KR102154544B1 - Device for glass sheet flattening and method of flattening a sheet of glass - Google Patents

Abstract

The glass sheet scoring machine includes a scoring device, a leveling device including a leveling device, and a scoring bar linkage functionally connecting the scoring device and the leveling device. The flattening mechanism may be in contact with the glass sheet at or near a portion of the glass sheet to be scored before the scoring device scores the glass sheet. A method of separating the glass beads of a glass sheet from a glass sheet includes flattening the glass sheet with a flattening device and scoring the glass sheet with a scoring device.

Description

A device for flattening a glass sheet and a method for flattening a sheet of glass{DEVICE FOR GLASS SHEET FLATTENING AND METHOD OF FLATTENING A SHEET OF GLASS}

Cross on related applications -Reference

This application enjoys the benefit of the priority of U.S. Provisional Application No. 61/734,623 filed December 7, 2012, the content of which is the basis of this application and is hereby incorporated by reference in its entirety as if fully set forth below. .

Technical field

TECHNICAL FIELD This disclosure relates generally to a method and apparatus for flattening a glass sheet, and more particularly to a device for flattening a thin glass sheet near a score head assembly.

The continuous glass ribbon can be formed by a process such as a fusion draw process or other similar down draw process. The melt drawing process results in a continuous glass ribbon having a surface with superior flatness and smoothness compared to glass ribbons made by other methods. Individual glass sheets cut from a continuous glass ribbon formed by a melt drawing process can be used in a variety of devices including flat panel displays, touch sensors, photoelectric devices and other electronic fields.

Continuous glass ribbons, whether formed by a melt drawing process or otherwise, are often due to the temperature gradient in the glass as the ribbon cools, such as the temperature gradient between the glass sheet bead and the central region of the glass sheet. Due to bend or bend in the lateral direction Distortion of the glass sheet may worsen when the glass sheet is thin, for example 1 mm or less, as the thin central region may cool faster than the bead portion. After the glass ribbon is drawn and the glass sheet is separated from the glass ribbon, the beads are cut from the glass sheet by supporting the glass sheet with a suction device as the glass sheet is scored and the beads are separated along the scoring line. The suction device can create a mechanical stress field such as a "bulls-eye" due to localized sheet deformation. This stress field can be located near the score line and thus pull the score line away from the scored median crack, thereby causing sheet breakage. Contact between the scoring device and the curved glass sheet can also introduce motion into the glass sheet, which propagates upstream of the scoring device, causing undesirable stresses and warps in the sheet. The purpose of scoring a glass sheet for bead removal is to create a uniform intermediate vent at the same time both at the vertical bead scoring machine entrance and at the position where the glass sheet is supported by, for example, suction. On a flat sheet, the intermediate crack depth can be easily controlled by applying a stable force to the score wheel. However, when scoring on deformed glass, it is not possible to control the vent depth using a stable force. Clamping has a limited effect on flattening the score line due to the length of the seat and the friction of the clamping nosing required to impede seat motion.

Thus, there is a need for an alternative method of stabilizing glass sheets during bead scoring.

According to one embodiment, a glass sheet scoring machine comprises a scoring device, a flattening device comprising a flattening device, and a scoring bar linkage functionally connecting the scoring device and the flattening device. The flattening mechanism may be in contact with the glass sheet at or near a portion of the glass sheet to be scored before the scoring device scores the glass sheet.

In yet another embodiment, a method of scoring a glass sheet is provided. A leveling device including a leveling mechanism and a scoring device may be located at or near one end of the glass sheet. The flattening mechanism can then be extended toward the glass sheet such that the flattening mechanism is in movable contact with the glass sheet. A portion of the glass sheet can be flattened by moving the flattening device along the length of the glass sheet to the opposite end of the glass sheet, and a portion of the glass sheet is scored by moving the scoring device along the length of the glass sheet to the opposite end of the glass sheet. Can be. After the movement is complete, the flattening mechanism can be retracted so that the flattening mechanism is no longer in contact with the glass sheet. The planarizing device and scoring device may then be repositioned at or near one end of the glass sheet. According to an embodiment of this method, the flattening mechanism flattens a portion of the glass sheet before the portion of the glass sheet is scored. The steps of extending, smoothing, scoring, retracting and relocating are controlled by timing sequence logic.

