US3709190A

US3709190A - Coating apparatus

Info

Publication number: US3709190A
Application number: US00045444A
Authority: US
Inventors: Gottberg H Von; G Schaefer; G Joerns
Original assignee: Ransburg Gema GmbH
Current assignee: Ransburg Gema GmbH
Priority date: 1970-02-14
Filing date: 1970-06-11
Publication date: 1973-01-09
Anticipated expiration: 1990-01-09
Also published as: FR2080345A5; GB1332234A; DE2006878A1; BE759240A

Abstract

A coating apparatus including a programmed, movable member carrying coating means dispensing particles of a protective or decorative coating material toward the irregular surface contours of the front and the rear of automobile bodies. The programmed member displaces the coating member in a vertical direction across the irregular surface contours of the automobile bodies, maintains a substantially uniform distance between the coating means and the plane of the irregular surface contours of the automobile body to be coated and aligns the axis of the coating means with respect to the plane of the irregular surface contours of the automobile bodies so as to be substantially perpendicular with such plane of the automobile bodies when dispensing the protective or decorative coating material toward the automobile bodies. A method of coating a series of articles with a protective or decorative coating material.

Description

United States Patent 1191 Von Gottberg et a1. 14 1 Jan. 9, 1973 54 COATING APPARATUS 3,121,024 2/1964 Wampler et a1. ..118/2 [75] Inventors: Horst Von Gottberg; Gerd Schaeier; P Exam," r Mervin St in fleisenstamm 21:11-31:11: ExaniirfelLeo Mills tein f i llr f f l g V, Attorney--Merrill N. Johnson, Harry E. Downer, 1 Assigneer Rallsburg GmbH, Hellsenstamm David H. Badger and Charles W. Hoffmann near Frankfurt, Germany 22 Filed: June 11,1970 [57] ABSTRACT [21] Appl No: 45,444 A coating apparatus including a programmed, movable member carrymg coating means d1spens1ng part1- cles of a protective or decorative coating material [30] Foreign Application Priority Data toward the irregular surface contours of the front and Feb 14 1970 German p 20 06 878 4 the rear of automobile bodies. The programmed y member displaces the coating member in a vertical direction across the irregular surface contours of the 'g 6 automobile bodies, maintains a substantially uniform [58]' Field of Search ..1 18/631, 2, 321, 323, 7, 8, t matmg means and the P of 118/, 239/15 62 the irregu ar surface contours of the automobile body v v to be coated and aligns the axis of the coating means with respect to the plane of the irregular surface con- [56] Referencesclted tours of the automobile bodies so as to be substantially UNITED STATES PATENTS perpendicular with such plane of the automobile bodies when dispensing the protective or decorative 3,086,495 4/1963 Knlght ..118/7 coating material toward the automobile bodies 3,561,398 2/1971 Rose et al..... 118/7 2,900,950 8/1959 Peeps ..118/2 A method of coating a series of articles with a protec- 3,255,037 6/1966 Knight ..118/2 tive or decorative coating material. 3,001,504 9/1961 Gengenbach et a1 ..118/2 3,279,421 10/1966 Tilney et al..; ..118/323 6 Claims, 4 Drawing Figures 37 37 i 1 34 i 24 23 1 19 1 I 32 l 31 f il fl PATENTEDJAN 9 1975 PATENTEDJAN 9197a 3.709.190

SHEET 2 OF 3 INVENTORS HORST VON GOTTBERG GERD SCHAEFER GUENTER JOERNS PATENTEU JAN 9 I975 SHEET 3 OF 3 G R E B S QM 0 FE 6M J SNH CR O SE NS ERRE www N COATING APPARATUS The present invention relates to a method and to a coating apparatus including coating devices used to deposit a protective or decorative coating material upon an article having one or more irregular surface contours. More particularly, the present invention relates to a method and to a coating apparatus including one or more coating devices displaceable to each of a plurality of different positions during a coating cycle to thereby facilitate the coating of an article having irregular surface contours such as an automobile body.

