device and method for forming a sheet of glass

Abstract

The present invention relates to a bending station (4) for a bending device comprising two bending dies, a pressing frame (5) arranged to fit the glass sheet and press it against an upper die, the upper die (6) comprising a forming face whose area defined by the projection of the contour of the upper die onto a horizontal plane is greater than the area defined by the projection of the outer contour of the pressing frame and the glass sheet onto the same horizontal plane, the pressing frame (5) comprising a pressing ring (50) having a continuous surface, the upper die comprising a flexible sheet (60) associated with an upper series of translational elements (70), characterized in that the upper die is capable of deforming under the effect of the translational elements of the upper series to obtain a deflection value varying by at least 5 mm. Fig 1

Description

Title of the invention: device and method for forming a glass sheet

[0001] The invention relates to a technique for bending a glass sheet, followed by a cooling step. The technique according to the invention is either suitable for bending a glass sheet, in particular intended to be tempered, or for bending glass sheets which are then cooled and then assembled two by two to form a laminated glazing unit. Prior art

[0002] To give a shape to a glass sheet, several techniques are used. Among these techniques, one of them consists of having the glass sheets which are brought one by one through a heating furnace to raise their temperature to a temperature close to the softening temperature, the glass sheets being conveyed on a bed of rollers. The glass sheets are then taken, as soon as they leave the furnace, to a bending station. In the bending station the glass sheet is lifted from the conveyor by a frame having the shape that it is desired to give to the glass sheet. This frame is commonly called a "pressing frame" or "pressing ring". Depending on the configuration of the bed of rollers, the frame is continuous or discontinuous so as to be able to pass through the bed of rollers on which the glass sheet initially rests.The frame then lifts the glass sheet to press it against a solid upper mold whose shape complements that of the frame and therefore corresponds to the desired shape for the glass sheet. After pressing, the glass is sucked up and held against the mold, then it is dropped either onto the bed of rollers or another frame called a transfer frame towards the cooling or tempering area. In the first case, the rollers then start moving again to carry the glass sheet to the tempering station.

[0003] In addition to the particularity of the lower frame which crosses the bed of rollers which acts as a conveyor, this type of technique is characterized by the fact that the bending operation takes place outside the furnace or at least in an enclosure maintained at high temperature. By "high temperature" we mean temperatures typically above 250-300 °C. This type of technique must therefore be considered as a glass forming technology by cold pressing, this qualifier defining the location of the bending station outside an enclosure maintained at high temperature: in this configuration, controlling the positioning of the bending tools is simpler than in the case of hot technologies. On the other hand, the bending process is a race against time since as soon as it leaves the furnace, the glass sheet will cool, changes to the bending operation or its conditions are therefore delicate and limited.

[0004] A disadvantage of this method is that the upper form and the frame are specific parts. This means that, for each glass shape, the upper form and the frame must be machined to the exact dimensions of the glass shape to be produced. It is also possible that for the same shape or surface, several upper forms are necessary due to the thickness or color of the glass. The upper form is rigid and the frame generally has adjustment screws which give it a deformation capacity limited to approximately + / - 5mm. Thus, it is only possible to adjust the lower form.

[0005] Modifications can also be made to the upper shape by re-machining its surface, an operation called "re-machining" which can modify its geometry over a thickness ranging from a few tenths of a millimeter up to approximately 15 millimeters. Thus, each glass shape requires its own tooling, which involves a significant cost. Indeed, during development, the compromise of the process parameters can lead to modifying the geometry of the mold in order to obtain the correct final geometry for the glazing. This re-tooling operation is costly financially and in terms of time. This cost can be increased if several production lines are used to manufacture said glass, each production line requiring its own tooling. Summary of the invention

[0006] An object of the present invention is to solve the problems of the prior art by providing a device for forming a glass sheet and its method allowing greater flexibility of operation and in particular allowing the forming of sheets having different shapes and / or surfaces.

[0007] In this respect, the present invention relates to a bending station for a bending device comprising two bending forms, a pressing frame arranged to fit the glass sheet and press it against an upper form, the upper form comprising a forming face whose area defined by the projection of the contour of the upper form onto a horizontal plane is greater than the area defined by the projection of the outer contour of the pressing frame and the glass sheet onto the same horizontal plane, the pressing frame comprising a pressing ring having a continuous surface, the upper form comprising a flexible sheet associated with an upper series of translation elements, characterized in that the upper form is capable of deforming under the effect of the translation elements of the upper series to obtain a deflection value varying by at least 5 mm.

[0008] The invention also relates to a bending station for a bending device comprising two bending forms, a pressing frame arranged to fit the glass sheet and press it against an upper form, the upper form comprising a forming face whose area defined by the projection of the contour of the upper form onto a horizontal plane is greater than the area defined by the projection of the outer contour of the pressing frame and the glass sheet onto the same horizontal plane, the pressing frame comprising a pressing ring having a continuous surface associated with a lower series of translation elements, the upper form comprising a flexible sheet associated with an upper series of translation elements, characterized in that the upper form and the pressing frame are capable of deforming under the effect of the translation elements to obtain a deflection value varying by at least 5 mm.

[0009] The invention also relates to a bending station for a bending device comprising two bending forms, a pressing frame arranged to fit the glass sheet and press it against an upper form whose surface or area defined by the projection of the contour of the upper form on a horizontal plane is at least equal to the surface or area defined by the projection of the outer contour of the pressing frame, the pressing frame comprising a pressing ring having a continuous surface associated with a lower series of translation elements, characterized in that the pressing frame is capable of deforming under the effect of the translation elements of the lower series to obtain a deflection value varying by at least 5 mm.

[0010] The advantage of the bending station according to the invention is to allow, via an action on the translation elements, the upper form and / or the pressing frame to form glass sheets for single or laminated glazing having different shapes or sheets with the same shape but different thicknesses.

[0011] According to one example, the area of ​​the forming face of the upper form is equal to at least 101% of the surface area of ​​the glass sheet to be formed, preferably at least 105%, and even more preferably at least 110%.

