KR20180021914A - Method and apparatus for edge finishing of glass substrates - Google Patents

Abstract

A glass support system for a glass edge finishing apparatus includes a vacuum member configured to extend long in the glass feed direction along the edge of the glass substrate. The vacuum member has a vacuum body including a pressure chamber therein and a support surface extending therethrough and having an array of vacuum openings communicating with the pressure chambers. The arrangement of the vacuum openings is arranged in a plurality of parallel rows and the spacing between the vacuum openings along each of the plurality of rows is substantially uniform.

Description

Method and apparatus for edge finishing of glass substrates

This application claims priority to U.S. Provisional Application No. 62 / 194,952, filed July 21, 2015, under 35 U.S.C. §119, which is dependent upon the contents of this application and is incorporated herein by reference in its entirety.

This disclosure relates to methods and apparatus for edge finishing of glass substrates, and more particularly to methods and apparatus used to increase the symmetry of edge beveling.

Conventional glass edge finishing devices have been developed for relatively thick glass substrates that have relatively high stiffness compared to mostly thin glass substrates. In one example, the glass sheet is formed through mechanical scoring and breaking processes and then has an edge that is generally polished using an abrasive grinding wheel. In certain applications, for example in the automotive industry, it may be desirable to provide a round profile on the edge of the glass sheet at the periphery of the glass sheet.

Flat panel displays and other applications often use glass sheets that are much thinner than those used in the automotive industry. Thin glass sheets can have reduced stiffness and increased flexibility compared to thick glass sheets. The edge finishing of such a thin glass sheet with reduced stiffness and increased flexibility can cause problems at least in part due to the forces involved in the edge finishing process. Accordingly, there is a need for a method and apparatus for edge finishing of a glass substrate comprising a relatively thin glass substrate.

One technique for improving the mechanical reliability of the flexible glass substrate is to grind and polish the edge of the flexible glass substrate so as to obtain a predetermined edge strength, for example, to prevent undesired cracks and cracks in the flexible glass layer It is to remove fractures. To this end, a method and apparatus for finishing a glass substrate that provides a rounded edge in a process referred to herein as a bevel ring, effectively terminating the glass substrate using an edge finishing apparatus, is described herein.

According to one embodiment, a glass support system for a glass edge finishing apparatus includes a vacuum member, for example a vacuum chuck configured to extend along the glass feed direction and the edge of the glass substrate. The vacuum member includes a vacuum body including a pressure chamber located therein and a support surface including an array of vacuum openings extending therethrough and communicating with the pressure chamber. The arrangement of the vacuum openings is arranged in a plurality of parallel rows and the spacing between the vacuum openings along each row of the plurality of rows is substantially uniform.

According to another embodiment, the glass edge finishing apparatus comprises a glass conveying system and a glass support system which is moved in the glass feeding direction by a glass conveying system. The glass support system may be configured to support a glass substrate having a thickness of about 0.7 mm or less. The glass substrate generally includes a flat surface and an out-of-plane orientation that is generally perpendicular to the flat surface. The glass supply direction is perpendicular to the out-of-plane direction. The glass support system may include a vacuum member, for example a vacuum chuck configured to extend along the glass feed direction and the edge of the glass substrate. The vacuum member may include a vacuum body including a pressure chamber located therein, and may further include a support surface including an array of vacuum openings extending therethrough and communicating with the pressure chamber. The vacuum opening arrangement may include at least about 25 openings per 100 square centimeters of support surface area.

According to another embodiment, a method of finishing an edge of a glass substrate having a thickness of about 0.7 mm or less is provided. The method includes supporting a glass substrate on a glass support system. The glass substrate generally includes a flat surface, an out-of-plane direction that is generally perpendicular to the flat surface, and a glass feed direction that is perpendicular to the out-of-plane direction. The glass support system may include a vacuum member, for example, a vacuum chuck configured to extend along a glass feed direction and an edge of the glass substrate. The vacuum member may include a vacuum body including a pressure chamber disposed therein, and the support surface may include an array of vacuum openings extending therethrough and in communication with the pressure chambers. The arrangement of the vacuum openings may comprise at least about 25 openings per 100 square centimeters of support surface area. A negative pressure can be applied to the generally flat surface facing the vacuum member through the arrangement of vacuum openings. The edge of the glass substrate may be beveled using an abrasive wheel assembly.

According to yet another embodiment, a glass edge finishing apparatus includes a glass delivery system and a glass support system that is moved in a glass feed direction by a glass delivery system. The glass support system may be configured to support a glass substrate having a thickness of about 0.7 mm or less. The glass substrate generally includes a planar surface and an out-of-plane orientation that is generally perpendicular to the planar surface. The glass supply direction is perpendicular to the out-of-plane direction. The glass support system may include a vacuum member, for example a vacuum chuck configured to extend along the glass feed direction and the edge of the glass substrate. The vacuum member may include a vacuum body including a pressure chamber disposed therein, and a support surface extending through and having a plurality of vacuum openings in communication with the pressure chamber. A grinding wheel assembly may also be provided, wherein the grinding wheel assembly is configured to bevel the edges of the glass substrate while the glass substrate is being moved in the glass feeding direction by the glass delivery system. An edge guiding assembly may be positioned between the polishing wheel assembly and the vacuum member and may include a lower edge guiding member spaced from the upper edge guiding member such that a passage through which the upper edge guiding member and the glass substrate can be provided is provided.

