FR2570366A1 - Process and plant for extruding a plastic of the butyl rubber-based type and application to the manufacture of multiple glazings - Google Patents

Abstract

Placing of a plastic beading of the butyl rubber-based type on the periphery of a glass sheet intended to form part of the composition of a multiple glazing. It proposes to deposit the beading with the aid of an extrusion unit comprising a nozzle, the glass sheet and the nozzle both being capable of being driven in motions which are reduced to translations, these translations of the glass sheet, on the one hand, and of the nozzle, on the other hand, taking place in different directions. The invention applies to the manufacture of multiple glazings of large size.

Description

 The present invention relates to the manufacture of multiple glazing with plastic seals and it relates more particularly to the laying of a bead of a plastic material of the butyl rubber type on the periphery of one face of a sheet of glass, this bead being intended to serve as a seal and as an interlayer between this first sheet on which it is deposited and a second sheet of glass applied subsequently, against the bead, on its other side, parallel to the first sheet of glass.

 In the context of the manufacture of multiple glazing units, various techniques for injecting plastics of the polysulphide type at the periphery of double glazing units are known.

 But on the one hand plastics of the polysulfide type have a completely different behavior from materials based on butyl rubber, in particular their viscosity is much lower and on the other hand the installation conditions and the constraints to be fulfilled are completely different.

 Consequently, these techniques cannot be used for laying a bead of a material of the butyl rubber type on the periphery of one face of a single sheet of glass.

 This bead must have well-defined physical characteristics for sticking to the glass sheet on the one hand and for playing its role of interlayer on the other hand. In particular, it must have a very precise consistency or viscosity defined in the French patent published under number 2 294 313 as having to be greater than 115 Mooney after eight minutes and 400 C. It must be continuous to form a tight seal . It must also be perfectly calibrated since it is its height that determines the space between the two consecutive sheets and this height must be constant at all points along its length.

It must also be deposited on the glass sheet so as to form with it at the time of bonding an angle between 15 and 450. and preferably between 25 and 350
We manage to meet all these requirements by forming the bead using an extruder whose nozzle forms with the glass sheet the required angle of 15 to 45, this extruder being fixed and the glass sheet moving under it. to successively present each of its sides. Such a laying process and the installation necessary to implement it are described in the French patent publication 2 294 313 already cited.

 The glass sheet is translated horizontally under the extruder nozzle thanks to a conveyor and it is turned to present successively each of its sides under the nozzle thanks to a rotation arm with an axis perpendicular to the plane of the conveyor enclosed between the elements of said conveyor described in French patent publication 2,211,413.

 Glass sheets having a perimeter of around 5m can thus be handled without problem.

 Thanks to this previous installation, the glass sheet always travels in the same direction, under a single nozzle, so that the angle of 15 to 450 that the nozzle must make with the plane of the glass sheet to have a good bonding of the cord, perhaps obtained once and for all, by blocking the. nozzle in the desired position and therefore has no risk of being altered when one passes from the laying of the bead along one side of the glass sheet, to its laying according to another side. In the same way, given that there is only one nozzle, one can achieve great consistency in the dimensions of the cord supplied.

 In addition, the extruder being fixed, there is no drawback that the means for producing the cord, in particular elements of the extruder or linked to the operation of the extruder such as a motor, a brake clutch, etc. ., be big and heavy.

 Furthermore, the glass sheets moving flat on a conveyor, for example with simple rollers or fitted with annular rings, can have precise movements, in particular accelerations and braking, this precision being due to the fact that the glass sheets rest for their entire surface on the rollers or their rings and therefore their inertia is offset by the large contact surface.

However, if the removal of the cord from a fixed nozzle on a sheet of glass laid flat and having successively all of its sides to the nozzle, has advantages, it also has disadvantages
Indeed, the handling and in particular the rotation on the conveyor of glass sheets of large sizes, for example of perimeter of the order of 15 m is too bulky and practically impossible to achieve.

