AU607287B2 - Process and apparatus for spraying a product onto opposite faces of a panel - Google Patents

Description

By: A 30 /1 1/:e8 Regist red Patent Attorney S0031--/45~ To: The Commissioner of Patents 'COMMONWEALTH OF AUSTRALIA L, i r. -CL ~-rr~rWL~-rrJZ-.fL~ i I- r r: ru.rYL 602 87 COMMONWEALTH OF AUSTRALIA Patents Act 1952 CO M P L E T E S P E C I FICATION

(ORIGINAL)

Application Number Lodged Complete Specification Lodged Accepted Published *1 Priority 8 December 1987 Related Art I Name of Applicant Address of Applicant Actual Inventor/s Address for Service AEROSPATIALE SOCIETE NATIONALE

SINDUSTRIELLE

37 Boulevard de Montmorency 75781 Paris Cedex 16, France Daniel LE FLOCH Michel GRASSET F.B. RICE CO.

Patent Attorneys 28A Montague Street, Balmain N.S.W. 2041 Complete Specification for the invention entitled: Process and apparatus for spraying a product onto opposite faces of a panel The following statement is a full description of this invention including the best method of performing it known to us/%a:- Soci6t6 Nationale Industrielle To: The Commissioner of Patents, Commonwealth of Australia.

This Form is suitable for any type of Patent Application.

Status Jacques BALAZARD No legalisation required. S aus Ja Directeur Technique F.B. RICE CO., *a Delete whichever is inapplicable. Patent Attorneys, b Delete if not a Convention application, Sydney.

it la Description The present invention relates to a process and an apparatus making it possible to spray a product, more particularly paint, onto the opposite faces of a panel, which may be curved.

In the aeronautical and space fields, it is necessary to paint or protect with the aid of a protective product panels, whose shape is generally curved, because they can e.g.

be fuselage elements. At present; use is made of conventional 0 &0 industrial painting methods for painting such panels.

Generally, the panel is brought to a loading station, where I it is attached beneath a girder or beam travelling in an Soverhead rail. A travelling crane manipulates the assembly "o and positions the points in order that the panel can be manually brought into a painting chamber. Within the latter the paint is applied manually by an operator using a pneumatic gun. As the panels generally are of a considerable I *"size, which can e.g. represent a height and/or length of several metres, certain difficulties are encountered when painting the top and bottom parts. In order to paint the i top parts (which can be approximately 2.5 metres above the ground), use is made of an appropriate auxilliary means, whereas in the case of the bottom parts (positioned approximately 0.5 metre above the ground), the operator has to stoop. This succession of movements in such a difficult environment makes this work unpleasant.

However, automated painting systems already exist.

In a first system, an operator applies the paint or protective product to the first part by manually moving a robot.

z -i -I I- 2 The movements of the latter are recorded, together with information on the products, i.e. the nature thereof as a function of the location to be painted or protected and this constitutes the painting or protection program for such parts.

In a second system, the operator carries out the application of the protective product or paint to the first part by moving a means which is lighter than a robot, said means being called a "syntaxer". It is the movments of said syntaxer which are recorded, together with the information concerning the products and constituting the program for this type of part. It is this program which is carried out by the robot during the subsequent treatment of a series of parts of this type.

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o *04 0 04 In a third system, the operator moves a syntaxer, which represents the robot and the movements performed by the syntaxer are reproduced by the robot, which consequently carries out the first part. The movements of the robot are recorded, together with the information on the products and this represents the program for the particular part type in question.

1' 25 Finally, in other systems, use is made of a computer which determines the displacements of the robot as a function of the coordinates of certain points of the part. For example, a programmer can give the computer the coordinates of certain points linked by velocities and accelerations, 30 as well as the information on the products. The computer 6 carries out a calibration in order to calculate a mean value and correct possible errors, said mean value constituting the program for the considered type of part.

