US2894485A - Apparatus for electrostatically applying multi-coatings - Google Patents

Description

July 14, 1959 Filed Aug. 18, 1958 COATING MATERIAL APPARATUS FOR ELECTROSTATICALLY APPLYING MULTI-COATINGS SOURCE J. SEDLACSIK, JR

2 Sheets-Sheet 1 HYDRAULIC AOTUATOR 1. as 35 CONVEYOR 0ONTROL 53 ATOMIZER 7? SPEED CONTROL Arrow/15 ull July 14, 1959 J. SEDLACSIK, JR 2,894,485

APPARATUS FOR ELECTROSTATICALLY APPLYING MULTI-COATINGS Filgd Aug. 1a, 1958 I 2 Sheets-Sheet 2 INVENI 'OR JOHN SEDLACSIK JR.

5% iORfiY Unite APPARATUS FOR ELECTROSTATICALLY APPLYING MULTI-COATlNGS This invention relates to spray coating of articles, and

States Patent more particularly means utilized in electrostatic coating systems employing centrifugal atomization.

A feature of the present invention provides nove means for producing improved surfaces and finishes in multi-color blending of coating materials for industrial spray coating of articles.

Another feature or advantage of the invention is the provision of a unitary composite atomizer array for simultaneously spraying different articles movable through separated discrete spray areas, thereby providing flashoff intervals to effect increased economy, improved surface quality, and the generation of novel and unique type surface finishes employing coating material of one color type, multiple colors or types, or a combination thereof to provide unique coating patterns and finishes hereto: fore not available.

The invention utilizes novel spraying techniques involving a variety of atomizer arrays each employing one or more atomizers and one or more deflector heads which may be rotary and/or electrostatic. The apparatus is particularly adaptable to provide variable and complete control over the results desired whereby blending ofa wider variety of coating materials and solvents is possible, thereby greatly increasing the range in patterns, colors, types and quality of finishes of the coating material deposited on the articles. 7

Other features and advantagesof the invention may become apparent from a perusal of the drawings considered in conjunction with the specification. The drawings show illustrations of preferred arrangements of the.

invention, but it is to be understood that various changes and modifications may be made in the invention without departing from the spirit of the appended claims.

In the drawings:

Fig. 1 is a pictorial representation of a complete system utilizing one form of atomizer arrangement.

Fig. 2 is a representative plan view of a continuous conveyor using a multi-color atomizer arrangement to provide two discrete spray sectors simultaneously from a unitary atomizer array.

Fig. 3 is one form of an atomizer having a peripheral discharge edge on the lower portion thereof.

Fig. 4 is the view somewhat similar to Fig. 3 but wherein the peripheral discharge edge is on the upper portion of the atomizer.

Figs. 5 and 6 are pictorial representations of top and side views, respectively, of a dual disc array relative .to a conveyor for carrying articles to be coated.

Figs. 7 and 8 are top and side views, respectively, of

in an array wherein the respective peripheral edgesare disposed in different horizontal planes and in overlapping relation.

Fig. 11 is a sectional view taken along lines 1111 of Fig.5.

Referring to the drawings and more particularly to Figs. 1 and 2, there is shown a conveyor 30 having articles 31 to be coated, suspended on hook wires 32 carried by the movable carrier portion of the conveyor, which may be of any suitable or conventional type. The conveyor generally includes a conveyor track 36 having linked carriers movable in the track and connected by a shaft 35 with a variable speed drive and conveyor control 34, and coupled thereto by any convenient means, such as a suitable gear train.

A pair of atomizer heads, such as 38 and 40, are mounted on shafts 42 and 44, respectively, which shafts are insulated from the drive motors 50 and 52. The

' drive shafts 42 and 44 are inserted through insulator shaft housings 46 and 48, respectively. The drive motors are mounted on an elongated horizontal mounting bracket 54. The piston bracket 56, in one form, has its lower portion connected to the upper portion of mounting bracket 54, while the upper portion of the piston bracket is secured to the lower surface or portion of piston 58. A hydraulic cylinder 60, shown in part, is of the conventional type, and receives the piston 58 which reciprocates vertically in said cylinder.

The hydraulic actuator 61 has a pair of conduits, 62 and 63, connected to the hydraulic cylinder, whereby the piston will be actuated to raise or lower the heads or atomizers 38 and 40 according to the fluid flow arrangement of the hydraulic system. A pair of limit switches 64 and 65, are each operatively connected by conductors to the hydraulic actuator 61 for operating conventional elec'tro-responsive means such as relays, motors or solenoids for controlling the operation of conventional valves which control fluid flow to the conventional fluid actuated piston which provides reciprocating vertical motion of the atomizer array.

A cable arrangement including a pair of cables 66 and 67 have their respective one ends operatively coupled with the piston, and with the other ends thereof passing over guide pulleys 68 and 69 of the stroke control 70 connected to the respective ends of the movable shoe 71. When the device is in operation for reciprocating the spray heads by movement of the piston, fluid flows in either one or the other of the conduits 62 and 63 to urge the piston in a particular direction. As the piston moves,

the cables 66 and 67 are moved accordingly so that the shoe 71 of the stroke control may be moved in a direction to engage one or the other of said limit switches for actuating its respective electro-responsive means such as the motor or solenoid valve means to control fluid flow in conduits 62 and 63 by the hydraulic actuator 61, for reversing the direction of the piston movement. The adjustable vertical position of the limit switches 64 and 65 relative to the shoe 71 determines the length of stroke of the piston, to provide the desired vertical reciprocating action of the spray heads or atomizers. The piston hydraulic cylinder 60 is shown carried by supporting beams 170.

A variable paint supply and pump 72, indicated by legend as coating material source, has shown two conduits 73 and 74 connected to the feed tubes 75 and 76 of the atomizers 33 and 40 for connecting separate sources to each of the atomizers. The coating material source has valve means 173 and 174 to control the flow of coating material to the particular atomizer. However, any combination of sources of material may be coupled to the heads in any suitable arrangement. An atomizer speed control 77 is shown connected via electrical conductors 78 and 79 to the atomizer drive motors 50 and 52 for individually or jointly controlling the speed of the respective rotary heads.

