Abstract
A device and a method for bending, by gravity, a sheet of glass or a stack of sheets of glass including a plurality of sides, called the glass, including a skeleton for supporting the glass in its peripheral zone by a contact track, the contact track including concave curvatures on each of the sides of the skeleton, and a counter-skeleton capable of entering into contact with the glass in the zone of the middle of at least one side of the peripheral zone of the top main face of the glass.
Claims
1. A device for bending by gravity a sheet of glass or a stack of sheets of glass comprising a plurality of sides, comprising a skeleton for supporting the glass in its peripheral zone by a contact track, said contact track comprising concave curvatures on each of the sides of said skeleton, and a counter-skeleton capable of entering into contact with the glass in a zone of the middle of at least one side of the peripheral zone of a top main face of the glass.
2. The device as claimed in claim 1, wherein the device is configured to give the glass forms that are concave when seen from above in its central zone and on each of its sides.
3. The device as claimed in claim 1, wherein the counter-skeleton enters into contact in the zone of the middle of all of the sides of the peripheral zone of the top main face of the glass.
4. The device as claimed in claim 1, wherein the zone of the middle of at least one side comprises 5 cm on either side of the middle parallel to the edge of the glass and in the peripheral zone.
5. The device as claimed in claim 1, wherein the counter-skeleton enters into contact with the glass by a refractory fibrous material.
6. The device as claimed in claim 5, wherein the fibrous material is capable of being compressed under the effect of the force of gravity acting on the counter-skeleton.
7. The device as claimed in claim 6, wherein a counterweight system linked to the counter-skeleton reduces the pressure force of the counter-skeleton on the glass.
8. The device as claimed in claim 1, wherein the skeleton comprises a metal band an edge of which is directed upward, said edge being covered by a refractory fibrous material forming the contact track for the glass, the counter-skeleton comprises a metal bar, the device comprising a means for imposing a given minimum distance Dm between the metal band of the skeleton and the metal bar of the counter-skeleton.
9. The device as claimed in claim 8, wherein the means for imposing Dm comprises a limit stop-forming element secured to the metal band of the skeleton and on which a prop secured to the metal bar of the counter-skeleton can rest.
10. The device as claimed in claim 1, wherein the means for imposing Dm is adjustable.
11. The device as claimed in claim 1, wherein the counter-skeleton comprises a metal bar of metal band type whose edge is turned downward, comprising a plurality of sectors linked to one another by articulations, each articulation comprising a pivot link with substantially horizontal axis linking two sectors to one another.
12. The device as claimed in claim 11, wherein the ends of two sectors are linked to one another by an articulation, these ends each comprising an adjoining zone, these adjoining zones being adjoined in a direction at right angles to the axis of the articulation, said axis passing through the joining zones of the two sectors.
13. The device as claimed in claim 12, wherein the downward-turned edges of two sectors linked to one another by an articulation are aligned when seen from above, the adjoining zone of at least one of the two sectors being, when seen from above, offset relative to its downward-turned edge, so as to form a space occupied by the adjoining zone of the other sector.
14. The device as claimed in claim 11, wherein the sectors are grouped in as many bands as the glass has sides, each band corresponding to a side of the glass, the ends of the bands not being linked to their neighboring bands.
15. The device as claimed in claim 11, wherein the skeleton comprises a metal band an edge of which is directed upward and a plurality of limit stops linked to the metal band and placed facing articulations of the counter-skeleton, props being linked to the counter-skeleton facing the limit stops to come to bear on the limit stops, such that a minimum distance Dm between the metal band of the skeleton and the metal bar of the counter-skeleton can be imposed on each sector when the props rest on the limit stops.
16. The device as claimed in claim 1, further comprising a progressive system capable of progressively modifying, during the bending, the distance between the skeleton and the counter-skeleton.
