FR2601942A1 - APPARATUS FOR ALIGNING GLASS SHEETS IN A PRODUCTION LINE, ESPECIALLY A WINDSHIELD - Google Patents

Abstract

SHEETS OF GLASS 24, 26 ARE TRANSPORTED ONE AFTER THE OTHER BY A CONVEYOR 20 WITH ROLLERS 30 TO THE ENTRY 31 OF AN OVEN 21 WHICH IS FOLLOWED BY A BENDING DEVICE IN THE MANUFACTURE OF WINDSCREENS GALBES SHEETS . THE SHEETS OF EACH WINDSHIELD HAVE DIFFERENT DIMENSIONS. THE ALIGNMENT APPARATUS 25 TAKES ACCOUNT OF THIS DIFFERENCE AND ENSURES THE AUTOMATIC POSITIONING OF EACH SHEET, RELATIVE TO THE AXIS 38 OF THE LINE, USING CLIP-ON STOPS 45 WHICH ACT ON THE FRONT EDGE 34 AND D ' LATERAL POSITIONING BODIES 57 ACTING ON THE SIDE EDGES 36, 37 OF THE SHEETS. THE STOPPERS 45 AND THE LATERAL POSITIONING DEVICES 56 ARE MOVED, ACCORDING TO THE SIZES OF THE SHEETS, BY AN ELECTRIC AND PNEUMATIC SYSTEM CONTROLLED BY A COMPUTER.

Description

The present invention relates generally to an apparatus for

  aligning glass sheets in a production line and it relates more particularly to an apparatus for

  align sheets for windshield bending.

  The movement of glass sheets Along a production line poses the problem of proper alignment of the

  sheets at one or more work stations. The U.S. Patent

  No. 3,638,564 discloses an alignment apparatus of the prior art, in which a sheet of glass is moved over a conveyor belt to an orientation station, where a pair of members comes into contact with a longitudinal edge and a pair of members coming into contact with the lateral edges orient the glass sheet longitudinally and laterally on the conveyor belt. Suction is then applied to hold the glass sheet in place while the belt transports the glass sheet to a work station, where a predetermined pattern is applied by a screen printing process. Each of the members coming into contact with an edge of the sheet is hydraulically controlled 20 and its relative position is manually adjustable by rotation of a threaded rod in a threaded sleeve, on which is articulated

a hydraulic cylinder.

  U.S. patents Nos. 3,701,643 and 3,992,182 both describe alignment devices for positioning a moving glass sheet on a conveyor in a glass sheet production line. Two members coming into contact with the edges of the sheet are installed on the opposite sides of the conveyor and move therewith at the speed of the glass sheet. These members are mounted on carriages with reciprocating movements to come into contact with opposite edges of the

  glass sheets and to deviate therefrom, for their alignment.

  The U.S. Patent No. 4,205,744 describes a device for positioning a windshield while it is being moved between two lines of conveyors. A positioning bar is manually adjustable on a threaded spindle to allow positioning of windshields of different lengths. Two positioning pads

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  are provided at the ends of the bar. A first conveyor transports a windshield into a holding structure which rotates the windshield by 180 and moves it laterally to bring it to the end of a second conveyor offset from the first. During lateral movement, an edge of the windshield comes into contact with one of the pads so that the windshield is

  positioned when it is brought on the second conveyor.

  The U.S. Patent No. 4,367,107 describes an apparatus for aligning two curved glass sheets in an assembly station. The glass sheets, placed one on the other when they are introduced into the assembly station, come into contact with guide rollers by their upper and lower edges and by their lateral edges. The two sheets are then gripped by suction members and separated from each other in the vertical direction, while an intermediate layer in the form of a flexible sheet is inserted between them. The glass sheets are then reassembled to form a sandwich intended to be

  laminated, that is to say transformed into a laminated product.

