US2980337A - Paint spraying system - Google Patents

Description

April 18, 1961 J. KOZINSKI PAINT SPRAYING SYSTEM Original Filed March 4, 1954 OBJECT 7'0 55 PAINTED INVENTOR. Jwwfi (az/rmf ATmQA/EV PAINT SPRAYING SYSTEM Joseph Kozinski, Chicago, 111., assignor to H. G. Fischer 8: Co., Franklin Park, 111., a corporation of Illinois 2 Claims. (Cl. 239-15) This invention relates to a paint spraying system, and particularly of the type involving the use of high potential electrostatic fields for directing particles of paint toward the object to be painted. Electrostatic field paint spraying systems depend upon the fact that paint to be applied to an object is finely divided andthen disposed in an electrostatic field. The electrostatic field either terminates at or passes through the article to be painted. The paint particles as electrified fine particles move along lines of potential gradients.

The efiiciency of an electrostatic paint system depends, among other things, on the fineness of the paint particles and the velocity attained by the paint particles just prior to their impact upon the article to be painted.

While a variety of means for obtaining paint in finely divided form and disposing the same in an electrostatic field are known, such means are relatively complicated or inefiicient. The quick-drying characteristics of paint or lacquer or whatever material is used, together with the high potential insulation requirements, render this problem diflicult of solution; Furthermore, the requirement that a paint spraying system be simple, safe and foolproof and also be free from service trouble, imposes additional requirements. v

In accordance with this invention, a simple system is provided whereby the material to beapplied, such as paint, lacquer, varnish or the like, is first atomized in a simple and effective manner and is disposed in an electric field so that the finely atomized particles may move in the proper direction toward the article to be covered.

In order that the invention may be understood, an exemplary embodiment will now be disclosed in connection with the drawings.

Referring to the drawings:

Figure l is a partly diagrammatic view of a paint spraying system embodying the present invention.

Figure 2 is an elevation of the atomizing means.

Figure 3 is a sectional detail on line 3-3 of Figure 2.

The paint or lacquer or whatever material is being applied may be stored in paint tank of any desired construction. Tank 10 may be as large as necessary and may be of metal or an insulating material and may have a cover or not, as desired. Tank 10 has outlet 11 from the bottom thereof to which is attached pipe 12. Pipe 12 is preferably of insulating material and may be of flexible hose of rubber or of plastic material having the desired chemical characteristics and having good electrical insulating qualities. A valve is provided for controlling the flow of liquid from tank 10 into pipe 12.

Pipe 12 has end 13 which is provided with a suitable slip joint engaging hollow shaft 14 of motor 15. Motor 15 may be of any desired construction and because of the possibility of explosion, may be of the enclosed type.

Motor 15 is different from a conventional motor only in having a hollow shaft 14 rather than a conventional solid shaft. Motor 15 may be supported in any suitable manner provided, however, that the entire motor is inpaint particles pass through electrode 40.

2,980,33? Patented Apr. 18, 1961 sulated from ground for the full potential used in the electrostatic system.

Motor 15 supports concave electrode 17, the electrode being stationary and being rigidly supported from the motor casing in any suitable fashion. Electrode 17 may have any desired .shape and as illustrated here, has the general shape of a hollow bowl. The electrode may consist either of metal, such as copper, aluminum or iron, or may consist of any insulating material having a metal film of copper, aluminum, iron or any other material desired. Electrode 17 has centrally disposed aperture 18 (Figure 3) through which hollow motor shaft 14 passes. The end of motor shaft 14 has rigidly attached thereto spinner 20 for atomizing liquid.

Spinner 26 has tubular attaching portion 21 for engaging motor shaft 14. Attaching portion 21 forms part of spider 22 extending outwardly of the spinner and terminating in annular fiat ring 24. Ring 24 has a number of radially disposed blades or vanes 25. Spider 22 also carries fixture 27 defining chamber 28 for capping the open end of motor shaft pipe 14. Fixture 27 may assume a variety of forms and, as shown here, consists of circular disc 29 and flat annulus 30 joined together by rim 31. Rim 31 has a number of apertures therethrough for connecting chamber 28 within the fixture to thecxterior of the fixture. 33 rigidly attached to rim 31 so that in effect the fixture has a number of radially directed tubes. Preferably, these tubes are so arranged as illustrated in Figure 2 so that the tubes are along radii which extend between adjacent vanes, the tubes themselves terminating short of the inside edges of the vanes. The fixtures and tubes are disposed so as to lie within thespread of the varies as illustrated in Figures 1 and'3. I

The spinner will be rotated at high speed by motor 15, paint being suppliedto chamber 28 through the hollow shaft of the motor. .Motor 15 is energized by secondary 36 of transformer 37. Transformer 37 has primary 38 for connection to a conventional power circuit such as, for example, .a 110 volt. 60 cycle line. 1 Transformer 37 has secondary, 36 insulatedfor high potential from primary 38 and from the iron core. Secondary 36 is connected by suitable leads 40 to the winding of motor 15.