A conventional high voltage source 100 is connected between ground and the atomizers 38 and 40. The conveyor 30 is shown electrically connected to ground, as are the articles 31, by means of any suitable type or arrangement of the conveyor. With the presentationas showrhthe coating material is fed through feed tubes 75 and 76, then through openings in the tops of the atomizers onto the inner surface for atomization.

The mounting bracket 54 shown in Fig. 1 may have the motors 50 and 52 mounted on studs 80 and 81whieh are slideable in slots .82 and 83, respectively, for positioning the atomizers 38 and 40 longitudinally on the mounting bracket 54 to move the atomizers relative to the articles 31. The mounting bracket 54 may be rotatable on the piston bracket 56 so that the entire atomizer array may be rotated about the pivot pin 86. The piston bracket 56 may be of one piece of material or have sectional upper and lower portions pivoted together to tilt the atomizers, as will be explained in detail later.

In Fig. 2, the conveyor track 88 is shown carrying a multiplicity of objects, or articles 31, to be coated. A pair of heads or atomizers 91 and 92 are slideable longitudinally in slots formed in the mounting bracket 9.0, which slots may be similar to slots 82 and 83 in mounting bracket 54 of Fig. 1, but the heads and mounting brackets may assume a difierent design from that shown in Figs. 1 and 11. A series of articles 31 in Fig. 2 are shown equidistantly spaced from one another andcarried on opposite parallel sides of a continuous conveyor belt. The heads or atomizers 91 and 92 are rotatable to provide coating material 'which is fed into the atomizers substantially uniformly by centrifugal action to the atomizing edge of the respective atomizers. While the coating material is centrifugally projected, in one preferred form, at least to the peripheral discharge edge of the atomizer, a motive agent, such as air dispensed in a suitable manneror pattern, may be used to urge the coating material to the atomizing edge or spray zone. It will be noted that the atomizers 91 and 92 are each connected to one side of a high .potential source 100, while the opposite side of the high voltage source is connected to ground, as is the conveyor. However, any arrangement may be used to assist in .electrostatic deposition of the coating material on the articles.

Normally, in electrostatic spraying, when .only one centrifugal atomizer is used in electrostatic spraying, the coating material is centrifugally moved toward the pcripheral discharge edge of the atomizing disc, and there is created annular atomizing zone adjacent the peripheral edge wherein the coating material in said zone is atomized due to the centrifugal action and the electrostatic charge of the particles so that atomized particles of coating material mutually repel each other and are attracted to the articles which have an electrostatic polarity similar to the polarity of the articles on the grounded conveyor and which article polarity is opposite to that of the atomizer.

In the present arrangement and in the showing of Fig. 2, both heads or atomizers 91 and 92 are electrostatically charged and are of like polarity. Each atomizer functions in a dual capacity. When supplied with coating material, the atomizing disc provides an atomized spray of coating material. The head or disc also acts to repel atomized material from neighboring heads or discs and keeps itself clean by virtue of its rotation. Thus the electric field acts to repel atomized material from other discs while the spinning head or disc will throw off any stray material from other heads or discs which may be present in spite of the repelling action.

Each atomizer provides a separate spray pattern sector with particles being deposited from one portion of the discharge edge of one atomizer nearest to the adjoining conveyor portion, with the other atomizer providing a similar spray pattern portion or sector for spraying articles on the other adjoining conveyor portion. It will be noted that when both atomizers 91 and 92 are individw grete spray patterns, each spraying, articles to be coated in a discrete spray area or sector, on a respective parallel side of the conveyor.

Two types of atomizer heads are shown in Figs. 3 and 4. Fig. 4 shows an upright type head wherein the atomization discharge edge 101 is on the upper extremity of the head, whereas Fig. 3 shows an inverted type head having the atomization discharge edge on the lower annular extremity -of the .head.

The coating material to the head of Fig. 3 is fed through the feed tube 75 into a well 102 of the ring 103. A plurality,of. op en ings 104 permit the coating material to be centrifugally fed from the well through the openings in the ring and onto the-inner surface of thehead 91, where it is centrifugally urged outwardly to the annular discharge edge 101 in the atomization zone.

The coating material to the head of Fig. 4 is fed through the feedline 105.0nto :the deflecting plate 106 where the coating material .iscentrifugally urged outwardly on the mixing cup portionof the head and along the inner surface.of.-the r-im to;thetatomizingdischarge edge 101.

A bracket 107 .in Figs. 3 and 4 is securely positioned on .the insulation shaft housing such as 48. It will be noted that in Figs. 3 and 4 the shaft .such as 44 is secured to .its respective head, and is connected to an insulation section of the shaft-within the insulation shaft housing 48 to :connect with :its respective .drive motor by insulation shaft 880121011 44.

@111 the .various arrangements of heads or atomizers sh wnin'Figs. 5 through 10, theparticular heads or atomizersnare represented as being of the disc or saucer type. However, .the heads may be .used as atomizers or merely as deflectors, and may be of any suitable type such as cones, flat or shaped elements, or discs, or even needles orltubes in a predetermined arrangement or pattern. The atomizer heads are used in various combinations, depending .on the-particular results desired.

An atomizer array is shown in Figs. 5 and 6 having a pair .of saucers .or heads #91 and 92 rotatably mounted on the mounting bracket 90, which bracket may be similar lto the mounting bracket 54 of Fig. 1. The heads or atomizersmay be moved longitudinally along the mounting bracket to vary the spacing between the heads on opposite sides of the piston bracket 56. Conveyor portions '88 represent the positional arrangements of the heads 91 and'92relative to the opposed parallel side portions 'of'the conveyor, with the loading and unloading sta tions to be suitably located.

The discs shown in Figs. 5 and 6 may be rotated in the direction indicated by the arrows thereon, so that the both discs rotate in the same direction. However, one disc may rotate in a direction opposite to the other, if

- desired.

With the arrangement shown in Figs. 5 and 6, the articlescarried on the opposed sides of the conveyor would pass through the discrete spray pattern sectors similar to that represented in Fig. 2, which spray pattern sectors may be altered in their range and effectiveness depending on the position of the heads to each other, and other factors such as the particle charging potential impressed between the heads and the conveyor, the spacing and size of the articles, and the distance between the articles themselves, and the articles and heads.