Additional features and advantages will be described in the following detailed description, in part, which will be readily apparent to those skilled in the art from that description, or the embodiments described herein, including the following detailed description, claims, and also the accompanying drawings. It will be recognized by implementing it.

It should be understood that both the above general description and the following detailed description are intended to describe various embodiments and provide an overview or framework that understands the nature and features of the claimed subject matter. The accompanying drawings are included to provide a further understanding of various embodiments, and are incorporated into and constitute a part of this specification. The drawings illustrate various embodiments described herein and together with the detailed description serve to explain the principles and operation of the claimed subject matter.

1 is a schematic diagram of a glass manufacturing apparatus according to an embodiment of the present invention.
2 is a schematic diagram of a glass ribbon formed by a drawing process according to an embodiment of the present invention.
3 is a schematic side view of a vertical bead scoring machine according to an embodiment of the present invention.
4 is a schematic diagram of a planarization apparatus according to an embodiment of the present invention.
5 is a schematic diagram of a flattening apparatus including a trailing flattening wheel according to an embodiment of the present invention.
6A-6C are schematic views of a flattening wheel according to an embodiment of the present invention.
7 is a schematic diagram of a glass making system using a vertical bead scoring machine to separate glass beads of a glass sheet from a glass sheet according to an embodiment of the present invention.

Reference will now be made in detail to the embodiments in which examples are shown in the accompanying drawings. Where possible, the same reference numbers will be used throughout the drawings to indicate the same or similar parts.

1 depicts a melting process according to an embodiment employing a forming structure 37 that receives molten glass (not shown) within a cavity 39. The forming structure 37 may include a root 41, where molten glass from the two converging sides of the forming structure joins to form a continuous glass ribbon 15. It should be understood that other forming techniques may be used. After leaving the route, the ribbon first traverses the edge rollers 27 and then the pull rolls 29. As the ribbon is moved down by drawing, the glass passes through its glass transition temperature region (GTTR) 31 shown in FIG. 1. At temperatures above the GTTR, the glass basically behaves like a viscous liquid. At temperatures below the GTTR, the glass basically behaves like an elastic solid. As the glass cools through its GTTR from high temperatures, the glass does not exhibit a sharp transition from viscous to elastic behavior. Instead, the viscosity of the glass gradually increases, and both the viscous and elastic response pass through the remarkable viscoelastic region, and eventually the glass behaves as an elastic solid.

Although the GTTR may vary depending on the specific composition of the glass to be processed, as a representative value, the upper limit of GTTR may be about 850°C or less, and the lower limit of GTTR may be about 650°C or higher. In an embodiment of the present invention, the lower limit of GTTR may be about 700° C. or higher.

As shown in Fig. 1, the corner rollers 27 can be in contact with the continuous glass ribbon 15 at a position above the GTTR while the pull rolls 29 can be placed in the GTTR. The tow roll can also be positioned under the GTTR on demand. In an embodiment of the present invention, the edge roller may be water cooled or air cooled. The temperature of the edge roller is lower than that of the glass. As a result of this low temperature, the edge rollers can locally lower the temperature of the glass. This cooling can reduce the thinning of the ribbon. The pull roll 29 can also generally be colder than the glass to which these rolls come into contact, but since these rolls can be placed further below the draw, the temperature difference can be smaller than in the edge rollers 27.

2 shows a continuous glass ribbon 15 according to an embodiment of the present invention. As shown in Fig. 2, the ribbon has outer edges 19a, 19b, centerline 17 and bead portions 21a, 21b that may extend inwardly toward the centerline 17 from the edges 19a, 19b. Can include. The maximum thickness portion of the bead portion may exist along the line 23a (line 23b), and the inner size of the bead portion may be considered to exist along the line 25a (line 25b), here At, the final thickness of the ribbon first rises above 1.05*t _center , where t _center is the final thickness of the ribbon along the _center line. A thickness of 1.05*t _center can be considered to be a quality or near quality thickness. Thereafter, the thickness may decrease slightly as the glass cools based on the coefficient of thermal expansion (CTE) of the glass. Although the bead portions 21a, 21b are shown as symmetrical in FIG. 2, in an embodiment of the present invention, these bead portions may have different widths, and the position of the maximum thickness portion may be different for the two beads. I can. For example, in an embodiment of the invention, the maximum thickness portion need not be in the center of the bead portion.