Additional features and advantages described herein will be set forth in part in the description which follows, and in part will become apparent to those skilled in the art from the description, or may be learned by practice of the invention, including the following detailed description of the invention, And will be recognized by practicing the embodiments described herein.

It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory and are intended to provide further explanation of the nature and characteristic of the claimed subject matter. The accompanying drawings are included to provide a further understanding of the various embodiments, and are incorporated in and constitute a part of this specification. The drawings illustrate various embodiments described herein and serve to explain the principles and operation of the claimed subject matter in conjunction with the description of the invention.

BRIEF DESCRIPTION OF THE DRAWINGS These and other features, aspects and advantages of the present disclosure will become better understood when the following detailed description of the present disclosure is read with reference to the accompanying drawings,
Figure 1 shows a beveled edge of a glass substrate;
Figure 2 shows a plot showing the relationship between the out-of-plane vertical displacement of the glass edge and the resulting edge bevel asymmetry;
Figure 3 is a schematic view of a glass finishing apparatus;
4 is a detailed view of a vacuum member and a glass substrate used in the finishing apparatus of Fig. 3;
Figure 5 shows a plot showing the glass edge flatness;
Figure 6 is a top view of the vacuum member of Figure 4 shown separately;
Figure 7 is a perspective view of an exemplary vacuum member;
Figure 8 is a cross-sectional view of the vacuum member of Figure 7;
9 is a cross-sectional view of another exemplary vacuum member;
10 is a cross-sectional view of yet another exemplary vacuum member;
11 is a top view of yet another exemplary vacuum member;
12 is a plan view of another exemplary vacuum member;
13 is a top view of yet another exemplary vacuum member;
Figure 14 is a schematic view of a glass support structure comprising a plurality of vacuum members;
Figure 15 is a schematic detail view of a polishing wheel used in the glass finishing apparatus of Figure 3;
16 is a plot showing reduced edge bevel asymmetry provided through a regular distribution of vacuum openings;
17 is a plot of glass stiffness for a position along a glass substrate;
18 is a plot of the flexural rigidity of the glass substrate against the glass substrate thickness;
19 is a schematic view of an edge induction assembly and a grinding wheel;
20 is a schematic view of an edge guiding assembly;
21 shows a glass edge finishing apparatus;
Figure 22 shows the glass edge finishing apparatus of Figure 21 as viewed in a different direction;
Figure 23 shows another glass edge finishing apparatus;
Figure 24 shows the glass edge finishing apparatus of Figure 23 as viewed in a different direction;
25 is a schematic view of an edge guiding assembly;
Figure 26 is another view of an edge guiding assembly;
Figure 27 is another view of an edge guiding assembly;
Figure 28 shows an exemplary plot showing reduced edge bevel asymmetry provided through use of an edge induction assembly.

Glass is an intrinsically strong material, but its strength and mechanical stability are a function of its surface defect or defect size density distribution, and cumulative exposure to stress of material over time. The edge strength may be an important factor for the mechanical stability of the glass substrate. During the entire product life cycle, glass substrates can undergo a variety of static and dynamic mechanical stresses. Embodiments described herein generally relate to a method and apparatus for glass substrate finishing that efficiently finishes a glass substrate using an edge finishing apparatus and increases the edge strength and mechanical stability of the glass substrate.

Glass substrates trimmed from glass ribbons or larger glass substrates tend to have sharp edges formed during trimming operations. The sharp edges of the glass substrates are susceptible to damage during handling. Edge defects, such as chips, cracks, etc., can reduce the strength of the glass. The edges of the glass substrate can be treated to remove sharp edges by grinding and forming, e.g., beveling, to remove sharp edges that are easily damaged. By removing the sharp edges from the glass substrate, defects in the glass substrate can be minimized, thereby reducing the possibility of damage to the glass plate during handling.

A variety of grinding wheels can be used to polish and shape the edges of the glass substrate and include the use of "cup" wheels and "molded" wheels. The cup wheel is generally circular and includes a recessed central area spaced from the circumference of the cup wheel. When the cup wheel contacts the glass substrate, the flat surface of the cup wheel contacts the glass substrate and the circumferential surface of the cup wheel is spaced from the glass substrate. The formed wheel includes a groove located at the edge of the circumferential surface of the formed wheel. The grooves include a profile corresponding to the shape in which the substrate edge is to be machined. The grooves of the molded wheel come into contact with the edges of the glass substrate to polish and shape the edges.

1, which shows an exemplary substrate edge 12, the term "first surface" and other variations thereof are used herein to denote a relatively flat first region of the glass substrate 10. [ The first surface is represented by 14 in Fig. Similarly, the term " second surface " and other variations thereof are used herein to denote a relatively flat second region of the substrate 10 that is substantially parallel to the first surface 14. The second surface is represented by 16 in Fig.

