TW201318981A - Pulling rolls for use in glass manufacturing processes and glass manufacturing processes incorporating the same - Google Patents

Abstract

In one embodiment, a pulling roll for drawing glass sheet in a down-draw process includes a shaft member and a compliant cover assembly positioned on the shaft member. The compliant cover assembly includes at least one traction disk positioned on the shaft member. The at least one traction disk includes an annular hub and a plurality of spring elements integrally formed with the annular hub. The spring elements project outward from the annular hub such that a free end of each spring element is positioned radially outward from a base of each spring element. Each of the spring elements has a spring constant in a range from about 2 lbf/mm to about 2000 lbf/mm. When the compliant cover assembly is engaged with a planar surface of a glass sheet, the spring elements deflect radially inward, towards a center of the annular hub, thereby preventing damage to the glass sheet.

Description

Pulling rolls for use in glass manufacturing processes and glass manufacturing processes incorporating such drawn rolls sequence

The present application claims the priority of the priority of the International Patent Application No. PCT/US11/54525, filed on Oct. 3, 2011, which is hereby incorporated by reference. The manner of citation is incorporated herein in its entirety.

The present specification is generally directed to a draw roll for use in the manufacture of glass sheets, and more particularly, the present specification relates to a draw roll comprising a spring element for applying a tensile force to a glass sheet.

The draw rolls are used in the manufacture of glass sheets to apply a tensile force to a glass ribbon or glass web from which a separate glass sheet or glass mesh is formed. Since the glass is drawn from the molten glass (for example, as described in U.S. Patent Nos. 3,338,696 and 3,682,609, or in a similar glass manufacturing process), the glass is applied to the glass by a draw roll. The pulling force is used to control the nominal thickness of the glass.

The draw rolls are generally designed to contact a glass web at the outer edge of the draw rolls, typically in the area just inside the thickened beads, which are formed at the outer edges of the glass web. Since the draw rolls are in direct contact with the surface of the glass web, damage to the glass surface may occur due to the wear characteristics of the drawn roll material. For example, the glass particles can become embedded in the surface of the draw rolls, causing damage to the glass when the draw rolls contact the glass.

Similarly, the draw rolls can discharge particulate matter as the material of the draw rolls degrades as they are used at elevated temperatures in the glass drawing process. This particulate matter can become embedded in soft glass to form defects in the glass. In addition, particulate matter (eg, debris, dust, glass fragments, and the like) produced from the glass stretching process can become embedded in the surface of the draw rolls, creating repeating defects in the glass web. Damage to the glass web caused by any of these mechanisms can cause uncontrolled breakage and/or early breakage of the glass sheet during the stretching process, thereby reducing manufacturing efficiency and increasing cost.

Therefore, there is a need for an alternative design for a draw roll in a glass manufacturing process.

The embodiments described herein relate to draw rolls for use in a glass drawing process that reduces the occurrence of early breakage and/or uncontrolled breakage of the glass sheets stretched by the draw rolls. Also disclosed is a method of forming a glass sheet using a draw roll that slows early breakage and/or uncontrolled breakage of the glass sheet during the glass drawing process.

According to one embodiment, a draw roll for reducing early breakage and/or uncontrolled breakage in a glass sheet can include a shaft member and a malleable lid assembly that is positioned on the shaft member. The flexible cap assembly can include at least one traction disk positioned on the shaft member. The at least one traction disk can include an annular hub and a plurality of spring elements integrally formed with the annular hub. a plurality of spring elements can protrude outward from the annular hub to allow a plurality of springs The free end of each of the spring elements is radially outwardly positioned from the bottom end of each of the plurality of spring elements. Each of the plurality of spring elements can have a radial spring constant in a range from about 2 lbf/mm to about 2000 lbf/mm (about 8.9 N/mm to about 8896.4 N/mm). When the tough cap assembly is engaged with the flat surface of the glass sheet, at least a portion of the plurality of spring members are deflected radially inward toward the center of the annular hub to prevent damage to the glass sheet.

In another embodiment, a draw roll for reducing early breakage and/or uncontrolled breakage in a glass sheet can include a shaft member and a malleable lid assembly that is positioned on the shaft member. The tough cap assembly can include a plurality of traction plates positioned on the shaft member. Each of the plurality of traction disks may be rotationally offset from the adjacent traction disk and each of the plurality of traction disks may include an annular hub and a plurality of spring elements, the plurality of spring elements being integrally formed with the annular hub . A plurality of spring elements can project outwardly from the annular hub such that the free ends of each of the plurality of spring elements are radially outwardly positioned from the bottom end of each of the plurality of spring elements. Each of the plurality of spring elements is bendable between a free end and a bottom end in a direction opposite to the direction of rotation of the pull roll. Each of the plurality of spring elements can have a radial spring constant in a range from about 2 lbf/mm to about 2000 lbf/mm (about 8.9 N/mm to about 8896.4 N/mm). When the flexible cap assembly engages the flat surface of the glass sheet, the spring member deflects radially inward toward the center of the annular hub to prevent damage to the glass sheet.