In an embodiment of the present invention, the cross-drawing thickness profile of the continuous glass ribbon 15 is non-uniform, where the bead portion of the glass may be thicker than the center. In an embodiment of the present invention, the bead portion of the glass may be twice or more thicker than the center. This can result in a temperature profile that includes local maxima within the bead portion, and for most of the ribbon length, the bead can be relatively hotter compared to the centerline. High temperatures within the bead portion can cause undesirable stresses and undesirable shapes in the ribbon and final glass article. These stresses can lead to a twist in the shape of the ribbon that can adversely affect the scoring process used during bead removal. The apparatus and methods disclosed below provide a stable shape within the bead portion when scoring the bead portion to be removed from the ribbon.

Referring now to FIG. 3, one embodiment of a vertical bead scoring machine (VBS) 300 having a planarizing device 310 and a scoring device 320 is schematically shown from its side. VBS 300 with flattening device 310 and scoring device 320 may be used in conjunction with one or more embodiments of a method of separating bead portions of a glass sheet shown and described herein. In the embodiment shown in FIG. 3, the VBS 300 also includes a scoring bar linkage 330 connecting the flattening device 310 and the scoring device 320. The VBS may also include a nosing 345 positioned to create the glass conveyance path and support the glass sheet during scoring. For example, the nosing may be positioned such that the glass sheet 340 can be inserted into the glass conveying path 346 formed between the nosing 345 and the flattening device 310 and between the nosing 345 and the scoring device 320. have. When the glass sheet is present in the glass conveying path, the scoring device 320 or the flattening device 310 can apply a force to the glass sheet such that the glass sheet is in close contact between the flattening device 310 and the nosing, thereby flattening and /Or flattening and supporting the glass sheet during the scoring process. In an embodiment of the present invention, the glass conveyance path 346 may be oriented vertically. However, in an alternative embodiment, it is noted that the VBS 300 may be configured with a different scoring linkage than that shown in FIG. 3 or even without scoring linkage, for example when the flattening device 310 and the scoring device 320 are separate devices. It must be understood.

With continued reference to FIG. 3, the flattening device 310 generally includes a support frame 311, a flattening wheel 312, an actuator 313 and a sliding mechanism 314. The axis of rotation of the flattening wheel 312 may be oriented horizontally as shown in FIG. 3. However, it should be understood that other configurations of planarization devices are possible.

The support frame 311 may be formed from any suitable rigid or semi-rigid material. In an embodiment of the present invention, the support frame 311 may be made of metal such as steel or aluminum. In another embodiment, the support frame 311 may be made of plastic or polymer. The support frame 311 may be a bracket for supporting at least one of the actuator 313 and/or the sliding mechanism 314. As shown in the embodiment shown in Fig. 3, the support frame 311 can be attached to the scoring bar linkage 330 by, for example, bolts or rivets, whereby the support frame 311 is the scoring device 320 And move in the vertical direction (ie, +/- y-direction). However, it should be understood that the support frame 311 and the scoring device 320 can be moved simultaneously in the vertical direction by other mechanisms without departing from the scope of the present invention.

The flattening device 310 may include an actuator 313 that moves the flattening wheel 312 in the lateral direction (ie, +/- x-direction). The embodiment shown in Fig. 3 shows an actuator 313 as a low friction air cylinder. However, in embodiments of the present invention, the actuator may include a hydraulic cylinder, a pneumatic cylinder, a motor driven linear actuator, or a similar linear actuator used to move the leveling wheel 312 in the lateral direction.