  U.S. patents Nos. 4,440,288 and 4,488,846 20 both describe sensors for controlling the spacing of objects moved between two conveyors. In the first of these two documents, molds filled with dough, coming from an unloading conveyor, are assembled at a gate installed at the end of a grouping conveyor. A mold detector is moved along the grouping conveyor to determine the instant when a moving mold is at a predetermined distance from one or more stopped molds, so that the speed of the conveyor can be reduced below d '' a speed at which the dough during the rise would fall back if the mold were to strike a stopped mold. Patent 4,488,846 describes a device for controlling the movement of an auxiliary conveyor which feeds sheets of glass onto a main conveyor. The auxiliary conveyor is stopped until the distance between the last sheet on the main conveyor and the next sheet on the auxiliary conveyor is equal to a predetermined distance; at this time the auxiliary conveyor

  is started to transfer the glass sheet - previously stopped -

to the main conveyor.

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  The U.S. Patent 4,493,412 describes a system for positioning glass sheets on a conveyor platform before their removal by a robot. Each glass sheet is applied by its front edge against fixed stop rods. Two transversely movable tables then advance to grip the opposite side edges of the article. Finally, adjustable rods are moved vertically and longitudinally to come into contact with the rear edge of the article to align it in a position

  precise with respect to a fixed reference point.

  The U.S. Patent No. 4,458,628 describes a turntable for supporting a glass panel and for moving it relative to a robot which applies an adhesive to one of the edges of the panel. The glass panel is brought to the turntable by a conveyor. It is positioned on this plate by means of 15 positioning shoes hydraulically controlled in the vertical direction to apply against the peripheral edges of the glass panel. This is then gripped by suction cups and hooves

  are removed before the platter begins to rotate.

  In a production line for laminated safety windscreens 20 preventing cuts by broken glass in the event of breakage, a curved outer sheet, a curved inner sheet and a curved cover plate are stacked with interposition of plastic layers. The glass sheets should be oriented properly before the rolling or joining process in order to ensure proper alignment of the edges for the arrangement around them of a vacuum application ring or belt. Because the glass sheets are curved, they are made with a length which decreases from the outer sheet to the inner cover or protective plate, so that their edges can be aligned. All of the prior art systems described in the foregoing would pose problems in obtaining the proper alignment of three sheets

of different sizes.

  The present invention provides an apparatus for feeding glass sheets of different sizes when they are transported in a predetermined order to the entry of a fQur. The

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  sheets are oriented - by their length - transversely to the direction of transport. The furnace brings the glass sheets to softening temperatures suitable for bending. The front edge of the glass sheet is applied against two stops, extending vertically, in front of the inlet opening of the furnace. Two lateral pushers are actuated horizontally to come into contact with the opposite ends of the glass sheet in order to adjust it to a predetermined position. The pushers and the front stops are then removed and the conveyor passes the sheet through the oven. The distance between the side lifters is automatically adjusted by a drive device with a stepping motor for adaptation to the different

lengths of glass sheets.

  The apparatus also comprises a control system 15 and sensors which react to the absence or a misalignment of a sheet of glass. Sensors mounted on the sides of the conveyor, near the oven entrance, detect the absence of a sheet and trigger an alarm indicating that the normal succession of glass sheets has been interrupted. Sensors in the bending area detect the possible bias orientation of the

  sets or stacks of sheets entering the bending apparatus.

  If the stacks are oriented obliquely, the front stops will be adjusted automatically to realign the glass sheets when they enter the oven. It is also possible to use a sensor at the inlet of the oven to detect marks provided on the glass sheets to determine that the sheets follow one another in the desired order and / or to detect the absence of a sheet. . It is also possible to provide sensors in front of the oven to detect a problem of biasing and to readjust the positions of the front stops in order to eliminate the problem.

  before the glass sheets reach the bending area.

  The invention therefore aims to provide an alignment device which facilitates the use of a conventional vacuum application belt on stacks of sheets intended to be assembled into curved laminated windscreens.

  Another object of the invention is to provide an apparatus for aligning glass sheets which automatically adjusts on sheets of different sizes during

  as they move along an assembly line.

  Other characteristics and advantages of the invention will emerge more clearly from the description which follows

  of several nonlimiting exemplary embodiments, as well as annexed drawings, in which: - Figure 1 is a top view of part 10 of an installation for bending windshields comprising an alignment or positioning device according to the 'invention; - Figure 2 is a perspective view of the alignment apparatus of Figure 1, but with the omission of most of the actuating mechanisms for clarity; - Figure 3 is a plan view of the front stop mechanism of the alignment apparatus of Figures 1 and 2; - Figure 4 is a plan view of the lateral alignment mechanism of the alignment apparatus of Figures 1 and 2; - Figures 5, 6 and 7 are respectively a cross section taken along the line 5-5, 6-6 and 7-7 of Figure 3; - Figure 8 is a cross section taken along line 8-8 of Figure 5; - Figure 9 is a cross section taken along line 9-9 of Figure 4; and

  - Figure 10 is a cross section taken along line 10-10 of Figure 9.