In yet another embodiment, a method for forming a glass sheet can include: The molten glass batch is formed to form molten glass; and the molten glass is formed into a glass sheet, which reduces early breakage and/or uncontrolled breakage in the glass sheet. Subsequently, at least a first surface of the glass sheet can be in contact with at least one draw roll to transport the glass sheet in a downstream direction. The at least one pull roll can include a shaft member and a malleable cap assembly that is positioned on the shaft member. The tough cap assembly can include a plurality of traction plates positioned on the shaft member. Each of the plurality of traction disks may include an annular hub integrally formed with a plurality of spring elements that project outwardly from the annular hub such that each of the plurality of spring elements The free end is radially outwardly positioned from the bottom end of each of the plurality of spring elements. Each of the plurality of spring elements can have a radial spring constant in a range from about 2 lbf/mm to about 2000 lbf/mm (about 8.9 N/mm to about 8896.4 N/mm). When the flexible cap assembly contacts at least the first surface of the glass sheet, the spring member deflects radially inward toward the center of the annular hub to prevent damage to the glass sheet.

Additional features and advantages of the present disclosure will be set forth in the <RTIgt; These features and advantages are understood by the examples of the following detailed description, the claims, and the accompanying drawings.

It is to be understood that the foregoing general description and the following detailed description of the embodiments of the invention are intended to provide an overview or framework for understanding the nature and characteristics of the claimed subject matter. A further understanding of the various embodiments is provided to provide a further understanding of the various embodiments, and Part of the book. The drawings illustrate the various embodiments described herein and, together with the description

Reference will now be made in detail to various embodiments of the drawing rolls used in the manufacture of glass sheets and the glass making process incorporating such drawing rolls. Wherever possible, the same element symbols are used throughout the drawings to refer to the same or similar parts. One embodiment of a draw roll is schematically illustrated in Figure 2. The draw rolls generally comprise a shaft member and a flexible cap assembly positioned on the shaft member. The tough cap assembly is formed from a plurality of traction disks having spring elements extending radially outward from the annular hub. The spring element generally has a spring constant in the range of from about 2 lbf/mm to about 2000 lbf/mm (about 8.9 N/mm to about 8896.4 N/mm). The method of drawing a roll and stretching the glass piece using a draw roll will be described in more detail herein with reference to the accompanying drawings.

The glass sheet material can be formed generally by: melting a glass batch to form molten glass; and subsequently forming the molten glass into a glass sheet. Exemplary procedures include a floating glass plate method, a slot stretching program, and a fusion pull-down program. In each of these procedures, one or more draw rolls can be used to contact the glass sheet and transport the glass sheet in the downstream direction.

By way of example, referring to FIG. 1A, an exemplary glass manufacturing apparatus 100 for forming a glass sheet material from molten glass in which molten glass is formed using a fusion stretching machine is schematically illustrated. For the glass piece. The glass manufacturing apparatus 100 includes a melting tank 101, The refining tank 103, the mixing tank 104, the conveying tank 108, and the fusion stretching machine (FDM) 120. The glass batch is introduced into the melting tank 101 as indicated by arrow 102. The batch is melted to form molten glass 106. The refining tank 103 has a high temperature processing region that receives the molten glass 106 from the melting tank 101 and removes bubbles from the molten glass 106 in the high temperature processing region. The refining tank 103 is coupled to the mixing tank 104 by a connecting pipe 105. In other words, the molten glass flowing from the refining tank 103 to the mixing tank 104 flows through the connecting pipe 105. The mixing tank 104 is coupled to the conveying tank 108 by a connecting pipe 107 such that the molten glass flowing from the mixing tank 104 to the conveying tank 108 flows through the connecting pipe 107.

The trough 108 supplies the molten glass 106 to the FDM 120 via a downcomer 109. The FDM 120 includes a housing 122 in which an inlet 110, a forming slot 111, and at least one tensioning assembly 150 are positioned. As shown in FIG. 1A, the molten glass 106 from the downcomer 109 flows into the inlet 110 leading to the formation groove 111. The formation groove 111 includes an opening 112 that receives the molten glass 106, which flows into the groove 113 and then overflows, and is contacted and brought into contact before the molten glass 106 is fused together at the roots of the two side joints. The molten glass 106 flows down through the two converging sides 114a and 114b to form a continuous glass sheet 148 before the stretching assembly 150 is stretched in the downstream direction 151.

Referring to Figure 1B, a cross section of the tensioning assembly 150 is schematically illustrated. As illustrated in FIG. 1B, the stretching assembly 150 generally includes a pair of opposed draw rolls 200a, 200b that contact the glass sheets 148 on opposite sides. Therefore, it should be The glass piece 148 is subjected to an impact between the drawing roll 200a and the drawing roll 200b. The pull roll 200a and the draw roll 200b may be powered (i.e., the draw roll 200a, the draw roll 200b is effectively rotated and thus imparts a tensile force to transport the glass sheet 148 in the downstream direction 151) or the draw roll 200a, the drawing roll 200b can be passive (that is, the drawing roll 200a, the drawing roll 200b contacts the glass piece 148 and stabilizes the glass sheet when the glass piece is stretched in the downstream direction 151 by other drawing rolls. ).

