FR2619754A1 - Drawing table for the automatic application of paint to chosen portions of a receiving surface - Google Patents

Abstract

The drawing table comprises a framework 10 supporting the receiving surface 20 and two fixed rails 11, 12 for guiding in a first direction X'X at least one rail 30 which can move along the two guide rails 11, 12 in the first direction X'X, at least one tool-carrying carriage 50 which can move along the movable rail 30 in a second direction Y'Y perpendicular to the first direction X'X, means 40, 111 for driving the movable rail 30 and the tool-carrying carriage 50 and computerised means for controlling the said drive means 40, 111 and for controlling the operation of a tool 75 for applying paint, which tool is placed on the tool-carrying carriage 50 in order to apply paint to the chosen portions of the receiving surface 20 constituting a predetermined graphics object by spraying paint successively over unconnected elementary surfaces delimited by closed curves. Application particularly to painting letters, signs or symbols on surfaces of large dimensions.

Description

Plotter for the automatic application of paint on selected portions of a receiving surface.

 The present invention relates to a plotter for automatically applying paint to selected portions of a receiving surface.

 It is very often necessary to cover surfaces using paints in predefined geometric shapes, for example to create a message from symbols or graphic characters such as alphanumeric characters.

 For this purpose, stencils or masks, for example of self-adhesive paper, provided with openings corresponding to the geometric shapes to be painted, which are temporarily affixed to the receiving surface, are traditionally used. The paint can then be applied by brush or spray gun to the receiving surface. The stencils or masks are then removed and correspond to portions of the receiving surface not coated with paint.

 This traditional method used for the design of relatively large panels is Long and impractical to implement and also requires the use of a large number of non-reusable adhesive masks.

 We also know automatic plotters to reproduce on a flat support a predetermined graphics. Such plotters, however, only work with low-mass pens that are designed to perform linear or point-by-point patterns and are not suitable for making panels requiring the covering of relatively large areas with paint. Trade.

 The present invention aims to overcome the aforementioned drawbacks and to allow to achieve quickly and economically panels to be coated with paint on selected portions, which according to a particular application correspond to letters or characters or standardized symbols.

These goals are achieved through a plotter for
The automatic application of paint on selected portions of a receiving surface, characterized in that it comprises a frame supporting the receiving surface and two fixed guide rails in a first direction, at least one movable rail along the two rails in the first direction, at least one movable tool carriage along the movable rail in a second direction perpendicular to the first direction, means for driving the movable rail and the tool carriage and control computer means said means for driving and controlling the operation of a paint application tool placed on the tool carriage to achieve the application of paint on selected portions of the receiving surface constituting a predetermined graphic object by spraying paint successively on disjoint elementary surfaces delimited by closed curves.

 More particularly, said computer means for controlling said training means comprise a memory for storing a set of graphical or typographic characters decomposed into disjoint elementary surfaces delimited by closed curves, means for analyzing an object predetermined graph for decomposing this graphic object into pre-recorded characters in memory and disjoint additional elementary surfaces delimited by closed curves, and loop control means for controlling said drive means so that these drive the tool application of paint according to a succession of disjoint elementary surfaces constituted by elementary surfaces of pre-recorded characters and / or additional elementary surfaces.

 The means for analyzing a predetermined graphic object comprise means for creating a simplified graphic object by decomposing the predetermined graphic object into primary elementary surfaces delimited by closed curves, means for analyzing the overlaps of the elementary surfaces. primary materials and means for decomposing overlapping primary elementary surfaces into disjoint secondary elementary surfaces of smaller area.

 According to a particular embodiment, the receiving surface is inclined relative to the horizontal and the movable rail comprises a plurality of parallel bars for supporting the tool carriage and a counter-weight carriage moving in the opposite direction in said second predetermined direction.

 Advantageously, said drive means comprise at least two electric motors and two notched belts each cooperating with a pair of toothed pulleys, one of which is crazy and the other is driven by one of the electric motors.