Although these systems are automated, they suffer from a certain number of disadvantages when it is necessary i 'Yi 3 4 4 4o 4 4444 o *1 4 4 44 o 4D O 4 4 to paint the two faces of a curved panel. Thus, all these systems use robots only dealing with a single face of the panel at once. In order to paint or protect the two faces, it is necessary either to turn over the panel, or to pass the robot on the other side thereof, or have two facing robots. In all these cases, the program of the first face differs from that of the second face. It is therefore necessary to have a significant storage capacity and it is necessary to check that the face of the panel facing the robot does indeed correspond to the selected program. Moreover, it is necessary to ensure the good positioning of the part in space, which requires special attachment tools.

In one broad form the present invention provides 15 process for the spraying of a product simultaneously onto two opposite faces of a randomly shaped panel comprising the steps: positioning in facing manner at least one pair of spraying apparatuses disposed such that a fictitious impact point common to the or each pair of apparatuses is located on a median surface positioned equidistantly of the o-Losite faces of the panel, each apparatus being selectively moveable and having an orientation determined with respect to a plane, which is generally tangential to said median surface and passes through said fictitious 25 impact point, and wherein each apparatus is positioned a generally constant distance from said plane; and producing a relative displacement between the panel and the spraying apparatuses parallel to said plane, each of the spraying apparatuses being kept in said arrangement by simultaneously moving them in a transverse direction with respect to the panel in order to maintain the fictitious impact point on said median surface and by simultaneously orienting them about a common axis which is perpendicular to said transverse direction and which passes through the fictitious impact point in order to keep constant the orientation of each apparatus with respect to -the tangential plane.

i ,j -1 -4spraying apparatuses being kept in said arrangement by simultaneously moving them in a transverse dir ion with respect to the panel in order to mainta'j he fictitious impact point on said median surf and by simultaneously orienting them about a c on axis perpendicular to said transverse direct '-nand passing through the fictitious impact pot in order to keep constant the orientation of ch apparatus with respect to the tangential plane.

Through using two facing spraying apparatuses, it is possible to simultaneously treat the two faces and reduce the time II and therefore cost of an operation. Moreover, through |i permanently maintaining said apparatuses in a given orientation with respect to the plane tangential to the median surface of the panel and passing through the fictitious impace point and at a given distance from said plane, it 0 0 Q. is possible to simultaneously treat the two faces of a o o curved panel with the aid of a single program, whilst only oon having two movements to control for the spraying apparatuses, e.g. and as will be shown hereinafter, a translation and o o a rotation of the supports on which are mounted the spraying apparatuses.

Within the context of the present description, the word a 25 "jet" is considered in its most general sense for desigo 0 nating a mist discharged by a sprayer, as well as a jet of liquid ejected under pressure.

i In view of the fact that use is made of two spraying apparatuses discharging jets of product onto each of the faces Sof a panel, it is obvious that there are at least two impact points, one on each face of the panel. Within the present description, the expression "real impact point" can designate both a small spot corresponding to the location where the product is deposited on the panel at a given

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time and the centre of said spot when using apparatuses making it possible to cover a relatively large area, e.g.

a sprayer. The expression "the fictitious impact point" in all cases designates the centre of the segment joining the real impact points of each face.

According to another aspect of the process according to the invention, said relative displacement between the panel and each of the spraying apparatuses is brought about by moving the panel between the or each pair of sprayer apparatuses in a first direction parallel to said common axis and by simultaneously giving the spraying apparatuses a regular, reciprocating movement in a second direction perpendicular to the first direction and to the transverse direction.

According to another aspect of the process according to the invention, the panel is firstly passed infront of a learning system, which determines the shape and dimensions of the panel and on the basis of said characteristics establishes a program for controlling said relative 20 displacement between the panel and the spraying apparatuses.

Thus, an individual program is produced for each panel to be treated, so that it is no longer necessary to have a program for each type of part, as was necessary in the prior art. This required a large storage capacity and therefore a more complex and costly apparatus.