In the embodiment shown in FIG. 4, actuator 313 is shown as a low friction air cylinder that can have a piston 410 mechanically coupled to a shaft 430. The shaft 430 may be extended or retracted by controlling the amount of air or compressed fluid supplied to the low friction air cylinder 313. In one embodiment, actuator 313 is an Airpel low friction cylinder with a 1 inch stroke length and 16 mm bore manufactured by Airpot Corporation. However, it should be understood that other similar low friction cylinders can also be used to actively planarize the glass sheet. The bracket 420 may connect the low friction air cylinder 313 to the scoring bar linkage 330. The first end of the low friction air cylinder 313 may be firmly attached to the base of the support frame 311. A second end (eg, shaft end) of the low friction air cylinder 313 may be attached to a flattening wheel 312 that is movably attached to the support frame 311. In an embodiment of the present invention, the flattening wheel mechanism may include a support structure 450 that connects the flattening wheel 312 to the low friction air cylinder 313. The support structure 450 may include a sliding mechanism 314 and any configuration to position the leveling wheel 312 at the desired location for the scoring device 320, the nosing 345 and the glass conveying path 346. It can be. As shown in FIG. 4, the slide mechanism 314 may be slidably attached to the support frame 311 and may be connected to the leveling wheel 312. In an embodiment of the present invention, the slide mechanism 314 is moved in the lateral direction (i.e., the +/−x-direction in FIG. 3) when the actuator 313 is extended or retracted, whereby the glass conveying path 346 Move the flattening wheel 312 to the required position for (shown in FIG. 3). For example, the support frame 311 may include a convex portion, and the slide mechanism 314 may include a concave portion configured to receive the convex portion of the support frame 311. When the slide mechanism is moved in the lateral direction, the slide mechanism may be supported and/or guided by the convex portion of the support frame.

Referring again to FIG. 3, the flattening wheel 312 extends the shaft 430 of the actuator 313 in the positive x-direction in the direction toward the nosing 345 (positive on the coordinate axis shown in FIG. 3). x-direction). The flattening wheel 312 can likewise be moved in the negative x-direction by moving the actuator 313 in the negative x-direction.

As shown in FIG. 3, the scoring device 320 may include a score head 321. A score wheel turret 322 may be located at the end of the score head 321 and may be located within the glass conveying path 346 and the glass sheet 340 at a position adjacent to the bead portion of the glass sheet. It includes a scoring wheel 323 capable of scoring. The axis of rotation of the scoring wheel 323 may be oriented horizontally as shown in FIG. 3. The score wheel turret 322 may include a plurality of scoring wheels 323 (five are shown in FIG. 3) together with a pivot 324 on which the score wheel turret 322 is rotated. The score wheel turret 322 may be configured to cause a different scoring wheel 323 to be positioned within the glass conveyance path 346 by a predetermined rotation of the score wheel turret 322 relative to the pivot 324. However, other embodiments need not include the score wheel turret 322, for example when the scoring device includes a single score wheel. Therefore, it should be understood that other configurations of scoring devices may be considered.

In the embodiment shown in Figure 3, the scoring device 320 includes a mechanical scoring mechanism such as a scoring wheel or scoring point. Alternatively, the scoring device 320 may include a laser scoring device. The scoring device 320 may be coupled to an actuator (not shown) operable to traverse the scoring device 320 in the +/- y-direction. The scoring device may also be coupled to an actuator (not shown) that facilitates positioning the scoring device in the +/- x-direction when the scoring device 320 is traversed in the +/- y-direction. The scoring device 320 may be positioned in the x-direction such that the scoring device specifically the scoring wheel 323 is directly opposed to the nosing 345 and is positioned within the glass conveying path 346 as shown in FIG. 3. Thus, the scoring device 320 can be used to score the glass sheet 340 when the glass sheet is supported on the nosing 345, thereby introducing a scoring line into the surface of the glass sheet opposite to the nosing. It must be understood.

The flattening wheel can have any suitable geometry that flattens a portion of the sheet of glass sheet 340 prior to scoring the glass sheet 340. In embodiments of the present invention, the flattening wheel 312 may be cylindrical and may have a diameter of about 0.50 inches to about 1.50 inches. In some embodiments, the flattening wheel 312 may have a diameter of about 0.75 inches to about 1.25 inches or even 1.00 inches. The flattening wheel 312 may have a width of about 0.25 inches to about 1.00 inches. In other embodiments, the flattening wheel may have a width of about 0.33 inches to about 0.75 inches or even 0.50 inches. In some embodiments, the flattening wheel may have a Shore A hardness of 90. However, it should be understood that flattening wheels with other Shore A hardness may also be used. In general, the hardness of the wheel can be varied based on the thickness of the glass sheet.