17. The device as claimed in claim 1, wherein the counter-skeleton comprises a metal bar and a structural element arranged above the metal bar, the structural element and the metal bar being linked to one another by a plurality of adjustable spacers making it possible to locally adjust the distance between the structural element and the metal bar.
18. The device as claimed in claim 1, wherein the counter-skeleton is removable.
19. The device as claimed in claim 1, wherein the counter-skeleton comprises laterally retractable bands.
20. The device as claimed in claim 1, further comprising means allowing the skeleton and the counter-skeleton to approach or move away from one another by a relative vertical movement without relative horizontal displacement relative to one another.
21. The device as claimed in claim 1, further comprising a kiln and a conveyor capable of horizontally displacing together the skeleton and the counter-skeleton in the kiln while they are facing one another, and vertical translation system allowing the skeleton and the counter-skeleton to approach or move away from one another by a relative vertical movement during their horizontal displacement and without relative horizontal displacement of one relative to the other.
22. The device as claimed in claim 1, wherein the counter-skeleton is capable of exerting a weight on the glass per linear meter of counter-skeleton less than 2 kg/m and greater than 0.1 kg/m.
23. A method for bending a sheet of glass or a stack of sheets of glass comprising a plurality of sides, by the device of claim 1, the method comprising the bending of the glass by gravity on a skeleton supporting the glass in its peripheral zone by a contact track, said contact track comprising concave curvatures on each of the sides of said skeleton, a counter-skeleton coming into contact with the glass in a zone of the middle of at least one of the sides of the glass in the peripheral zone of its top main face.
24. The method as claimed in claim 23, wherein the glass takes a concave form when seen from above in its central zone and on each of its sides.
25. The method as claimed in claim 23, wherein the counter-skeleton comes into contact with the zone of the middle of all of the sides of the glass of the peripheral zone of the top main face of the glass.
26. The method as claimed in claim 23, wherein the counter-skeleton comes into contact with the glass by a refractory fibrous material.
27. The method as claimed in claim 26, wherein the refractory fibrous material is compressed during the bending under the effect of the force of gravity acting on the counter-skeleton.
28. The method as claimed in claim 23, wherein the skeleton comprises a metal band an edge of which is directed upward, said edge being covered with a refractory fibrous material forming the contact track for the glass, said refractory fibrous material being compressed during the bending under the effect of the pressure exerted by the bottom face of the glass.
29. The method as claimed in claim 28, the counter-skeleton comprising a metal bar whose bottom face is covered with refractory fibrous material, the compression of the refractory fibrous material with which the skeleton and the counter-skeleton are equipped being limited by a means capable of imposing a minimum distance Dm between the metal band of the skeleton and the metal bar of the counter-skeleton.
30. The method as claimed in claim 23, wherein the skeleton and the counter-skeleton approach one another progressively during the bending.
31. The method as claimed in claim 23, wherein the peripheral zone is the zone between the edge of the glass and a distance from the edge of the glass of 50 mm.
32. The method as claimed in claim 23, wherein the glass is a stack of sheets of glass.
33. The method as claimed in claim 23, wherein the glass is bent at a temperature lying within the 570 to 650 C. range.
34. The method as claimed in claim 23, wherein, during the bending, the counter-skeleton exerts a weight on the glass per linear meter of counter-skeleton less than 2 kg/m and greater than 0.1 kg/m.
35. The method as claimed in claim 23, wherein the skeleton and the counter-skeleton are conveyed together into a kiln while the skeleton and the counter-skeleton are facing one another on either side of the glass, the glass being in contact with the skeleton for more than 10 minutes in the kiln and the counter-skeleton touching the glass for more than 10 minutes in the kiln.