[0012] According to one example, the area of ​​the forming face of the upper shape is such that it has a distance of at least 1 cm, preferably at least 5 cm between a portion of an edge of the upper shape and a portion of the edge of the glass sheet.

[0013] According to one example, the translation elements of the upper series of translation elements and / or of the lower series of translation elements are jacks.

[0014] According to one example, the translation elements of the upper series of translation elements and / or of the lower series of translation elements comprise an articulation means.

[0015] According to one example, the articulation means is a ball joint arranged between the end of a translation element and the upper form or the pressing frame.

[0016] According to one example, the articulation means comprises a connecting rod equipped with a ball joint at each of its ends, a first ball joint connects the end of the translation elements to the connecting rod while a second ball joint connects the other end of the connecting rod to the upper form or to the pressing frame.

[0017] According to one example, the ball joint fixed to the upper form or to the pressing frame is fixed by means of a compensation means capable of moving in translation, said compensation means comprising a pad mounted movably in a cage, said cage being fixed to the upper form and said pad being fixed to a translation element, or comprising a magnetic pad in contact with the upper form made at least locally magnetic.

[0018] According to one example, the upper shape is made at least locally magnetic by magnetic inserts or by a metal structure put in place during the production (casting) of the membrane.

[0019] According to one example, the flexible sheet of the upper form is a polymer membrane or a metal sheet provided with a plurality of through-cuts.

[0020] According to one example, the polymer membrane is reinforced by stiffening means.

[0021] According to one example, the stiffening means comprise overmolded rods or a sheet made of a more rigid material overmolded or glued to the polymer membrane or rods inserted into sheaths overmolded in the polymer membrane, the rods being able to slide in the sheaths.

[0022] According to one example, the pressing ring is made of a polymer material or comprises a metal sheet provided with a plurality of through-notch openings.

[0023] According to one example, the pressing ring comprises portions each comprising a plurality of stretchable segments separated from each other by plates, each portion further comprising a blade inserting into a suitable bore formed in each plate and stretchable segment of the portion, said pressing ring further comprising intersection plates comprising two bores allowing the insertion of the blades of two portions.

[0024] According to one example, the upper form and / or the pressing frame is covered with a fabric or a metallic knit.

[0025] According to one example, the translation elements of the upper series and / or the lower series are adjusted in translation manually.

[0026] According to one example, the translation elements of the upper series and / or the lower series are connected to a control unit allowing their adjustment in vertical translation.

[0027] According to one example, the translation elements of the upper series and the lower series are connected to a calculation unit allowing their adjustment in vertical translation in an interconnected manner.

[0028] According to one example, a suction device is arranged, this suction device comprising a vacuum box comprising an outlet connected to a pump and a plurality of inlets, said suction device further comprising a plurality of pipes each connected to an inlet of the vacuum box and to a through hole arranged in the upper shape.

[0029] According to one example, each pipe is connected to a through hole of the upper form via a manual valve or a controllable valve module.

[0030] The invention further consists of a bending device comprising a furnace for heating a glass sheet, a device for supporting and transporting the glass sheet in a substantially horizontal plane passing through the furnace to a bending station according to the invention.

[0031] The present invention also relates to a method for bending a glass sheet comprising heating the glass sheet to a softening temperature, transporting the glass sheet along a substantially horizontal path to a bending station according to the invention, and shaping the glass sheet by pressing between the two shapes.

[0032] According to one example, the method further comprises, before shaping, a step of acting on the translation elements of the upper series of translation elements and / or the lower series of translation elements to adjust the upper shape and / or the pressing frame.

[0033] According to one example, said device further comprises measuring means for measuring the distance between the surface of the upper form and the surface of the pressing frame, said measuring means being connected to a calculation unit in order to send a signal to the first series of translation elements and / or the second series of translation elements to compensate for a possible drift.

[0034] According to one example, said device further comprises measuring means making it possible to compare the shape of the curved sheet with a reference, said measuring means being connected with a control unit in order to send a signal during production to the first series of translation elements and / or the second series of translation elements to compensate for a possible drift of the curved shape or of the optical quality in reflection of the curved shape.

[0035] The invention also relates to a method for producing a series of laminated glazing units, each laminated glazing unit comprising a first sheet and a second sheet associated with an interlayer film, said method comprising the steps:

[0036] - Get some sheets of glass,

[0037] - Shape the glass sheets with the bending device according to the invention for obtaining a series of first glass sheets and a series of second glass sheets;

[0038] - Combining the first glass sheets, the second glass sheets and films spacers to form laminated glazing,

[0039] Characterized in that the step of shaping the glass sheets is carried out so that at least one first glass sheet and at least one second glass sheet are alternately formed.

[0040] According to one example, the step of shaping the glass sheets comprises repeating the following steps:

[0041] - Act on the translation elements of the upper series and / or the lower series to adjust the bending station to form the first glass sheet or the second glass sheet;

[0042] - Forming at least one first sheet of glass or at least one second sheet of glass ;

[0043] - Act on the translation elements of the upper series and / or the lower series to adjust the bending station to form the second glass sheet or the first glass sheet;

[0044] - Forming at least one second sheet of glass or at least one first sheet of glass. Description of figures

[0045] Other features and advantages will become clear from the description given below, for information purposes only and in no way limiting, with reference to the appended drawings, in which:

[0046] - [Fig.l] represents a bending station according to the invention.

[0047] - Figures 2 and 2' show a reversed bending shape for the station of bending according to the invention.

[0048] - [Fig.3] represents an upper form provided with a suction device

[0049] - figures 4, 4', 5, 5' represent articulation means for the shape upper and / or the pressing frame.

[0050] - figures 6 and 6' show a pressing frame for the bending station according to the invention;

[0051] - Figures 7, 8, 9 and 10 show a configuration of a pressing ring for the bending station according to the invention

[0052] - [Fig.l 1] represents interface means between the glass and the pressing frame or the upper form of the bending station according to the invention.