The first bevel, the "first bevel" and other variations thereof are used to indicate a first portion of the substrate edge located between the first surface 14 of the substrate edge 12 and the apex 18 Is used herein. The first bevel is indicated by 20 in Fig. Likewise, "second bevel "," second beveled portion "and other variations thereof are used herein to denote a second portion of the substrate edge located between the second surface 16 and the vertex 18. The second bevel is indicated by 22 in Figs. In certain embodiments, the first and second bevels 20, 22 may be curved as shown in Fig. However, the first and second bevels may be relatively flat in other, non-limiting embodiments.

The term "vertex" and other variations thereof are used herein to refer to the end regions of the substrate edge 12 where the first and second bevels 20,22 converge. Figure 1 shows the apex 18 as a flat area with a predetermined length but the apex 18 has a first and a second edge 18 so that the substrate edge 12 is a substantially continuous curve from the surface 14 to the surface 16. [ 2 It may be a finite point where the bevel meets.

The term "first beveled surface interface" and other variations thereof are used herein to denote the region in which the first beveled portion meets the relatively flat first surface 14. The first bevel plane interface is represented by 26 in FIG. Similarly, the term "second bevel surface interface" and other variations thereof are used herein to denote a region in which the second bevel portion meets a relatively flat second surface 16. The second bevel surface interface is represented by 28 in FIG.

The glass substrate 10 may have a thickness 30 of less than about 0.3 mm, for example in the range of about 0.01 to about 0.200 mm, such as in the range of about 0.05 mm to about 0.1 mm, for example in the range of about 0.1 to about 0.15 mm, About 0.15 to about 0.3 mm, about 0.100 to about 0.200 mm, and all ranges and subranges therebetween. Exemplary thicknesses are in the range of 0.3, 0.275, 0.25, 0.225, 0.2, 0.19, 0.18, 0.17, 0.16, 0.15, 0.14, 0.13, 0.12, 0.11, 0.10, 0.09, 0.08, 0.07, 0.06, 0.05, 0.04, 0.03, Or 0.01 mm. In some embodiments, the glass substrate 10 may have a thickness 30 of about 0.7 mm or less. The glass substrate 10 may be formed of glass, glass ceramic, or a composite thereof. A fusion process (i.e., a downdraw process) to form high quality glass substrates can be used in a variety of devices, one of which is a flat panel display. The glass substrate produced by the fusion process has a surface with excellent flatness and smoothness compared to glass substrates produced by other methods. Fusion processes are described in U.S. Patent Nos. 3,338,696 and 3,682,609. Other suitable methods of glass substrate formation include float processes, updraw and slot draw methods.

For a relatively thin glass substrate 10 (about 0.7 mm or less), the first bevel surface interface 26 for the horizontally oriented glass substrate 10 and the second bevel surface < RTI ID = 0.0 > The symmetrical shape characteristic of the interface 28 may have a direct effect on the edge resistance to plastic deformation during bending of the glass substrate 10. [ The edge asymmetry between the first bevel portion 20 and the second bevel portion 22, sometimes referred to herein as "edge bevel asymmetry ", is directly related to the edge strength of the glass substrate 10. The edge bevel asymmetry can be measured by the respective widths (W ₁ , W ₂ ) of the first and second bevel portions 20, 22 to the vertex 18 in the direction of the substrate thickness 30. The deflection (vertical displacement) of the substrate edge 12 out of the plane of the glass substrate 10 during the beveling process can cause edge bevel asymmetry. Figure 2 shows an exemplary relationship between the deflection of the substrate edge 12 and the resulting edge bevel asymmetry in a glass substrate 10 having a thickness of about 0.5 mm. As can be seen, deflection of the substrate edge 12 in the positional range R substantially increases (indicated by line 31), resulting in increased edge bevel asymmetry (indicated by lines 32 and 40).

The edge horizontal flatness (e.g., minimum vertical displacement) can be affected by the effectiveness of the support during the beveling process, especially for thin glass substrates 10. 3, a glass edge finishing apparatus 40 suitable for performing a beveling process includes a support apparatus 42 including a glass conveying system 44 and a glass support system 46. As shown in FIG. The glass delivery system 44 may move (i.e., translate) the glass support system 46 in a dispensing direction that may be generally aligned with the edge 48 of the glass substrate 50. The glass support system 46 may be transported in the feed direction by the glass delivery system 44 or otherwise moved. The glass support system 46 may include an edge vacuum member such as a vacuum chuck extending along the substantially entire length of the glass substrate 50 in the feed direction along both edges 48 and 58 of the glass substrate 50 54, 56). In some embodiments, the vacuum member 54, 56 may be formed of one elongated vacuum member. In other embodiments, for example, a plurality of vacuum members may be used and aligned in the feed direction. Although only the edge vacuum members 54, 56 are shown, an inner vacuum member may also be used (see Figure 14)

