KR20130036166A - Pulling rolls for use in glass manufacturing processes and glass manufacturing processes incorporating the same - Google Patents

Abstract

PURPOSE: A pulling roller for use in glass manufacturing processes are provided to reduce permanent damages of glass sheet in a glass drawing process by using spring members meeting a glass sheet. CONSTITUTION: A pulling roller for use in glass manufacturing process comprises a shaft member(202) and a compliant cover assembly located on the shaft member. The compliant cover assembly comprises at least one pulling disc located on the shaft member. The pulling disc comprises a ring-shaped hub(206) and a plurality of spring members(204). The plurality of spring member is integrated with the ring-shaped hub. Each spring member has a spring constant of 2-2000lbf/mm. When the compliant cover assembly is coupled to the flat side of a glass sheet(148), the spring member prevent the damages of glass sheet by moving toward the center of the ring-shaped hub and prevents the damages of glass sheet.

Description

Pulling Rolls For Use In Glass Manufacturing Processes And Glass Manufacturing Processes Incorporating The Same}

BACKGROUND OF THE INVENTION Field of the Invention The present invention generally relates to tension rolls for use in the manufacture of glass sheets, and more particularly to tension rolls comprising spring members for applying tensile force to glass sheets.

Tensile rolls are used in the manufacture of the glass of the sheet by tensioning the ribbon or web of glass from which the glass of the individual sheet is molded. The amount of tension applied to the glass by the tension rolls may be determined by drawing the glass from the molten glass of a glass making process, such as, for example, the overflow down-draw fusion process disclosed in US Pat. Nos. 3,338,696 and 3,682,609. It is used to control the nominal thickness of the glass.

Tensile rolls are generally designed to contact the glass web at the outer edge of the glass web, typically in the region just inside the thickened beads that form at the outermost edge of the glass web. Since the tension rolls are in direct contact with the surface of the glass web, damage to the surface of the glass may occur due to the wear characteristics of the tension roll material. For example, glass particles may be inserted at the surface of the tension rolls causing damage to the glass as the tension rolls contact the glass.

Similarly, tensile rolls can degrade particulate matter if the quality of the material of the tensile rolls is degraded by use at elevated temperatures in the glass drawing process. These particulate matter is inserted into the soft glass, causing defects in the glass. Moreover, particulate matter (eg, debris, dust, glass shards, etc.) resulting from the glass drawing process can be inserted into the surface of the tension rolls to create repetitive defects in the glass web. Damage to the glass web caused by any of these mechanisms can lead to uncontrolled and / or permanent failure of the glass sheet during the drawing process, which can reduce manufacturing efficiency and increase cost.

Accordingly, alternative designs for tension rolls for use in glass making processes are required.

Embodiments disclosed herein relate to tensile rolls for use in glass drawing processes that reduce uncontrolled and / or permanently generated breakage of glass sheets drawn with tensile rolls. Embodiments disclosed herein also relate to glass sheet forming methods that use tension rolls to mitigate uncontrolled and / or permanent breakage of the glass sheet during the glass drawing process.

According to one embodiment, the tension rolls for reducing permanent and / or uncontrolled breakage in the glass sheet may include a shaft member and a compliant cover assembly positioned on the shaft member. The compliant cover assembly can include at least one towing disk positioned on the shaft member. The at least one traction disc may comprise an annular hub and a plurality of spring members integrally formed with the annular hub. The plurality of spring members project outwardly from the annular hub such that a free end of each spring member of the plurality of spring members can be located radially outward from the base of the respective spring member of the plurality of spring members. Each spring member of the plurality of spring members may have a radial spring constant in the range of about 2 lbf / mm to about 2000 lbf / mm (about 8.9 N / mm to about 8896.4 N / mm). When the compliant cover assembly is engaged with the flat surface of the glass sheet, at least a portion of the plurality of spring members deflect radially inward, towards the center of the annular hub, to prevent damage to the glass sheet.

In another embodiment, the tension rolls for reducing permanent and / or uncontrolled breaks in the glass sheet include a shaft member and a compliant cover assembly positioned on the shaft member. The compliant cover assembly can include a plurality of traction discs located on the shaft member. Each of the plurality of towing disks may be offset in a rotational direction from an adjacent towing disk and each of the towing disks may include an annular hub and a plurality of spring members integrally formed with the annular hub. Can be. A plurality of spring members protrude outwardly from the annular hub such that a free end of each spring member of the plurality of spring members can be located radially outward from the base of each spring member of the plurality of spring members. Each spring member of the plurality of spring members may be curved between the free end and the base in a direction opposite to the down-draw rotation direction of the tension roll. Each spring member of the plurality of spring members may have a radial spring constant in the range of about 2 lbf / mm to about 2000 lbf / mm (about 8.9 N / mm to about 8896.4 N / mm). When the compliant cover assembly is engaged with the flat surface of the glass sheet, the spring member deflects radially inward toward the center of the annular hub, preventing damage to the glass sheet.

