arrangements for supplying power, e.g. charging power
    • G—PHYSICS
    • G05—CONTROLLING; REGULATING
    • G05F—SYSTEMS FOR REGULATING ELECTRIC OR MAGNETIC VARIABLES
    • G05F3/00—Non-retroactive systems for regulating electric variables by using an uncontrolled element, or an uncontrolled combination of elements, such element or such combination having self-regulating properties
    • G05F3/02—Regulating voltage or current
    • G05F3/08—Regulating voltage or current wherein the variable is dc
    • G05F3/10—Regulating voltage or current wherein the variable is dc using uncontrolled devices with non-linear characteristics
    • G05F3/16—Regulating voltage or current wherein the variable is dc using uncontrolled devices with non-linear characteristics being semiconductor devices
    • G05F3/18—Regulating voltage or current wherein the variable is dc using uncontrolled devices with non-linear characteristics being semiconductor devices using Zener diodes

Definitions

  • ABSTRACT An apparatus for coating articles or the like by means [21] Appl' 501,707 of electrostatically charged particles comprising at least two electrodes associated with an atomizer noz- [30] Foreign Application priority Data file l:or tlhese particles anfd a gelg ulatable or controllable 1g -vo tage generator or e iverlng a respective p0- Sept. 13,1973 Switzerland 13191/73 tential of different magnitude but the Same g o [52] U 8 Cl 3175, 321/15 both electrodes.
  • a stabilizing stage is provided be- [51] U B65) 5/02 tween the high-voltage generator and the electrodes, [58] Field iiiiiiiiiiiiiiii I. IIIIIIIIIII 321/15 this stage maintaining constant-the potential difference between the electrodes at a predetermined value [56] References Cited over the entire regulation range of the operating voltage of the high-voltage generator with regard to the UNITED STATES PATENTS articles. 3,335,322 8/1967 Epstein et a1.
  • the present invention relates toa new and improved construction of apparatus for coating articles or the like by means of electrostatically charged particles and comprising at least two electrodes associated with an atomizer nozzle for these particles, and a regulatable high-voltage generator which delvers to both electrodes a respective potential of different magnitude but the same sign.
  • the transport field exists between the electrodes on the one hand and on the other hand the articles to be coated which as a general rule are grounded.
  • the field intensity of this transport field is essentially dependent upon the operating voltage of the high-voltage generator with regard to the article, i.e. the absolute value of the potential delivered by the high-voltage generator to the electrodes as well as upon the spacing between the electrodes and the article. Further parameters which influence the local value of the field intensity of the transport field are, for instance, the geometric shapes of the articles or the electrodes and the atomizer nozzle respectively.
  • the field intensity of the transport field is regulated from case to case to an optimum value by adusting the high-voltage generator especially if the transport field is not solely decisive for the transport of the charged particles to the article to be coated. Quite to the contrary, for this transport there is decisive both the propellant gas used for the atomization of the particles as well as also the transport field.
  • the second field which is formed at such equipment exists between the electrodes and is hereinafter referred to as the charging field.
  • Its field intensity is dependent upon the potential difference between both electrodes which normally is only a fraction of the absolute value of the electrode potential, and upon the spacing between both electrodes which, in comparison to the'spacing between the electrodes on the one hand and the article on the other hand, is very small. Therefore as a general rule the field intensity of the charging field attains higher values than the field intensity of the transport field.
  • This charging field is decisive for the charging of the particles. It should be self evident that the charging of the particles is of paramount importance for the quality of the attainable coating. Therefore attempts are made to maintain this charging and therefore also the field intensity of the charging field always at a maximum value.
  • the proposed apparatus of this development is manifested by the features that there is provided a stabilization stage between the high-voltage generator and the electrodes and which maintains constant at a predetermined value the potential difference between the electrodes throughout the entire regulation range of the operating voltage of the high-voltage generator with regard to the articles.