Although the pull roll 200a and the draw roll 200b have been described herein as being used in conjunction with a device for forming a glass sheet using a fusion stretching machine, it will be appreciated that the draw roll can be used in a similar procedure, in such a similar procedure, The glass batch is melted to form molten glass and the molten glass is then formed into a glass sheet and stretched with a draw roll. By way of example and not limitation, the draw rolls described herein can also be used in conjunction with a pull-up procedure, a slit stretching procedure, a floating stretching procedure, and other similar glass stretching procedures.

As briefly described above, the draw rolls used in the above procedure are in direct contact with the glass sheets, and thus damage to the surface of the glass may occur due to the wear characteristics of the conventional draw rolls. For example, the glass particles can become embedded in the surface of a conventional draw roll, causing damage to the glass when the draw roll contacts the glass. Similarly, conventional pull rolls can degrade and expel particulate matter with long-term use at elevated temperatures. This particulate matter can become embedded in soft glass to form defects in the glass. Regardless of the source, such defects and/or damage can cause early breakage and/or uncontrolled breakage of the glass sheet during the glass stretching process, thereby reducing Low manufacturing efficiency and increased costs. The pull rolls described herein use spring elements to contact the glass sheets. The spring element is formed of a material that is stable at elevated temperatures, and thus the draw rolls are less prone to degradation or particulate matter after prolonged use. In addition, the draw rolls are formed with an open structure between the spring elements such that the particulate matter can be easily enveloped within the body of the draw rolls rather than being embedded in the surface of the draw rolls.

Referring now to Figure 2, an exemplary draw roll 200 for use in a glass manufacturing process is schematically illustrated. The draw roll 200 generally includes a shaft member 202 and a flexible cap assembly 208 positioned on the shaft member 202. The flexible cap assembly 208 includes a plurality of traction disks 210 that are positioned on the shaft member 202 and form a contact surface 209 of the flexible cap assembly. Although the embodiment of the draw roll 200 illustrated in FIG. 2 includes a plurality of traction plates, it will be appreciated that the flexible cover assembly 208 can be formed from a single traction disk.

The shaft member 202 can include a thread 224 on one end and a shoulder 222 on the opposite end. The traction disk 210 can be positioned against the shoulder and can be secured to the shaft member with a nut or another suitable fastener (eg, a tapered pin). The shoulder 203 can also assist in securing the draw roll 200 to the frame or mechanism for effectively rotating the draw roll 200. In some embodiments described herein, the shaft member 202 further includes a key 225 for engaging a corresponding keyway 250 formed in the traction disk 210 of the flexible cap assembly 208, as shown in FIG. In other embodiments (not shown), the shaft member is formed with a keyway for engaging a corresponding key formed in the traction disk. The interaction between the key and the keyway prevents the traction disk 210 rotates on the shaft member 202 as the pull roll 200 rotates.

Referring now to Figures 3 and 4, a traction disk 210 for drawing the tough cap assembly of the roll 200 is schematically illustrated. In the embodiments described herein, the traction disk 210 generally includes an annular hub 206 and a plurality of spring elements 204. A plurality of spring elements 204 are integrally formed with the annular hub 206 and project radially outward from the annular hub 206, as illustrated in FIG. As best shown in FIG. 4, each spring element 204 extends between a bottom end 214 and a free end 212. Specifically, each spring element 204 is integrally attached to the annular hub 206 at the bottom end 214 such that the free end 212 of the spring element is radially outwardly positioned from the bottom end 214 and the annular hub 206. In the embodiment of the traction disk 210 illustrated in FIG. 3, the annular hub 206 and the plurality of spring elements 204 are substantially coplanar.

The spring element 204 of each traction disk 210 is designed to flex elastically relative to the annular hub 206 such that when the pressing pull roll contacts the surface of the glass sheet to apply a tensile force to the glass sheet, the spring element 204 is opposite the ring The hub 206 is resiliently displaced. Thus, the spring element 204 does not damage the glass sheet when it provides a tensile force to the glass sheet.

More specifically, the spring element 204 of each traction disk generally has a range of from about 2 lbf/mm to 2000 lbf/mm (about 8.9 N/mm to about 8896.4 N/mm) or even from about 5 lbf/mm to about The radial spring constant in the range of 1500 lbf/mm (22.2 N/mm to about 6672.3 N/mm) (i.e., the spring constant that protrudes radially from the annular hub 206). The spring constants within these ranges create a draw roll that is sufficiently tough so as not to damage the glass sheet and at the same time be sufficiently stable to provide resistance Adequate traction on the surface of the glass sheet to help stretch the glass sheet with a draw roll.