Figs. 7 and 8 illustrate a system having more than two atomizing head's. As an example, three heads may be arranged at the points of a triangle or in alignment as shown in the drawing, or in other suitable configurations. In all cases, conveyor portions carrying work to be coated will bedispos ed in the fan shaped or sector spray pattern of a particular head or disc. If the heads are arranged at the points of a triangle, each disc may be supplied with paint. -In the aligned arrangement shown in' Figs. 7 and"8 the central disc '28 will not be supplied with "coating material.

Figs. 7 and 8 have the outer heads 91 and 92 positioned nearer the outer extremities of the bracket 90, whereas in Figs. and 6 the heads are positioned nearer the center of the bracket. The outer heads overlie the center head portion, which head is substantially similar to heads 91 and 92, but may be of the upright type, such as that shown in Fig. 4, and may have different dimensions. In the arrangement shown in Figs. 7 and 8, the heads may be all connected to a common particlecharging high voltage source, but with coating material being fed into only the outer heads 91 and 92, which are in eifect atomizers. The deflector center head 23 has its peripheral edge in a plane parallel to that of the peripheral edge plane of atomizers 91 and 92. The head 28 is shown overlapping the heads 91 and 92, but may not be in overlapping relation, and may be below rather than above the outer heads. If the atomizers 91 and 92 are receiving coating material for atomization, the inner head 28 may be used only as a rotary or centrifugal deflector, or an electrostatic charge may be impressed on the head 28, and may be of like polarity to heads 91 and 92. Any coating material which leaves either one of the heads 91 or 92 and which is centrifugally moved toward head 28 will be repelled either electrostatically only, or electrostatically and centrifu gally in the event that the particles actually impinge the surface of head 28. By this arrangement of using a particle deflector which provides both electrostatic and centrifugal deflection, there results an arrangement whereby there will be no build-up of the coating material since the electrostatic deflector actually provides detearing of the material from the deflector, and the spray pattern sectors will be generated depending on the characteristics and values of the elements employed. While the arrows in Fig. 7 show that all three heads are rotated in the same direction, it is pointed out that the directional rotation of the three heads in Figs. 7 and 8 may be varied from that shown in Fig. 7. For example: atomizers 91 and 92 may be rotated in the same direction as head 28, or head 28 may be rotated in a direction opposite to either one or both of atomizers 91 and 92. Although Fig. 8 shows one head 28 inverted, all three heads could be used in either direction. In the latter case, solvent or coating material could also be supplied to the third head for control purposes or intermixing of a third color, if desired.

In Figs. 9 and 10, heads 108 and 109 may be similar to the heads shown in Figs. 3 and 4 with said heads having a portion of their peripheral edges in overlapping parallel relation. In this arrangement both heads 108 and 109 may have coating material fed thereto, and each may act as an individual atomizer in much the same manner as that shown in relation to heads 91 and 92 in Figs. 5 and 6. However, the spacing arrangement and the type of heads employed along with their over-all relative position to each other, and to the articles to be coated, may be altered. The viscosity of the coating material and the individual speeds of the adjacent heads, and whether they act as deflector or atomizer, will contribute to the type, quality and color blending desired. If the coating materials are too wet, the speeds can be increased to flash-off the solvents faster, whereas if they are too dry the speed can be reduced.

Heretofore, the mounting bracket 90 has been referred to as being aflixed to piston bracket 56, which bracket has upper and lower surfaces parallel to one another. With the disc arrangement shown in Figs. 5 and 6, it will be noted that the spray pattern sectors would each be in substantially the same horizontal plane of the path of the moving articles carried by the conveyor. With this arrangement the approximate vertical extent of the spray pattern sector would be a controlled relatively narrow band. However, in some instances it is desirable to have the vertical extent of the spray pattern increased from that available with the arrangement shown in Fig. 6.

One form of the facilities for increasing the effective width of the spray pattern is shown by the arrangement in Fig. 11, wherein the piston bracket has an upper portion secured to the piston, and a lower portion 112 secured to the bracket 56, and each with an apertured flange such as 114 and 115 respectively, thereon, and being pivotably connected together by a pivot pin 116. A nut or other means may be used on a suitably threaded pivot pin to hold the atomizer at the desired angle for the particular pattern vertical height.

In the arrangement shown in Fig. 11, when the lower bracket 112 is in the position shown dotted, the peripheral atomizing edges 101 will be substantially in a horizontal plane like that of the article path of the conveyor so that the spray pattern sector will be horizontal as will be the articles moved therethrough. However, when the lower bracket 112 is tilted to the position shown in solid lines in Fig. 11, the plane of the lateral spray pattern will be inclined and similar to the plane of the discs, and accordingly similar to the plane shown by the dash-dot line 118. With the lower portion 112 tilted as shown in Fig. 11, the heads will be tilted angularly or displaced from the position shown in Fig. 1. Accordingly, the vertical extent of the spray pattern sector will now be angularly positioned so that the spray band will have a vertical extent depending on the particular angular displacement of the plane of the lower portion 112 from the normal horizontal position shown in dotted lines in Fig. 12. By tilting or rocking the mounting bracket 56' on the axis of the pin 116, the vertical extent of the individual spray pattern sectors may be varied and correspondingly controlled.

The arrangement shown in Fig. 11 indicates how the discs may be angularly disposed when suspended on an overhead mount. However, it is to be understood that the piston 56 may be positioned in a pedestal mount so that the disc may be carried by the floor rather than from an overhead structure. Obviously piston 58 could be replaced with a stationary mount or pedestal mount.

While a parallel side continuous conveyor is shown, it is to be understood that parallel sides of a conveyor may be provided from two independent conveyors, the conveyor need not have parallel sides but may be kidney shaped, have a spiral configuration, elliptical, or any other shape, depending on the particular spray coating results desired.