Fig. 4 shows a detailed view of the vacuum member 56 and the glass substrate 50. Fig. The vacuum member 56 may apply sufficient vacuum suction force to suppress movement (horizontal and vertical) of the edge 48 of the glass substrate 50 during the beveling process. As used herein, "vacuum suction force" refers to the cumulative area of all vacuum openings of the vacuum member 56 multiplied by the suction pressure. As can be seen, the vacuum suction force may be applied by a vacuum member 56 close to and spaced from the edge 48 of the glass substrate 50. This position of the vacuum member 56 forms a protruding area 60 of the glass substrate 50 having an overhang distance D _OH measured from the outer edge 62 of the vacuum member 56, The overhang begins at edge 48 in a direction perpendicular to edge 48 (or feed direction). In some embodiments, the overhang distance D _OH may be greater than about 6 mm, such as greater than about 10 mm, such as greater than about 15 mm, such as greater than about 20 mm. In some embodiments, the overhang distance D _OH may be between about 5 mm and 30 mm.

As described below, the vacuum member 56 has an array 64 of vacuum openings 66, and one or more areas of the array 64 may have a square, regular, or even distribution of vacuum openings 66 (E.g., rows and / or columns). The placement of the array 64 of vacuum openings 66 creates a relatively flat edge 48 of the glass substrate 50 at the free end edge 48 during beveling or other edge finishing operations, (FIG. 1) between the first bevel surface interface 26 and the second bevel surface interface 28 on the glass substrate 50 (FIG. 1). For example, Figure 5 shows edge flatness for a glass substrate having 0.5 mm and 0.3 mm thickness at various overhang distances and pressure values. As can be seen, the minimized vertical displacement of the glass edge can be achieved for example at less than about 0.1 mm over at least a portion, most or all of the length of the glass substrate.

Referring to Figure 6, the vacuum member 56 is shown separately and includes a vacuum body 70 that provides an arrangement 64 of pressure chambers and vacuum openings 66 disposed therein. The vacuum opening 66 communicates with the channel 67 extending from the support surface 72 of the vacuum member 56 and into the pressure chamber located within the vacuum body 70 (Fig. 8). 7 and 8, in some embodiments, the support surface 72 may be provided by a flexible member 74, which may be a layer of a flexible member (e.g., silicone, rubber, soft plastic, etc.) And is suitable for supporting the glass substrate thereon without contact and being in contact with the glass substrate 50. The compliant member 74 includes a vacuum opening 66 that mates with an array of openings 76 provided by the vacuum body 70 to provide a channel 67 between the vacuum opening 66 and the pressure chamber 78. [ (Fig. 8). The vacuum body does not coincide with the array 64 of vacuum openings 66 of the support surface 72 but may be a slot that can distribute negative pressure from the pressure chamber 78 to the arrangement and / And may include openings. The vent shown by arrow 75 may be provided to vent air or other suitable gas from the pressure chamber 78.

The vacuum member may be a single-piece or multi-piece construction. Referring to FIG. 9, for example, the vacuum member 81 may have a vacuum body 83 having a monolithic configuration. The vacuum body 83 is formed as a part of a pressure chamber 85 provided therein and a vacuum body 83 separate from the pressure chamber 85 and connected to the vacuum chamber 82 via a connect arrangement 87). The inlet port 77 and the outlet port 79 can supply positive pressure and negative pressure to the pressure chamber 85. 10 shows a multi-piece configuration in which a vacuum member 91 includes a vacuum body 93 formed by a chamber housing member 95 and a cap member 97. Fig. A connect arrangement 99 may be provided for connecting the vacuum member 91 to the glass delivery system.

6, the vacuum opening 66 of the array 64 can provide a localized suction point by being located in both the R ₁ -R _x row and the C ₁ -C _x column. In this example, the vacuum openings 66 in a particular R row have substantially the same width or, in this example, a radius (e.g., about 5 mm or less, e.g., about 2 mm or less) And are spaced apart from each other at equal intervals. In other embodiments, the one or more vacuum openings may have one or more different radii. In one example, adjacent vacuum openings 66 may be equally spaced about 20 millimeters across a particular R row. In other embodiments, the spacing between adjacent vacuum openings 66 may be less than 20 mm, for example about 15 mm or about 10 mm, or even less, depending on the size of the glass substrate, the type of finishing operation . In the embodiment of Figure 6, the vacuum openings 66 are equally spaced apart by a center-to-center distance of 10 mm, as indicated by S ₁ .

The vacuum openings 66 in a particular row of columns have substantially the same radius (e.g., less than or equal to about 5 mm, e.g., less than or equal to about 2 mm) and are spaced equally from one another along a particular C row. In another embodiment, the at least one vacuum opening has at least one different radius. In one example, adjacent vacuum openings 66 may be equally spaced along a particular row of C by about 20 mm. In other embodiments, the spacing between adjacent vacuum openings 66 along a particular row C may be less than 20 mm, for example about 15 mm or about 10 mm, depending on the size of the glass substrate, the type of finishing operation, It may even be less than that. In the embodiment of Figure 6, the vacuum openings 66 are equally spaced by a center-to-center distance of 10 mm, as indicated by S ₂ , to form a rectangular matrix of vacuum openings.