As shown in the embodiment of FIGS. 6A-6C, the flattening wheel may include one or more o-rings 610. The number of o-rings included on the flattening wheel 312 is not particularly limited, and in an embodiment of the present invention, the flattening wheel is one o-ring 610 as shown in FIG. 6A, in FIG. 6B. It may include two o-rings 610 as shown or three o-rings 610 as shown in FIG. 6C. A flattening wheel with a single o-ring can flatten the score line of the glass sheet by placing the o-ring over the location of the score line. A flattening wheel with two o-rings can flatten the area on both sides of the score line by placing the score line between the two o-rings. A flattening wheel with three o-rings can flatten the score line and the area on both sides of the score line by placing the score line in the middle of the three o-rings. The o-ring can have any suitable geometry. For example, the o-ring may be round or square in various embodiments. The rounded o-ring can provide minimal contact with the glass sheet 340 and thus minimal friction. The square o-ring can provide maximum contact with the glass sheet 340 and thus maximum friction. Thus, the o-ring geometry can be selected according to the required friction between the flattening wheel 312 and the glass sheet 340. As described above for the flattening wheel, the hardness of the o-ring can be selected based on the thickness of the glass sheet to which the o-ring is contacted.

The VBS 300 shown in FIG. 3 is one embodiment of a VBS suitable for use in connection with a method of separating beads of a glass sheet from a glass sheet, which will be described in more detail herein. However, it should be understood that VBS of other embodiments may also be used. For example, a VBS having two flattening wheels as shown in FIG. 5 may be used.

As shown in FIG. 5, the flattening device may include a trailing flattening wheel 510. The trailing flattening wheel may be positioned linearly on the scoring wheel 323 and flattening wheel 312. The support beam 511 may connect the trailing flattening wheel 510 and the flattening wheel 312. The distance between the trailing flattening wheel 510 and the flattening wheel 312 may be about 10 mm or more. For example, in some embodiments, the distance between the trailing flattening wheel 510 and the flattening wheel 312 may be about 10 mm or more and 100 mm or less. The spacing between the trailing flattening wheel 510 and the flattening wheel 312 is adjustable based on the thickness of the operated glass sheet. The trailing flattening wheel 510 can be moved in cooperation with the flattening wheel 312 in both the x- and y-directions. The trailing flattening wheel 510 is located on the opposite side of the scoring device 320 instead of the flattening device 310. As such, the trailing flattening wheel 510 maintains the flatness of the glass sheet 340 after the glass sheet has been scored. The configuration of the trailing flattening wheel can be varied to prevent surface tension on the score line before a bending moment is applied to separate the beads from the glass sheet, which will be discussed further below. For example, trailing flattening wheels can be positioned on either side of the scoreline or on a single side of the scoreline to create a local tension on an intermediate crack that develops due to scoring. However, it should be understood that other roller options are possible. For example, in the case of very thin glass, compressive stresses can be created on the glass surface using flattening and trailing flattening wheels to prevent or delay uncontrollable crack propagation. In either case, the tension or compression imparted to the glass surface is controlled by the interaction between the flattening wheel and also the flattening wheel and the trailing flattening wheel having a backup nosing geometry and hardness.

The bending moment separating the glass beads from the glass sheet can be applied by any suitable mechanism. In an embodiment of the present invention, a clamp bar (not shown) may be installed as part of the VBS. Referring again to Figure 2, the clamp bar may be positioned to contact the glass sheet at some point on the glass bead, for example between 19a, 19b and 25a, 25b, respectively, without contacting the thin central point of the glass sheet. The clamp bar can cover the entire length of the glass sheet or any portion thereof. Once the clamp bars are placed on the glass sheet, they can be moved to provide a bending moment that separates the glass beads from the glass sheet. In some embodiments, the clamp bar may be used on a thin glass sheet, such as a 0.3t glass sheet. The clamp bar clamps the entire edge of the glass sheet from top to bottom so that the surface of the glass sheet is in a single plane. When the clamp bar is used on a highly distorted glass sheet, pockets of non-uniformity (ie, distortion or twist) can remain and cause localized scoring problems within the area of non-uniformity, which can lead to breakage. The use of flattening rollers counters this problem.