[0053] - Figures 12a and 12b show a bending shape and a pressing ring controllable;

[0054] - [Fig. 13] represents the bending station and a bending line;

[0055] - figures 14, 15 and 16 represent measuring means making it possible to improve the bending; Detailed description

[0056] In [Fig.l], a furnace 1 in which a glass sheet 2 moves along a roller conveyor 3 is shown. During its stay in the furnace 1, the glass sheet 2 is brought to its softening temperature. The glass sheet 2 is then led, still supported by the conveyor 3, to a bending station 4.

[0057] This bending station 4 is where the softened glass sheet is manipulated to take its almost final shape.

[0058] In the bending station 4, a pressing frame 5 is arranged under the plane defined by the roller conveyor 3. When the glass sheet 2 arrives above this frame, members not shown in the figures ensure precise positioning of said glass sheet, then its movement is stopped by the stopping of the rollers in the bending zone. The pressing frame 5 then passes through the bed of rollers 3 to lift the glass sheet.

[0059] As mentioned above, the pressing frame 5 has the shape that is desired to be given to the glass sheet and makes it possible to shape the glass sheet. The pressing frame 5 is designed so as to be able to pass through the bed of rollers 3.

[0060] The pressing frame 5 having taken charge of the glass sheet 2 moves to press it against a bending form 6 positioned above the pressing frame 5. The shaping of the glass sheet is therefore done by pressing the glass sheet between the bending form 6 and the pressing frame 5. At the end of pressing, a suction system makes it possible to perfectly press the glass sheet onto the upper form.

[0061] The bending shape 6 (also called upper shape) comprises a bending face, preferably solid, i.e. continuous and uniform, the shape of which is preferably square but can take other shapes such as rectangular or any other. The bending face has a surface or area defined by the projection of the contour of the upper shape onto a horizontal plane and is at least equal to the surface or area defined by the projection of the outer contour of the pressing frame.

[0062] Cleverly according to the invention, the bending form 6 and / or the pressing frame 5 are arranged to allow the formation of glass sheets of different shapes.

[0063] In a first embodiment, the bending form 6 is adaptable. It is understood by this that the bending form 6 is such that it allows glass sheets of different shapes to be formed. For this, the bending form 6 comprises a flexible sheet 60 associated with an upper series of translation elements 70 as visible in [Fig.2], 2' where this bending form 6 is shown inverted or turned over. This allows the flexible sheet to have a deflection height which varies from 5 to 500mm, preferably from 10 to 300mm and even more preferably from 20 to 200mm.

[0064] The bending form 6 is cleverly universal, that is to say that it has a surface area larger than that of the glass sheet and than the surface area of ​​the pressing frame 5. It is understood by this that the surface area or area defined by the projection of the contour of the bending form (also called upper form) on a horizontal plane is greater than the surface area or area defined by the projection of the outer contour of the pressing frame and the glass sheet on the same horizontal plane. Preferably, the surface area of ​​the bending form 6 is equal to at least 101% of the surface area of ​​the glass sheet, preferably at least 105% of the surface area of ​​the glass sheet, and even more preferably at least 110%. In addition, it is preferred to have a minimum distance of at least 1cm, preferably at least 5cm between at least a portion of the edge of the glass sheet and a portion of the edge of the membrane.This configuration allows the upper form 6 to be used for different shapes of glass sheet as long as the shape of the latter fits into that of the upper form 6.

[0065] The flexible sheet 60 can take several forms. The first is a membrane made of a polymer material. This polymer material membrane can, optionally, include rigid elements that improve the hold. If the polymer material is too flexible, there is a risk that the shape of the membrane cannot be well controlled. By stiffening said membrane, this control is improved. These rigid elements can be metal or plastic rods inserted or overmolded in the membrane. These rigid elements can also be a metal sheet fixed to said membrane. The rigid elements can, optionally, be inserted into sheaths that are overmolded in the membrane. The presence of these sheaths allows the rigid elements to slide freely in the sheaths.

[0066] In a second form, the flexible sheet 60 comprises a thin sheet made of a material resistant to temperatures of 700 degrees, i.e. not softening at this temperature. Preferably, the material is a metal or a of these alloys. This thin sheet is provided with a plurality of openings in the form of through notches repeated on the surface of the thin sheet so that it can deform in two different directions.

[0067] In a variant visible in [Fig. 3], the bending station 4 comprises a suction device 100 at the level of the upper form 6, this suction device 100 making it possible to suck up a sheet of glass.

[0068] For this, the suction device 100 comprises a plurality of through holes 101 arranged in the upper shape 6. To provide the suction force, the suction device comprises a vacuum box 102. This vacuum box 102 comprises an outlet by which it is connected to a pump (not shown) so that the air from said box 102 can be sucked out.

[0069] The vacuum box 102 also comprises a plurality of inlets each connected to a through hole in the membrane. This connection is made by pipes 103, one end of which is connected to an inlet of the vacuum box 102 and the other end connected to the through hole 101 at the face opposite the facing face of the glass sheet.

[0070] The holes are preferably regularly distributed over the surface of the upper shape 6.

[0071] Since the upper shape 6 is said to be universal, that is to say that it can be used for different shapes of glass sheets, it is possible that not all of the holes 101 are used. To prevent these holes 101 from causing a loss of suction, the unused holes 101 are preferably plugged or connected two by two. They can be plugged by using a stopper or equipped with a controllable valve module that can close or open as desired. An alternative embodiment consists of equipping each pipe 103 with a % (quarter) turn type valve making it possible to cut the connection between the vacuum box 102 and the atmosphere in the case where the hole 101 of the membrane connected to this pipe is outside the contact surface between the membrane and the glass sheet.

[0072] The flexible sheet 60 is associated with an upper series of translation elements 70. These translation elements 70 are jacks 71. A jack 71 is defined as a mechanical or electromechanical element allowing the translation of two elements relative to each other.

[0073] A jack 71 can thus be in the form of a cylindrical tube in which a movable piston is arranged, a fluid making it possible to move the piston.

[0074] A jack 71 can also be in the form of a screw-nut assembly or a worm screw.

[0075] These translation elements 70 are fixed, by a first end, to a base 40 which may be in the form of a plate or a frame. The second end translation elements 70 are fixed to the flexible sheet 60 as visible in [Fig.2],

[0076] Each translation element 70 of the upper series is independently controllable, allowing said flexible sheet 60 to be deformed locally and giving it the desired shape within the deformability limits of the flexible sheet 60.