Other features and advantages of the invention will become apparent from the following description of a particular embodiment, given by way of example, with reference to the appended drawings, in which:
- Figure 1 is a schematic side view of a plotter according to the invention, comprising a movable rail and the movable carriages,
FIG. 2 is a perspective view showing part of the elements of the plotter of FIG. 1,
FIG. 3 is a front view of the upper part of the frame of the table of FIG. 1, provided with a part of the drive means of the sliding rail;
FIGS. 4 to 7 are partial sectional views along the lines IV-IV, VV, VI, VI and VII-VII of FIG. 3;
FIG. 8 is a detail view of the lower part of the movable rail of the table of FIGS. 1 and 2,
- Figures 9 and 10 are detailed views respectively in section along a plane perpendicular to the movable rail and from above parallel to the movable rail, showing two carriages sliding towards the movable rail,
FIG. 11 shows a geometric pattern to be painted over, composed of two overlapping elementary surfaces, and
- Figure 12 shows the geometric pattern of Figure 11 after modification of the elementary surfaces to remove the overlap.

 Figure 1 shows the main elements of the mechanical architecture of a plotter XV, said table to paint, according to an embodiment of the invention.

 The painting table essentially comprises a fixed frame 10 composed of a set of square metal tubes, for example aluminum, horizontal 11, 12, 15 and vertical 13, 14, reinforced by angles 16, 17. The frame 10 comprises in particular two parallel horizontal sections 11, 12 supporting two fixed guide rails 18, 19 oriented in a direction X'X (Figure 2).

One of the guide rails 18 is located at the lower front portion of the frame 10 while the other guide rail 19 is located at the rear top of the frame 10. The frame 10 further comprises a support plate 21 of the frame 10. a receiving surface 20, for example of paper, on which the paint is to be applied. The plate 21 is inclined relative to the horizontal and may have an angle, for example of the order of 30 to 600.

 A movable rail 30 is disposed in a direction Y'Y perpendicular to the guide rails 11, 18 and 12, 19 and at a short distance above the plate 21 so as to be able to move parallel to this plate 21 and to the receiving surface 20.

As shown in FIG. 2, the movable rail 30 may comprise a set of parallel elementary rails 33, 34, 35, 36 formed by flat sections, braced by transverse bars 37, 38 at the bottom and at the top of the rail. composite movable rail 30 to form a structure
H. The transverse bars 37, 38 also act as abutments for the mobile carriages 50, 60 which will be discussed later.

 The movable rail 30 is terminated at its lower and upper ends by two horizontal structures 31, 32 provided at their lower part with rolling or sliding members 310, 320 engaging on the upper end of the fixed rails 18, 19 respectively (Fig 1). The structures 31, 32 thus constitute two guide carriages of the movable rail 30 along the fixed rails 11, 18 and 12, 19.

 The movable rail 30 is driven in motion along the fixed rails 11, 18 and 12, 19 by means of a toothed belt system and toothed pulleys, which can act on one or the other of the guide carriages 31, 32.

 One of the pulleys used to drive the toothed belt is itself secured to the output shaft of an electric motor 111 while the other toothed pulley is mounted idle on means to maintain Permanently a suitable tension for the toothed belt. The guide carriage used for driving the movable rail 30 is itself fixed on one of the strands of the toothed belt.

 Figures 3 to 7 show by way of example fastening means on the frame 10 of the drive motor 111 and tensioning means of the toothed belt. For ease of understanding, the notched pulleys, the toothed belt, the guide carriage and the guide rail are not shown in Figures 3 to 7.

 FIG. 3 shows part of the frame 10 consisting of two vertical sections 103, 104 located on each side of the table to be painted and joined by two horizontal sections 101, 102 braced at one of their ends by an additional vertical section 105.

 The electric drive motor 111 which may be a stepper motor or an electric motor and the bearings 112 for supporting the output shaft of the motor 111 (not shown) are attached to the frame by tongues 113 on one side. sides of the frame (left in Figure 3). On the other side of the frame, the bearings 112 for supporting the axis of the idler pulley cooperating with the toothed belt are attached to the frame by a tensioning bar 123 to 126 guided around the spacer 105 by brackets. The tensioning bar comprises side plates 123 supporting at their free end the bearings 122 and joined at their other end by a plate 124 associated with a screw system 125- nut 126 for adjusting the position of the tensioning arch with respect to The lateral end 104 of the frame.

 As can be seen in Figure 1, a tool carriage 50 and a counterweight carriage 60, each mounted on a strand 46, 47 of a toothed belt 40 cooperating with two toothed pulleys 41, 42, can move in the opposite direction on along the movable rail 30 in the direction Y'Y of Figure 2. One of the pulleys 41, 42, for example The upper pulley 42 cooperates with an electric motor, not shown, similar to the motor 111, and serves as pulley d while the other pulley 41 cooperates with tensioning means such as those shown in FIG. 8.