 On the other hand, in a production line for multiple glazing, certain operations are necessarily carried out on the glass sheets arranged vertically, thus for example pressing, optical control, etc., it follows that when the peripheral bead is deposited on sheets of flat glass, it is necessary to practice handling to move from the flat position to the upright position to practice pressing, optical control, etc.

 The present invention aims to avoid the drawbacks of the prior art, namely difficulty in turning the large glass sheets to present successively all their sides under an extrusion nozzle, need to handle the glass sheets from one position flat has a vertical upright position to perform certain operations necessarily or conventionally in the upright position.

 To do this, she suggests placing a cord on. a sheet of glass using an extrusion assembly comprising a nozzle, the glass sheet and the nozzle being both capable of being animated with movements reducing to translations, these translations of the glass sheet on the one hand and the nozzle on the other hand taking place in different directions.

 In an advantageous embodiment for its simplicity of implementation during the manufacture of rectangular glazings, these directions of movement of the glass sheet on the one hand and of the nozzle on the other hand, are orthogonal.

 Advantageously, the glass sheets are arranged vertically or substantially vertically.

 Advantageously, to guarantee consistency in the size of the deposited bead, the movements of the glass sheet, of the nozzle supplying the bead, as well as the flow of the material leaving through the nozzle, are controlled simultaneously.

The invention also provides an installation for implementing the method described above
This installation comprises a vertical or substantially vertical table, a conveyor associated with the table, capable of scrolling a sheet of glass, leaning against the table in both directions, an extrusion assembly having at least one extrusion nozzle disposed opposite of the vertical or substantially vertical table, said nozzle being capable of being moved in translation parallel to the plane of the table, in a direction different from that defined by the conveyor associated with said table.

 Advantageously, the two directions of movement of the glass sheet on the conveyor on the one hand and of the nozzle on the other hand are orthogonal.

 According to a preferred embodiment, with a view in particular to depositing on the sheet very high beads, in horizontal or oblique and generally non-vertical directions, a roller type holding means is associated with the extrusion nozzle.

The invention will now be described in more detail with reference to the accompanying figures which represent
- Figure 1: a schematic profile view of the installation
of a cord on a sheet of glass
according to the invention,
- Figure 2: a schematic front view of the installation
according to Figure 1.

- Figure 3: a top view of the installation according to the
Figures 1 or 2.

- Figure 4: a block diagram illustrating how it works
ment of this installation associated with dia
grams of speed.

 In Figures 1, 2 and 3, there is shown an assembly 1 for transporting glass sheets 100 as well as an assembly 50 for preparing a plastic material.

 The assembly 1 makes it possible to scroll the glass sheets 100 in a vertical or substantially vertical position facing the assembly 50 which supplies the cord 101 of plastic material, so that said cord 101 is deposited on the periphery of the face of the glass sheet 100 oriented towards the assembly 50 supplying the plastic.

 This transport assembly 1 essentially comprises a conveyor 2 with rollers 3 with horizontal or substantially horizontal axes, disposed at the base of a vertical or substantially vertical table 4 against which the glass sheets 100 running on the conveyor 2 are backed. This table 4 is provided with rollers not shown or preferably with orifices 5 for blowing a gas, in particular air, with a view to avoiding the friction of the glass sheets 100 on the table 4 itself, by virtue of the cushion gas thus created between the glass 100 and the table 4. To avoid inconvenience the operators in the absence of a glass sheet 100, the orifices 5 at breast height are advantageously inclined downward or upward. This table 4 is equipped, facing the extrusion assembly 50, with at least one vertical row of rollers 6 projecting slightly from the plane of table 4 and intended to serve as hard support points for the glass sheets 100 during extrusion.

Advantageously, these rollers are retractable.

 The conveyor 2 is advantageously made up of a plurality of juxtaposed sections, each being able to run at a speed different from that of the other sections or, on the contrary, when desired, at the same speed. A conventional system of chains 7 meshing on pinions 8 arranged at the end of the axes of the rollers 3, of clutches 9, of motors not shown, makes it possible to obtain a movement of all the sections at the desired speeds. These motors are advantageously DC motors controlled for example by setpoint cards by the intermediary of a variator.