The invention also relates to an apparatus for performing this process. According to the main feature of said apparatus, it comprises: at least one pair of facing spraying apparatuses which have a common fictitious impact point, means for producing a relative displacement between the panel and each of the spraying apparatuses and means for maintaining each of the spraying apparatuses in an arrangement such that their common

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-6o r i cic i i 000D (i ci 'c i1 0 C. 0; cic 00 C. a0i Ciii 9 ii 00 c C 90 9 ii 9 ci fictitious impact point is located on a median surface positioned equidistantly of the opposite faces of the panel and that their orientation with respect to a tangential plane to said median surface, which passes through said fictitious impact point, and their distance from said plane, remain constant, whereby said latter means comprise first means for simultaneously displacing each of the spraying apparatuses in a transverse direction with respect to the panel in order to keep constant the distance separating each apparatus from said plane, together with second means for simultaneously pivoting each of the spraying apparatuses about a common axis which is perpendicular to said transverse direction and passes through said fictitious impact point, so that the 15 orientation of said apparatuses with respect to said plane is kept generally constant.

Preferably, the means for producing a relative displacement between the panel and each of the spraying apparatuses comprises third means for passing the panel 20 between the or each pair of spraying apparatuses in a first direction parallel to said common axis and fourth means for simultaneously making each of the spraying apparatuses carry out a regular, reciprocating movement in a second direction perpendicular to the first direction 25 and to the transverse direction.

Preferably, each of the spraying apparatuses are mounted on carriages able to move simultaneously on two parallel posts of a support frame under the action of the fourth means, the support frame itself being able to move in its plane in accordance with said transverse direction under the action of the first means, whilst each spraying apparatus is mounted on one of the carriages so as to be pivotable about said common axis under the action of second means.

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SIn this case, the fourth means comprises a cable and pulley return system controlled by drive means and arranged on the frame in such a way that an actuation of the drive means produces a simultaneous displacement of the carriages in the same direction and by the same length.

i, Preferably, the third means successively pass the panel infront of a learning system and then between the spraying apparatuses, the learning system determining the shape 10 and dimensions of the panel and transmitting the characji teristics thereof to a computer, which draws up a control i program relative to the first, second and fourth means !i Iwhen the panel passes between the spraying apparatuses.

i 15 The invention can be better gathered from studying the S oo following description given in a purely illustrative and non-limitative manner with reference to the attached drawings, wherein show: o °20 Fig.l a diagrammatic plan view of a painting installation incorporating an apparatus according to the invention.

Fig.2 is a diagrammatic view in elevation of an apparatus according to the invention in accordance with arrow o 25 F in Fig.l.

a a On considering Fig.l, it can be seen that the painting installation firstly comprises a loading station 10 by which the panels to be painted arrive. The loading station has one or more linear rails 12 making it possible to move the panels or leave them in a waiting position. The panels are attached by their upper part to rails 12.

A transfer beam 14 manipulated with the aid of a travelling I crane (not shown in Fig.l) is displaceable between a first position 14a, shown in continuous line form, and a second f *I4 8 position 14b diagrammatically shown in mixed line form.

In position 14a, beam 14 is located substantially in the extension of rail 12, whilst in position 14b it is located in the extension of a rail 16 similar to rail 12 and which makes it possible to pass the panel firstly infront of a learning system 18 and then infront of the painting apparatus 26 according to the invention.

0o 0 00 0 OC The learning system 18 is an identification and telemetry apparatus, which can e.g. incorporate two detectors 19 between which the panel passes. System 18 determines the characteristics of the panel, such as its shape and size.

It is connected to a computer 20, which produces a painting program as a function of said characteristics. In an entirely automatic manner said program controls the painting apparatus 26, which will be described in greater detail hereinafter relative to Fig.2.

A partition 22 shown in mixed line form in Fig.1 and having 20 an opening 24,. in the painting installation shown therein separates the area where the learning system 18 and computer are located from the area where the painting apparatus 26 is located. Opening 24 is in the form of a thin vertical slit perpendicular to the plane of Fig.l), its width being just sufficient to permit the passage of the panel.

Partition 22 makes it possible to protect the remainder of the installation against sprayed paint.

Fig.l shows a second transfer beam 28, which moves between a first position 28a, shown in continuous line form, and one or more positions 28b, shown in mixed line form. In position 28a beam 28 is located in the extension of rail 16, but on the side opposite to beam 14 with respect thereto.