in several coating apparatus, successive articles to be coated are carried by a conveyor past the coating apparatus. When the articles are in a coating zone, as determined by the characteristics of the spray pattern or patterns emerging from the coating devices of the coating apparatus, the articles are coated by the particles of the spray. When operating the coating apparatus, it is preferred that the distance between the nozzle, extremity, edge and the like of the coating devices from which the coating material is atomized and the surface of the article being coated be maintained within specified limits. The distance between the nozzle, extremity, edge and the like of the coating devices is particularly important where the spray patterns emerging from adjacent coating devices of the coating apparatus are to be blended together on the article.

An article, such as a hand toy, having a relatively limited surface area generally presents little, if any, coating problem. The same can be said of an article having a relatively large but regular surface contour such as a refrigerator body. However, when the articles have a relatively large surface area, it is frequently necessary, in order to obtain a uniform coating over the surface of the article, to move the coating device or devices of the coating apparatus transversely of or across the article path as the article passes through the coating zone of the coating apparatus.

However, an article having both a relatively large surface area and irregular surface contour presents an additional problem. lf the distance between the nozzle, extremity, edge or the like of the coating device and the surface of the article is without specified limits or if the axis of the coating device varies too far from being perpendicular with the plane of the surface of the article being coated with the protective or decorative coating material, an undesirable finish may be produced on such surface of the article.

An automobile body is an example of an article having a large surface area with irregular surface contours. During a spray coating cycle, the automobile body presents several of the problems discussed above.

A tentative solution to the problem of coating irregular surface contours of the frontand rear of automobile bodies transported by a conveyor is to traverse such surface contours using a coating device carried by a reciprocator. The reciprocator is of the type which does not move the coating device in the horizontal plane but moves the coating device in thevertical plane across such irregular contours. Since the automobile bodies are substantially continuously displaced by the conveyor, the coating device, in order to maintain the approximate proper distance between itself and such surfaces being coated, should be displaced through the vertical plane rapidly by the reciprocator. However, rapid displacement of the coating device through the vertical plane by the reciprocator in order to maintain the approximate proper distance between the nozzle extremity, edge and the like of the coating device and the irregular surface contours of the automobile bodies may result in a coating material film on such surface contours which is not sufficiently thick to accomplish its intended purpose of protection, decoration or both. If the speed with which the coating device traverses or crosses such irregular surface contours is slowed to obtain a coating material film of the proper thickness to accomplish its intended purpose, the spray patterns emerging from adjacent spray coating devices may not blend properly due to, among other things, the substantially continuously changing distance between the nozzle, edge, extremity and the like of the coating device and the surface contours being coated with coating material. A tentative solution to the problems presented by the reciprocator which displaces the coating device or devices only in one plane is to position a vertically displaceable spray device on a suitable overhead carriage mechanism which moves with each automobile body in the horizontal direction for a short distance. However, the tentative solution proves to be unsatisfactory due to foreign particles such as dirt, dust and the like which may be accumulated upon the carriage and its cooperatively associated guide and be released by the movement of the carriage during the coating cycle. Such particles tend to fall or float into the coating zone and come to rest on the automotive body thereby undermining the quality of the coating and, at times, resulting in rejected bodies because of a lack of a quality coating.

The problems associated with coating automobile bodies is more acute if the upper portions of adjacent automobile bodies are separated by less distance than the lower portions of the adjacent automobile bodies. For example, where 'a plurality of adjacent spray devices are used, the spray patterns of the adjacent spray devices may not blend properly resulting in a finish on either the upper portion or the lower portion or both portions of the automobile body which is undesirable.

It is, therefore, an object of the present invention to provide a coating apparatus including means for moving a coating device or devices across the irregular surface contours of a substantially continuously moving series of articles such as automobile bodies in such a manner as to provide adequate time for coating such surface contours without materially altering the rate of movement of such articles. Another object of the present invention is to provide a coating apparatus with means for determinately aligning and maintaining a substantially uniform distance between the nozzle, extremity, edge or the like of the coating device or devices and the irregular surface contour of the substantially continuously moving series of articles. Yet another object of the present invention is to provide vertically displaceable and pivotal back-to-back rows of electrostatic spray coating devices which coat the front and the rear surfaces of articles such as automobile bodies.