 Only elements of the drive system of the conveyor 2 with rollers 3 are visible in FIG. 1.

 Advantageously, the rollers 3 are made of a non-adherent material of the Teflon type or coated with such a material.

 In the region facing the assembly 50 for preparing the plastic material and extruding a bead 101, the lower part of the table 4 is advantageously hollowed out, thus allowing the housing of a vacuum transport system 20 guaranteeing the precision of movements of glass sheets 100.

 Indeed, for high speeds of displacement of said glass sheets and rapid stops, there is a risk of sliding of the glass sheets on the rollers 3, the glass sheets resting only by their edges on said rollers 3.

 This transport system 20 essentially comprises two endless bands 21 and 22 of non-slip material, of the rubber type, arranged in parallel in the same plane parallel to that of table 4, slightly advanced with respect to this table 4 by a distance which corresponds to the thickness of the air cushion formed between the glass sheets 100 and said table 4, ie approximately 1 mm. These endless belts 21 and 22 are driven in the same direction and at the same speed which is also that of the conveyor 2 placed immediately below, by a motor system not shown.

 These endless bands 21 and 22 are arranged on either side of a vacuum channel 23, which transverse bars 24 divide into a number of separate vacuum chambers 25, connected by a vacuum outlet 26 to a box vacuum 27.

 The bands 21 and 22 are arranged slightly forward relative to the bottom of the channel 23 and relative to the bars 24. For example the bars 24 will be set back by about 0.3 mm relative to the surface of the endless bands 21, 22 while the bottom of the channel 23 will be set back about 2 mm from the surface of the same endless bands. The vacuum chambers 25a arranged at the ends or near the ends of this transport system 20 have smaller dimensions than the chambers 25 of the middle part, in order to exert an excellent holding force on the glass sheets during taken up by the system or during their unloading, even if a reduced number of chambers 25 are covered by the glass sheets. Always to reinforce the maintenance of the glass sheets 100 when they approach or leave the system 20, several vacuum orifices 26 may be provided in the end chambers 25 or close to the ends.

 Optionally, the system 20 can be in several separate sections, the strips of each section running at the same speed, and advantageously, the chambers 25a at the ends of each section being provided so that the depression is greater there than in the middle chambers, c '' it means that they can be of more restricted dimensions for example they will have only 5 to 10 cm of width instead of 20 to 25 cm in median zone that is to say also that they can have several vacuum intakes 26 The space between two sections of the vacuum system can in particular allow the housing of the vertical row of rollers 6. This transport system can be advanced or retracted with respect to the plane of Table 4 using rods not shown on the figures.

 The structure of the transport assembly 1 also carries four detectors 30, 31, 32 and 33 for the presence of glass sheets 100, detectors of the photoelectric cell type. The detectors 30 and 31 are placed upstream of the vertical row of rollers 6, while the detectors 32 and 33 are placed downstream, respectively symmetrical of the detectors 31 and 30 with respect to said row of rollers 6.

 These detectors 30, 31, 32, 33 emit signals which trigger variations in speed of the conveyor 2 and of the vacuum transport system 20 and which act on the extrusion.

 The structure of the transport assembly 1 also carries a means 34 for measuring the thickness of the glass sheets 100, upstream of the vertical row of rollers 6, for example at 5 cm and also upstream of the detector 30. This measuring means comprises a plate 35 brought into contact with the surface of the glass sheets 100 using a jack 36, a potentiometer 37 which is driven during the advancement of the plate 35. This measuring means makes it possible to position the extrusion assembly 50 relative to the glass sheets, according to their thickness.

 Advantageously, the table 4 is inclined at a small angle relative to the vertical, around 60 ensuring the balance of the glass sheets 100.