  • this stabilization stage can contain a diode operating in the cut-off range and the breakdown voltage of which essentially corresponds to the predetermined value.
  • a high-voltage generator possessing a voltage divider arrangement or voltage multiplier circuit arrangement, of which arrangement two different stages are connected with the electrodes, when it is advantageous to bridge both of these different stages by means of the diode.
  • FIG. 1 is a schematic illustration of an exemplary embodiment of apparatus .designed according to the teachings of the invention; and I I FIG. 2 schematically illustrates part of a variant embodiment.
  • an atomizer nozzle 11 constructed as a tube or pipe.
  • the atomizer nozzle 11 is charged in the direction of the arrow 12 with a suspension of particles in a propellant gas.
  • the electrodes 13 and 15 and the electrodes 14 and 16 are arranged in offset relationship in the peripheral direction by with respect to one another. Both of these electrode pairs can be located at the same height in the atomizer nozzle 11 or also offset in lengthwise direction.
  • an article or object 17 hereinafter simply referred to as article, which is grounded by means of the conductor or line 18.
  • This conductor 18 as a general rule is formed by the support or holder by means of which the article 17 is held in front of or-movedpastin front of. the atomizer '11.
  • the last stage of the cascade is connected through the agency of a current limitingresistor 27 and the conductors .or lines 28, 29 and 30 with the electrodes 14and l6. Bothof these elec- .trodes therefore always possess the same potential.
  • third last stage of the cascade is connected on the other hand via a resistor 31 as well as the conductors 32,33 and 34 with the electrodes 13 and 15. Both of these electrodes 13 and therefore possessthe same potential which however is different from the potential of both electrodes 14 and 16.
  • This potential difference between the electrodes 13 and 15 and 14 and 16 as well as the distance d between the electrodes 15 and 16 are decisive for the field intensity of the charging field which prevails at the region of the outlet opening of the atomizer nozzle 1 1
  • a diode 35 which bridges or shunts both of the last I stages of the cascade.
  • This diode operates in its cut-off range and maintains the charging voltage of the capacitors 24 and 25 of the last two stages of the cascade at a value which approximately corresponds to the diode breakdown voltage. Accordingly the potential differg ence prevailing between the electrodes 13, 15 and 14,
  • 16 equals the breakdown voltage of the diode and taken is in the order of between 'and 100 kV, and that the potential difference which is ideal for the charging is in the order of between 5-10 kV, then'it is 1' sufficient to select a diode 35, the breakdown voltage of which in the cut-offrange is in the order of 5 10 kV.
  • An apparatus for coating articles by means of electrostatically charged;- particles comprising at'least two A electrodes operatively associated with an atomizer noz- -zle-forthe particles, a regulatable high-voltage genera- 30 tor .for delivering to both electrodes a respective poten- -tial of different magnitude but the same sign, the improvement comprising a stabilizing stage provided between the high-voltage. generator and the.,electrodes, .said stabilizing stage maintaining substantially constant -at a predetermined value the potential-difference between the electrodes over the entire regulation range of the operating voltage of the high-voltage generator with regard to the articles.
  • said stabilizing stage contains a diode operating in the cut- .off rangeand the breakdown voltage of which essentially corresponds'to said predetermined value.

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  • Engineering & Computer Science (AREA)
  • Physics & Mathematics (AREA)
  • Nonlinear Science (AREA)
  • Electromagnetism (AREA)
  • General Physics & Mathematics (AREA)
  • Radar, Positioning & Navigation (AREA)
  • Automation & Control Theory (AREA)
  • Power Engineering (AREA)
  • Electrostatic Spraying Apparatus (AREA)
  • Application Of Or Painting With Fluid Materials (AREA)
US501707A 1973-09-13 1974-08-29 Apparatus for coating articles by means of electrostatically charged articles Expired - Lifetime US3895262A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
CH1319173A CH555704A (de) 1973-09-13 1973-09-13 Einrichtung zum beschichten von gegenstaenden mittels elektrostatisch aufgelandenen partikeln.