[0077] Being a universal tool suitable for forming a large number of glazing shapes, the flexible sheet 60 has the following characteristics: its area is greater than the area of ​​a main face of the formed glass sheet and the contour of the glass sheet is included inside the contour of the flexible sheet. More precisely still, the contour of the upper face (face in contact with the flexible sheet) of the formed glass sheet is contained in the lower surface (face in contact with the glass sheet) of the flexible sheet.

[0078] The density of the translation elements 70 can vary depending on the desired surface but also on the radius of curvature. This density can be such that the translation elements are arranged in a grid of 500 x 500 mm to 50 x 50 mm.

[0079] The pressure exerted on the glass sheet held between the pressing frame 5 and the bending form 6 does not imply that the shape of the glass sheet freezes. As the glass sheet is not necessarily completely cooled during forming, said glass sheet may still see its shape evolve slightly.

[0080] The increase in curvature leads to the appearance of stresses on the translation elements 70 or on the flexible sheet 60.

[0081] Indeed, the increase in the curvature tends to reduce the dimensions of the surface of the glass projected onto a horizontal plane while the projection of the translation elements 70 is independent of the geometry of the upper shape 6. Stresses are exerted on the translation elements 70 and on the upper shape 6. They can cause them to deform and therefore to operate incorrectly. However, the translation element 70 must remain as vertical as possible to operate correctly.

[0082] One solution, to prevent the occurrence of such constraints, consists of having each translation element 70 provided with one or more articulation means 72 as visible in [Fig.4].

[0083] In a first example visible in [Fig.4], the articulation means 72 are in the form of a ball joint 72' arranged at the end of the translation element 70. This ball joint 72' is composed of a sphere and a complementary female shape having the shape of a hollow sphere. The ball joint 72' is thus arranged between the translation element and the flexible sheet 60.

[0084] In a second example visible in [Fig.4], the articulation means 72 is in the form of a connecting rod 70 equipped with a ball joint 72 at each of its ends. Each ball joint 72 is composed of a sphere and a complementary female shape. having the shape of a hollow sphere. As shown in [Fig.4]', the first ball joint 72' connects the end of the vertical rods of the translation elements 70 to the connecting rod 70' while the other connects the other end of the connecting rod 70' and a base secured to the flexible sheet 60.

[0085] An alternative is to have the ball joint 72' arranged at the interface between the upper form 6 and the translation element 70 which is capable of sliding. It is understood by this that the ball joint 72' is capable of moving slightly at the surface via a compensation means 74 as visible in [Fig.5].

[0086] A first embodiment of the compensation means 74 consists of a cage 740 in which a pad 742 can move freely. The pad 742 is a circular part. The cage 740 comprises a circular base from which an annular wall extends. From the annular wall, a peripheral rim extends towards the axial center of the circular base and defines a housing into which the pad 742 can be inserted. The peripheral rim is such that once the pad 742 is inserted, it cannot come out of the cage. The diameter of the circular base and the height of the annular wall of the cage are dimensioned so that the pad 742 can translate freely inside the cage 740 in 2 directions, parallel to the plane containing the base of the cage 740.

[0087] The cage 740 is fixed to the upper form 6. The fixing of the cage 740 to the membrane can be done by gluing or, in the case of an upper form 6 in the form of a membrane, it can be directly overmolded in the membrane.

[0088] The pad 742 is fixed to the translation element 70 so that when the flexible sheet 60 is shaped, the pad 742 can move in the cage to compensate for the stress that may appear. The pad 742 is designed to allow the fixing of a ball joint 72'. This ball joint 72' is fixed directly to the end of the cylinder.

[0089] In a second embodiment visible in [Fig.5]', the translation elements 70 are fixed to the flexible sheet 60 by means of a compensation means 74 in the form of a magnetic pad 742'. For this, the flexible sheet 60 is itself at least locally magnetic. This magnetism is obtained in several ways.

[0090] A first way consists of having the entire surface of the flexible sheet 60 which is magnetic. For this, the flexible sheet 60 can be made of a magnetic material such as a flexible metal sheet pierced with a pattern giving this sheet a flexible form. The flexible sheet can also be in the form of a sheet of non-magnetic flexible material such as a polymer which is made magnetic via an insert of magnetic material extending over its entire surface.

[0091] A second way consists of locally providing the membrane with magnetic zones, these magnetic zones being placed at the locations where the translation elements must be connected to the membrane. For this, inserts 744 magnetic are fixed to the flexible sheet 60. This fixing can be gluing or screwing, in particular when the flexible sheet 60 is a metal sheet, but it can be overmolding in particular when the flexible sheet is a polymer membrane.

[0092] The pad 742' is designed to allow the attachment of a ball joint. This ball joint is attached directly to the end of the cylinder 71 or to the connecting rod 70'.

[0093] In one configuration, each translation element 70 is fixed to the upper form 6 by articulation means 72 using two ball joints 72' and a connecting rod 70'. Other configurations are however possible.

[0094] Thus, another configuration consists of having the translation elements 70 arranged in the center of the upper shape 6 which do not include a connecting rod 70' associated with two ball joints 72 unlike the translation elements 70 arranged at the periphery, but equipped with a single ball joint 72'. Indeed, with all of the translation elements 70 having two ball joints 72', for certain geometries, too many degrees of freedom would be present. Thus, for surfaces with a small curvature, there is a risk that the system will lack strength. In the configuration with the translation elements 70 arranged in the center equipped with a single ball joint 72', this risk is reduced.

[0095] According to a second embodiment, the pressing frame 5 is adaptable. The pressing frame comprises a pressing ring 50. This pressing ring 50 is continuous and is connected to a lower series of translation elements 70 as visible in Figures 6, 6'. The translation elements 70 are jacks 71 like those previously described. These translation elements 70 are fixed, by a first end, to a base 40 which may be in the form of a plate or a frame. The second end of the translation elements 70 is fixed to the pressing ring 50.