In another embodiment, a method of forming a glass sheet that reduces permanent and / or uncontrolled breakage in the glass sheet comprises melting the glass batch material for forming the molten glass and the molten glass Molding to a sheet. Thereafter, at least the first surface of the glass sheet may contact the at least one tension roll to transfer the glass sheet in the downstream direction. The at least one tension roll may comprise a shaft member and a compliant cover assembly positioned on the shaft member. The compliant cover assembly can include a plurality of traction discs located on the shaft member. Wherein each of the plurality of traction discs comprises the annular hub integrally formed with a plurality of spring members protruding outwardly from the annular hub, such that the free ends of each of the plurality of spring members are radially from the base of each of the plurality of spring members. It may be located outward. Each of the plurality of spring members may comprise a radial spring constant in the range of about 2 lbf / mm to about 2000 lbf / mm (about 8.9 N / mm to about 8896.4 N / mm). When the compliant cover assembly contacts at least the first surface of the glass sheet, the spring member deflects radially inward toward the center of the annular hub, preventing breakage of the glass sheet.

Additional features and advantages of the invention are set forth in the detailed description set forth below, and one of ordinary skill in the art will readily appreciate, at least in part, by practicing the embodiments disclosed herein, including the following detailed description, claims, as well as the accompanying drawings. Could be.

It will be appreciated that the general details set forth above and the details set forth below constitute various embodiments and are intended to aid the overall understanding of the features and characteristics of the claims. The accompanying drawings are provided to further aid in understanding the various embodiments, and are incorporated into and constitute a part of this specification. The drawings illustrate various embodiments disclosed herein and the description used to explain the principles and operation of the appended claims.

1A is a schematic drawing of a glass drawing apparatus for forming a glass sheet in accordance with one or more embodiments disclosed and described herein;
1B is a cross sectional view of a drawing assembly including a pair of opposed tension rolls for use in glass sheet drawing;
2 is a schematic partial exploded view of a tension roll formed from a plurality of traction discs in accordance with one or more embodiments disclosed and described herein;
3 is a diagram of a schematic traction disc of the tension roll of FIG. 2 in accordance with one or more embodiments disclosed and described herein;
4 is a schematic illustration of a single spring member and annular hub of the traction disc of FIG. 3 for illustrative purposes;
5 is a schematic illustration of a pulling disk for a tension roll in which the spring member of the pulling disk has a complex curvature;
FIG. 6 is a schematic illustration of a towing disk for a tension roll in which the spring member of the towing disk includes a contact leg;
FIG. 7 is a view schematically showing a pulling disk for a tension roll in which a spring member of the pulling disk is connected by a rim; FIG.
FIG. 8 is a schematic illustration of a traction disc for a tension roll with an upper side in which the spring member is inclined with respect to the lower side; FIG.
9 is a schematic illustration of a single spring member and annular hub of the traction disk of FIG. 8 for illustrative purposes;
10 is a schematic illustration of another embodiment of a traction disc for a tension roll in accordance with one or more embodiments described herein;
FIG. 11 is a schematic illustration of a portion of a traction disc of a tension roll coupled to a surface of a glass sheet. FIG.

Various examples of tension rolls used in the manufacture of glass sheets and glass fabrication processes incorporating the tension rolls are described in detail and are referred to this. Wherever possible, the same member numbers are used throughout the drawings to indicate the same or similar members. An example tension roll is shown schematically in FIG. 2. The tension roll generally includes a shaft member and a compliant cover assembly located on the shaft member. The compliant cover assembly is formed from a plurality of traction discs with spring members extending radially outward from the annular hub. The spring member generally has a spring constant in the range of about 2 lbf / mm to about 2000 lbf / mm (about 8.9 N / mm to about 8896.4 N / mm). The method of using the tension roll for drawing the tension roll and the glass sheet is disclosed in more detail herein, in particular with reference to the accompanying drawings.

The glass sheet material may generally be formed by melting the glass batch material to form molten glass followed by molding the molten glass into a glass sheet. Exemplary processes include float glass processes, slot draw processes, and fusion down-draw processes. In each of these processes, one or more tension rolls may be used to contact the glass sheet and to transport the glass sheet in the downstream direction.