Description
[0046] FIG. 1 represents in cross section a device according to the invention comprising a skeleton 320 and a counter-skeleton 321. A limit stop 327 is fixed to the metal band 322 of the skeleton. The upward-turned edge of this metal band is covered with a refractory fibrous material 323. The counter-skeleton comprises, as metal bar, a metal band 324 whose downward-turned edge is covered with a refractory fabric 325 to enter into contact with the glass 328. A prop 326 is linked to the metal bar 324 and can rest on the limit stop 327, blocking the descent of the counter-skeleton toward the skeleton. Off load (in a)), the gap E between skeleton and counter-skeleton is less than the thickness e of the glass 328. When the glass 328 is placed between these two tools (in b)), the refractory fibrous materials 325 and 323 are compressed under the weight of the counter-skeleton until the prop 326 rests on the limit stop 327. The gap between the bar 324 of the counter-skeleton and the metal band 322 of the skeleton is the minimum distance Dm. Limit stop 327 and prop 326 are a means of imposing a minimum distance between 324 and 322. In this way, the force of pressure on the glass exerted by the skeleton and the counter-skeleton is limited.
[0047] FIG. 2 represents a motor vehicle glazing of windshield type seen from above, and placed on a horizontal plane, concave face turned downward. It comprises four sides, two transverse sides 350 and 351 and two longitudinal sides 352 and 353. One side meets another side by a corner having small surface radii of curvature R (seen at right angles to the surface of the glass and in each corner) compared to the surface radii of curvature toward the middles of the sides. This glazing is symmetrical relative to the vertical plane of symmetry PS. This plane PS passes through the middles 354 and 355 of the transverse sides. This glazing rests on four points 356, 357, 358, 359 located in the corners. The segments 360, 361, 362 and 363 linking these four points have been plotted by dotted lines. These are the segments closest to the edges. An edge has an associated segment. Each of these segments has a middle 364, 365, 366, 367. For each segment, there is a plane (368, 369, 370, 371) at right angles to the segment and passing through its middle. Each of these planes intersects with the closest edge of the glass at a point 372, 355, 373, 354 which is the middle thereof. The glazing is concave (in this figure, the concave face is turned downward) at least at the middle points 372, 355, 373, 354 and in all the shaded zones on either side of these middle points, said concavity being considered parallel to the outer edge of the glazing. The same applies for the skeleton having supported this glass and for the zones of the skeleton corresponding to the zones of the middles of the sides of the glass, said concavity being considered parallel to the outlines (inner or outer) of the skeleton and seen from above in bending situation. The dotted line 376 is at 50 mm from the edge of the glass and forms the limit of the peripheral zone which is contained between the edge of the glass and this line. The zone of the middle of the side 353 of the peripheral zone of the top main face of the glass is the shaded zone on the left. This zone surrounds the middle point 373. The shaded zone is contained in the peripheral zone between the points 374 and 375 on the edge. These points 374 and 375 are each at a distance from the point 373 of at least 5 cm, even at least 10 cm, even at least 20 cm. The counter-skeleton presses on the glass at least in this zone and, if necessary, continuously throughout the length of this zone parallel to the edge of the glass, that is to say without discontinuity between the points 374 and 375, but not necessarily throughout the width of this zone.
[0048] FIG. 3 represents a device according to the invention at the moment when a counter-skeleton 8 (greyed in the figure) is in the process of being placed in position on top of the glass, the latter not being represented in the figure in the interests of clarity. A frame 1 is distinguished on which is fixed the skeleton 2 via tabs 3 and 4. The glass (not represented) is placed on the skeleton 2. Operators hold the counter-skeleton 8 by handles 6. These handles are fixed onto a frame 7 to which the counter-skeleton 8 is also fixed via tabs 9 and 10. The exact positioning of the counter-skeleton is ensured by guidance by virtue of four positioning columns (11 and 12 in the foreground), one at each corner. These columns are secured to the frame 1. Tabs 13 and 14 fixed to the frame 7 of the counter-skeleton each comprising an orifice are threaded onto the columns 11 and 12 by their orifices. The pillars 15 and 16 form part of the means of imposing a given minimum distance Dm between the skeleton and the counter-skeleton. They are each provided with bearing surfaces 17 and 18 that are adjustable heightwise via screws 19 and 20. The frame 7 of the counter-skeleton comprises tabs 21 and 22 which will rest on the bearing surfaces 17 and 18 when the operators have finished placing the counter-skeleton. The weight of the counter-skeleton therefore rests on the bearing surfaces 17 and 18, the height thereof being so that the separation between the counter-skeleton and the skeleton is the chosen height. The bearing surfaces 17 and 18 form limit stops secured to the skeleton and the tabs 21 and 22 are props secured to the counter-skeleton. The skeleton and the counter-skeleton here form a carted assembly capable of being displaced horizontally in a kiln. The four positioning columns (11 and 12 in the foreground) form part of vertical translation means allowing the skeleton and the counter-skeleton to move closer to or away from one another by a relative vertical movement without horizontal displacement relative to one another. In this way, the skeleton and the counter-skeleton remain facing one another (on either side of the glass) during the horizontal displacement of the skeleton/counter-skeleton assembly in the kiln.