Generally speaking, the present invention relates to a method and to a coating apparatus including either an electrostatic or non-electrostatic coating device or devices for spray coating an irregular surface contour or area such as the front and rear surfaces of an automobile body. The apparatus includes a conveyor for transporting a series of automobile bodies to be coated with protective or decorative coating material through a coating zone. Where electrostatic coating devices are used, a high voltage direct current source is connected to the electrostatic coating devices. An electrical charge difference is produced between the particles of coating material and an automobile body in the coating zone whereby the particles of coating material are deposited upon the surface of the automobile body. A programmed member carries the electrostatic or nonelectrostatic coating device or devices as the case may be. The member moves the coating device or devices into the gap or spacing between successive automobile bodies. The member displaces the coating device or devices across the irregular surface contours of the automobile body. Pivotal movement of the member assists in maintaining the coating device or devices at a substantially constant distance from the irregular surface contours of the automobile body and assists in aligning the axis of the coating device or devices with respect to the plane of the irregular surface contour of the automobile body, such as inwardly sloping surface contours of the front and the rear surface of the automobile body, so as to be substantially perpendicular to such plane of the surface contours of the automobile body when dispensing coating material toward the automobile body.

it is to be understood that the present invention is applicable to either an electrostatic or non-electrostatic coating device or devices which dispense or emit either liquid or non-liquid coating materials. Suitable liquid coating materials are paint lacquers, varnishes, enamels, and the like. Suitable non-liquid coating materials are thermosetting powders such as epoxy resin and the like and thermoplastic powders such as polyvinyl-chloride, polypropylene, polyester, polyethylene and the like. For'illustration only and not for limitation, the invention will be disclosed in conjunction with the use of electrostatic coating devices which emit a liquid coating material such as paint.

in the drawing:

FIG. 1 is a diagrammatic side view of a coating apparatus embodying the invention;

FIG. 2 is a diagrammatic top view of the coating apparatus of FIG. 1 with components removed;

FIG. 3 is a diagrammatic side view of the apparatus used to move or displace the coating devices; and

FlG. 4 is a diagrammatic illustration of the movement of the coating devices shown in dotted lines.

Referring now to the several FIGURES of the drawing, and in particular to FIGS. 1 and 2, a series of automobile bodies to be coated with a film of a suitable protective or decorative coating material are transported to a coating station by any suitable means such as carriage means 11. The automobile bodies 10 are illustrated as being electrically grounded through the carriage means 11. The automobile bodies are transported by a conveyor line which include tracks 12 and a conveyor chain 13. The conveyor substantially continuously moves the automotive bodies 10 in the direction of arrow 14.

Each automobile body 10 is subjected to a spray of the protective or decorative coating material emerging from or dispensed by

electrostatic spray devices

15 and 16 which are part of the coating station. The

electrostatic spray devices

15 and 16 are disposed on opposite sides of the conveyor line and each are faced toward the conveyor line. The

electrostatic devices

15 and 16 are reciprocated in the vertical plane by suitable reciprocators l7 and 18.50 as to coat the sides of automobile bodies 10. The reciprocators l7 and 18 for the

electrostatic spray devices

15 and 16 may be carried by suitable

movable bases

19 and 20. The

movable bases

19 and 20 engage with

guide tracks

21 and 92 so as to facilitate movement toward and'away from the conveyor line along the

tracks

21 and 92 as the surface contours of each automobile body 10 demand. The primary function of the

electrostatic spray devices

15 and 16 is to spray coating material toward the side surfaces of each automobile body 10 as each automobile body passes thereby.