Referring to FIG. 1A as an example, an exemplary glass making apparatus 100 for forming a glass sheet material from molten glass is schematically illustrated, in which a fusion drawer is used to form molten glass into a glass sheet. do. The glass making machine 100 includes a melting vessel 101, a refining vessel 103, a mixing vessel 104, a transfer vessel 108, and a fusion drawer (FDM: Fusion Draw Machine) 120. The glass batch material is guided to the melting vessel 101, as indicated by arrow 102. The batch material is melted to form molten glass 106. Purification vessel 103 has a high temperature treatment area for receiving molten glass 106 from melting vessel 101 and bubbles are removed from molten glass 106 in the melting vessel. Purification vessel 103 is connected with mixing vessel 104 by connecting tube 105. That is, molten glass that flows from the purification vessel 103 to the mixing vessel 104 flows through the connecting tube 105. The mixing vessel 104 is consequently connected to the transfer vessel 108 by a connecting tube 107, so that the molten glass flowing from the mixing vessel 104 to the transfer vessel 108 is connected to the connecting tube 107. Flow through.

The transfer container 108 feeds the molten glass 106 through the downcomer 109 to the FDM 120. FDM 120 includes an enclosure 122 where an inlet 110, a forming container 111, and at least one drawing assembly 150 are located. As shown in FIG. 1A, the molten glass 106 from the downcomer 109 flows to the inlet 110, which is directed to the forming container 111. The forming container 111 includes an opening 112 for receiving the molten glass 106 flowing down the two converging sides 114a and 114b after flowing into the trough 113 and before overflowing and fusing together at the root. And two sides in the route are connected before being drawn and contacted in the downstream direction 151 by the draw assembly 150 to form a continuous glass sheet 148.

Referring to FIG. 1B, a cross-sectional view of the drawing assembly 150 is schematically shown in the figure. As shown in FIG. 1B, the draw assembly 150 generally includes a pair of opposed tension rolls 200a, 200b that are in contact with the glass sheet 148 on the opposite side. Accordingly, it will be appreciated that the glass sheet 148 acts between the tension rolls 200a and 200b. Tensile rolls 200a and 200b may be actuated (ie, impart tensile force to actively rotate and thus convey glass sheet 148 in downstream direction 151) or may be passive. (Ie, the tension rolls 200a, 200b are in contact with the glass sheet 148 and stabilize the glass sheet as it is drawn in the downstream direction 151 by various tension rolls).

While the tension rolls 200a and 200b are described herein in connection with use in connection with an apparatus using a fusion drawer to form a glass sheet, the tension rolls can be used in a similar process and glass in the similar process. It will be appreciated that a batch material is melted to form the molten glass and the molten glass is then molded into a glass sheet and drawn into the tension roll. For illustrative purposes only, the tension rolls disclosed herein may also be used in connection with up-draw processes, slot-draw processes, float-draw processes, and many similar glass draw processes.

As briefly described above, the tension rolls used in the above-mentioned process are in direct contact with the glass sheet, and as such, surface damage of the glass may occur due to the wear characteristics of conventional tension rolls. For example, glass particles may be inserted on the surface of a conventional tensile roll, causing damage to the glass as the tensile roll contacts the glass. Similarly, conventional tension rolls can degrade with long periods of use at elevated temperatures and can degrade particulate matter. Such particulate matter can be embodied in soft glass, forming defects in the glass. Regardless of the glass source, such defects and / or damages result in permanent and / or uncontrolled breakage of the glass sheet during the glass drawing process, reducing manufacturing efficiency and increasing costs. The tension rolls disclosed herein use spring members in contact with the glass sheet. The spring member is formed of a material that is stable at elevated temperatures, so that the tension roll does not easily degrade or degrade particulate matter after long periods of use. Moreover, the tension roll is formed as an open structure between the spring members, so that particulate matter can be easily surrounded by the body of the tension roll rather than inserted into the surface of the tension roll.

2, an exemplary tension roll 200 is shown schematically for use in a glass making process. Tension roll 200 generally includes a shaft member 202 and a compliant cover assembly 208 positioned on the shaft member 202. The compliant cover assembly 208 includes a plurality of traction discs 210 positioned on the shaft member 202 and forming a contact surface 209 of the compliant cover assembly. It will be appreciated that while the tension roll 200 of the embodiment shown in FIG. 2 includes a plurality of towing disks, the compliant cover assembly 208 may be formed from a single towing disk.