[0049] FIG. 4 represents a part in cross section of the device according to the invention in which there is a stack 30 of two sheets of glass comprising a thin sheet (for example 1.1 mm thick) in the top position and a thicker sheet (for example 2.1 mm thick) in the bottom position. The gap between the glass and the counter-skeleton (and also therefore between the skeleton and the counter-skeleton) is being adjusted using the shim 40. This operation is done on a glass previously already bent. The glass rests on its bottom main face 31 on the skeleton 32, which is composed of a metal band 33 and of a fibrous refractory material 34 covering the contact surface for the glass. The counter-skeleton 35 has the same structure. Skeleton and counter-skeleton are exactly facing one another on either side of the glass. There is a separation 36 between the counter-skeleton 33 and the top face of the glass 37, filled by the adjustment shim 40. Skeleton and counter-skeleton act entirely within the peripheral zone 38 of the glass contained between the edge of the glass and 50 mm from the edge of the glass.
[0050] FIG. 5 represents, in plan view, a counter-skeleton comprising a rigid structural element 50 above a part 51 of the counter-skeleton comprising a vertical flat (not visible) coming onto the glass. The visible part 51 is a horizontal flat 57 coming above the vertical flat and to which it is linked. This structural element is a metal tube of square section and has the form of a rectangular frame in plan view. It comprises a plurality of extensions 52 linked to its inner or outer vertical faces, said extensions coming, in plan view, above zones 53 of local adjustment of the position of the bottom edge of the counter-skeleton. These adjustments are made by jack screws 54 here passing through the rigid structural element 50.
[0051] FIG. 6 shows the counter-skeleton of FIG. 5 according to the section AA in a) and the side view according to the direction B in b). There is the metal square of the rigid structural element 50, an extension 52 being welded to an outer vertical face of said square. This extension is also in the form of a metal square. The vertical flat 55 is linked indirectly to the rigid structural element 50 such that it is secured thereto. The bottom rim 56 of this vertical flat 55 comes onto the glass and its distance to the skeleton can be finely adjusted by the screw jack 54 by screwing or unscrewing the nuts 58 and 59. The vertical flat 55 is welded by its top rim to a horizontal flat 57, in order to stabilize the position of the flat 55. The horizontal flat 57 is linked to the bottom end of the jack screw 54 via a pivot link 60, the pivoting of which can be adjusted and blocked in a given position by virtue of the nuts 61 and 62. The adjustment of this pivoting makes it possible to adjust the inclination of the rim 56 in order for the latter to be correctly parallel to the skeleton and for the distance between the skeleton and the counter-skeleton to be correctly constant over all the periphery of the glass.