As mentioned above, debris, such as glass fragments or other particulate matter, can contact the draw rolls during the pull down procedure. The spring element 204 of the traction disk 210 is sufficient in the axial and tangential directions in order to prevent the debris from becoming embedded in the contact surface of the flexible cap assembly of the draw roll and thus damaging the glass piece drawn by the draw roll Toughened such that when debris is impacted between the contact surfaces of the flexible cap assembly, the spring elements are displaced tangentially and/or axially to allow debris to pass between the spring elements, thereby allowing debris to be completely The sheet is pulled or turned into an envelope in the tough lid assembly away from the surface of the tough lid assembly to mitigate damage to the sheet. In the embodiment of the draw rolls described herein, the spring element 204 generally has an axial spring constant (i.e., a spring constant in the +/- z direction of the coordinate axis illustrated in Figure 3), The axial spring constant is low enough to help set the roll tilt angle (i.e., the angle of the long axis of the roll relative to the horizontal). For example, the axial spring constant can range from about 0.25 lbf/mm to about 150 lbf/mm (about 1.1 N/mm to about 667.2 N/mm) or even from about 5 lbf/mm to about 75 lbf/mm (about 22.2 N/mm to approximately 333.6 N/mm). The tangential spring constant (i.e., the spring constant in the direction of arrow 240) should be high enough to prevent excessive deflection at the free end of the spring element, which may interfere with maintaining a constant sheet rate. In embodiments described herein, the tangential spring constant can range from about 2 lbf/mm to about 75 lb/mm (about 8.9 N/mm to about 333.6 N/mm) or even from about 5 lbf/mm to about 50 lbf/mm (about 22.2 N/mm to About 222.4 N/mm).

Referring now to Figures 2 through 4, in the embodiment of the draw rolls described herein, the spring elements 204 of the traction disk 210 are formed on the annular hub such that the bottom of the adjacent spring elements 204 in the circumferential direction The spacing G between the ends is greater than or equal to about 0.01 mm. This spacing is sufficient to allow debris to pass between the circumferentially adjacent spring elements 204 rather than being embedded in the contact surface 209 of the flexible cap assembly 208. In some embodiments, the spacing G can be greater than or equal to about 0.05 mm.

The thickness T of the spring element 204 in the circumferential direction is substantially dependent on the type of material forming the traction disk 210 and the desired spring constant of the spring element. In the embodiments described herein, the thickness T of the spring element 204 is generally in the range of from about 0.25 mm to about 3.00 mm. In some embodiments, the thickness T of the spring element can be from about 0.25 mm to about 1.5 mm. However, it should be appreciated that the spring element 204 can have other thicknesses depending on the type of material from which the traction disk 210 is made and/or the desired spring constant of the spring element. Moreover, the thickness T of the spring element 204 can be non-uniform between the bottom end 214 and the free end, as shown in FIG. 4, while in other embodiments (not shown), the thickness of the spring element 204 is at the bottom. The end 214 and the free end 212 may be uniform.

Still referring to Figures 2 through 4, in the embodiment of the draw roll 200 described herein, the annular hub 206 of the traction disk 210 generally has an outer diameter d in the range of from about 18 mm to about 75 mm. And the outer diameter D of the traction disk is in the range of from about 60 mm to about 200 mm. Therefore, it should be understood that the flexible cap assembly of the pull roll 200 also has a self-approximately 60 mm. The outer diameter in the range of up to about 200 mm.

The axial thickness t of the spring element 204 (i.e., the thickness in the +/- z direction of the coordinate axis illustrated in Figure 3) and the thickness of the annular hub 206 are generally in the range of from about 0.50 mm to about 105 mm. in. Moreover, for a given material, the axial thickness t of the spring element 204 can be increased or decreased to adjust the axial spring constant of the spring element 204. In some embodiments, the annular hub 206 can have an axial thickness that is greater than the axial thickness of the spring element 204. In such embodiments, when the traction disk 210 is secured to the shaft member 202, the annular hub 206 is used to achieve the desired spacing between axially adjacent spring members 204. Accordingly, it should be appreciated that the traction disk 210 can be formed with annular hubs having different thicknesses to achieve a desired spacing between axially adjacent spring elements.

In the embodiment of the draw roll 200 described herein, the spring element 204 can be formed with a particular profile to achieve the desired mechanical response (ie, the desired elastic deformation and when the draw roll is pressed against the flat surface of the glass substrate). stress). By way of example, Figures 2 through 4 illustrate one embodiment of a draw roll 200 constructed from a traction disk 210 having spring elements that are bent between a free end 212 and a bottom end 214 such that When the free end of the spring element engages the flat surface of the glass sheet, the spring element resiliently deflects radially inward toward the center of the annular hub. In some embodiments, the radius of curvature R of the spring element 204 is constant between the free end 212 and the bottom end 214. In such embodiments, the radius of curvature R can be from about 10 mm to about 80 mm or even from about 10 mm to about 40 mm. The spring elements 204 in these embodiments are generally in tension with the draw rolls The pull-down direction of rotation is curved in the opposite direction so that the spring element 204 is easily bent when it contacts the surface of the glass sheet. For example, the pull roll 200a of Figure 1B has a direction of rotation in a clockwise direction and the spring element 204 is curved in a counterclockwise direction.