Beam 28, which can be manipulated by a travelling crane, makes it possible to transfer thepanels leaving the painting

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idl~iiihrr l- -L1 iii -I1.--li~~il~ 9apparatus 26 and bring them into an oven 30 where they are dried. A system of rails 32 located in the upper part of the oven makes it possible to transfer said panels from one end of the oven to the other. When the beam 28 occupies one of the positions 28b, it is located in the extension of a rail 32. Rails 32 can be constructed in the same way as rails 12 and 16.

Painting in the installation illustrated in Fig.l takes If 10 place in the following way. The panels to be painted are ji attached by their upper part to rails 12, which makes it possible to bring them to the right-hand end thereof on considering the drawing, i.e. into the vicinity of the circulation zone of beam 14. By means of the travelling crane, the latter is brought facing the rail 12 where the o panel to be painted is located and said panel is transferred from rail 12 to beam 14. This transfer can take place by using any known means in the handling field.

Beam 14 is at this instant in position 14a and then, when the panel is attached thereto, it is moved to position 14b. By a manipulation which is the opposite to that described hereinbefore, the panel is detached from beam 14 and attached to rail 16. It then moves along the latter, from right to left considering Fig.l. It firstly passes infront of the learning system 18 between the two detectors 19. As the panel moves between the detectors 19, system 18 determines the shape and exact dimensions of the panel and these characteristics are transmitted to the computer which produces the painting program as a function of i 30 the thus determined shape. The panel continues its path, passes through the slit 24 of partition 22 and arrives level with apparatus 26.

In the preferred embodiment illustrated here and which will be described in greater detail hereinafter relative i- 1 .Y II_. 10 to Fig.2, apparatus 26 essentially comprises a frame having two vertical posts along which travel the paint spraying apparatuses or guns. The displacements of the frame, the guns with respect to the frame and the supply of paint to the panel are determined, as the latter moves, by the program previously produced by computer Once the operation is completed, i.e. once the panel has completely left the apparatus 26, it is positioned at the left-hand end of rail 16 on considering Fig.l. Beam 28 is then brought into position 28a and the panel is transferred from rail 16 to said beam This operation can be carried out in the same way as hereinbefore. The travelling crane carrying the beam 28 is then manipulated until the beam reaches one of the positiones 28b. If necessary, at said level the panel can undergo a desolvation operation.

o The panel is then detached from the beam 28 and attached to the corresponding rail 32. It can then pass through oo °the oven at an adequate speed to ensure that drying is completed during said passage. When the panel arrives o at the end of the rail 32 opposite to beam 28, i.e. its right-hand end when considering the drawing, beam 14 is brought into an intermediate position between positions 14a and 14b and in which it is located in the extension 25 of rail 32. The panel is then detached from the latter and attached to beam 14, then the travelling crane manipulates the latter in order to bring the panel to the dis- 6 charge system.

A description will now be given of the paint spraying °r "apparatus 26 according to the invention with reference to Fig.2.

In the preferred embodiment, apparatus 26 essentially i comprises a frame 34 having two parallel vertical posts 36 and 38 of substantially the same length and whose upper

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11 and lower ends are connected by two horizontal cross-beams 40,42 respectively. This frame is located in a plane perpendicular to the displacement direction of panel 88 and is mounted on a fixed framework 43, so as to be movable in its plane in accordance with a horizontal direction contained therein, i.e. from right to left and vice versa when considering Fig.2. To this end, a screw-nut system is mounted between the upper part of frame 34 and the fixed framework. The nut is constituted by a connecting part 44 fixed the centre of the upper cross-beam 40. This nut cooperates with a horizontal screw 46 supported by the framework and manipulated by a motor 48. Rollers 50 fixed to the lower cross-beam 42 of frame 34 enable the latter to be guided by a rail 52 integral with the framework during 15 said movement.

E 0 0 0o 00 0 0000 0 0 00 0 0 00 0 e o o o D ouo rg 0 e v1 o If <J The apparatus also has two paint spraying devices or guns, which are positioned facing one another on frame 34.

0 0 0 0 0 0 44 I 4 t The first of these guns 54 is mounted on the vertical post 36 of frame 34, whilst the second gun 56 is mounted on vertical post 38. Guns 54 and 56 are identical. Each of the guns 54,56 is mounted on a carriage 55,58 mobile in translation along post 36,38, carriages 55 and 58 being at the same height on frame 34; as is shown in Fig.2.

