|Publication number||US2933414 A|
|Publication date||Apr 19, 1960|
|Filing date||Jan 27, 1958|
|Priority date||Jan 27, 1958|
|Publication number||US 2933414 A, US 2933414A, US-A-2933414, US2933414 A, US2933414A|
|Original Assignee||Louis Beck|
|Export Citation||BiBTeX, EndNote, RefMan|
|Patent Citations (4), Referenced by (7), Classifications (15)|
|External Links: USPTO, USPTO Assignment, Espacenet|
Apnl 19, 1960 L. BECK 2,933,414
ELECTROSTATIC SPRAY PAINTING METHOD AND APPARATUS Filed Jan. 27, 1958 INVENTOR.
LOU I S BE C K wadm ATTORNEYS United States atent bra! ELECTROTATIC SPRAY PAINTING METHOD AND APPARATUS 7 Louis Beck, Seven Hilis, Ohio Application January 27, 1958, Serial No. 7il,5-:i
tClaims. (Cl. 117-93) This invention relates generally to an electrostatic spray painting method and apparatus for practicing the same.
A primary object of the invention is to provide a method of electrostatic painting in which the paint is converted into a fog-like vapor or cloud which is espe cially well adapted to be moved in an eflicient manner through the electrostatic zone.
Another object of the invention is to provide a method of electrostatic painting, in which the paint is utilized in a condition in which it is unmixed with air or other gaseous medium or vehicle, whereby the difficulties encountered when the paint is so mixed are obviated.
A further object of the invention is to provide a method of electrostatic painting, in which novel means,
including a high pressure jet or stream of'paintis used,
in conjunction with a strike plate against which said stream impinges.
Other objects and advantages of the invention will be come apparent in the course of the following description,
taken in connection with accompanying drawing, which forms a part of this application, and in which the single figure illustrates more or less diagrammatically the principal features of the invention.
Referring more particularly to the drawing, reference numeral 1 designates a paint container or receptacle, in which paint, unmixed with air or other gaseous vehicle, is subjected to a high pressure, as by means of a hydraulic pump or the like, so that the paint is discharged at a relatively high velocity, through a nozzle 2.
The paint emerges from the nozzle 2 in a straight needle-like stream 3 at a velocity such that the stream of paint impinges against a strike plate 4, which is disposed in the path of the stream, and at an angle to the stream. The paint impinges upon the strike plate 4 with sufiicient energy to cause the paint to become atomized by the strike plate, and the plate directs the atomized paint particles, indicated by reference numeral 5, towards articles 6, which. are to be coated with the paint.
The articles or work may be conveyed past the atomized paint, as by means of a conventional mechanical conveyor, moving in the direction indicated by the arrow.
The atomized paint particles pass through an electrified or electrostatic zone, which is created between the strike plate 4 and the articles 6, by making the plate the positive terminal of the zone, and the articles 6, the negative terminal of this zone. The particles of paint are thus attracted to and coat the articles 6. in some cases, the container or receptacle :1 may be included as part of the positive terminal of the electrified or electrostatic zone.
The paint, as it leaves the strike plate, becomes atomized, forming a fog-like vapor, which is exceptionally well adapted to be moved in an-efiicient manner through the electrostatic zone; This results from the fact that the particles are well dispersed throughout the vapor or fog, are moving at a relatively low speed, as compared to the speed at which they left the nozzle 2, and are unmixed with air or other gaseous medium, such as is commonly used in propelling paint through nozzles of "ice accounted for by the fact that the force of the stream from the nozzle 2 is expended against the strike plate, and the fog or vapor which is created is virtually invisible.
The pressure at which the stream of paint emerges from the nozzle 2 may be varied, depending upon the size of the passageway through the nozzle, and this pressure may be varied in accordance with the distance of the strike plate from the nozzle, the size and shape of the strike plate, the distance of the strike plate from the articles to be coated, the strength of the electrostatic zone or field, the viscosity of the paint, and other factors.
The size and shape of the strike plate may be varied in accordance with the nature, size and shape of the articles which are to be coated, and it is desirable to so shape the strike plate as to form a paint or fog pattern which conforms to the nature, size and contour or shape of the articles.
For this purpose, the strike plate may, in some instances, assume a concave or convex or other shape or form.