 Figure 8 shows the lower portion of the movable rail 30 with four elementary rails 33, 34, 35, 36 braced by a crossbar 37 which is secured to the elementary rails 33-36 through reinforcing brackets. Two lateral plates 440, 450 joined at their lower part to a bottom plate 91 by means of angles 92 constitute a tensioning bar whose position relative to the bar 37 can be modified by a screw 93 - nut 94 system. plates 440, 450 placed against the central elementary rails 34, 35 respectively carry bearing cages 44, 45 for the axis 43 of the lower toothed pulley 41 on which is engaged the belt 40. The position of the pulley 41 and the tension of the belt 40 are modified by action on the screw-nut system 93, 94.

 Figures 9 and 10 show in more detail an example of constitution of the carriages 50, 60 movable along the movable rail 30.

 Each carriage 50, 60 comprises a rectangular frame consisting of four faces 51 to 54 and 61 to 64 respectively secured by brackets 55, 65 respectively. Each carriage 50, 60 further comprises two shafts 71, 72 and 81, 82 respectively, each carrying two bearings 56, 57, 66, 67 whose cage is provided with a groove 58, 59, 68, 69 intended to come to engage on one of the elementary rails 33 to 36. Each carriage 50, 60 which can roll on a pair of elementary rails 33, 34 or 35, 36 thanks to its rolling cages 56, 57 or 66, 67 forming wheels, is integral with one of the strands of the toothed belt 40.

Thus, one of the strands of the belt 40, for example the lower strand 46 is clamped between brackets 73 integral with the carriage 50 and plates 74 screwed onto the brackets 73 and in the same way the other strand 47 is clamped between angles 83 integral with the carriage 60 and 84 plates screwed on the brackets 83. The carriages 50 and 60 are always actuated in opposite directions by the same belt 40.

 The mechanical structure of the painting table according to the present invention can thus be very simple since apart from the axes, the electric drive motors, the transmission members (toothed belts) and rolling, all the elements can be made from profiles, for example of aluminum in the form of square tube, tee, flat or angle, cut perpendicularly, drilled, tapped and assembled by screws. An embodiment from sheets, however, is also possible.

 In order to facilitate the movement of the carriages 31, 32, 50, 60, it is advantageous for the rails 18, 19, 33 to 36 to be covered with a strip of plasticized adhesive fabric. The bearing cages used for the axes of the toothed pulleys and as running gear for the mobile carriages can be made from aluminum washers or PTFE.

 The tool carriage 50 is equipped with a tool consisting of a paint gun 75 of known type for mixing several primary colors (the mixture that can be controlled by computer), provided with a tube 76 for supplying paint and a micropulverization nozzle 77 (Figure 1).

 In order to avoid the deterioration of the engines by products suspended in the ambient air, and in order to ensure minimum cooling in the event of intensive use, the electric motors ensuring the retention of the movable rail 30 and the mobile carriages 50, 60 are placed in housings in which an air overpressure is maintained, either by bypassing the main supply circuit, when using tools operating with compressed air, or by independent power supply.

The painting table according to the present invention can be made in the form of a large XY table (with for example 2 m of useful surface for the movement of the tool 75) and of low definition (for example no 1 mm) allowing the movement of a tool 75 whose mass is several kilograms (for example 5 kg) at a speed for example of the order of 0.4 ms
The painting table designed to paint large areas automatically is a specific device equipped with a microcomputer and which can be associated with an external microcomputer itself provided with a control software table to paint and editing graphic which constitutes a graphic editing system, in order to constitute a complete system of edition of painted panels.

The movements of the moving part and the tool carriage, the actuation of the spray gun and the possible mixing of the paints are controlled from the microorindator integrated in the table so as to apply paint to the selected portions of the surface. receiver which constitutes a predetermined graphic object, for example a set of
Letters.

 The specificity of the painting table according to the invention compared to a conventional plotter lies in the fact that it performs not a plot by points or vectors, but by closed surface elements.

 In addition, the painting table constitutes an "intelligent" device that interprets the orders it receives and executes them autonomously.

Here is the type of command he can execute
DC! C! NP! XYAB! XYAB! ...! FC which must read itself in the following way:! : field delimiter (typographic only)
DC: start of order
C: color
NP: number of points
XY: coordinates of a point
A: type of curve to apply to reach it
B: possible parameter (for an arc of circle for example)
FC: end of order
Such a command defines entirely a basic surface ready to paint if one adopts the following conventions:
- we must reach the first point without tracing.