In its part turned towards the interior of frame 34, each of the carriages 55,58 supports a toothed segment 60 mobile in translation with respect to said carriage and on which are mounted the nozzle 64 used for the discharge of the paint or any other product which it is wished to deposit on the panel. The two toothed segments 60 have a common rotation axis passing through a fictitious impact point, common to the two guns 54,56 and perpendicular to the piane of .the frame 34. A tooth system 61 formed on each of the toothed segments 60 meshes on a worm screw 62, whose axis plane, each of the spraying apparatuses being kept in said arrangement by simultaneously moving them in a transverse direction with respect to the panel in order to maintain the fictitious impact point on said median surface and by /2 E1 12 is parallel to posts 36 and 38 and which is supported in rotary manner by the corresponding carriage 55,58. Consequently, the rotation of each screw 62, controlled by a motor 63, drives that of the toothed segment 60 about the aforementioned common axis.

In the particular case described here, there is a nozzle 64 at each end of the toothed segments 60 and the incidence of the jet projected by each of the nozzles onto the corresponding surface of the panel is approximately 450. However, it would not pass outside the scope of the invention to equip each gun 54,56 with a single nozzle e.g. placed in the centre of the arc formed by the latter, or a number I 0 of nozzles exceeding 2. It would also not pass beyond i15 the scope of the invention to use two guns e-uipped with o a different number of nozzles, or even the same number *f of nozzles, but whose incidence with respect to the corresponding surface of the panel is not the same. The number and arrangement of the nozzles are a function of each particular envisaged application.

Finally, a flexible tube 66 makes it possible to supply i to each gun 54,56 the paint, together with the electrical I oenergy necessary for controlling the motor 63. Tube 66 can be a large tube contai'ing both smaller diameter tubes I for supplying each nozzle 64 individually, as well as the jI electric wires supplying motor 63. However, it would not Sextend beyond the scope of the invention to use a different arrangement.

In the embodiment described here, tube 66 passes over a pulley 68 carried by carriage 58, which makes it possible to keep it in place without it having to undergo stresses, which may lead to the deformation thereof furing the movement of the carriage 58 along post 38. However, the presence 1F7T71 ILOW 13 of pulley 68 is not obligatory, the essential point being that the tube 66 has a length and a flexibility wich are adequate to follow the movements of the carriage.

The apparatus shown in Fig.2 also comprises a return system making it possible to simultaneously displace at the same speed the two guns 54,56 along posts 36,38.

It can be seen that the return system essentially comprises a first cable 70, whereof one end is fixed to the upper part of carriage 55 of gun 54. As from this point, cable has a first substantially vertical part and passes over a pulley 72 positioned level with the junction between post 36 and the upper cross-beam 40 of frame 34. Cable 15 70 then has a substantially horizontal part and passes ao over a pulley 74, disposed in the same way as pulley 72, 0 0 but which is located level with the junction between crossbeam 40 and post 38. Cable 70 then has a substantially Q f1 vertical part parallel to post 38 and passes under another O pulley 76, whose axis is fixed to the lower part of post 38. Finally, cable 70 has a last vertical part between pulley 76 and the lower part of carriage 58 of gun 56 l to which it is fixed.

The return system comprises a second cable 78, whereof one end is fixed to the upper part of the carriage 58.

Cable 78 has a first substantially vertical part and passes over a pulley 80 located at a certain distance from pully r" 74 level with the junction between posts 38 and the upper cross-beam 40. Cable 80 then passes along the upper crossbeam 40 of frame 38 upto a pulley 82 located in the vicinity of pulley 72, in the same way as pulley 80 with respect to pulley 74. However, between pulleys 80 and 82, cable 78 performs a dead turn about a drum controlled by a motor 84 carried by the connecting part 44. Motor 84 rotates I r; L. 14 the drum about a horizontal axis perpendicular to the plane of frame 34. After passing over pulley 82, cable 78 has a vertical part up to the lower part of post 36 along which it pasSes before passing below a pulley 86 positioned in the lnwer part of post 36, like pulley 76 with respect to the lower part of post 38. After passing around pulley 86, cable 78 has a final vertical part between the latter and the lower part of carriage 55 to which it is fixed.