In conjunction with the various paths of travel of the articles on a conveyor, the atomizer array may have the various atomizer heads or portions positionable to provide various results, and to operate under conditions which provide maximum benefits from the spraying. While it has been mentioned that the atomizer heads may be moved longitudinally on the atomizer bracket 90, and the atomizer bracket may be tilted as shown in Fig. 11, the atomizer bracket may also be rotated about the pin 86 to the position shown dotted in Fig. 2 or to any other angular position about the axis of piston 58. Further, the bracket 90 may be moved longitudinally in the conveyor loop as shown in Fig. 2. This may be done by providing a bracket disposed at right angles to the bracket 90, and with bracket 9t) being slideable thereon. Further, in one arrangement, the bracket 90 may be swung to the angular position shown in dotted lines in Fig. 2, and one atomizer may be moved toward the outer end of its bracket, while the other atomizer may be moved inwardly so that the atomizers are each spaced from their nearest respective articles a dissimilar distance. With this arrangement, as the article moves around the conveyor path from the loading station, the initial acting atomizer is nearer to the article than the remaining atomizer in order to provide greater penetration of the coating material by the initial acting atomizer, and by providing a finishing coat of less dense mist or spray by the secondary atomizer to prevent excessive build-up on corners.

Thecomplete separationof identities of two fan shaped or sector spray patterns makes it possible to spray one article first with spray from one spray pattern and then with theother. This creates a suitable interval between the spraying by opposed atomizers in an atomizer array, as the articles are transported from one spray area to the next spray area. Hence, a suitable flash-off interval between the successive coatings permits a buildup or greater mil thickness to be obtained Without the paint running. Such asuitable heavy coating layer could not be had by a simple disc atomizer having an annular pattern. In some cases it may be desirable to heat the parts as they pass through one spraying pattern of the atomizer array in order to permit a better flow for the particular characteristic of the paint or coating material, including its viscosity.

This invention provides a system which is remarkable in that at least one fan-shaped spray pattern is generated while utilizing contrifugal atomizing means with substantially no waste or loss of coating material or deposition of coating material outside of the fan-shaped pattern. In other words, the fan-shaped or sector spray patterns contain all of the spray emitted by the centrifugal atomizing means. By virtue of the invention a plurality of atomizing means may be provided each having its own discrete fan-shaped or sector spray pattern and operating at high atomizing efficiency.

Concerning the relative positions, dimensions and characteristics of one form of the invention, for instance, that form shown in Fig. 5, the following example may be considered representative: With the two disc arrangement as shown in Fig. 5, satisfactory results have been obtained by using each of the atomizers 91 and 92 having an atomizing discharge edge diameter of 20 inches, with approximately 4 inches and up between the nearest edges of the atomizer heads and with 12 inches between each of the atomizer heads and the outer surface of the nearest article to be sprayed. A satisfactory charging potential applied across the atomizer heads and the articles to be sprayed in the example given was 120 kilovolts. However, desirable results have been obtained for coating certain articles wherein distances between articles and the respective atomizer heads was adjusted between to 24 inches, and with the atomizer heads being anywhere from overlapping to inches apart. The voltage has been varied from kilovolts to 300 kilovolts. The diameter material and general characteristics of the heads may be determined or varied according to the par ticular results desired.

By pivoting the atomizer bracket about the axis of the piston, the conveyor arrangement is adaptable to various size objects. For example, if flat sheets are to be coated, the atomizer head bracket can be normal to the parallel conveyor path. However, if large objects such as cabinets are to be sprayed, the discs can be swivelled to vary the distance between the article and the atomizer to obtain the necessary spacing to prevent areover, and to provide the effective spacing for optimum results.

By tilting the discs of the arrangement shown in Fig. 11, not only is the eflective height of the spray band increased, thereby providing greater article height coverage but also there is improved coverage on the respective upper and lower surfaces and cavities of the articles due to directional spray effect on opposed sides of the conveyor.

With the two discs providing two discrete spray patterns, one spray pattern complements the other when the discs are tilted to increase the effective coverage not only on the front and on the top and bottom of the respective articles, but on the surfaces of any upper and lower cavities. This method of using complemental directional sprays in opposed directions on opposite sides of a unitary atomizer array provides novel and beneficial techniques.

The head or the effective spray pattern plane of the centrifugal atomizer is positionable about .a vertical -or horizontal axis, and may be individually and independently positionable laterally relative to the vertical axis. Centrifugal .atomizers are shown, but they may be of the non-rotating type or may be any air actuable spray device. The individual heads may be not only atoniizers but may function also as combination electrostatic and centrifugal deflectors as shown at least, in Figs. 5 and 9. The rotational speed of the heads may be individually controlled as may be the respective sources of coating materials.

While several embodiments-of the invention have been illustrated and described .in detail, it is to be expressly understood that the invention is not limited thereto. Various changes may also be made in the design and arrangement of the parts without departing from the spirit and scope of the invention as the same will now be understood by those skilled in the art.

What is claimed as new and desired to be secured by Letters Patent of the United States is:

1. Apparatus for electrostatically coating articles comprising an atomizer array for providing spray of coating material, conveyor means for transporting said articles along a predetermined loop path through said spray, and means for creating an electrostatic field between said atomizer array and said articles for atomizing and depositing said coating material on said articles, said atomizer array including at least one rotating atomizer head with an atomizing edge and at least one rotating electrostatic deflector having an extended lateral edge, said rotating atomizer head and said rotating electrostatic deflector being spaced from each other and aligned normal to said predetermined loop path and having electrical interaction between said atomizer and said deflector for forming a fan-shaped spray pattern from the atomizing edge of the rotating atomizer head opposite the deflector, said rotating atomizer head and said rotating electrostatic deflector being relatively positioned to one another for electrostatically concentratedly directing said spray pattern and electrostatically coating said articles with the coating material of the fan-shaped spray pattern from said atomizing edge of the rotating atomizer head adjacent said articles.

2. Apparatus for electrostatically coating articles com prising a multiple-head electrical-interacting atomizer array for providing coating material spray for coating said articles, carrier means for transporting said articles along a predetermined path through at least a portion of said coating material spray, and means for creating an elec trostatic field between the atomizer array and said articles for electrostatically charging and depositing said coating material onto said articles, said multiple-head atomizer array including at least a pair of rotatable atomizer heads disposed side by side and each having an atomizing edge in substantially the same plane and intersecting the plane ofthe path of the articles, said atomizing edges being electrostatically charged and of the same polarity to mutually repel coating material from adjacent portions of said atomizing edges for forming a separate fan-shaped spray pattern from each of said atomizing edges of the respective rotatable atomizer heads adjacent said articles.