Referring now to FIG. 7, one embodiment of an exemplary glass making system 700 is schematically illustrated. The glass manufacturing system uses VBS 300 as shown in FIG. 3. The glass manufacturing system 700 includes a melting vessel 710, a fining vessel 715, a mixing vessel 720, a delivery vessel 725, a fusion draw machine (FDM) 741, and a sheet Separation device 761 and VBS 300 are included. Glass batch material is introduced into the melting vessel 710 as indicated by arrow 712. The batch material is melted to form molten glass 726. The refining vessel 715 has a high temperature treatment area that receives the molten glass 726 from the melting vessel 710 and air bubbles are removed from the molten glass 726. The purification vessel 715 is fluidly coupled to the mixing vessel 720 by a connecting tube 722. The mixing vessel 720 is in turn fluidly coupled to the delivery vessel 725 by means of a connecting tube 727.

The delivery vessel 725 feeds the molten glass 726 into the FDM 741 through a downcomer 730. The FDM 741 includes an inlet 732, a forming vessel 735, and a pull roll assembly 740. As shown in FIG. 7, molten glass 726 from downcomer 730 flows into an inlet 732 leading to a forming vessel 735. The forming vessel 735 flows into a trough 737 and then an opening to receive the molten glass 726 that overflows from the two sides 738a, 738b before being fused at the root 739 and proceeds down. Including (736). The root 739 is where the two sides 738a, 738b converge and the two overflow walls of the molten glass 726 are recombined (e.g., reused) before being drawn downwards by the pull roll assembly 740 to be continuous. This is where the glass ribbon 15 is formed.

When the continuous glass ribbon 15 is ejected from the pull roll assembly 740, the molten glass solidifies. Due to the difference in the thickness of the molten glass at the edge and center of the continuous glass ribbon 15, the center of the continuous glass ribbon cools and solidifies faster than the edge of the continuous glass ribbon 15 and thereby from the edge of the continuous glass ribbon 15 to the center. Produces a temperature gradient of As the molten glass cools, the temperature gradient causes the stress to develop within the glass, which in turn causes the glass to flex or bend in the lateral direction (ie, in the direction of one edge of the glass to the other). Accordingly, it should be understood that the continuous glass ribbon 15 has a radius of curvature in the lateral direction.

Referring now to the glass manufacturing system 700 schematically illustrated in FIG. 7, the pull roll assembly 740 is a drawing (having a curved/curved shape in the manufacturing process at this point) with a sheet separation device 761. Delivered the continuous glass ribbon (15). The continuous glass ribbon 15 is delivered to a sheet separation device 761 that separates the glass sheet from the ribbon. The configuration of the sheet separating device is not specifically limited. An exemplary embodiment of a sheet separation device is disclosed in US Pat. No. 8,146,385, which is incorporated herein by reference in its entirety.

The carriage then transfers the glass sheet to VBS to remove the glass beads from the glass sheet. In an embodiment of the present invention, the VBS shown in FIG. 3 can be used to remove glass beads from the glass sheet. The glass sheet entered into the VBS may be cooled and may have a temperature from room temperature to about 450°C or even from about 100°C to about 400°C. In some embodiments, the glass sheet may have a temperature of about 150° C. to about 350° C. or even 200° C. to about 300° C. when the glass sheet enters the VBS. The method of using the VBS 300 to separate the beads of the glass sheet from the glass sheet 340 will now be described in more detail with reference to FIG. 3.