Thus, when motor 84 is put into operation to drive the drum in the direction of arrow Fl, this has the effect of moving cable 78 from pulley 82 to pulley 80. Consequently, the end of cable 78 fixed to the lower part of carriage 55 pulls the latter downwards. A rotation of a given angle of said drum consequently brings about a 0 displacement of given length x of carriage 54 in the downwards direction. This has the effect of driving downwards by a length x, that part of cable 70 between pulley 72 and carriage 55. The other end of cable 70 consequently moves downwards by a distance x. Thus, the two carriages 55,58 are moved downwards by the same distance. Therefore motor 84 makes it possible to simultaneously move the two carriages 55 and therefore the two guns 54,56. The latter remain in facing manner during said displacement t if care has been taken to mount the carriages 55,58 at the same height on posts 36 and 38 of frame 34.

Fig.2 also shows the rail 16 to which is attached the panel 88 via a connecting system 90 diagrammatically represented in mixed line form. The arrangement is such that rails 16 is located in the vicinity of the upper cross-beam 40, but slightly below the latter, in such way that the rail 16, panel 88 and attachment system 90 are located within the space defined by posts 36,38 I"I F ,e In a first system, an operator applies the paint or protective product to the first part by manually moving a robot.

-il 15 and cross-beams 40 and 42. Rail 16 is oriented perpendicular to the plane of frame 30 and the attachment system is such that the advance direction defined by the rail is parallel to a tangent to the median surface of the panel.

In Fig.2, frame 34 occupies its mean position, i.e. rail 16 is located approximately in the centre of cross-beam but said position can vary by means of the screw nut system 44,46 as a function of the curvature of the panel and the location thereof which it is wished to paint.

This displacement is limited, because rail 16 must always be located between posts 36 and 38.

The apparatus illustrated in Fig.2 functions as follows.

Initially, the guns 54,56 are located in the upper part 0o o of frame 34 and occupy the positions 54a,56a shown in uo continuous line form. The painting program is produced 0 0 by computer 20 as the panel passes in front of the learning system 18. As a function of this program, frame 34 is moved by the screw nut system 44,46, so that the common 0oo° o fictitious impact point of guis 54,56 is located on the median surface equidistant of the opposite faces of the o panel. As a function of this program, the toothed segments 60 are simultaneously oriented by means of motors 63 act- S° a uating screws 62, so that the guns 54,56 carrying the nozzles 64 have the desired orientation or incidence with I respect to a plane tangential to the aforementioned median i' surface and passing through the fictitious impact point si 30 of the guns. Panel 88 then advances along rail 16 in a direction perpendicular to the plane of frame 34 until the front part thereof is positioned between the two guns 54,56.

The advance of panel 88 is stopped and motor 84 is started i -r c L~.

Although these systems are automated, they suffer from a certain number of disadvantages when it is necessary 6 p16 up, in such a way that the two guns 54 and 56 simultaneously descend along posts 36,38. During this movement, frame 34 is if necessary displaced with the aid of the screw nut system to maintain the fictitious impact point on the median surface at the fictitious impact point. By construction, the distance separating each gun from the plane tangential to said median surface from the fictitious impact point remains constant during said movement. In addition, there is a simultaneous and quasi-continuous manipulation, as a function of the panel curvature, of the screw 62 so as to constantly orient the toothed segment in such a way that the orientation of the guns, i.e.

the incidence of the painting jets, with respect to the plane tangential to the median surface of the panel at o o 915 the fictitious impact point. Thus, guns 54 and 56 arrive 04 at the bottom of their travel, in positions 54b and 56b 0 .1) respectively (said positions being shown in mixed line 0 form in Fig.2).

Thus, a layer of paint has been deposited on each face of the panel over a vertical strip thereof having a certain width. The panel can be advanced (perpendicular to the o plane of the drawing) by a distance equal to the width of said strip and paint is then applied to a second strip during the raising movement of the guns, motor 84 being actuated in the reverse direction. This is continued until the entire panel 88 is painted.

t It should be noted that for safety reasons, the part of the guns 54,56 having the worm screws 62 and the toothed sector 60 is protected by a skirt 92, which only reveals the spraying nozzles.