  The invention provides an apparatus for aligning or positioning sheets of different dimensions with respect to a reference point, which is characterized by at least two stop rods arranged in a plane in which the sheets are aligned, the rods stop being intended to retain the sheets by their front edge, located in this plane, in order to align the sheets with respect to the reference point, at least one lateral alignment member disposed in said plane at a distance selected from at least 35 two different predetermined distances from said point of

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  reference, the lateral alignment member being intended to come into contact with a lateral edge of the sheets, an edge which is situated in said plane, in order to align the sheets with respect to the reference point, a device for automatically selecting the one of the predetermined distances according to a predetermined succession of sheets brought up against the stop rods, as well as by a device for moving the lateral alignment member by

  report to the reference point, in response to an action of the automatic selector device.

  FIG. 1 represents part of an installation for bending windscreens, comprising a first conveyor 20 or supply conveyor which delivers glass sheets to the inlet of an oven 21 which is intended to carry the glass sheets to bending temperatures. Leaving the oven 21, the 15 sheets enter a bending station 22 where they are put into the desired curved form by a bending apparatus 22a, from which they are transported by a second conveyor 23 to a cooling station (not represented). In FIG. 1, a sheet of glass 24 has been transported by the feed conveyor 20 to the entrance to an alignment device 25 according to the invention. Another glass sheet 26 has just left the alignment device 25 and is about to enter the furnace 21. The alignment device 25 positions the glass sheets so that they enter the processing station. bending 22 with the appropriate orient25 tation and they leave the furnace 21 with the same orientation. Precise alignment of the sheets - of different sizes with respect to the bending machine-22a is necessary so that, after shaping, the sheets of each set fit together, with their edges aligned, to ensure a good fit of the vacuum application belt used in the

  lamination or assembly process.

  As shown in Figure 2, the conveyor 20 may include a number of rollers 30 which are aligned in a horizontal plane leading to an inlet opening 31 of the furnace 21. The drive mechanism for the rollers is conventional and does not is not shown. In Figure 2, the glass sheet 26 is shown in the alignment apparatus 25, while the glass sheet 24 is shown as the next sheet in a succession of glass sheets, as described by

the following.

  The alignment apparatus 25 comprises a frontal positioning mechanism 32 or mechanism acting on the front edge of the sheets and a lateral positioning mechanism 33 or mechanism acting on the lateral edges of the sheets, which are both shown without part of the members associated control elements 10 in order to better bring out the contact with the edges of the glass sheet 26. The glass sheets 24 and 26 are shown as elements of a laminated windshield. For example, the sheet 26 may constitute an outer blade, having a lower edge 34, an upper edge 35 and lateral edges 36 15 and 37. The glass sheets are oriented so that the lower edge 34 is the front edge during the transport on the production line. This involves positioning the glass sheet 26 so that the lateral edges 36 and 37 are located equidistant from a central line or imaginary axis 38, extending through the furnace 21 and the bending apparatus. 22a, to ensure that when the glass sheets are stacked for assembly, their edges are properly aligned for receiving a vacuum application belt. The glass sheet 24 may constitute, for example, an inner blade which is arranged on the glass sheet 26 in an assembly station (not shown)

  to form a sandwich with an intermediate plastic sheet.

  In the case of the manufacture of a safety windshield of the type preventing cuts by broken glass, a third sheet of glass, forming a removable cover plate, is placed over the sheet of glass. glass 24, with an anti-cut sheet between them, to complete the stacking intended to form

the windscreen.