In other embodiments, the spring element 204 may have a composite curvature. For example, in some embodiments, the radius of curvature of each spring element can increase from the bottom end 214 of the spring element 204 to the free end 212 of the spring element 204. In other embodiments, the radius of curvature of each spring element may decrease from the bottom end 214 of the spring element to the free end 212 of the spring element 204. In other embodiments, the spring element 204 can be formed with a composite curvature, wherein different portions of the spring element have different radii and/or the different portions are curved in different directions. For example, FIG. 5 illustrates an embodiment of a traction disk 234 in which the spring element has a lower portion 227 (ie, a portion of the spring element that is closest to the annular hub 206) and an upper portion 226. In this embodiment, the lower portion 227 of each spring element 204 has a first radius of curvature and is curved in a counterclockwise direction, while the upper portion 226 of the spring element 204 has a second, different radius of curvature and is curved in a clockwise direction. In these embodiments, the spring element upper portion 226 is generally curved in a direction opposite the direction in which the pull rolls are pulled downward. Thus, in the embodiment of the traction disk 234 illustrated in Figure 5, the pull-down direction of the pull rolls will be in the counterclockwise direction.

Referring now to Figure 6, another embodiment of a traction disk 230 is schematically illustrated. In this embodiment, the traction disk 230 is formed with spring elements 204 that include the freedom to form each spring element 204. Contact pin 216 on end 212. The contact foot 216 increases the contact area between the spring element 204 and the surface of the glass sheet stretched with the traction disk 230. Increasing the contact area between the spring element 204 and the surface of the glass sheet increases the friction between the traction disk and the glass sheet, which allows the glass sheet to be imparted with greater torque from the shaft member so as not to reduce the elasticity of the spring member 204. In this case, the pulling force applied to the glass sheet is increased, thereby reducing the possibility of damaging the glass sheet during the pull-down procedure.

As mentioned above, the traction disk can be formed with keyways that prevent the traction disk from rotating on the shaft member. In the embodiment of the traction disk 230 illustrated in FIG. 6, the keyway 250 is an aperture formed in the annular hub 206. The keyway 250 is shaped to receive a corresponding key (not shown) attached to the shaft member to prevent the traction disk 230 from rotating on the shaft member.

Referring now to Figure 7, another embodiment of a traction disk 232 is schematically illustrated. In this embodiment, the traction disk 232 includes a rim 218. The rim 218 joins the free ends of each of the plurality of spring elements to the free ends of adjacent spring elements on the same traction disk. In this embodiment, the rim 218 increases the contact area between the spring element and the surface of the glass sheet stretched by the traction disk 232. Increasing the contact area between the spring element 204 and the surface of the glass sheet by the rim 218 increases the friction between the traction disk and the glass sheet, thereby allowing the shaft member to apply a greater torque to the glass sheet, thereby increasing the application to the glass sheet. pull. In addition, the curved spring element 204 of the traction disk 232 allows the rim to be displaced relative to the annular hub 206, thereby reducing the likelihood of damage to the glass sheet during the pull down procedure.

Although the drawn rolls have been described herein as having curved springs Traction disc construction of the components, but it should be understood that other embodiments of the traction disc are contemplated. For example, Figures 8 and 9 illustrate a traction disk 236 formed with an angular spring element 204. Specifically, the traction disk 236 includes an annular hub 206 that is integrally formed with a plurality of spring elements 204 that extend radially outward from the annular hub 206, as described above. Each spring element includes an upper portion 226 and a lower portion 227, wherein the upper portion 226 of the spring element 204 is oriented at an angle a relative to the lower portion 227. Inclining the upper portion 226 of the spring element 204 relative to the lower portion 227 provides a point of flexion at the intersection of the lower portion 227 and the upper portion 226 and helps to form a spring element having the desired spring constant. In particular, the position of the bend point and the angle a can be selected to achieve the desired spring constant of the spring element. The angle a between the upper portion 226 and the lower portion 227 can be, but is not limited to, about 10 degrees or even about 30 degrees. In some other embodiments, the angle a can be about 45 degrees or even about 60 degrees.

The traction disk illustrated in Figures 3 through 9 can be formed from a material that retains mechanical properties at elevated temperatures encountered in a glass pull-down procedure, which can be as high as about 900 °C. Suitable materials include, but are not limited to, metals, ceramics, metal matrix composites, and mineral based materials. For example, the traction disk can be formed from a nickel-based alloy including, but not limited to, Rene 41, Haynes 282, or a similar nickel-based alloy. Examples of suitable ceramic materials include, but are not limited to, tantalum nitride, tantalum carbide, aluminum oxide, boron carbide, SIALON or similar ceramic materials. Suitable mineral materials include, but are not limited to, bulk mica materials such as phlogopite. Conventional processing techniques such as electrical discharge machining (EDM) or water jet processing techniques can be used. The traction disk illustrated in Figures 3 to 9 is formed.

An alternate embodiment of the traction disk 238 is schematically illustrated in FIG. The traction disk 238 includes an annular hub 206 and a plurality of spring elements 204. In this embodiment, the spring elements 204 are bristles that are shaped to achieve a desired spring constant (i.e., a spring constant in the range from 60 lbf/mm to 2000 lbf/mm). However, in this embodiment, the spring element 204 is formed by selectively etching away the hub material to form a separate spring element. The traction disk 238 of this embodiment can be formed from the same material as described above with respect to the embodiment of the traction disk illustrated in Figures 3 through 9.

Once the traction disk is formed, the traction disk can be coated with a material that improves the oxidation resistance and wear characteristics of the traction disk. For example, the traction disk may be coated with a cobalt chromium tungsten alloy 6, a cobalt chromium tungsten alloy 12, or other similar coating material that improves the oxidation resistance and/or wear resistance of the traction disk.