[0052] FIG. 7 represents a counter-skeleton according to the invention seen entirely in a), a part thereof being enlarged in b). This counter-skeleton comprises a structural element 75 produced from pieces of metal squares welded together. Seen from above, this structural element has a form similar to that of the skeleton and therefore of the glass to be bent. Lateral extensions 76 have been welded onto inner vertical faces of the structural element. Adjusting jack screws pass vertically through these extensions. The adjustment of a jack screw makes it possible to locally adjust the dimension of the bottom rim 77 of a vertical flat 78. This vertical flat is secured to a horizontal flat 79 by a system of brackets 80 and of screws and nuts. A pivot link 81 on top of the horizontal flat 79 makes it possible to adjust the local inclination of the horizontal flat 79 as part of the adjustment of the heightwise dimension of the rim 77. Also distinguished are handles 82 allowing operators to manipulate this counter-skeleton and to place it on top of the glass. The correct lateral positioning of the counter-skeleton is ensured by virtue of a centering means of the type of that already described for FIG. 3 and not represented here in the interests of simplification.
[0053] FIG. 8 shows, in side view and schematically, the assembly of a skeleton 90 and of its counter-skeleton 91. It can be seen that the contact track of the skeleton is concave over all the length of the visible side in the figure, parallel to its inner and outer contours, this concavity being in the plane of the figure. The counter-skeleton 91 is composed of a plurality of sectors (S1, S2, S3, S4, S5, S6) linked to one another by articulations. A sector has an elongate dimension parallel to the edge of the glass that is called length L (substantially horizontal in FIG. 8a), and a height (substantially vertical in FIG. 8a). Two sectors linked by an articulation exhibit a juxtaposition locally in the zone of the articulation. FIG. 8b) represents, in side view, a zoom of the pivot articulation 92 between the sectors S2 and S3 (of FIG. 8a) and of the associated limit stop and prop system. FIG. 8c) represents the same as FIG. 8b) but seen in the lengthwise direction of the sectors, the eye being on the side of the sector S2 and looking in the direction of the sector S3. In order to simplify the figures, the edges hidden in FIGS. 8a) to 8d) have not been represented and the fibrous material covering the tools has likewise not been represented. The counter-skeleton comprises a rigid structural element 92 whose heightwise dimension relative to the skeleton 90 is adjusted beforehand and approximately by jack screws 97 situated at the four corners of the counter-skeleton. The plurality of sectors S1 to S6 linked to one another by articulations (92, 93) in the manner of a chain form an articulated vertical flat. A sector S3 is linked by each of its ends to two neighboring sectors S2 and S4 by pivot links 92 and 93 with substantially horizontal axes. These articulations allow the possibility of the sectors to move relative to one another simply under the effect of their own weight. Each sector is provided with a rod 94 serving as prop and coming to bear on a limit stop 95 secured to the skeleton 90. When the heightwise-adjustable prop 94 bears on the limit stop 95, the desired skeleton/counter-skeleton gap is obtained. The lock nut 99 makes it possible to block the screw 94 and thus fix the skeleton/counter-skeleton gap. The pivot link 92 represented in FIG. 8c is composed of a horizontal axis 102 linking two sectors S2 and S3 which is linked to a bridge 103 which straddles the two sectors S2 and S3. The sectors S2 and S3 can therefore be moved freely in rotation relative to the bridge 103 and about the axis 102. A rod 98 is linked to each articulation axis via a bridge identical to the bridge 103 and can have a free vertical movement relative to the rigid structural element 96. As shown in detail in FIG. 8d), a runner 104 is inserted between the rigid structure 96 and the vertical rod 98. A mechanical play of between 0.3 and 0.5 mm between the inner bore of the runner 104 and the vertical rod 98 makes it possible to obtain a good mechanical compromise between the possible vertical translation of the rod 98 and the accuracy of its vertical guidance. This rod 98 is topped by a head 100 in order for the rod not to be able to pass through the rigid structural element 96. When the counter-skeleton is removed, each head comes to rest on the rigid structural element 96, which makes it possible simply to keep a cohesion of all of the sectors. Likewise, a limit stop 101 is also arranged on the rod 98 but this time under the rigid structure 96 in order to limit the upward movements of the sectors, in case of manipulation of the counter-skeleton in particular. A counterweight 105 (shown in FIG. 8c) has been arranged at each articulation but on the side opposite the adjustable prop 94. Such a counterweight makes it possible to counterbalance the weight exerted by the prop 94 and thus to favor the slip of each rod 98 in its runner 104. When the counter-skeleton is in position as in FIG. 8a), then the heads 100 do not rest on the rigid structural element 96, such that it is the position of the limit stops and props which determine the position of the sectors. The rigid structural element 96 then serves no reference role. During a thermal cycle, the sectors can move relative to one another by the play of the articulations such that the props always rest on the limit stops, which guarantees the retention of the desired skeleton/counter-skeleton gap during the thermal cycle.