Thus, the process and apparatus ,ccording to the invention have particularly tinteresting advantages, the most important ~y~ J E 17 being that they make it possible to simultaneously treat the two faces of the panel with a minimum number of controlled axes. Thus, the translation of the guns is simultaneous and the rotation of the toothed segments 60 can be controiled with the same program. Thus, the only movements are the displacement of panel 88, the simultaneous displacement of the guns in translation along posts 36,38, the simultaneous rotation of the toothed segments 60 and the displacement of frame 34 with the aid of the screw nut system 44,46.

Moreover, the use of the learning system 18 associated with computer 20 makes it possible to establish an individual program for each panel immediately prior to the actual painting operation. It is consequently no longer aa° necessary to carry out learning operations as in the prior So art, which takes time and makes the installation more o complex and therefore more costly through the need of having large storage capacities. Obviously all the movements described hereinbefore are synchronized and a function of one another. They are all controlled by the program produced by the computer.

S09 Thus, it is possible to avoid all the prior operations a5 necessary with the prior art apparatuses and in particular the individual programming of parts by an operator, either in situ, or in a simulator. There are no longer any storage, 1.,management, program loading or communication operations, tr: program modifications in the case of modifying parts, etc. Moreover, it is no longer necessary to carry out an operation of recognition with respect to a part or one face thereof and the two faces can be dealt with simultaneously without it being necessary to turn over the part or use two guns with two different programs.

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18 Furthermore, the apparatus according to the invention has a light weight and is simple to construct. Its movements are simple, which leads to a simplified movement control.

It is possible to deal both with large panels and a series of smaller panels, whilst it is easy to orient the nozzles to optimize the application of the product. This solution is not very expensive from the mechanical standpoint (simple construction) and its control is very simple.

Finally, the installation has a good flexibility, because the different movements make it possible to treat panels having different shapes and sizes and even panels with !i a considerable curvature. Such an apparatus makes it poss- 0009 S: ible to treat planar or curved panels with a thickness 15 between 1 and 150 mm.

990* o on otrn o o Although the above description has been given relative S0to the particular case of spraying paint, such an apparatus can be used for depositing on the panels any random type of product, i.e. not only paints, no matter whether it s is a primary coating or a finishing coating, as well as sweating, chemical working, rinsing or similar products, 0 00 together with varnishes or wood treatment products, scratchpreventing products for protecting surfaces or finishing agents for composite materials, etc. The apparatus according to the invention can be used for carrying out simultaneous 0 shot blasting of two faces of a thin panel, whilst avoiding deformation of said panel in the impact zone. The apparatus can be used for treating all materials which have to be sprayed.

In the frequent case where the treated panel have a uniform curvature, there are simple connection functions between the displacements of the carriages along posts and the A orientation angles of the spraying apparatuses around their ft I, I 19 common axis and the lateral displacements of the frame.

It is then posible to realize these connections mechanically without using a computer-controlled electromechanical system.

Finally, it is obvious that the invention is not limited to the embodiments described hereinbefore and numerous variants can be made thereto without passing beyond the scope of the invention, particularly with regards to the movements of the different parts and the control of said i movements, together with the supply of paint to the guns I 10 and/or the electric power supply for the same. Optionally, without passing beyond the scope of the invention, the 0 09 guns could be kept fixed and the panel could be moved with 0 0 o respect thereto, whilst it would be possible to simultan- S" eously use several pairs of identical or different spraying .QO4 0.0, 15 apparatuses or guns.