The shaft member 202 includes a threaded portion 224 at one end while the opposite end is formed with a shoulder 222. Traction disc 210 may be positioned relative to the shoulder and secured on the shaft member, for example, with a nut such as a tapered pin or another suitable fastener. The shoulder 203 can also easily secure the tension roll 200 to a frame or mechanism for actively rotating the tension roll 200. In various embodiments disclosed herein, the shaft member 202 is for engaging with a corresponding keyway 250 formed in the traction disk 210 of the compliant cover assembly 208, as shown in FIG. It further includes a key 225. In various embodiments (not shown), the shaft member is formed with a keyway for engaging a corresponding key formed in the traction disc. As the tension roll 200 rotates, the traction disk 210 is prevented from rotating on the shaft member 202 by the interaction of the key and the key groove.

3 and 4, a traction disk 210 for use in the compliant cover assembly of the tension roll 200 is schematically illustrated. In the embodiment disclosed herein, the traction disc 210 generally includes an annular hub 206 and a plurality of spring members 204. The plurality of spring members 204 are integrally formed with the annular hub 206 and protrude radially outward from the annular hub 206 as shown in FIG. 3. As best shown in FIG. 4, each spring member 204 extends between the base 214 and the free end 212. In particular, each spring member 204 is integrally attached to the annular hub 206 at the base 214 such that the free end 212 of the spring member is radial from the base 214 and the annular hub 206. Direction outward. In the traction disc 210 of the embodiment shown in FIG. 3, the annular hub 206 and the plurality of spring members 204 are substantially the same plane.

The spring member 204 of each traction disk 210 is designed to bend elastically relative to the annular hub 206 so that when the tension roll is pressed into contact with the surface of the glass sheet to exert a tension on the glass sheet The spring member 204 is elastically displaced with respect to the annular hub 206. As a result, the spring member 204 applies a tensile force to the glass sheet while not damaging the glass sheet.

More specifically, the spring member 204 of each traction disk ranges from approximately 2 lbf / mm to approximately 2000 lbf / mm (about 8.9 N / mm to about 8896.4 N / mm) or from about 5 lbf / mm to It generally has a radial spring constant in the range of approximately 1500 lbf / mm (22.2 N / mm to approximately 6672.3 N / mm) (ie spring constant along radial projection from annular hub 206). Tensile rolls with sufficient compliance so as not to damage the glass sheet have spring constants within these ranges, while at the same time the spring constant is suitable for the surface of the glass sheet to easily draw the glass sheet with the tension roll. The traction can be provided with sufficient reliability.

As described above, debris such as glass shards or particulate matter may contact the tension rolls during the down-draw process. In order to prevent debris from being inserted into the contact surface of the compliant cover assembly of the tension roll and thus to damage the glass sheet drawn by the tension roll, the spring member 204 of the traction disc 210 is axial Sufficiently compliant in the direction and tangential direction, when the debris is acted between the contact surfaces of the compliant cover assembly, the spring member is displaced tangentially and / or axially such that the debris is between the spring member. The debris can pass through the tension roll completely or be enclosed in the compliant cover assembly away from the surface of the compliant cover assembly, alleviating damage to the glass sheet. In the tension rolls of the embodiments disclosed herein, the spring member 204 generally has a sufficiently low axial spring constant to facilitate setting of the roll tilt angle (ie, the angle of the longitudinal axis of the roll relative to the horizontal direction). (Ie, a spring constant in the +/- z-direction of the coordinate axis shown in FIG. 3). For example, the axial spring constant ranges from about 0.25 lbf / mm to about 150 lbf / mm (about 1.1 N / mm to about 667.2 N / mm) or about 5 lbf / mm to about 75 lbf / mm (about 22.2 N / mm to approximately 333.6 N / mm). The tangential spring constant (ie, the spring constant in the direction of arrow 240) can very well prevent excessive deflection at the free end of the spring member that would interfere with maintaining a constant sheet speed. In the embodiment shown herein, the tangential spring constant ranges from about 2 lbf / mm to about 75 lb / mm (about 8.9 N / mm to about 333.6 N / mm) or about 5 lbf / mm to about 50 lbf / mm (approximately 22.2 N / mm to approximately 222.4 N / mm).

2-4, in the tension rolls of the embodiments disclosed herein, a spring member 204 of the traction disc 210 is formed on an annular hub, such that the base of the adjacent spring member 204 in the circumferential direction. The gap G between them is about 0.01 mm or more. This gap allows the debris to pass sufficiently between the circumferentially adjacent spring members 204, rather than being embodied at the contact surface 209 of the compliant cover assembly 208. In various embodiments, the gap G may be about 0.05 mm or more.