Referring again to FIG. 2, a separate traction disk 210 is assembled to the shaft member 202 such that the keyway 250 of each traction disk 210 engages the key 225 formed on the shaft member 202. In the embodiment of the draw roll 200 illustrated in Figure 2, the traction disk 210 is positioned against the shoulder 222 and a nut (not shown) is threaded over the thread 224 of the shaft member to secure the traction disk to On the shaft member 202, a tough cap assembly 208 for the draw rolls is formed. In some embodiments, each of the traction disks is positioned on the shaft member such that the axial spacing S between adjacent traction disks (i.e., the spacing in the z-direction of the coordinate axes shown in FIG. 2) is It is greater than about 0.0 mm to about 25 mm or even from about 0.0 mm to about 25 mm. In some embodiments, The axial spacing S between adjacent traction disks can range from about 0.75 mm to about 6 mm. The axial spacing S between adjacent traction plates in combination with the spacing G between the spring elements on the single traction disk (shown in Figure 3) allows debris to penetrate into the flexible cap assembly 208 and through the tough cap assembly. It is not embedded on the surface of the flexible cover assembly to prevent damage to the glass during the pull down procedure.

In the embodiment of the draw rolls 200 illustrated in FIG. 2, the individual traction plates 210 are keyed such that when the traction plates are positioned on the keys 225, each of the traction plates is rotationally offset from the adjacent traction plates, and Therefore, the spring elements of the axially adjacent traction disks are not aligned with each other. However, in other embodiments, the separate traction plates 210 can also be keyed in such that the spring elements of the axially adjacent traction disks are aligned with one another.

Referring now to FIGS. 1B and 11 , during the pull-down glass forming process, the draw rolls 200a and the draw rolls 200b of the tensioning assembly 150 contact the glass sheets on the first flat surface 149 and the second flat surface 152, respectively. 148 such that at least the free end 212 of the spring element 204 contacts the glass sheet. When each spring element contacts the surface of the glass sheet, the spring element deflects radially inward toward the center of the annular hub 206 (i.e., in the direction of arrow 350), transmitting torque from the shaft member to the glass sheet 148, thereby The glass piece is stretched in the downstream direction 151. For example, as illustrated in FIG. 11, the pull rolls rotate in the counterclockwise direction 153. The spring element 204a and the spring element 204c are not in contact with the surface 149 of the glass sheet 148, and therefore, the spring element 204a and the spring element 204c are not deflected. However, since the rotating shaft member applies the glass sheet to the sheet by the pulling roller The torque is applied to stretch the glass sheet in the downstream direction 151 such that when the spring element 204b is in rotational contact with the surface 149 of the glass sheet 148, the spring element deflects radially inward toward the center of the annular hub 206.

Still referring to Fig. 11, in the case where debris or other particulate matter (such as particles 300) is present on the surface 149 of the glass sheet 148, the spring element 204 contacting the particles 300 when the glass sheet 148 is stretched in the downstream direction 151 By the radially inward deflection of the particles 300, the point load of the particles 300 against the surface 149 of the glass sheet 148 is reduced, and thus damage to the glass sheet is reduced. Moreover, any point load of the particles 300 against the surface of the glass sheet 148 is limited by the size of the particles to a single spring element or to a localized group of spring elements. Thus, the remainder of the spring element remains in contact with the glass sheet and continues to impart a tensile force to the glass sheet.

It should now be appreciated that the draw rolls described herein can be used in glass manufacturing processes to stretch and/or guide glass sheets. In particular, the spring element of the traction disk presents a smooth resilient contact surface against which the glass sheet can contact without damaging the surface of the glass sheet. Because the draw rolls are constructed of materials that are suitable for use at elevated temperatures, the draw rolls are less prone to degradation or discharge of particulate matter and/or debris that can contaminate the glass drawing process as they are used for extended periods of time at elevated temperatures. Further, the spring elements of the traction disk are sufficiently resilient in the axial, radial and tangential directions to promote enveloping the particulate matter between the spring elements, thereby reducing damage to the glass sheets.

The spring elements of the draw rolls described herein increase the radial toughness of the rolls to provide a more uniform tensile force to the glass sheets. In addition, the spring element The piece also provides an increased contact area of the roll surface while reducing the contact pressure and imparting shear to the glass sheet. In particular, the spring element reduces or eliminates point loading from the particles on the surface of the glass sheet, which in turn reduces cracking and/or sudden failure of the glass sheet.

Those skilled in the art will appreciate that various modifications and changes can be made to the embodiments described herein without departing from the spirit and scope of the claimed subject matter. The modifications and variations of the various embodiments described herein are intended to be included within the scope of the appended claims.