3. Apparatus for electrostatically coating articles comprising a reciprocating multiple-head electrical-interacting atomizer array for providing coating material spray for coating said articles, means for transporting said articles along a predetermined path through at least a portion of said coating material spray, and means for creating an electrostatic field between the atomizer array and said articles for depositing said coating material onto said articles, said multiple-head atomizer array being electrostatically charged and including at least a pair of rotatable atomizer heads disposed relative to each other to provide electrical interaction therebetween and each having an atomizing edge of the same polarity for forming a separate tan-shaped spray pattern from each of said atomizing edges adjacent said articles, the general plane of each of said atornizing edges of the reciprocating multiple-heads being substantially the same and substantially at right angles to the predetermined path.

4. Apparatus for electrostatically spray coating articles having surface irregularities, comprising carrier means for transporting said articles to be coated along a predetermined path, a composite centrifugal atomizer array having a plurality of electrical-interacting atornizing heads each having an atornizing edge spaced from one another in substantially the same plane and intersecting the plane of the path of the articles and adapted for spray coating said articles as they move along said path, separate motor means drivingly connected to each of said atomizer heads, control means for controlling the rotational speed of the respective motor means of the centrifugal atomizer array, means for establishing an electrical field between said atornizing edges and also between said edges and said articles for simultaneously providing electrical-interaction between said edges for forming separate fan-shaped spray patterns of coating material particles from portions of the electrical-interacting atornizing edges in separated areas along said path and for depositing said coating material onto said articles, and means for adjustably positioning said electrical-interacting atornizing edges relative to one another for varying the degree of said electrical-interaction and accordingly varying the concentration of particles of the fan-shaped spray from said atornizing edges to control the degree of penetration of said particles centrifugally projected from said edges into the surface irregularities of said articles.

5. Apparatus for electrostatically coating articles comprising an atomizer array for providing spray of coating material, conveyor means for transporting said articles along a predetermined path through said spray, and means for generating an electrostatic field between said atomizer array and said articles for atornizing and depositing said coating material on said articles, said atomizer array including at least one atomizer head having an atornizing edge and electrostatic rotary deflector means including a rotating extended lateral edge, said atomizer head and said electrostatic rotary deflector means being spaced from each other to provide controlled electrical interaction therebetween for forming a fan-shaped spray pattern from the atornizing edge of the atomizer head opposite the deflector means, the general plane of each of said atornizing edges being substantially the same and substantially at right angles to the predetermined path.

6. Apparatus for electrostatically coating articles comprising an atomizer array for providing spray of coating material, conveyor means for transporting said articles along a predetermined path through said spray, and means for creating an electrostatic field between said atomizer array and said articles for at least partially atornizing and depositing said coating material on said articles, said atomizer array including at least one circular atomizer head having an atornizing edge and at least one electrostatic rotary deflector having an extended lateral edge and spaced from each other and aligned with each other and disposed substantially at right angles to said predetermined path and having electrical interaction therebetween for forming a fan-shaped spray pattern from the atomizing edge of the circular atomizer head opposite the deflector, said atornizing edge of the circular atomizer head and the extended lateral edge of said electrostatic rotary deflector being substantially in the same plane, said plane intersecting the plane of the path of the articles.

7. Apparatus for electrostatically coating articles comprising an atomizer array for providing spray of coating material, means for transporting said articles along a path through at least a portion of said spray, and means for establishing an electrostatic field between said atomized array and said articles for atomization and deposition of said coating material onto said articles, said atomizer array including at least one atomizer head having an atomizing edge and at least one electrostatic defic tor having a curved surface, said atomizer head and said deflector each being rotatable and variably positionable relative to one another and said articles, said electrostatic deflector curved surface having a sufficient lateral extent for electrostatically forming a fan-shaped pattern from the atornizing edge of the atomizer head portion opposite the deflector, the general plane of the atornizing edge of the atomizer head being substantially normal to said path for transporting said articles therealong through at least a portion of said fan-shaped spray pattern.

8. Apparatus for electrostatically coating articles comprising an atomizer array including electrical-interacting multiple-heads for providing coating material spray for coating said articles, means for transporting said articles along a path through at least a portion of said coating material spray, means for creating an electrostatic field between the multiple-heads of said atomizer array and said articles for depositing particles of said coating material onto said articles, said multiple-heads including at least a pair of electrical-interacting rotatable atomizer heads disposed side by side and each having an atoming edge in a plane substantially parallel with one another and electrostatically charged and of the same polarity for forming a fan-shaped separate spray pattern from only a sector of the respective atornizing edges adjacent said articles, each of said substantially parallel planes of the respective atornizing edges of said rotatable atomizer heads intersecting the plane of the path along which the articles to be coated are transported for receiving the coating material, and means for rotating each of said multiple-heads of the atomizer array at a controllable predetermined speed.

9. Apparatus for spray coating a multiplicity of articles with spray particles, comprising a unitary atomizer device for providing a plurality of discrete fan-shaped spray patterns of coating material, carrier means for transporting said articles sequentially within each of said discrete fan-shaped spray patterns, and means for establishing an electrostatic field between the unitary atomizer device and the articles for deposition of the particles of coating material onto said articles electrostatically, said unitary atomizer device including a plurality of centrifugal electrically charged spray heads each having an atornizing edge, and at least one deflector head, said deflector head having an extended lateral surface and being electrostatically charged to the same polarity as said spray heads and positioned relative to the plurality of centrifu gal spray heads for forming a discrete fan-shaped spray pattern from each of the atornizing edges of said spray heads, the plane of each of the atornizing edges substantially intersecting the plane of the path of the articles for depositing said coating material on said articles as they are transported by said carrier means.

10. Apparatus for electrostatically coating articles, comprising carrier means for transporting said articles to be coated along a predetermined loop path, a vertically reciprocal composite atomizer array having a plurality of separate rotary atornizing edges spaced from one another and disposed relative to said predetermined loop path and adapted for spray coating said articles as they move therealong, and means for establishing an electrical field between said atornizing edges and said atomizing edges and said articles and adapted for simultaneously electrostatically generating separate substantially similar sector spray patterns from the atornizing edges adjacent the articles to be coated in separated areas along said predetermined loop path, the general plane of the respective atornizing edges intersecting the plane of the path of the articles for simultaneously coating articles with material of the respective sector spray patterns in different areas of the predetermined loop path.