[0054] FIG. 9 shows, in side view and schematically, the assembly of a skeleton 110 and of its counter-skeleton 111 composed of a plurality of sectors (S1, S2, S3, S4, S5, S6) linked to one another by pivot articulations with substantially horizontal axes. Contrary to the case of FIG. 8 (where the minimum skeleton/counter-skeleton gap is set using a combination of limit stops and props arranged at each articulation), the tool is used here with direct pressure, without any system of limit stops and props. FIG. 9 schematically represents a counterweight system which can be installed at the ends of the rods 118 in order to lighten the effective weight of each sector, and therefore the contact pressure that the counter-skeleton exerts on the glass 114 during bending. The counter-skeleton comprises a rigid structural element 116 whose heightwise dimension relative to the skeleton 110 is adjusted beforehand and approximately by jack screws 117 situated at the four corners of the counter-skeleton. The plurality of sectors S1 to S6 linked to one another by articulations (112, 113) in the manner of a chain, form an articulated vertical flat. A sector S3 is linked by each of its ends to two neighboring sectors S2 and S4 by pivot links 112 and 113 with substantially horizontal axes. These articulations allow the possibility for the sectors to move relative to one another under the sole effect of their own weight. The articulation 112 is linked by a bridge 119 which straddles the ends of the two sectors S2 and S3.
[0055] The sectors S2 and S3 can therefore be moved freely in rotation relative to the bridge 119 and according to the articulation 112. A rod 118 is linked to the articulation 112 via a bridge 119 and can have a free vertical movement relative to the rigid structural element 116. This rod 118 is topped by an articulation 120. The counterweight system is composed of a vertical bar 121 provided with an articulation 124 at its top end, of a rod 122 revolving, at a point situated between its ends, freely about the articulation 124 and of a weight 123 attached to the end of the rod 122. The bar 121 is secured to the rigid structure 116 and situated in proximity to the rod 118. The second end of the rod 122 is linked to the articulation 120 linked to the rod 118.
[0056] FIG. 10 shows schematically, in plan view, all of the sectors which make up the counter-skeleton according to the invention and described in FIG. 8. The sectors are grouped in as many bands as the glass has sides (four bands B1, B2, B3 and B4), each band corresponding to a side of the glass, the ends of the bands not being linked to their neighboring bands. For simplification reasons, only the different sectors (S1, S2, S3, S4, S5, etc.), their rotation axes (A1, A2, A3, A4, etc.) and the outer perimeter of the glass 130 have been represented. The sectors positioned at the ends of each band (such as, for example, the sectors S1, S4 and S5) are not linked to the neighboring sector belonging to an immediately adjacent band. They are slightly shorter in order to allow a free movement about their horizontal axis without interference with the neighboring sectors belonging to an adjacent band. A means described in FIGS. 11 to 13, but not represented here, makes it possible to limit the downward displacement of the sectors situated at the ends of the bands. Thus, the sectors situated at the ends do not come to interfere with the glass in the loading and the unloading of the counter-skeleton.