Any suitable arrangement of vacuum openings forming a localized suction point may be used. In some embodiments, an arrangement with about 25 vacuum openings to about 200 vacuum openings per 100 cm2 with a width (or diameter) of about 10 mm or less, e.g., 4 mm or less, may be provided. In the embodiment of Figure 6, the array 64 has about 100 vacuum openings 66 per 100 square centimeters.

Figures 11-13 illustrate another vacuum member embodiment having a different arrangement for a vacuum opening. In the embodiment of Figure 11, the vacuum member 80 includes many of the features described above with respect to the vacuum member 56. [ In this exemplary embodiment, the vacuum member 80 provides a localized suction point by including an array of vacuum openings 84 located in both the R ₁ -R _x row and the C ₁ -C _x column. In this embodiment, however, the row spacing S ₁ is greater than the column spacing S ₂ along the row. Figure 12 line spacing along the line (S ₁₎ it is shown another exemplary embodiment of a large vacuum member 81 than row spacing (S ₂₎ along the column. Figure 13 line spacing along the line (S ₁₎ it is shown another exemplary embodiment of a large vacuum member 86 than row spacing (S ₂₎ along the column. In this embodiment, the rows are offset from each other to form a row in the diagonal direction. The table below shows some characteristics when using a glass substrate with a thickness of 0.2 mm under an applied pressure of 50 kPa of the vacuum member embodiment shown in Figs. 5 and 11-13. These values are by way of example only and not by way of limitation.

Example of Vacuum Member Example Explanation Overall suction slot area (㎟) Vacuum suction force (N) Reaction force
(N) Maximum principal stress (MPa) 5 R _aperture = 2 mm
Spacing = 10 mm (S ₁ ) and 10 mm (S ₂ )
Glass dimensions = 0.2 mm x 925 mm x 225 mm 4551.0 364.1 360.1 13.7 11 R _aperture = 2 mm
Spacing = 15 mm (S ₁ ) and 10 mm (S ₂ )
Glass dimensions = 0.2 mm x 925 mm x 225 mm 3050.0 244.0 241.8 14.8 12 R _aperture = 2 mm
Spacing = 20 mm (S ₁ ) and 10 mm (S ₂ )
Glass dimensions = 0.2 mm x 925 mm x 225 mm 2312.1 185.0 182.1 17.3 13 R _aperture = 2 mm
Spacing = 20 mm (S ₁ ) and 10 mm (S ₂ )
Glass dimensions = 0.2 mm x 925 mm x 225 mm 2263.0 181.0 159.0 17.3

As can be seen from the above table, the maximum principal stress calculated using a finite element analysis (FEA) can be less than 20 MPa stress during use, which can reduce the possibility of glass damage at or near the edge of the glass substrate. The maximum principal stress shows the total tensile stress effect on the glass substrate.

14, there is shown an exemplary glass support system 100 (e.g., that can be used in the finishing apparatus of FIG. 3) that includes a plurality of vacuum members 102,104, 106,108. In one example, the vacuum member may be any one or more of the above-described vacuum members. As can be seen, the vacuum members 102 and 108 are the outermost vacuum members closest to the edges 110 and 112 of the glass substrate 114 and the vacuum members 104 and 106 are the edges 110 and 112, Is the innermost vacuum member. The vacuum members 102, 104, 106, and 108 may all be the same size (or different dimensions) and may extend substantially along the entire length of the glass substrate 114. Overhang areas 116 and 118 may be provided for a glass finishing operation as described above.

3, once the glass substrate 50 is supported by the glass support system 46, the glass substrate 50 and the glass support system 46 are transferred to the finisher 40 by the glass transport system 44, To the edge polishing system 120 of FIG. The edge polishing system 120 may include a polishing wheel assembly 122, 124 generally located at the edges 48, 58 of the glass substrate 50. In another embodiment, only one abrasive wheel assembly may be used, or up to four abrasive wheel assemblies may be present, or one at each edge 48, 58, 126, 128 of the glass substrate 50 .

The grinding wheel assemblies 122 and 124 each include a grinding wheel 127 and a motor 129 used to rotate the grinding wheel 127, respectively, used to grind and shape the edges 48 and 58 of the glass substrate 50, . ≪ / RTI > In some embodiments, the polishing wheel assemblies 122 and 124 may further include a driving device 130 that may be used to move the polishing wheel 127 close to or away from each edge 48 and 58. A control 135 may be provided to control the operation of the polishing wheel assemblies 122, 124, the glass support system 46, and the glass delivery system 44. In the illustrated embodiment, the grinding wheel 127 is a molded wheel. However, other grinding wheels may be used. 15, molded wheel 127 has a generally cylindrical shape and has a profile that is complementary to the profile desired for each edge 48, 58 and serves as the abrasive surface of molded wheel 127 (Not shown). In another embodiment, one or both of the abrasive wheels 127 may include a pair of cup wheels in contact with the edge of the glass substrate 50 on its flat side.