  As shown in Figure 2, the front positioning mechanism 32 comprises a grooved bar 40 disposed 35 parallel to the rollers 30 and above the path of transport of the glass sheets 24 and 26 on the rollers 30. The bar 40

26,019 42

  is supported so that it can be rotated, as described below, and passes through two support blocks 41 of two front stops. Although the drawing represents two, any number of front retainers can be used. Each support block 41 is fixed to the top of a front retainer slide holder 42. A sliding mechanism 43, actuated by an electric motor 44, is mounted on the underside of each of the slide holders 42. A stop tube 45 extends vertically downward from the sliding mechanism 43. The stop tubes 45 are typically placed at an equal distance from the axis 38 to come into contact with the lower edge or front edge 34 of

the glass sheet 26.

  A lever 46 for rotating the grooved bar 40 is mounted on the latter between the support blocks 41. The other end of the lever 46 is connected to the piston rod of a pneumatic cylinder 47. Although this is not shown in Figure 2, this cylinder is fixed relative to the bar mount 40. When the pneumatic cylinder 47 is retracted, the lever 46 rotates the bar 40 and the retainers secured to it in the opposite direction to that of clockwise for an observer placed at the end of the grooved bar 40 represented on the right in FIG. 2. The stop tubes 45 are then moved away from the front edge 34 of the glass sheet 26, so that that -this can advance on the conveyor 20 towards the inlet opening 31 of the oven 21. The lateral positioning mechanism 33 comprises

  two pins 50 and 51 which are provided with threads of opposite pitch and are connected to each other by a coupling 52.

  The pins 50 and 51 are rotatably mounted in a support device (not shown) which will be described later. An electric stepper motor 53 is coupled to the free end of the spindle 50. Each of the spindles 50 and 51 passes through a part forming a nut 54. The latter is fixed to the top of a side push-button console 55. A pneumatic cylinder 56 is mounted on the underside of the console 55 and the piston rod of this cylinder is connected to a lateral plunger 57 which is oriented approximately parallel to the axis 38. When the cylinders 56 are operated for the retraction of the piston rods, the pushers 57 are applied against the lateral edges 36 and 37 of the glass sheet 26, by positioning the latter relative to the axis 38. The stepping motor 53 can be actuated to rotate the threaded pins 50 and 51 by a predetermined amount for the purpose of adjusting the distance between

  the pushers 57 for sheets of different lengths.

  The front positioning mechanism 32 is shown in more detail in FIGS. 3 and 5 to 8. The glass sheet 26 is supported by several rollers 30. The lower edge or front edge 34 of the sheet 26 is advanced towards the oven until it comes to abut against the lower ends of the stop tubes 45. At least this end of each tube 45 is hollow and contains a helical spring 60. The lower end of this spring is applied against the end upper 15 of a stop rod 61. The lower end of this rod projects in

  bottom of the tube 45 for retaining the glass sheet by its edge 34.

  The stop rod 61 is typically formed from a material which does not

  no risk of scratching the glass sheet 26, "Nylon" for example.

  The spring 60 and the stop rod 61 can be held in the tube 45 in any conventional manner allowing

  the insertion of the rod into the tube, against the force of the spring.

  This arrangement avoids breaking glass sheets in the event that the tube 45 is lowered so that the lower end of the stop rod 61 is applied to the top of a sheet instead of being applied against its front edge. . The lower edge proper of the tube 45 is situated above the plane containing the face

  top of the glass sheet 26.

  The tube 45 is attached at the top to a slide 62 forming part of the sliding mechanism 43. This mechanism is commercially available from Velmex Inc., E. Bloomfield, New York, USA under the designation "Velmex Unislide no S-B2503W1J ". The electric motor 44 attached to it can be a Bodine type "K" model 730, which can be obtained from Bodine Electric Co., Chicago, Illinois, USA. 35 The sliding mechanism 43 and the motor 44 allow the selective positioning of the stop rod 61 to fix the point O10 at which the glass sheets will be stopped before entering

The oven.

  Figures 5 and 8 show that the upper end of the stop tube 45 has a screw connection with a drive shaft 63 coupled to the motor 44. When this motor rotates the shaft 63 in one direction, the tube 45 and the stop rod 61 are moved in one direction, for example to retain the sheets at a greater distance from the opening of the oven; when the direction of rotation of the motor 44 is reversed, the tube 45 and the stop rod 41 will be approached to the opening of the oven. FIG. 8 best shows that the upper end of the stop tube 45 is attached to a slide 64 of trapezoidal section at a point located under the point of attachment of the drive shaft 63. The slide 64 moves in a groove 65 of complementary shape, formed in the lower surface of the sliding mechanism 43. The groove 65 is parallel to the longitudinal axis of the drive shaft 63 and serves to support and guide the tube 45

during its movement.