It is to be understood that various changes in the method and apparatus, as described, may be made, without departing from the spirit of the invention or the scope of the appended claims.
Having thus described my invention, I claim:
1. The method of electrostatically painting articles which comprises projecting a thin stream of paint substantially free of admixture with air or other gas' and at a high pressure through a nozzle and against a strike plate disposed in the path of the stream but at an angle to said path, whereby the paint, after striking the plate is deflected at the point of impingement in a direction angular to the direction of said stream, and is broken up into particles forming a fog-like vapor, and causing said vapor to pass through an electrostatic zone between said strike plate and said articles, to coat said articles.
2. The method, as defined in claim 1, in which the electrostatic zone is created by making the strike plate one terminal of a high potential circuit, and the articles the other terminal of said circuit.
3. The method, as defined in claim 2, .in which the articles are conveyed past said electrostatic zone.
4. The method of electrostatically painting articles which comprises projecting a thin stream of paint sub stantially free of admixture with air or other gas and at a high pressure through a nozzle and against a strike plate disposed in the path of the stream but at an angle to said path and being stationary with respect to said nozzle, whereby the paint, after striking the plate is defiec'ted at the point of impingement in a direction angular to the direction of said stream, and is broken up into particles forming a fog-like vapor, and causing said vapor to pass through an electrostatic zone between said strike plate and said articles, to coat said articles.
5. The method of painting articles which comprises projecting a thin stream of paint substantially free of admixture with air or other gas and at a high pressure through a nozzle and against a strike plate disposed in the path of the stream but at an angle to said path, whereby the paint, after striking the plate is deflected at the point of impingement in a direction angular to the direction of said stream, and is broken up into particles, which are directed to coat said articles.
References Cited in the file of this patent UNITED STATES PATENTS 2,684,656 Ransburg July 27, 1954 2,723,646 Ransburg Nov. 15, 1955 2,733,172 Brennan Jan. 31, 1956 2,805,642 Tuttle et al. Sept. 10, 1957 Notice of Adverse Deszision in Interference In Interference No. 91,630 involving Patent N 0. 2,933,414, L. Beck, Electrostatic spray painting method and apparatus, final decision adverse to the patentee was rendered. Feb. :21, 1963, as to claim 1.
[Ofiicz'al Gazette July 23, 1.963.]
|Cited Patent||Filing date||Publication date||Applicant||Title|
|US2684656 *||Jul 30, 1949||Jul 27, 1954||Ransburg Electro Coating Corp||Electrostatic coating apparatus|
|US2723646 *||Apr 1, 1950||Nov 15, 1955||Ransburg Electro Coating Corp||Apparatus for electrostatic atomization and coating|
|US2733172 *||Feb 27, 1952||Jan 31, 1956||Apparatus and method of producing|
|US2805642 *||Oct 28, 1954||Sep 10, 1957||Gen Motors Corp||Electrostatic spray painting apparatus|
|Citing Patent||Filing date||Publication date||Applicant||Title|
|US2975757 *||Feb 26, 1958||Mar 21, 1961||Gen Motors Corp||Electrostatic paint spray|
|US3144350 *||Jan 3, 1958||Aug 11, 1964||Nakako Oda||Electrostatic coating method and apparatus|
|US3601313 *||Jun 17, 1969||Aug 24, 1971||T G Owe Berg||Method and means for the removal of liquid or solid particles from a volume of gas|
|US3619230 *||Mar 23, 1970||Nov 9, 1971||Matthews Refractories Ltd||Particulate coating method|
|US4981716 *||May 3, 1989||Jan 1, 1991||International Business Machines Corporation||Method and device for providing an impact resistant surface on a metal substrate|
|US5915621 *||Oct 16, 1997||Jun 29, 1999||Nippon Paint Co., Ltd.||Electrostatic powder coating method and apparatus|
|US6368674 *||Jun 24, 1999||Apr 9, 2002||Sarnoff Corporation||Method of fabricating a support with dry deposited compounds thereon|
|U.S. Classification||427/483, 427/477, 118/627, 118/629, 118/626|
|International Classification||B05B5/08, B05B1/26, B05B5/035, B05B5/025|
|Cooperative Classification||B05B5/035, B05B5/08, B05B1/267|
|European Classification||B05B5/08, B05B5/035, B05B1/26A2|