[0096] The pressing ring 50 of this second embodiment is designed to deform and have its curvature change. This allows the pressing ring 50 to have a boom height that varies from 0 to 500mm, preferably from 0 to 300mm and even more preferably from 0 to 200mm.

[0097] For this, the pressing ring 50, visible in [Fig.6], can take different forms.

[0098] In a first form, the pressing ring 50 is in the form of a ring made of a polymer material such as that used for the bending shape 6.

[0099] In a second form, the pressing ring 50 is in the form of an annular metal sheet provided with a plurality of through-cut notches repeated on the surface of the annular metal sheet so that the latter can deform in two different directions.

[0100] In a third form, the pressing ring 50 is in the form of a structure comprising a plurality of segments attached to each other to form a wavy or sinusoidal structure. The segments are arranged to form a ring.

[0101] According to a configuration of this third form, the pressing ring 50 comprises a certain number of “sides” or portions 500, each of which can be linear or curved. In the present case, this ring is composed of four “sides” 500 as visible in [Fig.7].

[0102] Each side 500 comprises a plurality of stretchable segments or sections 501. Each stretchable section 501 is composed of an elastic material cut into an accordion shape, which gives it its properties of significant and reversible elongation. A rectangular bore is made in the accordion material in order to allow a flexible non-stretchable blade 502 to slide in a substantially median plane of the accordion as visible in [Fig. 8]. This blade 502 gives rigidity to each section 501 and makes it possible to obtain a continuous and regular curve along the entire periphery of the pressing ring 50.

[0103] The stretchable sections 501 are separated from each other by rigid sections 503 like plates, these stretchable sections 501 are fixed to the plates 503. Each plate 503 also includes a bore allowing the non-stretchable blade 502 to slide therein.

[0104] The intersection of two adjacent sides 500 is achieved with an intersection plate 505 provided with two superimposed rectangular bores in order to allow the metal blade 502 to slide on each of the two sides 500 as visible in [Fig.9]. These bores have an angle equal to the angle of intersection between the ends of the two adjacent sides that it connects. Each of the two adjacent sides can be inserted therein as visible in [Fig.9],

[0105] The glass therefore comes into contact with the following elements of the pressing ring: the upper surface of each stretchable section 501, the upper surface of each plate 503 and the upper surface of each intersection plate 505.

[0106] The bores of an intersection plate 505 are not at the same level so that there is a bore which is located closer (distance bore - contact surface ep. 1) to the contact surface with the glass sheet (called upper bore) and a lower bore. In this case, the upper accordion-shaped part of the stretchable section 501 in which the blade 502 inserted in the upper bore slides is thinner than the upper accordion-shaped part of the stretchable section 501 in which the blade 502 inserted in the lower bore slides. This makes it possible to ensure continuous and regular pressing of the edge of the glass and which has the effect of standardizing the pressure exerted by the lower pressing ring and the upper form on the edge of the glass. This precaution minimizes the formation of optical defects visible in reflection at the edge of the glass.

[0107] The fixing of the pressing ring 50 to the translation elements is done by means of the plates 503 and intersection plates 505.

[0108] These plates 503 and 505 are equipped with a sphere 506 at their lower surface. Each sphere 506 is in contact with two half-shells 73 installed at the end of each translation element 70 to form a ball joint as visible in [Fig. 10].

[0109] Each translation element 70 can perform movements along a vertical axis but its position on the horizontal plane is fixed.

[0110] Thus, the pair formed by a sphere, a plate and the double shells secured to the end of the mechanical jacks forms a ball joint. A screw-nut type connection 75 makes it possible to lock the ball joint to make it a rigid connection between the jacks 71.

[0111] The contact between the glass sheet and the contact surface of the pressing ring 50 may have an angle called a draft.

[0112] If the draft is zero then the contact between the glass and the pressing ring takes place on a marginal surface of the glass located at the periphery of the latter.

[0113] On the contrary, a non-zero draft makes it possible to have linear contact between the periphery of the glass and the pressing ring 50, which minimizes geometric and optical defects at the edges of the glazing after forming.

[0114] This draft angle is generally limited by the thickness of the glass to be formed as well as the marginal length of the pressing ring which is not covered by the glass sheet. The greater the latter and the lower the thickness of the formed glass, the lower the accessible draft is also.

[0115] For shaping the pressing ring 50, the method consists of loosening the screw-nut connection to allow all of the ball joints that connect the pressing ring 50 to the translation systems 70 to be movable. Then the jacks 71 or translation elements 70 are adjusted in height so that the plates 503 and intersection plates 505 come into contact with the upper form 6. The position of the plates 503, 505 is then locked using the screw-nut torque present at each end of the translation elements 70. In the case where a clearance of a given angle is desired, a suitable surface of the upper form is momentarily generated taking this clearance into account and then the previous adjustments and the locking of the screw-nut torques are carried out as described previously. The upper shape then takes on a geometry adapted to the shape of the glazing that we want to produce and production can be initiated.

[0116] In a variant, the translation elements 70 comprise a connecting rod 70' equipped with a ball joint at each of its ends. Each ball joint may be composed of a sphere and a complementary female shape having the shape of a hollow sphere. The first ball joint connects the end of the vertical rods of the translation elements 70 to the connecting rod 70', while the ball joint which connects the other end of the connecting rod and the pressing frame 50 comprises the sphere and the double shells described previously.

[0117] In a variant, it is possible to have certain translation elements 70 associated with the pressing ring 50 having an articulation with a double ball joint 72' as explained previously and others equipped with a simple ball joint, which makes it possible to eliminate certain degrees of freedom which would make the pressing frame too flexible and unusable. The ends of the translation elements 70 equipped with simple ball joints are preferably located in the middle of the different sides of the pressing ring.

[0118] In a variant of the two embodiments, the articulation means 72 for the pressing frame 5 or the upper form 6 are lockable. For this, the ball joints 72' are provided with a locking mechanism allowing the position of the ball joint 72' to be blocked.

[0119] In a variant of the two embodiments, the pressing ring 50 and / or a flexible sheet 60 forming the bending shape 6 comprise interface means 80 as visible in [Fig. 11]. These interface means 80 are used to improve the contact of said pressing ring 50 and / or said flexible sheet 60 with the glass sheet V.