  The slide carrier 42 and the support block 41 are integral in rotation with the grooved bar 40. FIG. 5 shows that when this bar is turned clockwise, the tube 45 and the rod stop 61 are moved along arrow 66 to the position shown in phantom. The stop rod 61 is thus spaced from the front edge 34, which allows the rollers 30 of the conveyor to make the sheet 26 penetrate into the opening of the oven. The angle of rotation of the front positioning mechanism can be varied by changing the stroke of the pneumatic cylinder 47 and / or by contact between a surface

  bottom of the slide carrier 42 and an upper surface of a tubular member 67 of the frame.

  As can be seen in FIGS. 3 and 5, an angle 68, carrying sensors for detecting the possible oblique orientation, extends transversely to the direction of transport of the glass sheets on the conveyor, above it. this. The angle 68 is itself fixed to one end of a support arm 69 which is fixed by its other end to the underside of the tube 67 of the frame. The top of this tube carries a bearing 70 located

  above the edge 69 and supporting in rotation the splined bar 40.

  Two sensors 71 are mounted on the opposite ends of the angle iron 68. These are typically photoelectric elements which are commercially available and which are used as explained in the following to determine whether or not the glass sheet 26 is oriented obliquely after it has

  been released by the stop tubes 45.

  Figures 3 and 6 show that the tube 67 of the frame 10 carries, on one of its lateral faces, a fixing lug 72 for mounting and articulation of the lower end of the pneumatic cylinder 47. This has a rod piston 74 ending in a female yoke articulated on one end of the lever 46 for the rotation of the grooved bar. The other end of this lever comprises a removable part 76 which is fixed to the main body of the lever by two screws 77. The main body of the lever and the removable part 76 define an opening for receiving the grooved bar 40. One or several hexagon socket screws 78 can be screwed into the removable part 76 or into the main body of the lever 46, until they come to bear against the bar 40, to secure the latter in rotation with the lever 46. When the cylinder 47 retracts its rod 74, the lever 46 and the splined bar 4Q are turned clockwise to the position shown in phantom. The ends of the bar 40 are rotatably mounted, on the top of the tubular piece 67 of the frame, in two bearings 79 which are

similar to level 70 in the center.

  The stop tubes 45 are also combined with means for their positioning transverse to the axis 38. A first adjustment rod 80 is attached at one end to the slide carrier 42 shown on the left in FIG. 3. This attachment can be carried out by any suitable means, for example by two rods. The rod 80 passes through an opening in the other slide carrier 42 and ends in an adjustment slide 81. This is attached to the vertical wing of a support angle 82. The wing approximately horizontal of this angle is fixed on the top of the tube 67 of the frame and

  the angle 82 is oriented transversely to this tube.

  The angle iron 82 carries a locking mechanism 83. The rod 80 passes through this mechanism and can slide freely in the latter when it is in the unlocked position. The rod 80 can therefore be used to move the slide carrier 42 from the left side, together with its stop tube 45, along the

  bar 40 to position the tube 45 relative to the axis 38.

  When the desired position is reached, the operation of the locking mechanism 83 makes it possible to immobilize the stop tube 45 at this position. A second adjustment rod 83, which is shorter than the rod 80, is attached by one end to the slide holder 42 shown on the right. The rod 83 passes through a locking mechanism 85 similar to that designated by 83 and which is also mounted on the angle 82. After having crossed the vertical wing of the angle 82, the rod 84 ends in a slide of

  setting 86 similar to that designated by 81.

  As shown in more detail in FIG. 7, the adjustment slide 86 contains a slide 87 of roughly square section. The rod 84 crosses the center of this slide and is attached to it. The slide 87 is trapped in a U-shaped profile 88, the opening of which is directed upwards and the lateral wings of which are curved at the top, above the slide 87. The top of the latter carries a tenon 89 capped by a ball. 90 which forms a gripping element for displacement

  slide 87 along the axis of the profit 88.