3, with the glass substrate 50 supported by the glass support system 46 including the vacuum members 54, 56, the glass delivery system 44 is supported by the support system 46 and the glass The substrate 50 translates to the polishing wheel assemblies 122 and 124 and the polishing wheel 127 engages the edges 48 and 58 of the glass substrate 50. Referring now to FIG. 16, there is shown a representative plot showing the reduced edge bevel asymmetry provided by the regular distribution of vacuum openings, for example, as shown by the vacuum member 56 of FIG. As can be seen, the vacuum member 56 further stabilizes the edge 48, which allows the first bevel surface interface 26 (shown by line 140) and the second bevel surface interface 28 ) In a relatively high degree of symmetry. The asymmetry factor (FOA) indicated by line 144 represents a relatively small change in the symmetry between the first bevel plane interface 26 and the second bevel plane interface 28. The FOA is equal to the bevel delta (difference in bevel width) between the first bevel plane interface 26 and the second bevel plane interface 28 and the thickness of the glass substrate 50. The higher the FOA, the lower the symmetry between the first bevel plane interface 26 and the second bevel plane interface 28.

16, it can be seen that the FOA tends to increase in the front region 150 and the rear region 152 (e.g., at the corners) of the glass substrate 50. 17, the rigidity of the edges 48, 58 at the leading and trailing corners 154, 156, 158, 160 relative to the total overhang edges 48, 58 (FIG. 3) For example, as low as 60%). In addition, as shown in Fig. 18, flexural rigidity D tends to remain relatively low for a glass substrate thickness of less than about 0.6 mm, and relatively flat at about 0.25 mm or less. Flexural stiffness (D) is a function of Young's modulus (E), thickness (t) and Poisson's ratio (v)

In addition to having low stiffness, the inlet leading corners 154 and 156 of the glass substrate 50 (Figure 3) are subject to a sudden impact of coolant fluid (e.g., water) and abrasive wheel 127 , Which may result in a greater vertical displacement of the glass substrate 50 during the beveling process. The edge quality near corners 154, 156, 158, 160 may be lower than expected in some cases due to edge bevel asymmetry, which can lead to glass cracking and breakage problems, especially during handling.

Referring again to FIG. 3, the finisher 40 may include an edge guide assembly 170 that provides local support to the glass edges 48, 58 at the wheel / glass interface. As can be seen, the edge guide assembly 170 is stationary relative to the glass delivery system 44 outside the vacuum member 54, 56 for increased vertical support of the glass edges 48, 58, And between the vacuum members 54,56 and their respective abrasive wheels 127, as shown in FIG. 19 shows a schematic view of a grinding wheel 127 and an edge guiding assembly 170. Fig. In this embodiment, the induction length L that is in contact with and supported by the glass substrate is not more than the wheel diameter D of the grinding wheel. The distance T between the edge guide assembly 170 and the grinding wheel 127 in contact with the glass substrate 50 can be adjusted to minimize the overhang distance D _OH based at least in part on the glass thickness, Lt; RTI ID = 0.0 > stability. ≪ / RTI >

Referring to FIG. 20, a schematic diagram of an edge guide assembly 170 includes a lower edge guide member 172 and a top edge guide member 174. The lower edge guide member 172 includes a guide surface 176 disposed to contact a wide surface 178 of the glass substrate 50. The upper edge guiding member 174 also includes a guiding surface 180 facing the guiding surface 176 disposed to contact the broad surface 182 of the glass substrate 50. The guide surfaces 176, 180 may be rigid or formed of motion elements such as rollers, belts, etc., as described below. The guide surfaces 176 and 180 may be formed of any material suitable for contacting and guiding the glass substrate 50. One or both of the upper edge guiding member 174 and the lower edge guiding member 172 between the closed and open states (shown in phantom) for positioning the glass substrate 50 during the beveling process One or more positioning actuators 184 and 186 (e.g., pneumatic cylinders) that can move toward or away from each other. In other embodiments, one or both of the upper and lower edge guide members 174 and 172 may be fixed in position relative to one another.

21 and 22, a dressing apparatus 200 including a polishing wheel assembly 202 that includes a polishing wheel 204 and a support structure 206 that supports the polishing wheel 204 in the illustrated elevated horizontal orientation ). The finishing apparatus 200 may further include an edge guiding assembly 208. The edge guiding assembly 208 may include a lower edge guiding member 210 and a upper edge guiding member 212. The rollers 205 and 215 (205 and 215 in Figs. 21 and 22) that form the dynamic support surface configured to contact and guide the edge of the glass substrate both the lower edge guide member 210 and the upper edge guide member 212 215). 21, the edge guide assembly 208 is shown in an open state in which the upper edge guide member 212 is retracted from the lower edge guide member 210 by the actuator assembly 214. As shown in FIG. The lower edge guide member 210 may be fixed at a predetermined position. In some embodiments, the edge guide assembly 208 may be supported at least partially by a support structure 206 that supports the polishing wheel 204. In some embodiments, at least a portion of the edge guide assembly 208 includes a self supporting structure that is independent of the support structure 206. The actuator assembly 214 may move the upper edge guide member 212 to an extended position that is closer to the lower edge guide member 210 to support the edge of the glass substrate (FIG. 22).