[0120] The interface means 80 may be in the form of a fabric or a knit 82, for example based on metal fibers and resistant to high temperatures. This metal fabric or knit 82 is a material making it possible to absorb certain defects and improve thermal exchanges.

[0121] With the first embodiment and the second embodiment, it is possible to have several configurations.

[0122] The first configuration consists of having the bending shape 6 which is adaptable and the pressing ring 5 which is fixed. It is then understood that the bending shape 6 has a deflection height which varies by at least 5 mm and a pressing ring 50 whose deflection height varies by less than 5 mm. This configuration is advantageous because it makes it possible to reduce costs by having a bending shape 6 which can be used for several shapes of glass sheet.

[0123] A second configuration consists of having a fixed curving shape 6 whose surface or area defined by the projection of the contour of the upper shape onto a horizontal plane is at least equal to the surface or area defined by the projection of the outer contour of the pressing frame and an adaptable pressing ring 50. It is understood whereas the bending shape has a deflection height that varies by less than 5mm and a pressing ring whose deflection height varies by at least 5mm. This configuration is advantageous because it allows for cost reduction by having one pressing ring that can be used for several glass sheet shapes.

[0124] A third configuration consists of having an adaptable bending shape 60 and an adaptable pressing ring 5. It is then understood that the bending shape has a deflection height which varies by at least 5 mm and a pressing ring whose deflection height varies by at least 5 mm. This third configuration is the most advantageous because it makes it possible to produce a large number of glass sheet shapes without changing the tooling.

[0125] Thus, the method of shaping a glass sheet according to the invention comprises a step consisting of having the glass sheets which are brought one by one through a heating furnace to raise their temperature to a temperature close to the softening temperature, the glass sheets being conveyed on a bed of rollers.

[0126] In a following step, the glass sheets are then taken, as soon as they leave the furnace, to the bending station 4 according to the invention, that is to say in which the flexible form 60 and / or the pressing ring 50 is adaptable.

[0127] In the bending station 4, the glass sheet is lifted from the conveyor by the pressing ring 50. The pressing ring 50 then lifts the glass sheet 2 to press it against the flexible sheet 60, the shape of which is complementary to that of the pressing ring 50 and therefore corresponds to the desired shape for the glass sheet.

[0128] After pressing, the pressing ring 50 descends to a level lower than the bed of rollers and thus redeposits the glass sheet on said bed of rollers or on a transport frame 10 bringing the glass sheet to another station. This other station may be a cooling station 9 or a tempering station 8 as seen in [Fig. 13].

[0129] In the case of a bending shape 6 and / or an adaptable pressing frame 5, an adjustment step is necessary. This adjustment step consists of acting on the upper series of upper translation elements 70 and / or the lower series of translation elements 70 to adjust the bending shape and / or the shape of the pressing frame.

[0130] For this, a first solution consists of acting manually on these translation elements 70 of the upper series and / or the lower series. Each translation element 70 is therefore adjusted manually to obtain the desired curving shape 6 and / or the shape of the pressing frame 5.

[0131] A second solution consists of acting on the translation elements 70 of the upper series and / or the lower series by means of a control unit 76 as visible in figures 12a and 12b. This control unit 76 is connected electrically to each translation element 70 of the upper series and / or the lower series, these translation elements 70 being electromechanical. The control unit 76 is provided with or is connected to an interface (not shown) allowing the operator to enter the settings or to load a file containing said settings. These settings are thus processed so that a control signal is sent to each translation element 70 in order to control its translation.

[0132] In the case of the upper form 6 and the adaptable pressing frame 5, it is also possible to have an interconnection between the translation elements 70 of the upper series and those of the lower series. This interconnection consists of having a calculation unit UC connected to or included in the control unit 76 which is capable, from the settings entered for the upper form 6, of deducing the settings to be made for the pressing frame 5 and vice versa.

[0133] This adjustment step is carried out before forming a series of glass sheets or between each glass sheet.

[0134] The method may further comprise a regulation step. This regulation step consists of having measuring means 90 located at the outlet of the bending station 4. These measuring means 90 comprise different sensors such as an image sensor or a position sensor making it possible to take measurements of the curved sheet and to send the measurements to a calculation unit UC, which may be included in the control unit 76. This calculation unit UC compares the measured curved sheet with a theoretical model in order to determine whether there is a match. In the case of a mismatch, the calculation unit UC communicates with the control unit 76 in order to send a signal to one or more translation elements 70 making it possible to correct the curved shape.Indeed, since the bending shape 6 is a surface whose shape is an approximation of the geometry of the desired surface of the glass sheet after bending, it is possible to make corrections to achieve an adequate geometry as well as an improved optical quality in reflection. With the present invention, it is possible to do this easily. It is also possible to have measuring means 90 in the form of a control template associated with optical or position sensors. The template itself serves as a mechanical reference for the glazing to be measured.

[0135] In an alternative, the measuring means 90 make it possible to measure and control the optical quality in reflection of the glass parts produced can advantageously be introduced into this system for controlling the geometry of the upper shape.

[0136] This measurement of the optical quality can be carried out alone or in addition to a measurement of the geometry by the measuring means 90.

[0137] The method may further comprise an adjustment step. This step is carried out in the case where it is found that the pressing ring 5 and the bending shape 6 do not do not cooperate perfectly. Indeed, it is possible that, along the length of the pressing ring, the distance e between said ring and the curving form is not constant as visible in [Fig. 14].

[0138] For this, sensors 91 are used to measure the distance between the pressing ring 5 and the bending shape 6. One type of sensor that can be used is a video sensor 91a or image sensor for taking an image of the distance between the pressing ring 5 and the bending shape 6. The image is sent to a computing unit UC, which may be the control unit 76. This computing unit UC uses an algorithm to determine the value of the distance e' and compare it to the theoretical distance e. This algorithm can use the distance separating the video sensor from the pressing ring 5 and the bending shape 6, as well as the optical characteristics of the video sensor. The computing unit UC can then communicate with the control unit 76 in order to send a signal to one or more translation elements 70 for correcting the bending shape. Several sensors are used in order to cover the entire pressing ring 5 as seen in [Fig.15].