 The assembly 50 for preparing the plastic material and for extruding the bead 101 calibrated from said plastic material essentially comprises an extrusion head 51. This extrusion head has a nozzle 52 with an outlet inclined relative to the plane of the table 4 at an angle of 15 to 450 and preferably 25 to 350 as described in French patent 2,294,313 already cited. This nozzle 52 is equipped with a drawer, not shown, with adjustable position, allowing the modification of its section in order to extrude cords 101 of different heights, as well as a cord cutter also not shown, constituted by a blade. actuated by a jack, intended to cut the cord 101 at the end of extrusion. This nozzle 52 is pivotally mounted on a crown 53 rotating along an axis perpendicular to the plane of the table 4. A punch 54 allows said crown 53 to be locked in the desired position by engaging in not shown notches provided for this purpose at the periphery crown 53.

 FIGS. 1, 2 and 3 also show the means supplying the plastic material to the extrusion head 51 and arranged upstream of said head 51.

 In the embodiment taken as an example, these means consist of a reservoir 60 of the raw plastic material, that is to say as delivered and therefore having a high viscosity and hardness, too high to be able to be extruded on the one hand and to stick on the glass on the other hand. This tank 60 is fixed.

 A conical piston 61, heated, provided with heating appendages 62 in the form of candles which immerse in the plastic material, is applied with pressure against the plastic material contained in the tank 60. A rotary pump 63 with internal gears is arranged at the outlet of this piston 61 and provides at its outlet a plastic material under pressure. On this pump # 63 are connected bent rigid pipes such as 64 joined by rotary couplings such as 65 resistant to high temperatures and to high pressures of the order of 300 or 400 bars.

 These pipes are connected to a variable volume magazine 66 constituting a reserve of plastic material and regulating the pressure of the plastic material at its outlet. This store 66 is continuously supplied by all the elements arranged upstream and, on the contrary, at its outlet, it delivers the plastic material on demand.

 The output of this magazine 66 communicates with a positive displacement pump 67 driven by an electric motor (not shown), with direct current, controlled by instruction cards via a variator. The output of this pump 67 is connected directly to the extrusion head 51. The variable volume magazine assembly 66, positive displacement pump 67, extrusion head 51 is mounted on a carriage 68 carried by a plate 69 movable in a direction different from the direction of movement provided by the conveyor 2 with rollers 3, and advantageously in an orthogonal direction. This plate 69 is able to move along two slides 70, 71, parallel to table 4 and therefore in the plane of the glass sheets 100. The movement along these two slides 70, 71 is caused by a motor 72 which rotates an endless screw 73, parallel to the slides 70, 71, this endless screw 73 being engaged in non-illustrated ball bushings, integral with the plate 69. The slides 70, 71 as well as the endless screw 73 are fixed along a vertical console 74. The motor 72 is a direct current electric motor controlled by instruction cards.

 The carriage 68 is movable relative to the plate 69 in a direction orthogonal to the plane of the table 4 under the action on the one hand of an endless screw not shown, actuated by an electric motor also not shown, on the other hand a jack not shown. The electric motor is associated with a potentiometer not shown coupled to potentiometer 37. This electric motor makes it possible to adjust the distance glass-nozzle according to the thickness of the glass sheets 100, while the jack makes it possible to move away or on the contrary bring the nozzle 52 closer to the table, at predetermined distances, in particular for putting the nozzle into service or out of service.

 The extrusion head 51 also carries two detectors for the presence of glass 75 and 76, these two detectors acting on the movements of the plate 69 along its slides 70, 71. These two detectors 75 and 76 are arranged above the extrusion head 51, one 75 detects the upper edge of the glass sheet while the head 51 in its upward movement is still only a few millimeters from this upper edge, the other 76 detects the same upper edge when the head 51 has reached its maximum level in its upward movement.

 Two microswitches 77 and 78 are also provided on the console 74 along the worm 73, one 77 intended to be intercepted when during its translational movement along the slides 70 and 71, the extrusion head 51 carried by the plate 69 arrives at a determined distance, of the order of a few millimeters from its extreme low position, the other 78 intended to be intercepted when the extrusion head reaches this extreme low position corresponding to the position of the bead deposited on the lower portion of the glass sheet.

 Immediately before the outlet of the nozzle 52, is also arranged a decompression system capable of creating a vacuum in the circuit for supplying the plastic material at certain times. Such a system is described in French patent 2,207,799.