As will be readily understood, electrode 17 must be at a high direct potential with reference to ground for proper operation of the paint spraying system. In accordance with this invention, electrode 17, motor 15 and secondary 36 of the transformer will all be at high potential and will be adequately insulated from ground and also will be so designed or protected as to prevent an operator from contacting the same while the potential is being applied.

The dotted lines indicate the parts of the system at high potential. Inasmuch as paint supply tube 12, or at least part of it, will be of insulating material, hollow shaft 14 of the motor will be electrically insulated from the parts of the paint supply which might normally have to be handled, and no special means for insulating the paint tank and at least part of the piping will be required.

The object to be painted, .generally indicated by 49, may be any desired article. As a rule,.the article to be painted may be of metal or have a metal film thereon so that it functions as an electrode and may be at a suitable potential with respect to electrode 17. However, in certain instances, electrode 40 cooperating with electrode 17 may be disposed in back, that is, to the left of the article to be painted, so that the article is in the direct line of travel between electrode 17 and the cooperating electrode. In other instances, electrode 40 may be a metal screen or grille in front of the work so that th At these apertures are stub tubes.

If t c 7 3 ,7 lbo -polarity of electrodes-40 and electrode 17 vary -dep'ending uponthetype ofisystem and the material eused for painting or covering, Thus in certain cases, electrode 1 7 may have to be negative to electrode 40 and in I OTher instaiiCeSE-th 'PoIafit-y niust be reversed'." -'I= his is a simple matter and, as a rule, consists in' merely i'eversiing sioii leads-of manipulating-a; switchiina able in the As a rule,'fa"power supply; for ,a

system' of thischaracter. must generate or provide potentials iof tlie-order'of lgfl0oyolts or -niore,'-the current V interlocks may he provided 'toprevent: an operatorffforn toucliing-or themotofior elec tfode lq A's-a-i'u1e, the object-to bepainted, if of metal,

or electrode 40 cooperating therewith, will beat ground potential while electrode" 17 will be either atl e high'pdsitive or negative potential with respect to ground. Ihe revolution of thespinner will provide a pumpingaction independently of the ;tendency of paint to flow fi mthe-fank-to the spinner. In factLthe tank for paint,

need not. necessarily be locatedeabove the spinner, and in manyginstances,the-tank may be located below the level of thefspinner the supply pipe' 12 extending downwardly into the -tank-from the' bottom thereofi Thehigh:

speed -of the spinner} will serve to-throw out theliquid paint d; vaisnish orwhatever is being used, the blades striking the liquid and ato'mizing the same to fine' partie le s 'fl lfhef atomized particles have already acquirdieleetricecharges due to the high-potential of motor shaft ld,-

which will be of, steel," and the various 'spinner parts, I

piefei ably-bf metal." :Electrode 17,.is provided' principa1ly to shape =of eleptrical force going to electrode 40.1,

Thus ele'ctiodefllneed be shaped only to have a desired effect {on the shape of-the electric-field: The atomizing motor may be, conventional even though at high potential. .1,

' lnsfeadflof the atomizingnieausilluStreitedgother atomizing' means may be us'ed in 'connectiom-with the motor.

'i applicatipnis a division of my application Serial: No. 414,00 9, fi led March-451954. L

what isclailned isz Fo'r use m an electrostatic type paint spray system,

the combination of. an alternating I current electric motor supply toi obtaining adesiredihighpotentialg is iiof showij, sueli supplies being well known and availhaving a stator and rotor including e hollow metal shaft,

'ea -hollowlrotary coupling and stationary pipe providing a-connecting means between one end of said hollow shaft and a stationary paint tank, saicl connecting means including high potential insulation along the line of paint travel betweensaid shaft end and said paint tank, atomizing means carried byfthefbthbr end of said hollow shaft for receivi ai t datqae z eeth e me during motor rotation; a t'ransformer'having primary and secwindia a esqaae t oa be ween 3i15c1 IY and; said. electin motor iqrippe atiugi heis me r m s i t pq P a Y.,LW a i aP as r z dfiimm e nfi aa iets zia aisl esnfl 1 providing a 'suitable potential for operating a'motor, and high potential insulation ;between,,saidprimary alid 'se'condary windings,"nieansforsupportingsaid electric motor as a whole to provide high potential insulation, said atomizing means being adapted to be at high potential during "spraying whereby thei complete atornizi'ng system including .ithefrnoto'r may be; at high potential relative to ground withou t communicating such high potential to the,

paint supply or to the power'line, said electric motor being oi generally conventional construction and Hacking sufficient insulation -betwe enl its windings and name to withstaud-thehighlpotentiali 1 1 1 ---2. The combination according-to claim "1' wherein a stationary metal-bowl is supported by" said stator', .said metal bowl facing away from-the motor with-the motor shaft passin'g through the-san1eand theatomizifig means iae asfi t ia e ei fie a il a w s 1 Y liefelences Qited in the'fileof thisipatent ffi i PAT N S' Nov i 17,1 11931 1211.12, ;-1940 '2,6 98 ,'8l4* -Ransbur 1;- g 1211154 1955

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