100‧‧‧Glass manufacturing equipment

101‧‧‧melting tank

102‧‧‧ arrow

103‧‧‧Refiner

104‧‧‧ Mixing tank

105‧‧‧Connecting tube

107‧‧‧Connecting tube

106‧‧‧Solid glass

108‧‧‧ conveyor

109‧‧‧ downcomer

111‧‧‧ forming a trough

110‧‧‧Import

112‧‧‧ openings

113‧‧‧ Groove

114a‧‧‧ Convergence side

114b‧‧‧ Convergence side

120‧‧‧Integrated Stretching Machine (FDM)

122‧‧‧Shell

148‧‧‧Stainless glass

149‧‧‧First flat surface

150‧‧‧Stretching components

151‧‧‧ downstream direction

152‧‧‧Second flat surface

153‧‧‧counterclockwise

200‧‧‧ Pulling rolls

200a‧‧‧ Pulling rolls

200b‧‧‧ Pulling rolls

202‧‧‧Axis parts

204‧‧‧Spring elements

204a‧‧‧Spring elements

204b‧‧‧Spring elements

204c‧‧‧Spring element

206‧‧‧Circular hub

208‧‧‧Tough cover assembly

209‧‧‧Contact surface

210‧‧‧ traction disk

212‧‧‧Free end

214‧‧‧ bottom

216‧‧‧Contact feet

218‧‧ rim

222‧‧‧ Shoulder

224‧‧ thread

225‧‧‧ keys

226‧‧‧ upper

227‧‧‧ lower

230‧‧‧ traction disk

232‧‧‧ traction disk

234‧‧‧ traction disk

236‧‧‧ traction disk

238‧‧‧ traction disk

240‧‧‧ arrow

250‧‧‧ keyway

300‧‧‧ particles

350‧‧‧ arrow

‧‧‧‧ angle

D‧‧‧outer diameter

D‧‧‧OD

G‧‧‧ interval

R‧‧‧ radius of curvature

S‧‧‧ interval

T‧‧‧ axial thickness

T‧‧‧ thickness

1A schematically illustrates a glass drawing apparatus for forming a glass sheet according to one or more embodiments shown and described herein; FIG. 1B schematically illustrates a cross section of a stretching assembly The tensile assembly comprises a pair of oppositely drawn rolls for stretching the glass sheet; and FIG. 2 schematically illustrates a partial decomposition of the drawn rolls according to one or more embodiments shown and described herein The drawing roll is formed from a plurality of traction disks; FIG. 3 schematically illustrates a traction disk of the drawing roll of FIG. 2 according to one or more embodiments shown and described herein; FIG. The annular hub of the traction disk of FIG. 3 and a single spring element are schematically illustrated for illustrative purposes; and FIG. 5 schematically illustrates a traction disk for pulling a roll in which the drawn roll is The spring element of the traction disk has a compound curvature; Figure 6 is a schematic illustration of a traction disk for pulling a roll in which the spring elements of the traction disk comprise contact feet; Figure 7 schematically illustrates the traction of the drawn rolls a disk in which the spring elements of the traction disk are joined by a rim; FIG. 8 schematically illustrates a traction disk for pulling a roll, in which the spring element has an upper portion, The upper portion is angled relative to the lower portion; FIG. 9 schematically illustrates the annular hub of the traction disk of FIG. 8 and a single spring element for illustrative purposes; FIG. 10 is schematically illustrated for use in accordance with the text herein Another embodiment of a traction disk for pulling a roll of one or more embodiments; and FIG. 11 schematically illustrates a portion of a traction disk of a draw roll that engages the surface of the glass sheet.

148‧‧‧Stainless glass

149‧‧‧First flat surface

150‧‧‧Stretching components

151‧‧‧ downstream direction

152‧‧‧Second flat surface

200a‧‧‧ Pulling rolls

200b‧‧‧ Pulling rolls

202‧‧‧Axis parts

204‧‧‧Spring elements

206‧‧‧Circular hub

Claims (33)

