Abstract
A device for conveying sheets of glass running one after another, includes at least one roller including a conveying zone for the sheets of glass, the device including actuators situated on either side of the conveying zone that are able to curve the roller in its range of elastic deformation while leaving it able to be driven in rotation about fixed centers of the sections thereof, the actuators being able to give the roller, on either side of the conveying zone, a level and a direction that give it an asymmetric shape with respect to the plane that is orthogonal thereto and situated equidistantly from the actuators.
Claims
1. A device for conveying sheets of glass running one after another, comprising a first roller, comprising a conveying zone for the sheets of glass, said device comprising actuators situated on either side of the conveying zone that are configured to curve said first roller in its range of elastic deformation while leaving it able to be driven in rotation about fixed centers of sections thereof, the actuators being configured to give said first roller, on either side of the conveying zone, a level and a direction that give it an asymmetric shape with respect to a plane that is orthogonal thereto and situated equidistantly from the actuators.
2. The device as claimed in claim 1, wherein a first of the actuators of said first roller that is situated on one side of the conveying zone is not synchronized with a second of the actuators of said first roller that is situated on the other side of the conveying zone.
3. The device as claimed in claim 1, comprising a plurality of said first rollers, which are mutually parallel and form a bed of rollers in contact with which the sheets of glass are conveyed one after another.
4. The device as claimed in claim 3, wherein at least one actuator on at least one side of the conveying zone is configured to simultaneously curve at least two rollers of the bed of rollers.
5. The device as claimed in claim 1, comprising a second roller of the same type as the first roller, the first and second rollers forming a pair of rollers, being mutually parallel with a constant spacing along their entire length, the sheets of glass being to pass between the first and second rollers.
6. The device as claimed in claim 5, comprising a plurality of pairs of rollers forming a bed of lower rollers and a bed of upper rollers for applying a bend to the sheets of glass passing between the beds of lower and upper rollers, said bend having at least one transverse direction perpendicular to a conveying direction of the sheets of glass.
7. The device as claimed in claim 6, wherein the beds of lower and upper rollers have an upward or downward curved profile in the conveying direction of the sheets of glass in order to also apply a longitudinal bend to the sheets of glass.
8. The device as claimed in claim 3, further comprising air blowing nozzles that are configured to blow air between rollers of the same bed.
9. The device as claimed in claim 3, wherein actuators of rollers of a bed of rollers that are situated on one and the same side of the conveying zone are synchronized with one another such that a level and direction of the rollers on said side of the conveying zone are controllable in a centralized manner.
10. The device as claimed in claim 6, wherein actuators of rollers of the upper bed that are situated on one and the same first side of the conveying zone are synchronized with one another such that a level and direction of the rollers on the first side of the conveying zone are controllable in a centralized manner, and actuators of rollers of the lower bed that are situated on one and the same second side of the conveying zone are synchronized with one another such that a level and direction of the rollers on the second side of the conveying zone are controllable in a centralized manner.
11. A method for conveying sheets of glass, comprising conveying sheets of glass running one after another in contact with and in the conveying zone of the first roller of the device of claim 1, said first roller having an asymmetric shape with respect to the plane that is orthogonal to said first roller and situated equidistantly from the actuators.
12. The method as claimed in claim 11, wherein a plurality of sheets of glass are conveyed side by side.
13. The method as claimed in claim 11 wherein said device comprises a second roller of the same type as the first roller, the first and second rollers forming a pair of rollers, being mutually parallel with a constant spacing along their entire length, the sheets of glass passing between the first and second rollers, said device comprising a plurality of pairs of rollers forming a bed of lower rollers and a bed of upper rollers, the sheets of glass undergoing a bend on passing between the beds of lower and upper rollers, said bend having at least one transverse direction perpendicular to a conveying direction of the sheets of glass.
14. The method as claimed in claim 13, wherein the beds of lower and upper rollers have an upward or downward curved profile in the conveying direction of the sheets of glass, the sheets of glass also being bent in a longitudinal direction on passing between the lower and upper beds of rollers.
15. The method as claimed in claim 13, wherein two or four or eight sheets of glass are bent simultaneously side by side.
16. The method as claimed in claim 15, wherein the sheets of glass, upon being bent, take on shapes that give them mirror symmetries, with a first sheet passing on one side of the plane that is orthogonal to the roller and situated equidistantly from the actuators having, corresponding to it, a second sheet passing on the other side of said plane, the shape of the second sheet being symmetric to that of the first sheet.
17. The method as claimed in claim 14, wherein, after bending, air is blown onto the glass between rollers of one and the same bed in order to thermally strengthen the glass.