[0057] FIG. 11 shows different representations of the ends of two adjacent sectors of a counter-skeleton with sectors such as the sectors S3 and S4 of FIG. 8 intended to be linked by an articulation. FIG. 11a) represents the end of a sector, such as the sector S3 of FIG. 8a), in front, plan and side views. FIG. 11b) is similar to FIG. 11a) but represents the adjacent sector, such as the sector S4 of FIG. 8a). FIG. 11c) represents the assembly of the two ends of sectors arranged as articulated, such as the sectors S3 and S4 of FIGS. 8a) and 8b) in front view, plan view as well as three vertical cross-sectional views, two of which are situated in the vertical plane passing through the articulation axis between the sectors S3 and S4. To form the articulation, a rod (not represented) is passed into the hole 140, the axis of said rod corresponding to the axis 141. FIG. 11 shows that an appropriate cutout combined with a local embossing of the sectors in the zone of their articulation makes it possible to obtain a downward-turned face of constant width all along the band, without doubling the thickness at the articulations, which would be the case if the sectors, kept entirely flat, were simply juxtaposed. In fact, the contact tracks with the glass of the two sectors are well aligned in plan view. Each sector S3 and S4 is composed of a steel plate. Their cutout is symmetrical and is shown in front view in FIGS. 11a) and 11b). A hole 140 of axis 141 is provided at their end to allow the passage of the articulation axis. The end 142 of the sector S3 is cut out in half-ring form around the hole 140. Moreover, an embossing in the form of a disk of diameter greater than the half-ring 142 and of axis 141 makes it form a boss of half the thickness of the component steel plate S3 or S4. The deformations 143 by embossing of the steel plates are visible in the plan and side views and are schematically represented by fine lines 144 on the front views. Through this bossing, the zone of juxtaposition of a sector is, in plan view, offset relative to its downward-turned edge. This bossing forms a space 150 in which the zone of the articulation of a neighboring sector can be placed in order to form the articulation. Thus, the bosses of two sectors intended to be linked together by an articulation are complementary and allow the local juxtaposition of the two sectors of the articulation without thickening the downward-turned edge of the assembly of the two sectors. The assembly of the two assembled sectors is only thicker locally in the zones of juxtaposition of the sectors to form the articulation. These juxtaposition zones are juxtaposed in a direction at right angles to the axis of the articulation, which passes through the zones of juxtaposition of the two sectors. The downward-turned edges of the two sectors linked to one another by an articulation are aligned in plan view. Two notches 145 and 146 are cut out in the steel plate in order not to provoke any edge effect which could disrupt the rotational movement of the two sectors S3 and S4 relative to one another. Finally, a notch 147 is formed in the bottom part of each sector in order to form a recess that makes it possible to hold a fibrous material covering the bottom edge of the sectors. Two protruding parts 148 and 149, one (148) in the top part of each sector and the other (149) in the bottom part of each sector, are cut out along a line which passes through the axis of rotation 141 and which forms an angle with the vertical. This angle is present both to allow and limit the rotation of the two sectors relative to one another. In particular, the protruding parts 149 facing the two adjacent sectors can form limit stops by meeting one another, which makes it possible to limit the downward displacement of the sectors situated at the ends of the bands, particularly when the counter-skeleton is removed from the device.
[0058] FIG. 12 presents, in front view, two adjacent sectors of a counter-skeleton with sectors of a form identical to the sectors S3 and S4 of FIG. 11. These two sectors are centered along a common axis 181. FIG. 12a represents the two sectors S3 and S4, each being displaced upward while the axis of their common articulation remained in a lower position. On the contrary, FIG. 12b represents the two sectors S3 and S4, each being displaced downward while the axis of their common articulation remained in a higher position. The objective of FIG. 12 is to show that the appropriate cutout of the ends of the sectors S3 and S4 makes it possible to limit the relative angular travel of S3 and S4. The maximum angle that the sectors can form between them is limited by the parts 188 and 189 which act as limit stops. This angle is two times the angle of FIG. 11. The notches 187 make it possible to fix a fibrous material covering the bottom edge of the sectors. In fact, FIG. 12b shows the two sectors in closed position at the bottom and it can be seen that the space 190 between the notches 187 remains sufficient to allow the fibrous material to pass. The protruding parts 189 facing the sectors S3 and S4 can form limit stops by meeting one another (FIG. 12b), which makes it possible to limit the downward displacement of the sectors situated at the ends of the bands, particularly when the counter-skeleton is removed from the device.