The spray painting station may also include an overhead electrostatic spray device 22 faced toward the conveyor line. Electrostatic spray device 22 may be vertically reciprocated by any suitable reciprocator 90. As seen in FIG. 1, the spray device 22 is mounted so that it follows the surface contours of the roof of the automobile body' 10 thereby coating the roofand the upper extremities of the front and the back of the automobile body with coating material. The electrostatic device 22 may include a plurality of electrostatic spray devices aligned in a row across the top portion of the automobile body 10 in order to properly coat such portions of the automobile body.

The middle and lower extremities of the front and the back ends of each automobile body 10 are coated by coating material from the sprays of a plurality of back-to-back

electrostatic spray devices

27 and 28 supported by an overhead member 29; The overhead member 29 is operable to control the vertical position of the back-to-back

electrostatic spray devices

27 and 28 with respect to the automobile bodies 10. The overhead member 29 may include any suitable programmable device such as a hydraulic device having a vertically displaceable piston 30. The vertical position of the point 36 on piston 30 of the overhead member 29 determines the vertical position of the nozzles and the like of the

electrostatic spray devices

27 and 28 with respect to the front and the rear surfaces of the automobile bodies 10.

In the particular embodiment illustrated in the drawing, the electrostatic spray device27 and 28, respectively, are carried and positioned by

cross-bar members

31 and 32. The

cross-bar members

31 and 32, carried by pivotally

displaceable arms

23 and 24, determine the distance between the nozzle and the like of each

spray device

27 and 28 .and the rear or front ends or surfaces of the automobile body 10 and the position of the axis of the nozzle of each spray device with respect to rear or front ends of the automobile bodies 10. The

pivotal displacement ofthe

arms

23 and 24 is controlled by

hydraulic devices

33 and 34.

Hydraulic devices

33 and 34 may include a cylinder and a movable piston. The cylinder of each

hydraulic device

33 and 34 is fixedly connected to the piston 30 of the overhead member 29. Activation of either or both

hydraulic devices

33 and 34 causes their

respective arms

23 and 24 to pivot about the point 36 on the piston 30 to thereby appropriately space the nozzles and the like from the front and the rear ends of the automobile bodies and align each of the nozzles and the like of the electrostatic spray devices with the surface of the irregular contour to be coated with coating material.

It is seen that vertical displacement of the

electrostatic spray devices

27 and 28, carried by the

cross-bar members

31 and 32, over the automobile bodies 10 is accomplished by displacement of the point 36 of the piston 30 of the overhead member 29. Further, it is seen that pivotal displacement of each

electrostatic device

27 and 28 so as to space and align the nozzles and the like of the spray devices with the irregular contour of the surface of the automobile body to be coated is accomplished by displacement of the

cross-bar members

31 and 32 through pivotal movement of the

arms

23 and 24 by

hydraulic devices

33 and 34.

It is to be understood that each of the

electrostatic devices

15, 16, 22, 27 and 28 is connected to a suitable directcurrent source 35 capable of providing output voltages of up to 100 kilovolts or higher to each electrostatic'device connected thereto.

With continued reference to the several FIGURES of the drawing and in particular to FIG. 4, the movement of the

electrostatic devices

27 and 28 carried by

crossbar members

31 and 32, respectively, during a coating cycle will be described. It should be understood that during a spray coating cycle, the automobile bodies are substantially continuously moving in the direction of arrow 14. Therefore, the relative position of the automobile bodies 10 with respect to the vertical transverse plane of piston 30 is substantially continuously changing during the coating cycle. Several positions of the automobile bodies 10 with respect to the

electrostatic devices

27 and 28 during a single coating cycle are illustrated by dotted lines in FIG. 4.