 - after joining the last point we join the first.

 the parameters A and B of the first point define the curve to be applied to join it from the last one.

This is realized by the microcomputer integrated in the table and provided with a software whose main organs are the following ones

<tb><SEP> | INITIALIZATION <SEP> |
<tb><SEP> control
<tb><SEP> runtime
<tb><SEP> J
<tb><SEP> Filling <SEP> l <SEP> Messages <SEP> C <SEP> have <SEP> role <SEP> of
<tb><SEP> of <SEP> surfaces <SEP> of <SEP> Icommunica
<tb><SEP> Elementary <SEP> Service <SEP> tion
<tb><SEP> L
<tb><SEP> physical <SEP> of <SEP> The <SEP> edition
<tb> table <SEP> a <SEP> paint
<tb><SEP> Physical <SEP> of <SEP> The <SEP> Edition
<tb><SEP> tab <SEP> to <SEP> paint <SEP> chart
<Tb>
The graphic editing system itself consists of three main organs.

a base of graphic objects stored in a memory, a graphic object being an abstract compound consisting of graphic objects and elementary surfaces,
a panel generator, a panel corresponding to a complete drawing ready to paint, that is to say to a graphic object comprising only elementary surfaces that do not overlap,
- a user interface to intervene on the basis of graphic objects.

 The graphic object database and the user interface are elements whose realization can be traditional.

On the other hand, the generator of panels is particular insofar as it applies the concept of tracing of graphics by disjointed closed elementary surfaces.

 The function of the panel generator is to transform a graphic object into a collection of elementary surfaces and to realize this transformation by imposing all the elementary surfaces to be disjointed, any overlap preventing a good quality realization in paint applications. Once this transformation is completed, the panel generator sends the order corresponding to the table to be painted or calls a graphic screen controller to simulate it on a graphic screen.

The main organs of the graphic editing system are as follows:

<tb><SEP> KEYBOARD
<tb><SEP> MOUSE
<tb> I
<tb> Base <SEP> objects (<SEP> 4Interface <SEP> User <SEP> Screen
<tb> graphics <SEP> Text
<tb><SEP> 7
<tb><SEP> GENERATOR
<tb><SEP> PANN <SEP> WATER <SEP> controller
<tb><SEP> communication
<tb><SEP> Screen <SEP> Graphic | <SEP> | Table <SEP> åpeindr7
<Tb>
The main algorithm of the panel generator is Cutting. It works on simplified graphic objects that only have elementary surfaces but some elementary surfaces may overlap others.

 The purpose of the chopping operation is to decompose these elementary surfaces into smaller elementary surfaces (sometimes with deletions) such that none masks another.

 For example, there is shown in Figure 11 a simplified graphical object composed of two elementary surfaces 201, 202 (rectangular in the example) which overlap. In this case, the cutting operation consists in subdividing one of the elementary surfaces 202 into a smaller elementary surface 220 (FIG. 12) which in the example under consideration then has an L shape with a notch bounded by lines 221, 222 which are located a short distance from the adjacent boundaries 211, 212 of the other elementary surface 210 which is unchanged from the original elementary surface 201.

For the panel generator, the algorithm is given briefly below with the following vocabulary conventions
SE = elementary surface
OGS = simplified graphic object for an OGS:
for each x = SE
for each y = SE - next
add z in the OGS
color (z) = color (x)
delete x from the OGS
CUT (x, y) ::
current point = first point of x
FORWARD-TO-INTERSECTION
repeats-up to point-current = first point of x
ADVANCE- UNTIL INTERSECTION
CLOSER TO
point-current = note
CLOSER TO
creates new - SE
pc = current point
turn right
repeat-until intersection with x
pc = next point of y
adds pc to new - SE
note = pc
turn right
repeat-up to intersection with y
pc = next point of x
adds pc to new - SE
ADVANCE-TO-INTERSECTION:
repeat-up to 8 intersection with y
point-current = next point of x
NOTE
When more than two successive points of x are intersections with y, only the first and the last are considered as intersections.

 The actual intersection determination is purely computational and will not be detailed here.

 In the graphic editing system, the software makes it possible to draw shapes on the screen or to use objects already in place in the memory, according to an ascending structure.

 Each object consists of simpler and already defined objects, but with the possibility left to the user to create a complete image in a single object at the level of the memory.

This new element can therefore be called in another creation.