 Means for supporting the cord 101 when it is deposited along horizontal or oblique lines, therefore when it may tend to sag can be provided. It may in particular be a set of rollers, in particular two rollers, not shown in the figures. Advantageously, these rollers are attached to the extrusion head 51. They can be arranged in such a way that when the head 51 is pivoted and deposits the bead along a non-vertical path, they come to be positioned under said bead which comes from 'be extruded and just pasted on the glass sheet.

 Advantageously, they have a form of hyperbolold of revolution.

 The assembly supplying the plastic material to the extrusion head 51 is given only by way of example, other assemblies capable of supplying an extrusion head 51 movable in translation could be designed. We could in particular have a extruder, worm, said extruder being capable of moving in translation in a direction different from that defined by the conveyor 2 and advantageously orthogonal to this direction defined by the conveyor.

 A logic control system including the setpoint cards, the various detectors and contactors and comprising a whole electronic assembly capable of processing the data and signals supplied by these cards and detectors is also provided.

 The instruction cards can provide for translations to take place either of the sheets of glass 100 by driving through the conveyor 2 in a particularly horizontal direction, or of the extrusion head 51 in a direction notably orthogonal to that defined by the conveyor 2 by rotation of the endless screw 73, or else simultaneous translations of the glass sheets 100 and of the extrusion head 51.

 In the first case, cords can be deposited along rectangular glass sheets, in the second case, depending on the composition of the speeds of the two translations, cords can be deposited on glass sheets of any shape.

 By construction, the row of rollers 6 is arranged exactly opposite the nozzle 52.

The installation described above works as follows
At start-up, the extrusion head 51 is in its extreme low position and the nozzle 52 is oriented by rotation of its crown 53 so as to form the required acute angle with the part of the table 4 located above it.

 A glass sheet 100 intended to receive the cord 101 on its periphery arrives on the conveyor 2, in a vertical position, in the direction of the arrow F shown in the figures, at high speed, for example of the order of 50 m / min. When approaching the extrusion assembly 50, it is also supported by the vacuum transport system 20 with belts 21 and 22 made of non-slip material traveling at the same speed as the conveyor 2. Thanks to the vacuum exerted in each of the chambers 25 of this system, and thanks to the non-slip properties of the material of the strips 21 and 22, the movement of the glass sheets 100 is very precise, although said glass sheets rest on the rollers 3 of the conveyor only by their Before arriving in the zone for laying the cord 101, the glass sheet 100 is stopped using conventional presence detectors not mentioned hitherto and not shown, and its thickness is measured. This happens for example 5 cm before the row of rollers 6. The plate 35 is brought into contact with the surface of the glass by its jack 36, the potentiometer 37 is then driven and it delivers a voltage which is entered into a memory . This tension then serves to guide the correct positioning of the extrusion head 51. This is moved in the direction of table 4 by the electric motor which acts on the carriage 68. The potentiometer 37 is actuated, it delivers a tension and said electric motor acts as long as this voltage delivered does not equal that stored and delivered by the measuring means.

 The glass sheet having resumed its scrolling, then meets the detector 30 as shown in FIG. 4A. This emits a signal which, after adjustable delay, controls the slowing down of the conveyor 2 and of the system 20, up to a slow speed of the order of 3 m / min. The glass sheet 100 then meets by its edge before the detector 32. The latter then triggers the immediate stop of the conveyor 2 and of the system 20. It also triggers with a certain adjustable delay the operation of the positive displacement pump 67 at a speed predetermined, therefore the extrusion of the cord 101, then with a certain delay relative to the starting of the pump, delay also adjustable, the operation of the motor 72 at predetermined speed, in a direction such as #platin 69 and therefore the head d extrusion 51 rises along the slides 70 and 71. Cord is thus deposited along the vertical edge of the glass sheet 100 as shown in FIG. 4B. This continues until the detector 75 meets the upper horizontal edge of the glass sheet 100. It then controls, with adjustable delays, the deceleration of the motor 72 and in synchronism with that of the volumetric pump 67, the setting in action of the decompression system, the withdrawal of the nozzle 52 with respect to the glass sheet 100 by recoil movement of the carriage 68 under the action of its jack and the pivoting of the extrusion head.