[0139] It is also possible to carry out a reflection image analysis after forming to identify the areas of over-pressing and under-pressing and therefore to request the correction of the positions. For this, a video sensor and a grid pattern are used.

[0140] Another type of sensor 91a used may be capacitive or inductive or laser based on a modification of the capacitance or on the creation of eddy currents. The sensors 91b, visible in [Fig. 16], are thus arranged at the level of the flexible sheet 60 of the bending form or at the level of the pressing ring 50 and are there to measure the spacing e between the two. These measurements are sent to a calculation unit UC which compares them to a theoretical value to send a control signal to one or more translation elements.

[0141] Alternatively, the computing unit UC can compare the measurements from the sensors. This comparison then makes it possible to act on certain translation elements so that the measurements are all identical.

[0142] These adjustment or tuning steps make it possible to improve the process by limiting the number of curved glasses which do not correspond to the desired criteria, the yield is therefore improved.

[0143] Alternatively, the present invention is particularly suitable for the case where it is desired to produce laminated glazing composed of two sheets of glass perfectly parallel to each other and connected by the introduction of a sheet of elastomer adhering to the glass and of uniform thickness.

[0144] Indeed, the glazing produced can be composed of two sheets of glass having different characteristics such as their thickness or their tint. In this case, when If production is carried out with identical settings for both types of glass sheets, two different geometry families are generally obtained, the first for the outer glass and a second geometry different from the first for the inner glass sheet.

[0145] Indeed, these two types of glass sheets having different characteristics, they do not react in the same way during the forming process. Thus, it is classic that more tinted or thicker glass sheets give rise to more significant bending than their lighter or less thick counterparts. A classic but difficult to implement method consists of producing in two series, a first series for the outer glass sheets for example then sequentially a second series for the inner glass sheets. Such a method is difficult to implement and is risky when the geometries of the two glass sheets need to be very close to each other. It also requires carrying out significant intermediate stocks of the first sheets produced with risks of breakage or generation of significant defects.

[0146] The present invention is clever in that it allows a method for producing a series of laminated glazings making it possible to produce each pair of inner and outer glass sheets consecutively.

[0147] For this, the calculation unit UC acts on the translation elements 70 of the upper series and / or the lower series so that the bending form 6 and / or the pressing frame 5 can alternately form a sheet of glass to make a first sheet then form a sheet of glass to make a second sheet. This method therefore makes it possible to form the first sheet and the second sheet of the same laminated glazing almost simultaneously so that the temperature conditions for these two sheets of glass are identical. This makes it possible to have two sheets of glass which cooperate more easily.

[0148] Thus, the process for producing a series of laminated glazing units therefore comprises the steps:

[0149] - Take the glass sheets,

[0150] - Shape the glass sheets with the bending device according to the invention for obtaining a series of first glass sheets and a series of second glass sheets;

[0151] - Combining the first glass sheets, the second glass sheets and films spacers to form laminated glazing.

[0152] Cleverly, the shaping of the glass sheets is such that it includes the repetition of the following steps:

[0153] - Act on the translation elements 70 of the upper series and / or of the series lower to adjust the bending station to the forming of the first glass sheet or the second glass sheet;

[0154] - Forming at least one first sheet of glass or at least one second sheet of glass ;

[0155] - Act on the translation elements of the upper series and / or the lower series to adjust the bending station to form the second glass sheet or the first glass sheet;

[0156] - Forming at least one second sheet of glass or at least one first sheet of glass

[0157] Nevertheless, if the method for producing a series of laminated glazings according to the invention is capable of alternately producing a first sheet of glass then a second sheet, it is not limited to this. Thus, it is possible to adjust the method so that the bending station can produce several first sheets then several second sheets. The number of first sheets and the number of second sheets may be identical but may be different so that, for example, two sheets of the first sheet type are formed followed by three sheets of the second sheet type or vice versa. The number of first sheets or second sheets formed may vary as long as the advantage of having first sheets and second sheets formed under the same conditions is always present.

[0158] The invention details in particular the manufacture of laminated glazing, however this invention also works for the forming of monolithic glass of the tempered glazing type.

[0159] Of course, the present invention is not limited to the illustrated example but is susceptible to various variants and modifications which will appear to those skilled in the art.

Claims

Claims

1. Bending station (4) for a bending device comprising two bending forms, a pressing frame (5) arranged to fit the glass sheet and press it against an upper form, the upper form (6) comprising a forming face whose area defined by the projection of the contour of the upper form on a horizontal plane is greater than the area defined by the projection of the outer contour of the pressing frame and the glass sheet on the same horizontal plane, the pressing frame (5) comprising a pressing ring (50) having a continuous surface, the upper form comprising a flexible sheet (60) associated with an upper series of translation elements (70), characterized in that the upper form is capable of deforming under the effect of the translation elements of the upper series to obtain a deflection value varying by at least 5 mm.

2. Bending station (4) for a bending device comprising two bending forms, a pressing frame (5) arranged to fit the glass sheet and press it against an upper form (6), the upper form comprising a forming face whose area defined by the projection of the contour of the upper form onto a horizontal plane is greater than the area defined by the projection of the outer contour of the pressing frame and the glass sheet onto the same horizontal plane, the pressing frame comprising a pressing ring (50) having a continuous surface associated with a lower series of translation elements (70), the upper form comprising a flexible sheet (60) associated with an upper series of translation elements (70), characterized in that the upper form and the pressing frame are capable of deforming under the effect of the translation elements to obtain a deflection value varying by at least 5 mm.

3. Bending station (4) for a bending device comprising two bending forms, a pressing frame (5) arranged to fit the glass sheet and press it against an upper form (6) whose surface or area defined by the projection of the contour of the upper form on a horizontal plane is at least equal to the surface or area defined by the projection of the outer contour of the pressing frame, the pressing frame comprising a ring pressing frame (50) having a continuous surface associated with a lower series of translation elements (70), characterized in that the pressing frame is capable of deforming under the effect of the translation elements of the lower series to obtain a deflection value varying by at least 5 mm.