 In the basic software, a number of objects are already defined (fonts to enter texts ...), and thus allow immediate use of the program, with minimal but existing capabilities.

 The software offers of course basic graphic functions: drawing lines, circles ... And it is therefore by playing on these primary functions, and the use of already created figures that we can represent any Fig.

All these functions can be assigned modifiers (dashed lines, color gradients ...) that extend the capabilities of the software. For example, when inserting an object already in memory, it can be deformed, extended, or better:
To pass it in a "mold", that is to say, to assign to it modifiers put in memory, and which can thus serve frequently, without one having to reprecise them.

 The painted panel editing system according to the invention avoids the need to materialize on the receiving surface of the boundaries prior to the application of paint to the selected portions to be painted over.

 The design computer of the graphic editing system proceeds with the cutting of the letters and the analysis of the graphics to be made, as indicated above, by decomposing each graphic object into disjoint elementary surfaces delimited by closed curves and sends loop sequences to the control computer of the painting table to directly cause the application of paint on the successive elementary surfaces by selective horizontal scanning by acting on the control of the drive motors of the movable rail 30 and the tool carriage 50 .

Claims (10)

Plotter for the automatic application of paint on selected portions of a receiving surface, characterized in that it comprises a frame (10) supporting the receiving surface (20) and two fixed rails (11, 12) of guidance in a first direction (X'X), at least one movable rail (30) the Long of the two guide rails (11, 12) in the first direction (X'X), at least one tool carriage (50) movable along the movable rail (30) in a second direction (Y'Y) perpendicular in the first direction (X'X), means (40, 111) for driving the movable rail (30) and the tool carriage (50) and computer means for controlling said drive means (40, 111). ) and controlling the operation of a paint application tool (75) placed on the tool carriage (50) to realize Applying paint on selected portions of the receiving surface (20) constituting a predetermined graphic object by successively spraying paint onto disjoint elementary surfaces delimited by closed curves. 2. plotter according to claim 1, characterized in that said computer means for controlling said drive means (40, 111) comprise a memory for storing a set of graphical characters or typographic decomposed disjoint elementary surfaces delimited by closed curves, means for analyzing a predetermined graphic object to decompose this graphic object into pre-recorded characters in memory and additional disjoint elementary surfaces delimited by closed curves, and loop control means for controlling said means drive (40,111) so that these cause the paint application tool (75) to follow a succession of disjoint elementary surfaces consisting of elementary surfaces of pre-recorded characters and / or additional elementary surfaces. 3. plotter according to claim 2, characterized in that the means for analyzing a predetermined graphic object comprises means for creating a simplified graphical object by decomposition of the predetermined graphic object into primary elementary surfaces delimited by closed curves, means for analyzing the overlaps of the primary elementary surfaces and the means for decomposing the overlapping primary elementary surfaces into disjoint secondary elementary surfaces of smaller area. 4. plotter according to any one of claims 1 to 3, characterized in that said drive means (40, 111) comprise at least two electric motors (111) and two notched belts (40) each cooperating with a pair of toothed pulleys (41, 42) one of which (41) is crazy and the other (42) is driven by one of the electric motors (111). 5. plotter according to claim 4, characterized that for each pair of toothed pulleys (41, 42) the idler pulley (41) is mounted on tensioning means (91 to 94, 123 to 125). Plotter according to one of Claims 1 to 5, characterized in that the receiving surface (20) is inclined with respect to the horizontal and that the movable rail (30) comprises a plurality of parallel bars (33 to 36) for supporting the tool carriage (50) and a counterweight carriage (60) moving in opposite direction in said second predetermined direction (Y'Y). 7. plotter according to claim 4 and claim 6, characterized in that the tool carriage (50) and the counterweight carriage (60) are integral with the same toothed belt (40).  8. plotter according to any one of claims 1 to 7, characterized in that the movable rail (30) is secured at both ends of two carriages (31, 32) mounted respectively sliding on each of the two fixed rails (11 , 18; 12, 19) according to the first direction (X'X). 9. Plotter according to any one of claims 1 to 8, characterized in that the fixed guide rails (11, 18; 12, 19) and the movable rail (30) are coated with strips of plasticized adhesive fabric. 10. plotter according to any one of claims 1 to 9, characterized in that the frame (10), the two fixed guide rails (11, 18; 12, 19), the movable rail (30), the support (21) of the receiving surface (20) and the movable carriages (50, 60, 31, 32) are made from metal profiles of square tube type, tee, flat or angle.