Upon activation of the hydraulic cylinder 30 by the presence of automobile bodies 10, the hydraulic cylinder and, hence, the pivot point 36 carried by cylinder 30 is displaced substantially continuously in a downward direction from its initial position 40 until its lowest position at position 45 is attained. When the pivot point 36 attains position 45, the direction of movement of the hydraulic cylinder 30 and hence the directionof movement of pivot point 36 is reversed and displaced substantially continuously in an upward direction to its initial position, that is, position 40. In other words, the hydraulic cylinder is moved into the gap or space between adjacent automobile bodies 10 in the following operational cycle: the initial position of pivot point 36 carried by cylinder 30 is position 40; the pivot point 36 is displaced substantially continuously downward until position 45 is reached at which time the pivot point is displaced substantially continuously upward until initial position 40 is reached, thereby completing an operational cycle.

As the cylinder 30 goes through its vertical travel

hydraulic cylinders

33 and 34 are programmed to pivotally displace

arms

23 and 24 respectively forward or rearward, as required, to appropriately move

crossbars members

31 and 32 to thereby locate the

electrostatic devices

27 and 28 with respect to the automobile bodies 10. When the electrostatic devices are located,

each is maintained at a substantially constant nozzle-tosurface to be coated distance from the irregular surface contours of the automobile bodies 10 being coated with coating material.

The dotted line path provided by

location points

49, 50, 51, 52, 53, 54, 55, 56 and back to 50 and 49 illustrates the location of the nozzle or nozzles and the like of electrostatic device or devices 27 as substantially continuously moved vertically and horizontally by the combined action of

hydraulic cylinders

30 and 34. As the nozzles of electrostatic devices 27 approach about location 52, it is contemplated that the electrostatic devices 27 are activated or triggered on to thereby emit coating material toward surface 82 at the front of the trailing automobile body 10. At location 53, the electrostatic devices 27 coat surface 83, and so on until the electrostatic devices 27 return location 50 where the operational coating cycle is completed by the coating of surface 87 at the front of trailing automobile body 10. Thereafter, the electrostatic devices 27 are de-activated or triggered off. It should be noted that as the trailing automobile body 10 moves toward the vertical plane of cylinder 30, the electrostatic devices 28 tend to be pivoted rearwardly to maintain a more uniform nozzle-to-surface to be coated spacing or distance.

The nozzles and the like of electrostatic devices 28 follow a path illustrated by the dotted line path between

locations

59, 60, 61, 62, 63, 64, 65, 66 and back to

locations

60 and 59. The electrostatic devices 28 are activated or triggered on" at about location 61 and coat the upper portion of surface 71 at the rear of leading automobile body 10. At location 62 the electrostatic devices 28 coat surface 72 at the rear of leading automobile body 10 and so on until the electrostatic devices 28 reach location 66 whereupon after completing the coating of surface 76 at the rear of leading automobile body 10, the electrostatic devices 28 are deactivated or triggered off. It should be observed that pivotal arm 24 tends to be pivoted forwardly in the direction of travel of the automobile body 10 as the bodies move along the conveyor in the direction of arrow 14.

It should be understood that the

electrostatic devices

27 and 28 can be triggered on or off" during any portion of the vertical movement of hydraulic cylinder 30 to obtain a uniform coating over the irregular surface. The sequence of triggering the

electrostatic devices

27 and 28 recited above are merely illustrative of a typical coating cycle and is not intended to limit the concepts involved in the present invention.

It should be understood that the

electrostatic devices

27 and 28 are being pivoted in a substantially continuous manner throughout the coating cycle so as to maintain the approximate proper spacing and alignment between the nozzle and the like of each electrostatic device and the surface being coated with coating material. It should be further understood that the

electrostatic devices

27 and 28 may be retained at any particular location without further pivotal displacement during any portion of the cycle in order to obtain the desired coating thickness. Where the automobile bodies 10 have a substantially vertical front or rear surface or both, the

arms

23 and 24 may be included with a system of parallelogram like levers which avoid anpivoted. With an automotive body design having moreor less vertical surfaces at the rear and at the front, angling of the spraying devices while

arms

23 and 24 are pivoted is not desirable.