11. Apparatus for electrostatically applying multi-color coatings to articles, comprising a composite rotary spray device having means for producing a multiplicity of fanshaped spray patterns, means vfor supplying multi-color coating'materials atdesired rates to said composite rotary spray-device, and means for establishing an electrostatic field between said rotary spray device and said articles for electrostatic deposition of said'coating materials onto the articles to be multi-color coated, said composite rotary spray device including a pair of rotary atomizers each having an atomizing edge "of sufiicient lateral extent and being electrically polarized for mutually repelling particle transfer of the multi-color coating materials between adjacent portions of said atomizers and for forming said fan-shaped spray patterns from the atomizing edgesof said rotary atomizers, the ;planeof each of the atomizing edges being disposed .at an angle intersecting the plane of the path of the articles to be multi-color coated.

12. Apparatus for applying multi-color coatings of coating material onto articlescomprising a unitary multiple head spray device including a plurality of rotary spray 'heads each having an atomizing edge, meansfor feeding said coating material onto the spray heads at controlled rates, means for establishinganelectrical field for electrostaticaly charging said coating material and for forming a fan-shaped spray pattern from each of said atomizing edges, said spray heads being rotated at desired difierent speeds for contro'llingcentrifugal rprojection of the electrostatically charged coating material particles forming the fan-shaped spray patterns, and conveyor means for moving the articles through said fanshaped spray patterns, the atomizing edges of each of said spray heads being in a plane intersecting the plane of the path of travel of the articles carried by the conveyor means for depositing the coating material of said fan-shaped spray patterns onto said articles.

'13. Apparatus for electrostatically spraying articles with coating material as they arecarried by a conveyor providing a U-shaped portion of a spray path, at least one rotary atomizer head having an atomizing edge and one electrostatic deflector means having an extended rotating lateral edge spatially disposed relative to saidatomizing edge and adapted to form a fan-shaped spray pattern of coating material to spray said articles from the edge of the atomizer head opposite the deflector as said articles are carried along said spray path, said atomizer head and said rotary deflector means having electrical connections and adapted 'for electrical interaction therebetween and with said relative spatial disposition of the electrical interacting atomizer head and deflectorrneansto one another being a determinant of the lateral extentof said spray pattern, and means for establishing an electrical field to provide simultaneously said electrical interaction between said atomizer head and said deflector means and the atomizer head and the articles carried along said spray path, whereby the particles of coating material forming the fan-shaped spray pattern are deposited on said articles as they move-along-said U-shaped portion-of the spray path.

14. Apparatus for electrostatically spraying articles with coating material as they are carried by a conveyor providing a U-shaped 'portionof a spray .path, at least-one centrifugal atomizer head and one rotary deflector h'ead spatially disposed relative to one another andladapted to spray said articles by a spray pattern of coating material from anatomizing edge of said centrifugal atomizer head as said articles are carried along said spray gpath, said centrifugal atomizer head and said rotary deflector head having electrical interaction therebetween and with said relative spatial disposition of said heads to one another being preset to establish width control of said spray :pattern, means for establishing ;an electrical field to provide said electrical interaction between the heads .per 'se and at least the atomizer head and the articles carried along said-spray :path, said rotary-deflector :head including a rotating :extended lateral edge 'for forming .a fan-shaped spray pattern of particles :of coating material :from -the atomizingedge opposite the deflector for depositiomonto said articles as they move along said vU-shapedportion of said spray path, and control means for "varying the speed of said atomizer head to control centrifugall-y'the penetrating characteristics of the :faneshap'ed spray pattern particles =of1coating material to be deposited :on said articles.

15. Apparatus for electrostatically coating articl'escomprising' an atomizer arrangement for providing spray of coating material to :be deposited on said articles, and means for establishing an electrostatic field between said atomizer arrangement and -said'article for atomizing and depositing the particles of coating material on said articles, said atomizer arrangement including at least one aton1- ize'rhead having an'atomizing edge from which said spray of coating material emanates and electrostatic rotary deflector means having spray control surface means of extended lateral extent disposed relative to said atomizing edge, said atomizing "edge and said electrostatic rotary deflectorrmeans'being spaced from each other and "adapted to have electrical interaction 'therebetween for forming a single compositetfan shaped'spray patternfrom theedge of the atomizing head opposite the deflector, the rotary deflector spray control surface being positioned relative to said atomizing edge for directionally controlling the position of the single composite fan-shaped spray relative toth'e articles tobe coated.

16. Apparatus for electrostatically coating an article comprising an atomizer "arrangement for providing spray of coating material *to be deposited on said article, and means for establishing an electrostatic field betweenzsaid atomizer arrangement'a'nd said article for atomizing'and depositing said coatingmaterial on said article, said atomizer arrangement including at least one atomizer head having an atomizingedge from which said spray'o'f coating material emanates and electrostatic rotary deflector means having spray control surface means including a rotating extended lateral edge disposed relative to said atomizing edge, said atomizer edge and-said-electrostatic deflector means being spaced from each'o'ther and having-electrical connections and'a'dapted to have electrical interaction therebetween for forming a fan-shaped spray pattern from said atomizing edge opposite the rotary deflector, means for adjustably positioning the atomizing edge relative to the article to 'be coated for varying the distance between the atomizing edge and the article "to adjustably control the distance of travel-of the particles forming the fan-shaped spray pattern.

17. Apparatus for electrostatically coating an article comprising an atomizer arrangement for providing spray of coating material to be deposited on said article, and means for establishing an electrostatic fieldbetween said atomizer arrangement and said article, said atomizer arrangement including at least one atomizer head having a circular atomizing edge from which said spray of coating material'ema'nates and electrostatic rotary deflector-means having spray control surface means of extended lateral extent disposed relative -to said atomizing edge for forming a fan-shapedpattern-emanating therefrom, said atomizer head having a coatingmaterial receivingsurface portion disposed in one plane and a coating material dispensing surface portion adjacent-said atomizing edge disposed in a plane different from said plane 'of the receiving surface portion, said atomizer head andsaid electrostatic -rotary deflector means being spaced from-eac'h-other and having electrical connections and adapted to have electrical interaction therebetween for directionally con trolling said spray to be electrostatically depositedon said article.