Then, the detector 76 meets the edge of the glass sheet and it commands the immediate stopping of the motor 72 and of the pump 67.

The delay provided for the pivoting of the extrusion head is then completed and the crown 53 is turned, thus placing the nozzle 52 in the correct position for extrusion on another side of the glass sheet, then the carriage is closer to the glass and therefore also the nozzle 5 and finally the decompression system is released, the positive displacement pump 67 restarts and the conveyor 2 is restarted thus scrolling the glass sheet 100 in the direction of the arrow
F (Figure 4C).

 The laying of the bead continues at constant speed on the upper horizontal side of the glass sheet until the rear edge of said sheet meets the detector 30. This triggers with adjustable delays, slowing down of the scrolling of the glass and correlatively the slowdown of the pump 67, the recoil of the nozzle 52, the decompression and the pivoting of the extrusion head.

 The edge of the glass sheet then meets the detector 31, which stops the conveyor 2 and the pump 67.

 The extrusion head is pivoted and the device is then ready to deposit the bead 101. The bead 101 is laid on the vertical side of the glass sheet, the extrusion head 51 being driven in downward vertical translation, by movement of the plate 69 along its slides (FIG. 4D).

 The interception of microswitch 77 triggers with adjustable delays the slowing down of the translation movement, of the rotation of the pump, also triggers with adjustable delays the pivoting of the extrusion head, the activation of the decompression system and the recoil of the nozzle. When the microswitch 78 is intercepted, the translational movement stops and the pump 67 stops running. The expected delay times having elapsed the extrusion head pivots. Then as already described in relation to the laying of the bead on the upper horizontal side, the various operations for restarting the laying of the bead are engaged, and this time to deposit said bead along the lower horizontal side of the glass sheet , the latter moving in the opposite direction to the arrow F, and the extrusion head remaining fixed. (FIG. 4E). It is at the interception of detector 33 that the various slowdowns and preparations for stopping are controlled. The meeting of the front edge of the glass sheet with the detector 32 controls the stop of the conveyor 2. After the end of the laying of the cord, the latter is cut by the cord cutter and to guarantee separation, the conveyor initiates a short movement in the opposite direction to the arrow F.

 Then the glass sheet is discharged in the direction of arrow F.

As can be seen in the speed diagrams in FIG. 4F established under views 4A, 4B, 4C, 4D and 4E and corresponding to the different phases illustrated by these views, upon arrival of the glass sheet (FIG. 4A) before laying the cord, the speed of rotation of the pump 67 is zero (Vp = #), the speed of movement
P = O), the speed of movement of the extrusion head 51 by movement along the vertical slides 70, 71 is also zero (Vt = 0), only the speed of the conveyor is positive (Vc = positive).

 To install the cord along the front vertical edge of the glass sheet, the instruction cards control the speed increase of the pump motor 67 (Vp) of the motor 72 (Vt and the level of these speeds after starting ( Vp = constant, Vt = positive constant).

At the end of the laying of the cord along this vertical side, the instruction cards also control the decrease of these speeds Vp and Vt until a zero value Vp = O and Vt = O. During the pivoting of the head extrusion all speeds are zero. Then for laying the cord along the upper horizontal edge of the glass sheet, the setpoint cards # s control the acceleration of the rotation of the pump motor and of the conveyor 2 to:
Vp = constant and Vc = positive constant
Meanwhile Vt = 0
These speed diagrams are located under the 4C view. Then under the 4D view corresponding to the laying of the cord along the rear vertical side in the downward direction, it can be read that
Vc = 0 Vt = negative constant and Vp = constant
Then as before, during the pivoting of the nozzle
Vc = O Vp = O Vt = 0
Then during the laying of the cord along the lower horizontal side of the glass sheet (view 4E) we can read
Vp = constant Vt = O Vc = negative constant
This represents an example of laying a cord along the edges of a rectangular sheet of glass. In the case of a sheet of any shape, for example with oblique sides, we should have simultaneously moved the sheet of glass and the extrusion head, so we would have had simultaneously
Vt and Vc other than zero
Thus, thanks to the simultaneous control of the motor 72 which controls the translation of the head in the vertical or substantially vertical direction, of the conveyor motor 2, of the motor of the positive displacement pump 67, by instruction cards or possibly by other equivalent means, the accelerations and decelerations, the stabilized speeds of these engines are determined with precision.