  In FIG. 4, the tube 67 of the frame, as well as all the elements described above and which are attached to it, have been omitted to better illustrate the lateral positioning mechanism 33. FIGS. 3, 4 and 9 show that the ends of the tube 67 are each connected to the upper end of two plates or cheeks 100 extending downwards. As can be seen in Figure 9, the lower end of the cheek 100 attached to the end shown to the right of the tube 67, is attached to one end of a support plate 101 oriented approximately horizontally. A support column 102 connects the underside of

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  the plate 101 to a support beam (not shown) or to other support structures of the alignment apparatus 25 and of the conveyor 20 combined with it. The opposite end of the tube 67

  of the frame is supported analogously.

  In FIGS. 4 and 9, a first threaded control pin 103 is seen, passing through a bearing 104 mounted on the cheek 100. The pin 103 can be equipped with a digital counter 105 for the indication of its relative angular position. It can be a mechanical or electric meter found in Le com10 merce. The end shown to the right of the pin 103 is coupled to the stepping motor 53, itself mounted on a bracket 106 fixed on the top of the support plate 101. The opposite end of the pin 103 is attached to coupling 52, which is mounted

  rotatable in a central support 106 which can be fixed on the underside 15 of the tube 67 of the frame.

  The pneumatic cylinder 56 is fixed to a lower surface of a mount 107. This cylinder comprises a piston rod 108 connected to the lateral positioning mechanism 33. This mechanism comprises a T-profile made up of two angles. The upper angle 109 has a vertical wing of trapezoidal shape, which is best shown in FIG. 10, and a longer horizontal wing. This horizontal wing is fixed by its lower surface to the upper surface of the horizontal wing of a lower angle 110. This has a vertically oriented wing 25 downwards, to which a lateral pusher 111 is fixed by screws 112 The lower edge of the pusher 111 is located under the plane in which the glass sheets are transported on the rollers 30. For this reason, this lower edge has cutouts for the passage of the rollers 30, thus ensuring that the side pusher 111 is fully in contact with the edge of any sheet

of glass.

  FIGS. 9 and 10 show that a threaded support block 113 is fixed to the top of the mount 107. This block or nut 113 is crossed by the pin 103, the rotation of which causes the nut 103 to move along the longitudinal axis of the spindle. The block 113 is also supported and guided by two rods 114

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  which extend between the cheeks 100 and are also held in the central support 106. The block 113 can thus slide freely along the guide rods 114 when it is moved by the rotation of the spindle 103 produced by the motor step by step step 53. The tapped block or nut 113 is fixed to one end of the frame 107 and a block 115 is attached to the other end of this frame. The block 115 is also slidably mounted on the two guide rods 114, but it is not crossed by the spindle

103.

  Figures 4 and 10 show that a sequence sensor 116 can be mounted at one end of an arm 117 attached by its other end to the block 115. This sensor can be constituted by a photoelectric cell which is commercially available and it is positioned to detect a mark carried by each glass sheet and serving to identify the type of glass sheet passing through the alignment path. Although the drawing shows two, you can use any number of sequence sensors, depending on the number of marks you want to use and their location on the glass sheets. Thus, one could use, for example, a single sensor mounted on an arm extending from the tube 67 of the frame near the arm 69 carrying the

  angle iron with sensors to control the oblique orientation.

  Such a sensor can also be combined with positioning means such as those formed by the sliding mechanisms 43.

  In use, the positioning members located on either side of the axis 38 and forming part of the lateral positioning mechanism are brought into position by the rotation drive of the pins 103 and 118. Their positions correspond to a distance from the axis 38 equal to half the length of the glass sheet to be aligned, plus the stroke of the piston 108 of the pneumatic cylinder 56. The stop tubes 45 are initially positioned using the adjustment slides 81 and 86 and are then locked in the selected positions by means of the locking mechanisms 83 and 85. The piston rod 74 of the pneumatic cylinder 47 is in the extended position to maintain the stop tubes 45 in the desired vertical alignment. The conveyor rollers 30 then advance

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  the glass sheet 26 as far as against the stop rods 61. The pneumatic cylinders 56 are actuated to apply the lateral pushers 111 against the lateral edges 36 and 37 of the glass sheet 26. In this way, the sheet 26 is aligned on the axis 38 5 and is ready to be transported in the furnace 21. If the glass sheet deviates from the axis 38 during its path through the furnace 21, this difference can be corrected by shifting the apparatus alignment 25 en bloc and with precision, transverse to axis 38, constituting

  the reference point in the preferred embodiment.