18. Apparatus for electrostatically coatingarticles'comprising an atomizer array for providing'an eifective 'fanshaped spray pattern of coating material, conveyor means for transportingsaid ar'ticles along -a predetermined path through said spray, and means for creating an electrostatic held between said atomizer array and said article's,

said atomizer array including an atomizer having an atomizing edge and with the area adjacent said atomizing edge being open to permit the fan-shaped spray pattern to be electrostatically increased or decreased in Width for controlling the lateral range of the spray to be deposited on said articles, and electrostatic means including an extended lateral edge positioned adjacent said atomizer substantially diametrically opposite the articles to be coated for forming a fan-shaped spray pattern from the atomizing edge opposite the electrostatic deflector, and said conveyor means spaced remote from the atomize means but adapted to move the articles to be coated through the spray pattern.

19. Apparatus for electrostatically coating articles comprising an atomizer array for providing an effective spray pattern of coating material, conveyor means for transporting said articles along a predetermined path through said spray, and means for creating an electrostatic field between said atomizer array and said articles for atomizing and depositing said coating material on said articles, said atomizer array including electrostatic atomizer means having an atomizing edge and with the area adjacent thereto being open to permit the efiective spray pattern to be increased or decreased in width for controlling the coverage range of the spray to be deposited on said articles, and electrostatic particle repelling electrode means including an extended lateral edge for forming a fan-shaped spray pattern from the atomizing edge of the atomizer means opposite the deflector, and mounting means for said electrode means for positioning said extended lateral edge adjacent the atomizer means on the side thereof substantially diametrically opposite the articles to be coated, said conveyor means being spaced from the atomizing means but adapted to move the article to be coated through said spray pattern.

20. Apparatus for electrostatically coating articles comprising an atomizer array for providing a fan-shaped spray .of coating material, conveyor means adapted to transport said articles along a predetermined loop path through said spray, and means for creating an electrostatic field between said atomizer array and said articles for atomizing and depositing said coating material on said articles, said atomizer array including at least one atomizer head with a circular atomizing edge and at least one rotating electrostatic deflector having an extended lateral edge, said atomizing edge and said lateral edge having electricall interaction therebetween for forming a fan-shaped spray opposite said deflector, said atomizer head and said rotating electrostatic deflector being spaced from each other and aligned with each other and substantially normal to said predetermined path and means for controlling the amount of electrical interaction for electrostatically controlling the concentration of coating material of the fan-shaped spray.

21. Apparatus for electrostatically coating articles, comprising a unitary spray device having a plurality of spaced-apart rotary atomizing means located side by side, each having a principal axis of rotation and adapted for producing two discrete sector spray patterns on substantially opposite sides of and within a unitary conveyor loop along which said articles are transported in a spraying path, said atomizing means being mounted with their said principal axes extending parallel to each other and substantially normal to said spraying path, means for supplying coating materials to said atomizing means, and means for establishing an electrostatic field between said atomizing means and said articles to provide electrostatic deposition of said coating materials onto said articles, said spaced-apart rotary atomizing means having atomizing edges being charged at the same polarity and positioned relative to each other to provide electrical interaction therebetween for mutually repelling transfer of spray particles between adjacent sectors of the atomizing edges of the respective atomizing means for forming said two discrete sector spray patterns of coating material from the atomizing edges of the respective atomizing means opposite the deflector, the plane of the respective atomizing edges intersecting the plane of the spraying path of the articles for coating the article by the particles forming said two discrete sector spray patterns on said substantially opposite sides of the loop.

22. Apparatus for electrostatically coating articles comprising an atomizer array including electrical-interacting multiple atomizing heads for providing coating material spray for coating said articles, carrier means for transporting said articles along a predetermined path through at least a portion of said coating material spray, and means for establishing an electrostatic field between the multiple-heads of said multiple atomizer array and said articles for depositing said coating material onto said articles, said multiple-head atomizer array including at least a pair of rotatable atomizer heads disposed side by side and each having an atomizing edge electrostatically charged and of the same polarity mutually to repel transfer of particles from adjacent portions of the atomizing edge of said atomizer heads and to form a separate fan-shaped spray pattern from the atomizing edges of each of said atomizer heads adjacent said articles, each of said atomizing edges of the respective multiple atomizing heads of the atomizer array being substantially circular and with said atomizer heads being in substantially the same plane and with said plane intersecting the plane of the predetermined path of the articles.

23. Apparatus for electrostatically coating articles, comprising carrier means for transporting said articles to be coated along a predetermined path, a composite atomizer array having a plurality of separate rotary atomizing heads from one another and disposed relative to said predetermined path and adapted for spray coating said articles as they move therealong, and means for establishing an electrical field between said atomizing heads per se and between said atomizing heads and said articles for simultaneously generating separate similar sector spray patterns of coating material from the respective atomizing edges of the atomizing heads in areas along said predetermined path, and said heads separated a distance sufiicient to provide a predetermined flash-oil interval between applications of the spray coating deposited on said articles, the plane of the atomizing edges being substantially the same and with said plane intersecting the plane of the predetermined path of the articles for applying said spray onto said articles.

24. Apparatus for electrostatically spray coating articles having surface irregularities, comprising carrier means for transporting said articles to be coated along a predetermined path, a composite atomizer array having a plurality of electrical-interacting atomizing heads each having a circular atomizing edge spaced from one one another and disposed relative to said predetermined path and adapted for spray coating said articles as they move therealong, means for creating an electrical field between said atomizing edges and also between said edges and said articles for simultaneously providing electrical-interaction between said heads for forming separate fanshaped spray patterns of coating particles from the atomizing edges in separated areas along said path, and means for adjustably positioning said electrical-interacting atomizing heads relative to one another for varying said electrical-interaction and accordingly varying the concentration of said particles emanating from said atomizing heads to control the degree of penetration of said particles into the surface irregularities of said articles, said atomizer array being vertically reciprocable, the plane of the respective atomizing edges intersecting the plane of the path of the articles to be spray coated.