 Thus the constancy of dimensions of the cord 101 can be obtained.

 Large glazing units can be manufactured, with reduced handling which is limited to translations of said glazing units.

 The reduction in handling limits the size on the one hand and allows on the other hand excellent qualities of the glazing produced.

 The displacements of the extrusion head are also limited to translations, which allows relatively short lengths of the plastic material distribution circuit. Thanks to the means for preparing the plastic material, high flow rates at the outlet of the nozzle 52 are possible, even with a plastic material of the butyl rubber / polyisobutylene mixture type, a mixture whose viscosity, hardness and in general the difficulties are well known to those skilled in the art.

 The installation according to the invention in which the glass sheets and the nozzle are animated with crossed relative movements is particularly effective in the case where the glass sheets are arranged vertically or substantially vertically, because of the small size and the reduced number of manipulations.

 However, such crossed movements can also be advantageous in the case where the glass sheets have another arrangement, for example in the case where they are flat.

Claims (24)

 1. Method for extruding a plastic material of the butyl rubber type, in particular in the form of a calibrated bead and depositing it on the periphery of one face of a glass sheet using a set of extrusion supplying said plastic material through an extrusion nozzle, characterized in that said nozzle and the glass sheet are moved relative to each other, the nozzle and the glass sheet being the one and the other likely to be animated with movements reducing to translations, these translations of the glass sheet on the one hand and of the nozzle on the other hand taking place in different directions, the nozzle moving in parallel in the plane of the glass sheets.  2. Method according to claim 1, characterized in that the displacements of the glass sheet on the one hand and of the nozzle on the other hand are in orthogonal directions.  3. Method according to one of the preceding claims, characterized in that simultaneously controls the movements of the nozzle and the glass sheet as well as the flow rate of the plastic material extruded through the nozzle.  4. Method according to one of claims 1, 2 or 3, characterized in that the glass sheet is arranged vertically or substantially vertically and moves in a horizontal or substantially horizontal direction.  5. Method according to one of the preceding claims, characterized in that the nozzle forms an angle of 15 to 450 with the plane of the glass sheet and in that it is pivoted so that this angle is always identical whatever the direction and direction of movement of the sheet and / or the nozzle.  6. Method according to claim 5, characterized in that when approaching an angle of the glass sheet, the extrusion nozzle is subjected to a slight recoil relative to said glass sheet while continuing to extrude to the limit of the side of the sheet along which the plastic is deposited, then the extrusion is interrupted, the nozzle is pivoted, then the extrusion is restarted and the nozzle is brought closer to the glass sheet in view to make the deposit in the other direction of the angle.  7. Application of the method according to one of the preceding claims to the laying of an extruded bead on the periphery of one face of a rectangular glass sheet arranged vertically, character  sr w sée in that the said bead is deposited along a vertical side of the sheet leaving the said sheet stationary and moving the nozzle parallel to the sheet in an upward translational movement, the nozzle is pivoted at the end from this first side of the sheet, the nozzle is kept fixed and the sheet is advanced in front of the nozzle while the latter extrudes the bead, thus allowing deposition along the upper horizontal side of the sheet, at the end of this side, pivot the nozzle, then move it in a downward translational movement along the vertical edge of the glass sheet kept fixed and finally at the end of this vertical side, we pivot the nozzle again then it is held fixed while the sheet of glass translates in a recoil movement.  8. Application of the method according to one of the preceding claims to the laying of a bead on a glass sheet of any shape, characterized in that for depositing the extruded plastic material along an oblique direction relative to the two directions of movement of the glass sheet and movement of the nozzle or in a curved path, the glass sheet and the nozzle are simultaneously moved while the bead is extruded through the nozzle and placed on the sheet of glass.  