  The cylinders 56 are actuated to retract the lateral pushers 111 and the actuator 47 is actuated to retract its piston rod in order to rotate the stop rods 61 to their position above the glass sheet 26. The conveyor 20 makes then advance the glass sheet 26 on the rollers 30 15 in the opening 31 of the oven 21. The stepping motor 53 is started to adjust the position of the lateral positioning members of the mechanism 33 for the glass sheet following of the succession, the length of which is less than that of the glass sheet 26 which has just been aligned. Assuming that the first sheet of glass was the outer sheet of a windshield, that the second sheet of glass is the inner sheet and that the third sheet of glass is a cover plate, the distance between the positioning members lateral of the mechanism 33 becomes progressively smaller. After the third sheet 25 of glass has been aligned, the stepping motor 53 operates in opposite directions to widen the distance between the positioning members of the mechanism 33, in preparation for the alignment of a new outer sheet, forming the start of a new sequence or

succession of leaves.

  Figure 11 shows schematically a system

  for the automatic adjustment of the stop tubes 45.

  A source of compressed fluid 121 is connected by a conduit 122 to a distribution block 123. Although it is shown as a single element, this distribution block may include a distributor or a similar member for each pneumatic cylinder to be controlled. The distribution block 123 is connected to the cylinder 47 by a conduit 124 and it is connected to the pneumatic cylinders 56 by

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  two conduits 125. A central control 126, constituted for example by a programming computer for general use, is connected by a line 127 to the distribution block 123. The computer 126 delivers electrical control signals by the line 127 to control the application of compressed air from source 121 to cylinders 47 and 56 and to produce the exhaust of

these cylinders.

  The computer 126 is also connected to the stepping motor 53 by a line 128. Thus, the computer can control the actuation of this motor with a view to carrying out any desired sequence or succession of glass sheets of different lengths. The computer 126 is also connected by two lines 129 to the sequence sensors 116. These supply the computer 126

  the information necessary to generate the control signals and send them via line 128 to the stepping motor 53.

  The computer 126 is connected by two lines 130 to the electric motors 44 which control the sliding mechanisms 43. By two lines 131, it is also connected to the alignment sensors 71. These provide the computer with the information 20 necessary for the production of the control signals to be sent by the lines 130 to the motors 44 to bring the stop tubes 45 to the desired locations. As indicated above, two sensors 131 for detecting possible skewing can be installed at the bending station 22 to control the alignment of the glass sheets with respect to the bending apparatus 22a. These sensors 132 are connected by two lines 133 to the computer 126 to provide it with information on the alignment in this area. The computer can therefore also take account of the information relating to a possible skewing of the sheets at the bending station to generate the control signals.

  suitable for sending to electric motors 44 for positioning the stop tubes 45.

Claims (15)