A further explanation of FIG. 4 follows. The location of pivot point 36 at position 40 finds the

electrostatic devices

27 and 28 withdrawn from the gap or space between adjacent automobile bodies so that

such devices

27 and 28 are not in an interference path with the automobile bodies. Displacing the pivot point 36 from position 40 to position 41 causes the

electrostatic devices

27 and 28 to be displaced to

locations

49 and 59 respectively. Displacement of the pivot point 36 from position 41 to position 42 displaces the electrostaticdevices 27 and 28 to

locations

50 and 60 respectively. During displacement of pivot point 36 from position 42 to position 43, the

electrostatic devices

27 and 28 are pivotally displaced to locations 51 and to 61 respectively. During displacement of the pivot point 36 from position 43 to position 44, the

electrostatic devices

27 and 28 are pivotally displaced-to locations 52 and 62 respectively. During displacement of the pivot point 36 from position 44 to position 45, the

electrostatic devices

27 and 28 are displaced to locations 53 and 63 respectively. The pivot point 36 remains at position 45 and the

electrostatic devices

27 and 28 are displaced to locations 54 and64 respectively. During displacement of the pivot point 36 from position 45 to position 44, the

electrostatic devices

27 and 28 are displaced to locations 55 and 65 respectively. During displacement of the pivot point 36 from position 44 to position 43, the

electrostatic devices

27 and 28 are displaced to

locations

56 and 66 respectively. During displacement of the pivot point 36 from position 43 to position 42, the

electrostatic devices

27 and 28 are displaced to

locations

50 and 60 respectively. The pivot point 36 is then displaced to position 41 and

electrostatic devices

27 and 28 are withdrawn to

locations

49 and 59 respectively. The pivot point 36 is then displaced to position 40 thereby withdrawing the

electrostatic devices

27 and 28 from the gap or space between the automobile bodies 10. While the nozzles of electrostatic devices 27 are at

positions

52, 53, 54, 55 and 56 the front end surfaces 82, 83, 84, 85 and 86 respective-. ly of the trailing automobile body 10 are coated. While the nozzles of electrostatic devices 28 are at

positions

61, 62, 63, 64, 65 and 66 the rear end surfaces 71, 72, 73, 74, 75 and 76 respectively of the leading automobile body 10 are coated.

A slight reciprocation of the

electrostatic devices

27 and 28 in the horizontal plane across the surfaces of the automobile bodies 10 may be desirable to facilitate blending of the adjacent spray patterns emitted by the devices. 7

Programming of the overhead member 29 and

hydraulic devices

33 and 34 may be controlled by any suitable device (not shown) such as a sequential camming device which activates a fluid valve or valves (not shown) to thereby regulate the fluid flow into the cylinders associated with overhead member 29 and

hydraulic devices

33 and 34. The amount of fluid flow into such cylinders controls the movement or displacement of piston 30 and the movement or displacement of

pivotal arms

23 and 24.

It is contemplated that each electrostatic device 15,

16, 22, 27 and 28 will haveassociated with it at least one air-atomizing nozzle, as well as means for feeding paint to the center of the nozzle; the paint so fed being delivered to the nozzle of each electrostatic device and atomized by the action of air. A suitable air-atomizing electrostatic. spray device is illustrated in U.S. Pat. No. 3,169,882. It is also understood that each of the

electrostatic spray devices

27 and 28 may include'more than one air-atomizing electrostatic device. For example, it is contemplated that each of the

electrostatic spray devices

27 and 28 include at least a row of four air-atomizing electrostatic spray devices of the type shown in U.S. Pat. No. 3,169,882. a

it is contemplated that electrostatic devices other than air-atomizing electrostatic spray devices may be employed with the present invention. For example,

electrostatic devices using a rotating head, hydraulic force combinations thereof and the like may be substituted for the air-atomizing

electrostatic devices

27 and 28.

The location of the various electrostatic. spray devices l5, l6 and 22 relative to each other along the conveyor line may vary within relatively wide limits. It

is desirable that each of the electrostatic spray devices deposit the coating material in overlapping patterns and should not be spaced so far apart along the conveyor line that the coating material deposited by one electrostatic spray device will have dried before the overlapping spray is'deposited.