[0059] FIG. 13 presents an alternative that is simple to fabricate of ends of sectors of counter-skeleton with sectors. FIG. 12a represents the end of a sector, such as the sector S3 of FIG. 8a, in front, plan and side views. FIG. 12b represents the adjacent sector, such as the sector S4 of FIG. 8a, that has to be linked by an articulation with the sector of FIG. 13a. There is a half-ring 162 surrounding a hole 160 of axis 161, for these two sectors, the axis 161 being that of the articulation. The end of the sectors is roughly composed of three tongues 171, 172 and 173. The top tongue 171 is composed of a protruding part 168 which makes it possible to limit the closure of the two sectors S3 and S4 as already explained for the sectors of FIG. 12. This protruding part 168 forms an angle with the vertical. The tongues 171 and 172 on the one hand and 172 and 173 on the other hand are respectively separated by two re-entrant cutouts 175 and 176 which make it possible essentially to perform a simple folding of the central tongue 172 rather than a circular embossing such as that presented in FIG. 11. Such a folding is easier to produce than an embossing. The deformations of the central tongue 172 are visible in the plan views and are schematically represented in fine lines 164 in the front views. The tongue 172 comprises the zone of juxtaposition of the articulation. The offset of the tongue 172 induced by the deformations 164 forms a space 180 that is useful to the placement of the zone of juxtaposition of the neighboring sector to form the articulation of axis 161. The bottom tongue 173 is composed of a protruding part 169 which makes it possible to limit the closure of the two sectors S3 and S4 by forming a limit stop. This protruding part 169 forms an angle with the vertical. Finally, a notch 167 in the bottom part of each sector forms a space necessary to the passage of the fibrous material covering the bottom edge of the sectors.
[0060] FIG. 14 represents, in cross section, a schematic view of a counter-skeleton 205 comprising laterally retractable bands. For simplification, just one side 205 of the counter-skeleton has been represented, and this is seen in its lengthwise direction. The glass rests by its bottom main face 201 on the skeleton 202, which comprises a metal band 203 of which one edge is directed upward. The counter-skeleton comprises, as metal bar, a vertical flat 214 and a horizontal flat 215. Skeleton and counter-skeleton are both provided with a refractory fibrous material (not represented) to come into contact with the glass. The counter-skeleton 205 is secured to an inverted U-shaped structure 208. The latter is linked to a foot 206 which is itself secured to the structure 207 of the skeleton 202 via a pivot link of substantially horizontal axis 209. During the bending, the counter-skeleton touches the top main surface of the glass 210. The pivot link makes it possible to retract the assembly of counter-skeleton plus U-shaped structure once the bending of the glass has been performed, which makes it possible to easily release the bent glass. The assembly of counter-skeleton plus U-shaped structure is represented in retracted position by dotted line 212. The position of the axis of rotation 209 of the structure of the counter-skeleton, both fairly high and away from the edge of the glass 211, which allows the counter-skeleton to be moved away from the glass by a rotational movement (arrow 213) driving it both upward but also laterally. The retraction system is produced by a triggering system not described here but that can for example pass through the lateral walls of the kiln or else the bed of the kiln. The retraction performed during cooling makes it possible to obtain good glass edge stresses. Moreover, the retraction also makes it possible to remove the glass from the skeleton by a conventional harrow system pushing it from below, and to load it easily at the kiln entry, using a robot for example. The counter-skeleton is put back in place by an inverse rotary movement once the next glass is loaded on the skeleton.