The glass sheet 340 may be pulled through the VBS 300 by any acceptable mechanism, such as a pull roller (not shown) or an upper-clamp conveyor (not shown), for example. If within the VBS 300, the surface of the glass sheet 340 opposite the scoring device 320 and the planarizing device 310 (ie, b-surface) may be supported by the nosing 345. As shown in FIG. 3, the flattening wheel 312 may initially be positioned on top of or near the glass sheet 340 in the y-direction. The low friction air cylinder 313 and the low friction sliding mechanism 314 can be retracted so that the flattening wheel 312 does not initially contact the glass sheet. The scoring device 320 may be positioned above the top of the glass sheet 340 in the y-direction as shown in FIG. 3. After the glass sheet is placed in the VBS 300, the shaft of the flattening device is extended, thereby causing the slide mechanism 314 to move in the positive x-direction. For example, in an embodiment where the actuator 313 is a low friction air cylinder 313, the shaft is extended by supplying air pressure to the low friction air cylinder. The low friction air cylinder can extend approximately halfway through its stroke. The extension of the low friction air cylinder allows the flattening wheel 312 to removably engage the glass sheet 340. The pressure applied to the glass sheet 340 by the flattening wheel 312 depends on the composition and thickness of the glass, the amount of curvature or twist to be removed, the wheel geometry, the wheel hardness, the sheet stiffness, and the required scoring area (i.e., tensile or compression). ) Can be changed. In an embodiment of the present invention, the pressure applied by the flattening wheel may be from about 10 psi to about 30 psi or even from about 15 psi to about 25 psi. In some embodiments, the pressure applied to the glass sheet 340 by the flattening wheel 312 may be about 20 psi.

After the low friction air cylinder 313 is extended and the flattening wheel is movably engaged with the glass sheet, the VBS can be moved in the negative y-direction, whereby the glass sheet 340 is attached to the scoring wheel 323. Allow the flattening wheel 312 to engage a portion of the glass sheet 340 before being scored by. As mentioned above, in an embodiment of the present invention, the scoring device 320 and the flattening device 310 may be connected by a scoring bar linkage 330. As such, the scoring device 320 and the planarizing device 310 travel along the glass sheet at the same speed and at a constant relative position. The flattening of the glass sheet occurs prior to the scoring touchdown and remains active throughout the scoring until the scoring wheel 323 is removed from the glass sheet, thereby providing a flattened area of the glass sheet throughout the scoring operation. Having the flattening wheel 312 in contact with the glass sheet prior to the scoring wheel 323 can smooth out any curvature in the glass sheet at or near the glass bead, which allows the scoring wheel to create a uniform vent in the glass sheet. Keep. Although not limited thereto, a vent can be defined as an indentation line formed in the sheet surface opening the surface to a certain depth. In an embodiment of the present invention, the vent line may extend into the surface of the glass sheet to a vent depth equal to the depth of the surface compression layer but less than the depth that will cause fracture within the glass sheet. In an embodiment of the present invention, the vent may extend in a vertical direction from one end of the glass sheet to the other end of the glass sheet.

After the flattening wheel 312 and scoring device 323 have traversed the entire height of the glass sheet (i.e., reached the bottom of the glass sheet in the y-direction), the low friction air cylinder 313 is retracted, and This causes the sliding mechanism 314 and the flattening wheel 312 to move in the negative x-direction so that the flattening wheel 312 is no longer in contact with the glass sheet 340. Likewise, the scoring wheel 323 can be retracted so that the scoring wheel is no longer in contact with the glass sheet. The scoring device 320 and the planarizing device 310 can then be moved in the positive y-direction to their initial position on or near the glass sheet 340 without contacting the glass sheet. The glass sheet can then be removed from the VBS, and a new glass sheet can be entered into the VBS.

VBS 300 may be moved in the y-direction by any suitable mechanism. In an embodiment of the present invention, the leveling device 310 and the scoring device 320 may be moved in the y-direction by an electro-mechanical actuator, a pneumatic cylinder, a hydraulic cylinder or an electric motor. Alternatively, the VBS 300 may be positioned as a robotic device such as a robot arm. In an embodiment of the present invention, the movement of the flattening device 310 and the scoring device 320 in the y-direction and the extension and retraction of the low friction air cylinder are, for example, a common controller or separate It should be appreciated that it can be synchronized with the separation of individual glass sheets from the continuous glass ribbon when controlled by the controller of the.