23 and 24, another finishing device 220 includes a polishing wheel assembly 222 that includes a polishing wheel 224 and a support structure 226 that supports the polishing wheel 224 in the elevated horizontal orientation shown, . The finishing device 220 further includes an edge guidance assembly 228. The edge guiding assembly 228 includes a lower edge guiding member 230 and a top edge guiding member 232. Both the lower edge guiding member 230 and the upper edge guiding member 232 include a roller 235 that forms a dynamic support surface that is configured to contact and guide the edge 234 of the glass substrate 236. 23 and 24, the edge guiding assembly 234 is configured such that the lower edge guiding member 230 is pivoted by the actuator assembly 238 toward the upper edge guiding member 232 in a closed or closed state do. The upper edge guiding member 232 can be fixed at a predetermined position.

25, another edge guiding assembly 250 is shown and may include a lower guiding member 252 and an upper guiding member 254. In this embodiment, both the lower and upper guide members 252, 254 include belt assemblies 256, 258. The belt assembly 256 of the lower guide member 252 includes a belt 260 having an inductive surface 262 suitable to contact and guide the glass substrate. The belt 260 is supported by intermediate rollers 268 which can support the area of the belt 260 between the end rollers 264 and 266 and the end rollers 264 and 266, And can be driven. The belt assembly 258 of the upper guide member 254 includes a belt 269 having a guide surface 270 suitable to contact and guide the glass substrate. The belt 269 is supported and driven by terminating rollers 272 and 274 on which the belt 260 can be wound without the use of intermediate rollers. The edge guide assemblies 250 show lower and upper guide members 252, 254 having different roller arrangements, but they may have the same roller arrangement.

Referring to Figure 26, another edge guide assembly 280 is shown and includes a lower guide member 282 and an upper guide member 284. In this embodiment, both lower and upper guide members 282, 284 may be formed of rigid rods 286, 288 of material suitable for contacting the glass substrate. The lower guide member 282 and the upper guide member 284 may be spaced apart from each other to form a groove 290 of a size that extends in the feeding direction and accommodates the entire thickness of the glass substrate. In some embodiments, the groove 290 may include a lead-in portion 292 and a lead-out portion 294. The lead-in portion 292 and the lead-out portion 294 are wider than the rest of the groove 290 between them, so that the glass substrate can be guided to the inside and the outside of the groove.

27, another edge guiding assembly 300 is shown and includes a lower guiding member 302 and an upper guiding member 304. In this embodiment, the upper guide member 304 is formed of a rigid rod 306 of material suitable for contacting the glass substrate. The lower guide member 302 has a dynamic guide surface 308 formed by the roller 310. In other embodiments, the upper and / or lower guide member may be formed using air bearings, air / pressure bearings, or ultrasonic non-contact bearings.

28 illustrates a representative plot showing reduced edge bevel asymmetry provided through use of an edge guiding assembly, as shown by, for example, the edge guiding assembly 300 of FIG. As can be seen, the edge inducing assembly 300 further stabilizes the edge, which provides a relatively high degree of freedom between the first bevel plane interface (represented by line 312) and the second bevel plane interface (represented by line 314) Keep symmetry. The FOA indicated by line 316 represents a relatively small change in symmetry between the first bevel plane interface and the second bevel plane interface.

The glass support systems and methods described above provide one or both of a vacuum member with an array of regularly spaced and localized suction points and an edge guiding assembly that can be used to reduce glass edge asymmetry during beveling or other finishing operations . The reduction in glass edge asymmetry can be achieved by reducing the out-of-plane deflection of the glass substrate and by providing a flat edge on the grinding wheel. Improvement of glass edge symmetry can improve glass edge strength, which can reduce the possibility of glass breakage or breakage.

It will be apparent to those skilled in the art that various modifications and variations can be made to the embodiments described herein without departing from the spirit and scope of the claimed subject matter. Accordingly, this specification is intended to cover such modifications and changes as come within the scope of the appended claims and their equivalents as are the modifications and variations of the various embodiments described herein.

Claims (30)