9. Installation for extruding a plastic material of the butyl rubber type, in particular in the form of a calibrated bead, and depositing it on the periphery of one face of a glass sheet, using a extrusion assembly supplying said plastic material through an extrusion nozzle, characterized in that it comprises a vertical or substantially vertical table, a conveyor associated with the table, capable of running the glass sheet along the table , leaning against the table, in both directions, the table and the associated conveyor being arranged opposite the extrusion assembly, the nozzle of the extrusion assembly being capable of being moved in translation parallel to the plane of the table , in a direction different from that defined by the conveyor associated with said table.  10. Installation according to claim 9, characterized in that the direction of movement defined by the conveyor associated with the table and the direction of movement of the extrusion nozzle are orthogonal.  11. -Installation according to one of claims 9 or 10, characterized in that the table is slightly inclined relative to the vertical for example by an angle of about 60 to ensure the balance of the sheet of glass which scrolls on the conveyor associated with the table, backing onto said table.  12. Installation according to one of claims 9 to 11, characterized in that the table is pierced with blowing orifices for a gas, in particular air, so as to produce a gas cushion between the glass sheets and its surface.  13. Installation according to claim 12, characterized in that at least the orifices at breast height are directed obliquely, upwards or downwards, so as not to disturb the operators.  14. Installation according to one of claims 12 or 13, characterized in that a row of rollers projecting from the table by a distance equal to the thickness of the gas cushion, is embedded in said table, opposite the nozzle extrusion over the entire height of the possible displacement of said nozzle.  15. Installation according to one of claims 9 to 14, characterized in that it is provided at the base of the table, in a direction parallel to that of the movement defined by the conveyor associated with said table, a vacuum transport system comprising two endless bands of non-slip rubber-like material, slightly protruding from the table so as to be in contact with the sheets of glass which move against the table, these two endless bands being driven at the same speed and in the same sense that the conveyor associated with the switchboard, and delimiting a channel placed under vacuum, this channel being divided into a plurality of vacuum chambers by transverse bars arranged recessed with respect to the plane of said endless belts.  16. Installation according to claim 15, characterized in that the channel of the vacuum transport system is put under vacuum thanks to suction orifices opening into the vacuum chambers, and connected to a vacuum device.  17. Installation according to one of claims 9 to 16, characterized in that the extrusion nozzle is integral with a plate sliding along two slides arranged substantially vertically parallel to the table against which the glass sheets are leaning, under the action of an endless screw driven by a motor and engaged in ball bushings fixed on the plate.  18. Installation according to one of claims 9 to 17, characterized in that the extrusion nozzle is preceded by a positive displacement pump driven by an electric motor.  19. Installation according to claims 17 and 18, characterized in that the motor which actuates the conveyor associated with the switchboard as well as the vacuum transport system, the motor which moves the plate which carries the nozzle and the pump motor Volumetric are motors driven simultaneously according to each other, in particular by instruction cards.  20. Installation according to one of claims 9 to 19, characterized in that between the plate and the nozzle is interposed a carriage capable of being moved in a direction perpendicular to the plane of the table, to bring the nozzle closer to or away from the sheet of glass.  21. Installation according to one of claims 9 to 20, characterized in that the nozzle makes an angle of 15 to 45 and preferably 25 to 35 with the plane of the table and in that it is mounted orientable around an axis perpendicular to the plane of the table.  22. Installation according to one of claims 9 to 21, characterized in that the elements of the extrusion assembly movable in translation parallel to the plane of the table are connected to the other fixed elements of the same extrusion assembly by a series of bent pipes joined by swivel fittings.  23. Installation according to one of claims 9 to 22, characterized in that it comprises a means of holding the castor type secured to the nozzle, capable of being placed under the plastic material which has just been extruded and which is deposited on a sheet of glass in a non-vertical direction.  24. Installation according to one of claims 9 to 23, characterized in that series of detectors and / or micro-contactors are provided along the conveyor and along the direction of movement of the nozzle in order to control the movements of the glass sheets respectively along the conveyor and the nozzle along its direction of movement.