The method of separating the beads of the glass sheet from the glass sheet can be used in conjunction with a glass ribbon having a thickness of less than about 1.00 mm or even less than about 0.75 mm. In some embodiments, the thickness of the glass sheet may be less than about 0.50 mm or even less than about 0.30 mm. Although the VBS 300 and method described in the embodiments of the present invention can be used on a glass sheet of any thickness, using the VBS and method on a thin glass sheet provides a high yield (i.e., low incidence of glass breakage). can do. Typical yields when using thin glass such as 0.3t glass, for example, are about 30%. Yields using the VBS and methods described herein result in yields of about 80% or more and even up to 90%. However, it should also be understood that the techniques described herein may also be suitable for use in connection with glass sheets having a thickness greater than 1.00 mm.

The method described herein can be used to separate the beads of a glass sheet from a glass sheet, such as a glass sheet made by a melt drawing process or a similar down drawing process. It should be understood that stress, strain, and potential breakage of the glass ribbon during scoring can be significantly mitigated or eliminated by joining the glass sheet and the flattening wheel prior to scoring the glass sheet as described herein. Accordingly, it should be understood that the method described herein can be used to reduce the incidence of breakage in the glass sheet and thereby reduce waste and improve the throughput of the glass manufacturing system. It will be apparent to those skilled in the art that various modifications and changes may be made to the embodiments described herein without departing from the spirit and scope of the claimed subject matter. As such, this specification is intended to cover modifications and variations of the various embodiments described herein if they fall within the scope and equivalents of the appended claims.

Claims (24)

Is a glass sheet scoring machine,
A scoring device for scoring a sheet of glass, comprising a scoring wheel, wherein an axis of rotation of the scoring wheel is oriented horizontally;
A leveling device comprising a leveling wheel, wherein an axis of rotation of the leveling wheel is oriented horizontally;
A scoring bar linkage connecting the scoring device and the planarizing device;
As a support nosing, the support nosing is located oppositely spaced from the scoring device and the leveling device by the glass conveying path through the glass sheet scoring machine.
Glass sheet scoring machine comprising a. The glass sheet scoring machine of claim 1, wherein the flattening wheel and scoring device are positioned linearly in a vertical direction. The method of claim 2, further comprising a flattening wheel and a trailing flattening wheel positioned linearly on the scoring wheel, wherein the trailing flattening wheel is positioned on the opposite side of the scoring device instead of the flattening device, and between the flattening wheel and the trailing flattening wheel Glass sheet scoring machine with a distance of 10 mm or more. The method of claim 1, wherein the leveling device comprises an actuator movably coupled to the leveling wheel;
The leveling wheel is not in the glass conveying path when the actuator is in the retracted position;
The leveling wheel is present in the glass conveying path when the actuator is in the extended position,
Glass sheet scoring machine. The glass sheet scoring machine of claim 4, wherein the actuator is a low friction air cylinder. It is a method of removing beads from a glass sheet,
Positioning the glass sheet in the scoring device and a planarizing device including a planarizing device at or near one end of the glass sheet when the glass sheet is placed in the scoring device;
Extending the flattening mechanism toward the glass sheet such that the flattening mechanism is in movable contact with the glass sheet and the glass sheet is in close contact between the flattening mechanism and the supporting nosing;
Flattening a portion of the glass sheet by moving the flattening device along the length of the glass sheet to opposite ends of the glass sheet;
Scoring a portion of the glass sheet by moving the scoring device along the length of the glass sheet to the opposite end of the glass sheet.
Including,
The flattening mechanism flattens a portion of the glass sheet before the portion of the glass sheet is scored,
Way. 7. The method of claim 6, further comprising: retracting the flattening mechanism so that the flattening mechanism is no longer in contact with the glass sheet;
Repositioning the planarizing device and the scoring device at or near one end of the glass sheet.
How to further include. 7. The method of claim 6, wherein the flattening device is extended by actuating a low friction air cylinder that moves the flattening mechanism towards the surface of the glass sheet. 8. The method of claim 7, wherein the steps of extending, smoothing, scoring, retracting and relocating are controlled by timing sequence logic. 7. The method of claim 6, wherein a pressure of 10 psi (6.89 x 10 ⁴ Pa) to 30 psi (2.07 x 10 ⁵ Pa) is applied to the glass sheet by the flattening device when the flattening device is extended. delete delete delete delete delete delete delete delete delete delete delete delete delete delete

Images