Publications (1)

Publication Number Publication Date
US3895262A true US3895262A (en) 1975-07-15

Family

ID=4390177

Family Applications (1)

Application Number Title Priority Date Filing Date
US501707A Expired - Lifetime US3895262A (en) 1973-09-13 1974-08-29 Apparatus for coating articles by means of electrostatically charged articles

Country Status (6)

Country Link
US (1) US3895262A (de)
JP (1) JPS575586B2 (de)
CH (1) CH555704A (de)
DE (1) DE2438856C3 (de)
FR (1) FR2243741B1 (de)
GB (1) GB1456290A (de)

Cited By (14)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4073002A (en) * 1976-11-02 1978-02-07 Ppg Industries, Inc. Self-adjusting power supply for induction charging electrodes
US4157162A (en) * 1976-11-09 1979-06-05 Benedek Gyoergy Electrostatic spraying apparatus
US4385340A (en) * 1980-05-02 1983-05-24 Asahiokuma Sangyo Kabushiki Kaisha Method and apparatus for generating static electricity
US4554622A (en) * 1983-09-22 1985-11-19 Graco Inc Compact voltage multiplier for spray guns
US4745520A (en) * 1986-10-10 1988-05-17 Ransburg Corporation Power supply
US5159544A (en) * 1988-12-27 1992-10-27 Ransburg Corporation High voltage power supply control system
US5566042A (en) * 1993-04-08 1996-10-15 Nordson Corporation Spray gun device with dynamic loadline manipulation power supply
US5907469A (en) * 1996-04-16 1999-05-25 Samsung Display Devices Co., Ltd. Multiple charged developing gun
US5978244A (en) * 1997-10-16 1999-11-02 Illinois Tool Works, Inc. Programmable logic control system for a HVDC power supply
US6144570A (en) * 1997-10-16 2000-11-07 Illinois Tool Works Inc. Control system for a HVDC power supply
US20050136733A1 (en) * 2003-12-22 2005-06-23 Gorrell Brian E. Remote high voltage splitter block
DE102007060211A1 (de) 2007-12-14 2009-06-18 Itw Gema Gmbh Verfahren und Vorrichtung zum elektrostatischen Sprühbeschichten von Objekten
US7817208B1 (en) 1981-11-03 2010-10-19 Personalized Media Communications, Llc Signal processing apparatus and methods
US10272454B2 (en) * 2013-12-04 2019-04-30 Thomas Mayer Compressed air treatment chamber

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4323947A (en) * 1979-08-13 1982-04-06 J. Wagner Ag. Electrostatic gun with improved diode-capacitor multiplier

Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3335322A (en) * 1966-05-06 1967-08-08 Borg Warner Charge head array for electrostatic printing system
US3599038A (en) * 1969-07-28 1971-08-10 Hipotronics Apparatus and systems for high-voltage electrostatic charging of particles
US3608823A (en) * 1969-06-25 1971-09-28 Gema Ag Apparatus for the electrostatic coating of objects with atomized solids particles
US3731145A (en) * 1970-11-23 1973-05-01 Nordson Corp Electrostatic spray gun with self-contained miniaturized power pack integral therewith
US3787722A (en) * 1972-11-16 1974-01-22 Rca Corp Printing apparatus

Family Cites Families (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE1007417B (de) * 1955-01-14 1957-05-02 Licentia Gmbh Spannungsregel- und Stabilisierungseinrichtung fuer selbsterregte elektrostatische Generatoren
DE1402626C3 (de) * 1957-04-08 1975-06-12 Ransburg Electro-Coating Corp., Indianapolis, Ind. (V.St.A.) Vorrichtung zum elektrostatischen Niederschlagen von Überzugsmaterial auf einen Gegenstand
AT302511B (de) * 1969-06-25 1972-10-25 Gema Ag Appbau Vorrichtung zum elektrostatischen Beschichten von Gegenständen mit zerstäubten Feststoffpartikeln
FR2158582A5 (de) * 1971-08-02 1973-06-15 Tunzini Sames