25. Apparatus for electrostatically coating articles comprising a multiple-head electrical-interacting atomizer array for providing coating material spray for coating said articles, carrier means for transporting said articles along a predetermined path through at least a portion of said c'oatin'g rnaterial spray, and means for creating an electrostatic field betweenthe multiple-heads of said atomizer array and said articles for depositing said coating materia lonto said articles, said multiple-head atomizer array including at least a pair of rotatable atomizer "heads disposed side by side andeach having an atomizing edge electrostatically charged and all of the same polarity to restrict atomization-from the adjacent portions of I atomizing edges of said atomizer headsfor forming'a separate fan-shaped spray pattern from the edges of each of said atomizer heads adjacent said articles,-and means for inclining-said atomizer array relative to the carrier means predetermined path for controlling theextent ofthe spray pattern in at least one dimension, the general plane of each of theatomizing edges being substantially the same and substantially at right angles to the plane of the predetermined path.

26. Apparatus for-.electrostatically applying multi-color coatings to articles, comprising a composite rotary spray device having multi part atomizer means for producing a multiplicity of fan-shaped spray patterns, means for supplying multi-color coating materials at desired rates to the respective multi-parts of said atomizer means of the rotary spray device, and means for establishing an electrostatic field in a zone between the respective multiparts of the atomizer means of saiddevice including 'a direct current voltage source in the range of 40 *kilovolts to 300 kilovolts, said multi-partsof said atomizer means of the rotary spray device being electrically interacting and each having an atomizing'edge'electrically polarized to repel-transfer of the respective multi-color coating-materials between adjacent edge portions of said atomizers for forming a fan-shaped spray pattern from each of the multi-parts of said atomizer means adjacent said articles, the'atomizing edges being in'substantially'the same plane and said plane intersecting the plane of the'path of the articles.

27 Apparatus forelectrostatically coating articles comprising a reciprocating multiple=head electrical interacting atomizer array for-providing coating material spray for coating-said articles, means 'for transporting said articles along a predetermined path through at 'leasta portion of-said coating material spray, means forcreatingan electrostatic field between the multiple-heads of said atomizer array'andsaid articles for depositing said coating "material onto said articles, motor means drivingly connected to each of'said atomizer heads, control means for controlling the rotational speed of the motor means of the centrifugal atomizer array, said multiple hea'd atomizer array including 'at least a pair of rotatable electrical-interacting atomizer heads disposed side by side and 'each having an atomizing edge electrostatieally charged and of the same polarity for'forming a'fan-shaped spray pattern from the atomizing edge of respective multiple-heads, and means for rotating each of said reciprocating multiple-heads'ofthe atomizer array at a controlable predetermined speed, the general plane of each of said atomizingedges'beingsubstantially different'but substantially parallel to each other and substantially at right'angles to the predetermined path.

28. Apparatus for'electrostatically coating articles comprising a multiple head electrical-interactingatomizer array for -providing coating material spray for coating'said articles, means for transporting said articles along a predetermined path through atleast a portion of said coating material spray, means for creating an electrostatic field between the"multiple-heads of said atomizer array and said'articles'for depositing said coatingmaterialonto said articles, said multiple-head atomizer array including at least a pair'of rotatable electrical-interacting atomizer heads disposed side by side and each-having an atomizing edge electrostatically charged and of the same polarity for forming a fan-shaped pattern therefrom adjacent the articles-to be coated, means for rotating each-of'said-pair ofmulti'ple-heads'of the atomizer array at a-controllable predetermined speed, eachof said-pair of multiple-heads of-the atomizer array having supporting'structure means, and means for linearly adjusting the-location of'the'atomizer *heads relative to one another on the supporting structure means, said atomizing-edges being substantially in the same plane and-substantially atright angles to "the predetermined :path.

29. Apparatus for electrostatically spray coating articles having a surface irregularities, comprising carrier means for transporting saidarticles to be-coated along a predetermined path, -a composite centrifugal atomizer array having a'plurality of electrical-interacting atomizing heads each "having an atomizing 'edge 'spaced from one another 'in'substantiallythe same plane and intersecting th'eplaneof the 'pathof the articles "and adapted for spray'coating-saidarticles as-they move alongsaidpath, mo'tor'meansdrivinglyconnected toeach of said'atomizer heads, control means "for controlling the rotationalspeed of the motor means of the centrifugal atomizer array, means for establishing an electrical field between said atomizing edges and 'also between said edges and said articles for 's'imultaneousy providing e'lectrical interaction betWeensaid-edges "for forming separate fan shapedspray patterns of coating material particles from portions of the electrica'l int'eracting atomizing edges in separated areas alOngsaidpath'and for depositing said coating materialon'tosaid'articles,last said means including a voltage sourceof'direct'current in't'he range substantially from 40 kilovo'lts to 300 kilovolts, and means for 'adjustably positioningsaid electrical-interactingatomizing edges relativeto'one "another for varying the degree of said electrical-interaction'and accordingly varying the concentration ofparticles'o'fthe fan-shapedspray from said atomizing edges to control the degree of penetration of said particles 'centrifugally projected from said edges into thesurface'irregularities of said articles.

References Cited in the file of this patent UNITED STATES PATENTS 2,425,652 Starkey Aug. "12, 1947 2,456,853 Arbron Dec. 21, 1948 2,632,716 Starkey Mar. 24, 1953 2,651,287 Turner Sept. '8, 1953 2,658j009 'Ransburg Nov. 3, 1953 2,736,671 'Ransburg et al. Feb. '28, 1956 2,754,226 J uvinall July "10, 1956 2,780,565 Juvinall "Feb. 5, 1957 2,794,751 Juvinall June 4, 1957 2,795,516 Miller -'June 11, 1957 2,809,902 Ransburg Oct. '15, 1957 2,865,324 Stein Dec. 23, 1958 FOREIGN PATENTS 773,800 Great Britain May 1, 1957 UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent NO.I 2,894,485 July 14, 1959 John Sedlacsik, Jr

It is hereby certified that error appears in the printed specification of the above numbered patent requiring correction and that the said Letters Patent should read as corrected below.

Col-mm 9, lines '72 and 73, for "atomized" read atomizer 3 column 14, line 33, after "heads" insert spaced. line 53, strike out "one", second occurrence; column 15, line 34, before "m'dlti=pa:z"ts" insert atomizing edges of the column 16, line 19, "surface strike ou "ah Signed and sealed this day of Fe (SEAL) Attest:

KARL Ho AXLINE ROBERT C. WATSON Attesting Oflicer Commissioner of Patents

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