R E V E N D I C A T I 0 N S   1. Apparatus for aligning or positioning sheets of different dimensions with respect to a reference point, characterized by at least two stop rods (61) arranged in a plane in which the sheets (24, 26) are to be aligned, the stop rods (61) being intended to retain the sheets by their front edge, situated in this plane, in order to align the sheets with respect to the reference point, at least one lateral alignment member (56, 57) arranged in said plane at a distance selected from among at least two different predetermined distances from said reference point, the lateral alignment member (56, 57) being intended to come into contact with a lateral edge (36, 37) of the sheets, edge which is situated in said plane, in order to align the sheets with respect to the reference point, a selection device (126) for automatically selecting one of the predetermined distances according to a predetermined succession of sheets (24, 26) brought up to against stop rods (61) , as well as by a displacement device (50, 51, 53) for displacing the member   lateral alignment (56, 57) relative to the reference point, in response to an action of the selection device (126).   2. Apparatus according to claim 1, characterized in that   that the reference point is a central line or axis (38) defining the transport path for the sheets (24, 26).   3. Apparatus according to claim 1 or 2, characterized in that the lateral alignment member (56, 57) comprises a pneumatic cylinder (56) attached to the displacement device (50, 51, 53) and having a rod piston connected to a lateral pusher (57), as well as a device (126) for actuating this jack, the side pusher pressing against a side edge (36, 37) of a sheet 30 when the jack (56) is actuated and the pusher being moved away from   this edge when the jack (56) is not actuated.   4. Apparatus according to any one of claims 1   to 3, characterized in that the movement device (50, 51, 53) includes a sensor (116) for detecting sheets (24, 26) 35 and producing a sequence signal representing information 260 1,942   identification sheets, and the selection device (126) is sensitive to this signal to control the movement device (50, 51, 53).   5. Apparatus according to claim 4, characterized in that the selection device (126) is sensitive to the absence of the sequence signal to produce an alarm signal indicating the absence of a leaf.   6. Apparatus according to any one of claims 1   to 3, characterized in that the displacement device (50, 51, 10 53) comprises a support block forming a nut (54), which is attached to the lateral alignment member (56, 57) and is traversed by a threaded spindle (50), as well as a stepping motor (53) for rotating this spindle, the stepping motor having a shaft   output coupled to the pin (50) and being connected to be actuated by the selector device (126).   7. Apparatus according to any one of claims 2   to 6, characterized in that the two stop rods (61) are arranged on either side of the axis (38).   8. Apparatus according to claim 7, characterized by a transverse displacement device (80, 84) for displacing at least one stop rod (61) along a predetermined path transverse to the axis (38).   9. Apparatus according to claim 8, characterized in that the transverse displacement device (80, 84) comprises means (83, 85) for locking this device in a position   selected from the stop rod (61) along said path.   10. Apparatus according to claim 8 or 9, characterized   by a longitudinal displacement device (43, 44) for displacing at least one stop rod (61) along a predetermined path 30 parallel to the axis (38).   11. Apparatus according to claim 10, characterized by a sensor (71) for detecting the front edge (34) of the sheets and for producing a detection signal, as well as by a control device (126) sensitive to this signal for actuating the longitudinal displacement device 35 (43, 44) and thus move the rod   stop along said path parallel to the axis (38). 26 0 1 9 4 2   12. Apparatus according to claim 11, characterized in that   that the sensor (71) is arranged near the stop rod (61).   13. Apparatus according to claim 12, characterized in that the sensor (71) is spaced from the stop rod (61) along the path of transport of the sheets (24, 26).   14. Apparatus according to any one of claims 1   to 13 for automatically aligning glass sheets of different lengths prior to a manufacturing operation, characterized in that it comprises at least two stop rods (61) 10 arranged to come into contact with a front edge (34) d '' a glass sheet (24, 26) at a predetermined position relative to a reference line (38), at least one lateral alignment member (56, 57), arranged to come into contact with a lateral edge (36 , 37) of a sheet of glass at a predetermined distance 15 from the reference line (38), a device (50, 51, 53) for positioning the lateral alignment member (56, 57) at this distance   predetermined, as well as a device (126) for selectively changing said predetermined distance according to a predetermined sequence or succession of glass sheets (24, 26) of different lengths brought to the stop rods (61).   15. Apparatus according to any one of claims 1   to 13 for aligning glass sheets before a manufacturing operation, the sheets being transported on the alignment apparatus in a predetermined succession depending on the length of the sheets from one side edge to the other, characterized in that it comprises at least two stop rods (61) extending in a plane in which the glass sheets (24, 26) are to be aligned, the stop rods being intended to come into contact with an edge front (34) of the sheets, the stop rods (61) being arranged on either side of a reference line (38) defining a path along which the glass sheets are transported, in view of the alignment of the sheets with respect to this reference line (38), two lateral alignment members (56, 57), installed on either side of the reference line (38) and intended to come into contact with the opposite side edges (36, 37) of glass sheets (24, 26) for alignment of the sheets with respect to the line reference (38), as well as a device (50, 51, 53, 126) connected to the lateral alignment members (56, 57) for bringing these members automatically to one of several predetermined positions relative to the line reference (38) as a function of the length of a glass sheet (24, 26) in contact with the rods stop (61).