18. The device as claimed in claim 8, wherein the air blowing nozzles are configured to blow air to carry out heat strengthening of the glass.
19. The method as claimed in claim 17, wherein, after bending, air is blown onto the glass between rollers of one and the same bed in order to thermally temper it.
Description
[0034] FIG. 1 shows a prior art roller 1. Actuators 6 and 7 curve the roller in its elastic deformation range. The actuators are synchronized so as to apply symmetric movements with respect to the plane P that is orthogonal to the roller and situated equidistantly from the actuators (d1=d2). The roller is substantially in the shape of a circular arc of radius R. The actuators 6 and 7 are at the same height. The movements imparted by the actuators give the roller on either side of the conveying zone 14, at the points situated immediately outside the actuators and between the actuators (that is to say at the points 10 and 11), a level h that is identical to the right and to the left in the figure and directions 12 and 13 that are symmetric with respect to the plane P. These two directions intersect in the plane P. This roller clearly has a symmetric shape with respect to the plane P that is orthogonal to the roller and situated equidistantly from the actuators.
[0035] FIG. 2 shows a roller 20 according to the invention viewed in the longitudinal conveying direction of the sheets of glass. Actuators 26 and 27 impart movements indicated by the arrows on the roller in regions close to the ends 28, 29 thereof, on either side of the conveying zone 214, in order to curve it in its elastic deformation range. The actuators im part asymmetric movements with respect to the plane P that is orthogonal to the roller and situated equidistantly from the actuators (d1=d2). The roller is not really in the form of a circular arc but rather that of a comma. The actuators 26 and 27 are at different heights (h2>h1). The movements imparted by the actuators give the roller, at the points situated immediately outside the actuators and between the actuators (that is to say at the points 210 and 211), different levels h1 and h2 and directions 212 and 213 that are not symmetric with respect to the plane P. These two directions intersect outside the plane P. This roller has an asymmetric shape with respect to the plane P that is orthogonal to the roller and situated equidistantly from the actuators. In this case, the plane P is vertical, but this did not have to be the case.
[0036] FIG. 3 shows a view in the longitudinal conveying direction of a device according to the invention com prising a pair of two rollers 31, 32 that are disposed one above the other, are mutually parallel along their entire length and at a constant distance from one another along their entire length. These two rollers have been curved asymmetrically so as to give them an asymmetric shape with respect to the plane P that is orthogonal to the roller and situated equidistantly from the actuators, like the roller in FIG. 2. The two rollers are substantially the same shape as one another but they do not exhibit the same shape on either side of the plane P. On one side of this plane (to the right in the figure), the radii of curvature R′2 are smaller than those R2 on the other side of the plane P. In this configuration, the actuators 33 and 35 act on the lower roller and the actuators 37 and 38 act on the upper roller. All of these actuators are independent (that is to say not synchronized) and an operator adjusts them in order for the spacing of the two rollers to be constant and equal to the thickness e of the sheets of glass 39 throughout the conveying zone. The sheet 39 is subjected to transverse bending, corresponding to the shape of the rollers, on passing therebetween. Synchronizing the actuators 33 and 37 with one another, for the one part, and the actuators 35 and 37 with one another, for the other part, has not been ruled out. However, it is preferable to have four actuators that are not synchronized, each one being designed to act on one end of just one roller, since this makes finer adjustment of the spacing between the rollers possible.
[0037] FIG. 4 shows the same device as the one in FIG. 3, except that it is used to simultaneously bend two sheets of glass 41 and 42 side by side that come into simultaneous contact with the rollers. It may be a pair of panes of glass, right and left, that are intended to be fitted to the two sides of one and the same motor vehicle (the difference in shape between the two sheets has been exaggerated to make it easier to understand the invention). The aim is clearly to produce two sheets with the same shapes, these shapes being mirrored with respect to one another, however, the m irror being vertical and passing through the middle of the vehicle for an observer positioned facing the front of the vehicle and looking at it. The asymmetry created by the curve of the rollers is intended to correct a heating asymmetry prior to bending so as to ultimately create sheets that are symmetric to one another.