A draw roll for stretching a glass sheet in a pull-down process, the pull roll comprising: a shaft member; and a flexible cap assembly positioned on the shaft member, the tough cover assembly including positioning At least one traction disk on the shaft member, the at least one traction disk comprising: an annular hub; and a plurality of spring elements integrally formed with the annular hub, the plurality of spring elements being outwardly from the annular hub Protruding such that a free end of each of the plurality of spring elements is radially outwardly positioned from a bottom end of each of the plurality of spring elements, each of the plurality of spring elements The spring element has a radial spring constant in a range from about 2 lbf/mm to about 2000 lbf/mm, wherein the plurality of spring elements are engaged when the tough cap assembly engages a flat surface of the glass sheet At least a portion thereof is deflected radially inward toward a center of the annular hub to prevent damage to the glass sheet. A draw roll for stretching a glass sheet in a pull-down process, the pull roll comprising: a shaft member; and a flexible cap assembly positioned on the shaft member, the tough cover assembly including positioning a plurality of traction disks on the shaft member, wherein each of the plurality of traction disks is rotationally offset from the adjacent traction disk And each of the plurality of traction disks comprises: an annular hub; a plurality of spring elements, the plurality of spring elements are integrally formed with the annular hub, the plurality of spring elements projecting outward from the annular hub, Having a free end of each of the plurality of spring elements radially outwardly from a bottom end of each of the plurality of spring elements, wherein: each of the plurality of spring elements An element is bent between the free end and the bottom end in a direction opposite to a direction in which one of the pull rolls is pulled downward; and each of the plurality of spring elements has a ratio of from about 2 lbf/mm to about a radial spring constant in one of the ranges of 2000 lbf/mm, wherein when the tough cap assembly is engaged with a flat surface of the glass sheet, the spring members are radially inwardly deflected toward a center of the annular hub, Thereby preventing damage to the glass piece. The pull roll of claim 1, wherein each of the plurality of spring elements is bent between the free end and the bottom end. A pull roll as claimed in claim 3, wherein each spring element is bent upward in a direction opposite to a direction in which one of the pull rolls is pulled downward. The pull roll of claim 2 or claim 3, wherein each of the plurality of spring elements has a radius of curvature of from about 10 mm to about 80 mm. The pull roll of claim 2 or claim 3, wherein each of the plurality of spring elements has a constant radius of curvature. The pull roll of claim 3, wherein each of the plurality of spring elements has a compound radius of curvature. The pull roll according to claim 1 or claim 2, wherein the annular hub has an outer diameter d such that 18 mm d 75 mm. The drawing roll of claim 1 or claim 2, wherein each of the plurality of spring elements has a thickness T in a circumferential direction such that 0.50 mm T 3.0 mm. The drawing roll of claim 1 or claim 2, wherein a separation distance G between adjacent ones of the plurality of spring elements in a circumferential direction is such that G 0.01 mm. The drawing roll of claim 1 or claim 2, wherein the tough cap assembly has an outer diameter D such that 60 mm D 200 mm. The pull roll of claim 1 or claim 2, wherein each of the plurality of spring elements has an axial thickness t such that 0.50 mm t 105 mm. The pull roll of claim 1, wherein the at least one traction disk comprises a plurality of traction disks. The drawing roll of claim 2 or claim 13, wherein an axial spacing S between each of the plurality of traction disks is such that 0.0 mm S 25 mm. The pull roll of claim 1, wherein the at least one traction disk comprises a plurality of traction disks and each of the traction disks is rotationally offset from an adjacent traction disk in a circumferential direction. Pulling the roll as described in claim 1 or claim 2, wherein the ring wheel The hub includes a keyway that engages a corresponding key formed on the shaft member. The pull roll of claim 1 or claim 2, wherein the annular hub includes a key that engages a corresponding keyway formed on the shaft member. The pull roll of claim 1 or claim 2, the pull roll further comprising a rim that engages the free end of each of the plurality of spring elements to a single traction disk The free end of one of the adjacent spring elements. A pull roll according to claim 1 or claim 2, wherein each of the plurality of spring elements comprises a contact leg integrally formed with the free end of each spring element. The pull roll of claim 1, wherein each of the plurality of spring elements comprises an upper portion and a lower portion, wherein the upper portion is oriented at an angle relative to the lower portion. The draw roll of claim 1, wherein the tough cap assembly is formed from a metallic material, a ceramic material or a mineral material. The draw roll of claim 1 wherein the tough cap assembly is formed from a nickel based alloy. The pull roll of claim 1 or claim 2, wherein each of the plurality of spring elements has an axial spring constant of from about 0.25 lbf/mm to about 150 lbf/mm. The pull roll of claim 1 or claim 2, wherein each of the plurality of spring elements has a self-density of from about 2 lbf/mm to about 75 Everything in lbf/mm is constant to the spring. A method for forming a glass sheet, the method comprising the steps of: melting a glass batch to form a molten glass; forming the molten glass into the glass sheet; contacting the first surface of the glass sheet with at least one drawing roll Transmitting the glass sheet in a downstream direction, wherein the at least one pull roll comprises: a shaft member; and a flexible cap assembly positioned on the shaft member, the tough cover assembly comprising: a plurality of traction plates The plurality of traction disks are positioned on the shaft member, each of the plurality of traction disks includes an annular hub integrally formed with a plurality of spring elements, the plurality of spring elements being oriented from the annular hub Extending outwardly such that a free end of each of the plurality of spring elements is radially outwardly positioned from a bottom end of each of the plurality of spring elements, each of the plurality of spring elements A spring element having a radial spring constant in a range from about 2 lbf/mm to about 2000 lbf/mm, wherein the tough cap assembly and the glass sheet When the first surface is in contact, the spring elements are deflected radially inward toward a center of the annular hub to prevent damage to the glass sheet. The method of claim 25, wherein each of the plurality of spring elements is curved between the free end and the bottom end. The method of claim 25, wherein each of the plurality of spring elements has a constant radius of curvature. The method of claim 25, wherein each of the plurality of spring elements has a composite radius of curvature. The method of claim 25, wherein each of the plurality of spring elements has an axial thickness t such that 0.50 mm t 105 mm. The method of claim 25, wherein each of the plurality of spring elements has a thickness T in a circumferential direction such that 0.50 mm T 3.0 mm. The method of claim 25, wherein each of the traction disks is rotationally offset from an adjacent traction disk in a circumferential direction. The method of claim 25, wherein each of the plurality of traction disks further comprises a rim that engages the free end of each of the plurality of spring elements to a single The free end of one of the adjacent spring elements on the traction disk. The method of claim 25, wherein each of the plurality of spring elements further comprises a contact leg integrally formed with the free end of each spring element.