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Claims (2)

1. Process for the spraying of a product simultaneously t onto two opposite faces of a randomly shaped panel i comprising the steps: positioning in facing manner at least one pair of spraying apparatuses disposed such that a fictitious impact point common to the or each pair of apparatuses is located on a median surface positioned equidistantly of the opposite faces of the panel, each apparatus being selectively moveable and having an orientation determined with respect to a plane, which is generally tangential to said median surface and passes through said fictitious impact point, and wherein each o apparatus is positioned a generally constant distance from o said plane; and producing a relative displacement between the panel and the spraying apparatuses parallel to said plane, each of the spraying apparatuses being kept in said ooo arrangement by- simultaneously moving them in a transverse direction with respect to the panel in order to maintain the fictitious impact point on said median surface and by simultaneously orienting them about a common axis which is 64a o perpendicular to said transverse direction and which

060. 4 passes through the fictitious impact point in order to o keep constant the orientation of each apparatus with respect to the tangential plane. 2. Process according to claim i, wherein the relative movement between the panel and each of the spraying apparatuses is brought about by moving the panel between the or each pair of spraying apparatuses in a first direction parallel to said common axis, and by simultaneously making each of the spraying apparatuses perform a regular, reciprocating movement in a second direction perpendicular to the first direction and to the transverse direction, 3. Process according to claim 1, wherein the panel is firstly passed infront of a learning system, which ,i O~uC: V makes it possible to transfer thepanels leaving the painting I' I 00 o 0 '0 oo- 0' O 1 0 o t a i4o II 9 4' S4 21 determines the shape and dimensions of the panel and on the basis of these characteristics produces a program then making it possible to produce said relative displacement between the panel and the or each pair of spraying apparatuses or guns. 4. Apparatus for spraying a product simultaneously onto two opposite faces of a randomly shaped panel, said apparatus comprising: at least one pair of facing spraying apparatuses which have a common fictitious impact point, means for producing a relative displacement between the panel and each of the spraying apparatuses and means for maintaining each Qf the spraying apparatuses in an arrangement such that their common fictitious impact point is located on a median surface positioned equidistantly of the opposite faces of the panel and that their orientation with respect to a tangential plane to said median surface, which passes through said fictitious impact point, and their distance from said plane, remain constant, whereby said latter means comprise first means for simultaneously displacing each of the spraying apparatuses in a transverse direction with respect to the panel in order to keep constant the distance separating each apparatus from said plane, together with second means for simultaneously pivoting each of the spraying apparatuses about a common axis which is perpendicular to said transverse direction and passes through said fictitious impact point, so that the orientation of said apparatuses with respect to said plane is kept generally constant. Apparatus according to claim 4, wherein the means for producing a relative displacement between the panel and each of the spraying apparatuses cnmprise third means for passing the panel between the or each pair of spraying apparatuses in a first direction parallel to the common I i I 22 axis and fourth means for simultaneously making each of the spraying apparatuses perform a regular, reciprocating movement in a second direction perpendicular to the first direction and to the transverse direction. 6. Apparatus according to claim 5, wherein each of the spraying apparatuses are mounted on carriages able to move simultaneously on two parallel posts of a support frame under the action of the fourth means, the support frame being able to move in its plane in said transverse direction under the action of the first means, and each spraying apparatus is mounted on one of the carriages such 4. that they can each pivot about said common axis under the o action of the second means. 7. Apparatus according to claim 6, wherein said fourth means comprise a cable and pulley return system controlled by a drive means and arranged on the frame such that actuation of the drive means produces a simultaneous displacement of each of the carriages in the same direction and by the same length. 8. Apparatus according to claim 5, wherein the third o B means is adapted to move the panel infront of a learning oo-o system and then between the or each pair of spraying apparatuses, wherein the learning system is adapted to determine the shape and dimensions of the panel, and connected to a computer which is adapted to produce a control program for the first, second and fourth means and o controls the apparatus when the panel passes between the or each pair of spraying apparatuses. 9. Process for the spraying of a product simultaneously onto two opposite faces of a randomly shaped panel as hereinbefore described with reference to and as shown in the accompanying drawings. Apparatus for spraying a product simultaneously onto two opposite faces of a randomly shaped panel as 9 a ::r ii i i Li L_ i iiii___l ~_~1II_ 23 i hereinbefore described with reference to and as shown in j the accompanying drawings. ji DATED this 22nd day of November 1990 AEROSPATIALE SOCIETE i NATIONALE INDUSTRIELLE Patent Attorneys for the Applicant: F.B. RICE CO. S