4. Bending station according to one of the preceding claims, in which the area of ​​the forming face of the upper form (6) is equal to at least 101% of the surface area of ​​the glass sheet to be formed, preferably at least 105%, and even more preferably at least 110%.

5. Bending station according to one of the preceding claims, in which the area of ​​the forming face of the upper form (6) is such that it has a distance of at least 1 cm, preferably at least 5 cm between a portion of an edge of the upper form and a portion of the edge of the glass sheet.

6. Bending station according to one of the preceding claims, in which the translation elements (70) of the upper series of translation elements and / or of the lower series of translation elements are jacks (71).

7. Bending station according to claim 6, wherein the translation elements (70) of the upper series of translation elements and / or of the lower series of translation elements comprise an articulation means (72). 8 Bending station according to the preceding claim, wherein the articulation means (72) is a ball joint (72') arranged between the end of a translation element (70) and the upper form (6) or the pressing frame (5).

9. Bending station according to claims 7 or 8, in which the articulation means (72) comprises a connecting rod (70') equipped with a ball joint (72') at each of its ends, a first ball joint connects the end of the translation elements (70) to the connecting rod (70') while a second ball joint connects the other end of the connecting rod to the upper form or to the pressing frame.

10. Bending station according to claims 8 or 9, in which the ball joint fixed to the upper form (6) is fixed by means of a compensation means (74) capable of moving in translation, said compensation means comprising a pad (740) mounted movably in a cage (742), said cage being fixed to the upper form and said pad being fixed to a translation element (70), or comprising a magnetic pad in contact with the upper form made at least locally magnetic.

11. Bending station according to the preceding claim, in which the upper form (6) is made at least locally magnetic by magnetic inserts.

12. A bending station according to claims 1 or 2, wherein the flexible sheet (60) of the upper form (6) is a polymer membrane or a metal sheet provided with a plurality of through-cuts.

13. Bending station according to the preceding claim, in which the polymer membrane is reinforced by stiffening means.

14. A bending station according to the preceding claim, in which the stiffening means comprise overmolded rods or a sheet made of a more rigid material overmolded or glued to the polymer membrane or rods inserted into sheaths overmolded in the polymer membrane, the rods being able to slide in the sheaths.

15. A bending station according to one of claims 2 to 11, wherein the pressing ring (50) is made of a polymer material or comprises a metal sheet provided with a plurality of through-notch openings

16. Bending station according to one of claims 2 to 11, in which the pressing ring (50) comprises portions (500) each comprising a plurality of stretchable segments (501) separated from each other by plates (503), each portion further comprising a blade (502) inserted into a suitable bore formed in each plate and stretchable segments of the portion, said pressing ring further comprising intersection plates (505) comprising two bores allowing the insertion of the blades of two portions.

17. Bending station according to one of the preceding claims, in which the upper form and / or the pressing frame is covered with a fabric or a metallic knit (82).

18. Bending station according to one of claims 6 to 17, in which the translation elements (70) of the upper series and / or of the lower series are adjusted in translation manually.

19. Bending station according to one of claims 6 to 17, in which the translation elements of the upper series and / or of the lower series are connected to a control unit (76) allowing their adjustment in vertical translation.

20. Bending station according to the preceding claim, in which the translation elements (70) of the upper series and of the lower series are further connected to a computing unit (UC) allowing their adjustment in vertical translation in an interconnected manner.

21. A bending station according to one of the preceding claims, wherein a suction device (100) is arranged, this suction device comprising a vacuum box (102) comprising an outlet connected to a pump and a plurality of inlets, said suction device further comprising a plurality of pipes (103) each connected to an inlet of the vacuum box and to a through hole (101) arranged in the upper form.

22. A bending station according to the preceding claim, wherein each pipe is connected to a through hole of the upper form via a manual tap or a controllable valve module.

23. Bending device comprising a furnace for heating a glass sheet, a device for supporting and transporting the glass sheet in a substantially horizontal plane passing through the furnace to a bending station according to one of the preceding claims.

24. A method of bending a glass sheet comprising heating the glass sheet to a softening temperature, transporting the glass sheet along a substantially horizontal path to a bending station according to one of claims 1 to 22, and shaping the glass sheet by pressing between the two shapes.

25. A bending method according to the preceding claim further comprising, before shaping, a step of acting on the translation elements (70) of the upper series of translation elements and / or the lower series of translation elements to adjust the upper shape and / or the pressing frame.

26. A bending method according to the preceding claim, wherein said device further comprises measuring means (90) for measuring the spacing between the surface of the shape upper and the surface of the pressing frame, said measuring means being connected to a computing unit (UC) in order to send a signal to the first series of translation elements and / or the second series of translation elements to compensate for a possible drift.

27. ​​A bending method according to one of claims 24 to 26, wherein said device further comprises measuring means for comparing the shape of the curved sheet with a reference, said measuring means being connected with a control unit in order to send a signal during production to the first series of translation elements and / or the second series of translation elements to compensate for a possible drift of the curved shape or of the optical quality in reflection of the curved shape.

28. Method for producing a series of laminated glazing units, each laminated glazing unit comprising a first sheet and a second sheet associated with an interlayer film, said method comprising the steps: - Providing glass sheets, - Shaping the glass sheets with the bending device according to claim 23 to obtain a series of first glass sheets and a series of second glass sheets; - Combining the first glass sheets, the second glass sheets and interlayer films to form the laminated glazing units, Characterized in that the step of shaping the glass sheets is carried out so that at least one first glass sheet and at least one second glass sheet are formed alternately.

29. Production method according to the preceding claim, in which the step of shaping the glass sheets comprises the repetition of the following steps: - Acting on the translation elements of the upper series and / or the lower series to adjust the bending station to the forming of the first glass sheet or the second glass sheet; Forming at least one first glass sheet or at least one second glass sheet; Act on the translation elements of the upper series and / or the lower series to adjust the bending station to the forming of the second glass sheet or the first glass sheet; Form at least one second sheet of glass or at least one first sheet of glass.

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