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3335322A (en) * 1966-05-06 1967-08-08 Borg Warner Charge head array for electrostatic printing system
US3608823A (en) * 1969-06-25 1971-09-28 Gema Ag Apparatus for the electrostatic coating of objects with atomized solids particles
US3599038A (en) * 1969-07-28 1971-08-10 Hipotronics Apparatus and systems for high-voltage electrostatic charging of particles
US3731145A (en) * 1970-11-23 1973-05-01 Nordson Corp Electrostatic spray gun with self-contained miniaturized power pack integral therewith
US3787722A (en) * 1972-11-16 1974-01-22 Rca Corp Printing apparatus

Cited By (17)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4073002A (en) * 1976-11-02 1978-02-07 Ppg Industries, Inc. Self-adjusting power supply for induction charging electrodes
US4157162A (en) * 1976-11-09 1979-06-05 Benedek Gyoergy Electrostatic spraying apparatus
US4385340A (en) * 1980-05-02 1983-05-24 Asahiokuma Sangyo Kabushiki Kaisha Method and apparatus for generating static electricity
US7817208B1 (en) 1981-11-03 2010-10-19 Personalized Media Communications, Llc Signal processing apparatus and methods
US4554622A (en) * 1983-09-22 1985-11-19 Graco Inc Compact voltage multiplier for spray guns
US4745520A (en) * 1986-10-10 1988-05-17 Ransburg Corporation Power supply
US5159544A (en) * 1988-12-27 1992-10-27 Ransburg Corporation High voltage power supply control system
US5566042A (en) * 1993-04-08 1996-10-15 Nordson Corporation Spray gun device with dynamic loadline manipulation power supply
US5907469A (en) * 1996-04-16 1999-05-25 Samsung Display Devices Co., Ltd. Multiple charged developing gun
US5978244A (en) * 1997-10-16 1999-11-02 Illinois Tool Works, Inc. Programmable logic control system for a HVDC power supply
US6423142B1 (en) 1997-10-16 2002-07-23 Illinois Tool Works Inc. Power supply control system
US6562137B2 (en) 1997-10-16 2003-05-13 Illinois Tool Works Inc Power supply control system
US6144570A (en) * 1997-10-16 2000-11-07 Illinois Tool Works Inc. Control system for a HVDC power supply
US20050136733A1 (en) * 2003-12-22 2005-06-23 Gorrell Brian E. Remote high voltage splitter block
DE102007060211A1 (de) 2007-12-14 2009-06-18 Itw Gema Gmbh Verfahren und Vorrichtung zum elektrostatischen Sprühbeschichten von Objekten
DE102007060211B4 (de) 2007-12-14 2022-04-28 Gema Switzerland Gmbh Verfahren und Vorrichtung zum elektrostatischen Sprühbeschichten von Objekten
US10272454B2 (en) * 2013-12-04 2019-04-30 Thomas Mayer Compressed air treatment chamber

Also Published As

Publication number Publication date
CH555704A (de) 1974-11-15
DE2438856A1 (de) 1975-06-12
FR2243741B1 (de) 1976-10-22
GB1456290A (en) 1976-11-24
DE2438856C3 (de) 1984-09-13
JPS575586B2 (de) 1982-01-30
DE2438856B2 (de) 1979-06-21
JPS5055637A (de) 1975-05-15
FR2243741A1 (de) 1975-04-11

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Legal Events

Date Code Title Description
AS Assignment

Owner name: RANSBURG-GEMA AG, KUNKLERSTRASSE 9, 9015 ST. GALLE

Free format text: ASSIGNMENT OF ASSIGNORS INTEREST.;ASSIGNOR:GEMA AG APPARATEBAU, A SWISS CORP.;REEL/FRAME:004044/0937

Effective date: 19820823

Owner name: RANSBURG-GEMA AG, A SWISS CORP., SWITZERLAND

Free format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNOR:GEMA AG APPARATEBAU, A SWISS CORP.;REEL/FRAME:004044/0937

Effective date: 19820823