As a glass support system,
A vacuum body configured to extend in the glass feed direction along the edge of the glass substrate and including a pressure chamber disposed therein and a support surface including an array of vacuum openings extending therethrough and communicating with the pressure chamber And a vacuum member,
Wherein the array of vacuum openings is arranged in a plurality of parallel rows and the spacing between vacuum openings along each of the plurality of rows is substantially uniform. The method according to claim 1,
Wherein the arrangement of the vacuum openings is arranged in a plurality of parallel rows and the spacing between the vacuum openings along each of the plurality of rows is substantially uniform. The method according to claim 1,
Wherein the arrangement of vacuum openings has at least about 25 openings per 100 square centimeters of support surface area. The method according to claim 1,
Wherein the vacuum opening has a width of about 10 mm or less. The method according to claim 1,
Wherein the vacuum opening has a radius of about 2 mm or less. The method according to claim 1,
Wherein the support surface comprises a flexible material. The method according to claim 1,
An upper edge guiding member and a lower edge guiding member spaced from the upper edge member such that a passage through which the glass substrate can move is provided. 8. The method of claim 7,
Wherein at least one of the upper edge guiding member and the lower edge guiding member comprises a roller forming a dynamic support surface configured to contact the glass substrate. 8. The method of claim 7,
Wherein at least one of the upper edge guiding member and the lower edge guiding member comprises a bar of material configured to contact a glass substrate. 8. The method of claim 7,
Wherein at least one of the upper edge guiding member and the lower edge guiding member comprises a belt assembly including a belt including a guiding surface configured to contact a glass substrate. As a glass edge finishing apparatus,
Glass transport system; And
Wherein the glass support system is configured to support a glass substrate having a thickness of about 0.7 mm or less, the glass substrate having a generally planar surface and the generally Wherein the glass support system comprises a vacuum member configured to extend long in the glass feed direction along an edge of the glass substrate, the vacuum member having an out-of-plane orientation perpendicular to the flat surface, A support body including a vacuum body including a pressure chamber located therein and a support surface including a vacuum opening arrangement having an aperture density of at least about 25 apertures per 100 square centimeters of support surface area communicating with the pressure chamber,
The glass edge finishing device comprising: 12. The method of claim 11,
Wherein the arrangement of the vacuum openings is arranged in a plurality of parallel rows and the spacing between the vacuum openings along each of the plurality of rows is substantially uniform. 13. The method of claim 12,
Wherein the arrangement of vacuum openings is arranged in a plurality of side by side rows and the spacing between vacuum openings along each of the plurality of rows is substantially uniform. 12. The method of claim 11,
Wherein the vacuum opening has a width of about 10 mm or less. 12. The method of claim 11,
The vacuum opening has a width of about 4 mm or less. 12. The method of claim 11,
Wherein the support surface comprises a flexible material. 12. The method of claim 11,
An upper edge guiding member and a lower edge guiding member spaced from the upper edge member such that a passage through which the glass substrate can move is provided. 18. The method of claim 17,
Wherein at least one of the upper edge guiding member and the lower edge guiding member comprises a roller forming a dynamic support surface configured to contact the glass substrate. 18. The method of claim 17,
Wherein at least one of the upper edge guiding member and the lower edge guiding member comprises a bar of material configured to contact the glass substrate. 18. The method of claim 17,
Wherein at least one of the upper edge guiding member and the lower edge guiding member comprises a belt assembly including a belt including a guiding surface configured to contact a glass substrate. 18. The method of claim 17,
Further comprising a polishing wheel assembly configured to bevel the edge of the glass substrate. CLAIMS 1. A method for closing an edge of a glass substrate,
Supporting a glass substrate on a glass support system, said glass substrate comprising a generally planar surface, a thickness of about 0.7 mm or less, and an out-of-plane orientation normal to said generally planar surface, And a vacuum member configured to extend along the edge of the glass substrate in a glass feeding direction, the vacuum member having a vacuum body including an internal pressure chamber and at least about 25 < RTI ID = 0.0 > Comprising a support surface comprising a vacuum aperture arrangement having an aperture density of the aperture;
Applying a negative pressure to the generally flat surface through an array of vacuum openings; And
Beveling the edge of the glass substrate using the abrasive wheel assembly
≪ / RTI > 23. The method of claim 22,
Further comprising the step of supporting the glass substrate using an edge guiding assembly comprising an upper edge guiding member and a lower edge guiding member spaced from the upper edge guiding member such that a passage through which the glass substrate can be moved is provided. 23. The method of claim 22,
Wherein the array of vacuum openings is arranged in a plurality of parallel rows and the spacing between the vacuum openings along each of the plurality of rows is substantially uniform. 25. The method of claim 24,
Wherein the array of vacuum openings is arranged in a plurality of parallel rows and the spacing between the vacuum openings along each of the plurality of rows is substantially uniform. 23. The method of claim 22,
Further comprising positioning the glass substrate on the vacuum member such that an overhang is provided between the vacuum member and the edge of the glass substrate. As a glass edge finishing apparatus,
Glass transport system;
Wherein the glass support system is configured to support a glass substrate having a thickness of about 0.7 mm or less, the glass substrate having a generally planar surface and the generally Said glass support system comprising a vacuum member configured to extend long in the glass feed direction along the edge of the glass substrate, said vacuum member comprising a vacuum body including an internally located pressure chamber, And a support surface including a plurality of vacuum openings extending therethrough and communicating with the pressure chambers;
An abrasive wheel assembly configured to bevel the edges of the glass substrate as the glass substrate is moved in the glass feed direction by the glass transport system; And
A lower edge guiding member located between the abrasive wheel assembly and the vacuum member and spaced from the upper edge guiding member such that a top edge guiding member and a passage through which the glass substrate can be moved are provided,
And the glass edge finishing device. 28. The method of claim 27,
Wherein at least one of the upper edge guiding member and the lower edge guiding member comprises a roller forming a dynamic support surface configured to contact the glass substrate. 28. The method of claim 27,
Wherein at least one of the upper edge guiding member and the lower edge guiding member comprises a bar of material configured to contact a glass substrate. 28. The method of claim 27,
Wherein at least one of the upper edge guiding member and the lower edge guiding member comprises a belt assembly including a belt having a guiding surface configured to contact a glass substrate.

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