[0038] FIG. 5 is inspired by FIG. 1 of EP413619 and schematically shows a perspective view of an actuator 50 for curving a pair of bending rollers at one of their ends, it being understood that the other side of this pair of rollers is equipped with an equivalent actuator that is not synchronized with this actuator 50. This actuator 50 comprises two synchronized sub-actuators: a lower sub-actuator 50a for curving the lower roller 51a and an upper sub-actuator 50b for curving the upper roller 51b. The axes of the rollers (that is to say the curved line passing through the centers of all the sections thereof) 52a and 52b are in this case in one and the same vertical plane. When the rollers 51a and 51b are curved, their axes 52a and 52b take on the form of two parallel curves at a constant spacing along their entire length. The lower roller 51a has a free end 53a and is driven in rotation at its opposite end, not shown here. It is also guided in its terminal part by tangential supports formed by a set of two lower rolling cylinders 54a and 55a and a set of upper rolling cylinders 56a and 57a. These four rolling cylinders act as a rolling bearing for rollers. They are mounted on forks 58a and 59a so as to be mounted in a manner allowing them to rotate freely. These forks are fixed to a support arm 60a that can pivot about the axis 63a. The upper roller 51b is mounted vertically above the lower roller 51a and is similarly guided by the rolling cylinders 54b, 55b, 56b, 57b. The rolling cylinders guiding the roller 51b are positioned exactly vertically above the rolling cylinders guiding the lower roller 51a. These rolling cylinders are mounted on forks 58b and 59b fixed to a second support arm 60b pivoting about the axis 63b. The support arm 60a also carries a stop 62a that faces the stop 62b carried by the upper arm 60b. The stop 62b additionally has a passage 64b for the elements for driving the roller 51b in rotation.
[0039] The device schematically depicted in FIG. 5 has, corresponding to it, a perfectly symmetric device positioned on the other side (not visible in the figure) of the rollers 51a and 52b. If a movement is imparted on the free end 61a of the arm 60a along the direction of the arrow F, the angular movement of the arm is brought about, which pivots about the axis 63a. By way of the stops 62a and 62b, this force is transmitted directly to the arm 60b. In this way, perfectly identical bending of the rollers 51a and 51b is achieved. The bend adopted by the rollers depends directly on the vertical position of the arms 60a and 60b, it being possible for this position to be modified easily by a mechanical jack or a cam.
[0040] The system of stops 62a and 62b thus makes it possible to couple the sub-actuators 50a of the lower roller and 50b of the upper roller. The two rollers are thus curved simultaneously by a single movement being imparted on the actuator 50a.
[0041] As mentioned above, the actuator 50 is generally associated with another actuator of the same type 50′ (not shown here) that is situated at the other end of the rollers 51a and 51b, on the other side of the conveying zone. In this case, the asymmetry of bending of the rollers originates from the fact that each actuator 50 and 50′ imparts a different direction on each end of the pair of rollers 51a and 51b.
[0042] The pairs of forming rollers mounted as schematically depicted in FIG. 5 are advantageously used to form a conveyor, the path of which has a curved profile, with the concavity thereof preferably facing upward. A forming and tempering machine having such a conveyor is schematically depicted in FIG. 6.
[0043] FIG. 6 is a schematic depiction in side view (transverse view) of a bending and tempering machine to which the invention more particularly applies. A sheet of glass runs through and is heated in a furnace, then passes between two upward beds of rollers that form a shaping assembly, and then, at the outlet, through a secondary cooling zone. The sheet of glass 81, which is initially flat, firstly crosses a heating zone 82 of a tunnel furnace (the arrow in the furnace indicates the conveying direction, which is also the longitudinal direction), through which it is carried on a horizontal conveyor 83 moved by a bed of straight motorized rollers 64 that are aligned in a plane. At the outlet of the temperature-raising furnace, the glass is at its deformation temperature, allowing the thermal bending thereof. The sheet of glass 81 then passes into a shaping zone comprising a bed of upper rollers 67 and a bed of lower rollers 69 that are mounted with an upward curved profile in the form of a circular arc in side view. The running sheets of glass are squeezed and shaped between pairs 73 of rollers of these two beds of rollers. It can be seen that the rollers of a pair of rollers generally have different levels, one generally being higher than the other, except perhaps for the last pair of rollers, in which the rollers are substantially at the same height. The bed of rollers 67 and the bed of rollers 69 thus form an upward shaping assembly with an upwardly curved profile. The sheets of glass 81 are bent, starting at the first pairs 73 of rollers, in the transverse direction as shown in FIG. 3, and in the longitudinal direction corresponding to the upward circular arc shape of the beds of rollers. This shaping is followed by cooling between the two beds of rollers, in particular tempering. To this end, nozzles blow cool air between the rollers onto the two faces of the sheets. These nozzles are connected to box structures 70 that supply them with the necessary air. The glass is thus fixed just after it has been bent. The air is blown starting at the first pairs of bending rollers 73. On leaving the shaping and tempering assembly, the sheets of glass tip onto a conveyor 71. The sheets of glass 81 are then evacuated by a flat conveyor 72 that passes through a secondary cooling zone 93.