The electrostatic spray coating devices may be automatically activated upon the arrival of an automobile body 10 at the paint spray station. A suitable automatictriggering or activation device may be used to sense the presence of the automobile body 10. The triggering device may be any suitable automobile body sensing means such as a feeler switch (not shown) or it may include a light source 37 and a light-sensitive cell 38. The feeler switch or the light source 37 and the light-sensitive cell 38 of the triggering device are so disposed that the feeler of the switch is displaced from an initial or normal position or the light falling upon the cell is interrupted when an automobile body 10 is present in the coating zone, thereby activating the spray coating devices through an appropriate control apparatus (not shown). When an automobile body 10 has passed from the coating zone, the feeler of the switch returns to its normal or initial position or the light from light source 37 is permitted to impinge on light-sensitive cell 38 to thereby reset the electrostatic spray apparatus through a suitable control device (not shown) for a subsequent coating cycle.

Although the member 29 including cylinder 30 is shown as being installed overhead, it is recognized that the member 29 may be installed underground. In such an installation, the apparatus is initially displaced up-, wardly and then displaced downwardly to its initial position. Of course, the underground apparatus must be so constructed as not to be in an interference path with the automobile bodies as such bodies pass thereover.

We claim: I

l. A coating apparatus including means for transporting spaced apart articles including from and rear surfaces having irregular contours to be coated through a coating zone, coating means including nozzle means for dispensing particles of coating material toward the articles as the articles pass through the coating zone to deposit particles of coating material upon the articles, programmed movable member means including arm means carrying the coating means and fixedly retaining the axis of the nozzle means of the coating means at a right angle to the arm means, the movable-member means including means for maintaining the nozzle means at a determined distance from the irregular surface contours of the articles by pivoting the arm means in the direction of movement of the articles about a pivot point removed from the coating means, and means for moving the coating means into the space between adjacent articles and simultaneously dispensing particles of coating material toward the front surface of one of the articles and toward the rear surface of the adjacent article in the coating zone, the means moving the nozzle means of the coating means across each of the spaced apart articles in a plane transverse to the direction of movement of the articles as the articles are transported through the coating zone.'

2. The coating apparatus of claim 1, wherein 'the rent source.

3. The coating apparatus of claim 2, wherein the electrostatic coating means includes an air-atomizing electrostatic coating device.

4. The coating apparatus of claim 1, wherein the programmed member means aligns the axis of the nozzle means with respect to the planes of the irregular surface contours of each of the articles so as to be substantially perpendicular to such planes of each of the surface contours of the articles during at least a portion of the time the coating means is dispensing coating material toward the articles.

5. The coating apparatus of claim 4, wherein the articles having irregular surface contours are automobile bodies.

6. The coating apparatus of claim 5, wherein the

Claims

1. A coating apparatus including means for transporting spaced apart articles including front and rear surfaces having irregular contours to be coated through a coating zone, coating means including nozzle means for dispensing particles of coating material toward the articles as the articles pass through the coating zone to deposit particles of coating material upon the articles, programmed movable member means including arm means carrying the coating means and fixedly retaining the axis of the nozzle means of the coating means at a right angle to the arm means, the movable member means including means for maintaining the nozzle means at a determined distance from the irregular surface contours of the articles by pivoting the arm means in the direction of movement of the articles about a pivot point removed from the coating means, and means for moving the coating means into the space between adjacent articles and simultaneously dispensing particles of coating material toward the front surface of one of the articles and toward the rear surface of the adjacent article in the coating zone, the means moving the nozzle means of the coating means across each of the spaced apart articles in a plane transverse to the direction of movement of the articles as the articles are transported through the coating zone.

2. The coating apparatus of claim 1, wherein the coating means includes electrostatic coating means adapted to be connected to a high voltage direct current source.

6. The coating apparatus of claim 5, wherein the coating means dispenses coating material toward the irregular surface contours of a rear portion of the leading automobile body and of a front portion of the trailing automobile body.