The thickness T of the spring member 204 in the circumferential direction is generally determined in accordance with the type of material from which the traction disc 210 is formed, as well as the predetermined spring constant of the spring member. In the embodiment disclosed herein, the thickness T of the spring member 204 generally ranges from approximately 0.25 mm to approximately 3.00 mm. In various embodiments, the thickness T of the spring member may range from about 0.25 mm to about 1.5 mm. However, it will be appreciated that the spring member 204 may have various thicknesses and / or certain spring constants of the spring member, depending on the type of material from which the traction disc 210 is made. Moreover, the thickness T of the spring member 204 may not be constant between the base 214 and the free end, as shown in FIG. 4, while in some embodiments (not shown), the spring The thickness of the member 204 can be constant between the base 214 and the free end 212.

2-4, in the tension roll 200 of the embodiments disclosed herein, the annular hub 206 of the traction disc 210 generally has an outer diameter D in the range of approximately 18 mm to approximately 75 mm. On the other hand, the outer diameter D of the towing disk ranges from about 60 mm to about 200 mm. Accordingly, it will be appreciated that the compliant cover assembly of the tension roll 200 also has an outer diameter in the range of about 60 mm to about 200 mm.

The axial thickness T of the spring member 204 (ie, the thickness in the +/- z-direction of the coordinate axis shown in FIG. 3) and the thickness of the annular hub 206 generally range from about 0.50 mm to about 105 mm. Moreover, for a given material, the axial thickness T of the spring member 204 can be increased or decreased to adjust the axial spring constant of the spring member 204. In various embodiments, the axial thickness of the annular hub 206 may be thicker than the axial thickness of the spring member 204. In various embodiments, the annular hub 206 may be used to form the necessary clearance between the axially adjacent spring members 204 when the traction disc 210 is secured to the shaft member 202. Accordingly, it will be appreciated that the traction disc 210 may be formed from annular hubs having different thicknesses to form the necessary clearance between axially adjacent spring members.

In the tension rolls 200 of the embodiments disclosed herein, the spring member 204 has some mechanical response (ie, some elastic deformation and stress) when the tension roll is pressed against the flat surface of the glass substrate. It can be formed into a special shape to achieve. For example, FIGS. 2-4 show an embodiment of a tension roll 200 constructed from a traction disc 210 having a spring member curved between a free end 212 and a base 214, wherein the spring When the free end of the member engages the flat surface of the glass sheet, the spring member is elastically deflected radially inward toward the center of the annular hub. In various embodiments, the radius of curvature R of the spring member 204 is constant between the free end 212 and the base 214. In various embodiments, the radius of curvature R may range from about 10 mm to about 80 mm or from about 10 mm to about 40 mm. In these embodiments, the spring member 204 is generally curved in a direction opposite to the down-draw rotation direction of the tension roll, so that the spring member 204 easily bends when it comes in contact with the surface of the glass sheet. For example, the tension roll 200 of FIG. 1B has a clockwise down-draw rotation direction while the spring member 204 is curved in a counter-clockwise direction.

In various embodiments, the spring member 204 may have a complex curvature. For example, in various embodiments, the radius of curvature of each spring member may increase from the base 214 of the spring member 204 to the free end 212 of the spring member 204. In various embodiments, the radius of curvature of each spring member may decrease from the base 214 of the spring member to the free end 212 of the spring member 204. In various embodiments, the spring member 204 is formed with complex curvature, in which different segments of the spring member have different radii and / or bend in different directions. For example, FIG. 5 illustrates one embodiment of a traction disc 234 in which the spring member has a lower portion 227 (ie, the portion of the spring member closest to the annular hub 206) and It has an upper side 226. In this embodiment, the lower portion 227 of each spring member 204 has a curvature of the first radius and is curved counterclockwise while the upper portion 225 of the spring member 204 is second Are curved in a clockwise direction with curvatures of different radii. In various embodiments, the upper portion 226 of the spring member is generally curved in a direction opposite to the down-draw direction of rotation of the tension roll. Accordingly, in the pull disk 234 of the embodiment shown in FIG. 5, the downward-drawing direction of the tension roll will be counter-clockwise.

Referring to FIG. 6, a traction disk 230 of another embodiment is schematically illustrated. In this embodiment, the traction disc 230 is formed of a spring member 204 including a contact leg 216 formed at the free end 212 of each spring member 204. The contact leg 216 increases the contact area between the surfaces of the glass sheet drawn into the traction disc 230. The increase in the area of contact between the spring member 204 and the surface of the glass sheet increases the friction between the traction disc and the glass sheet, which allows greater torque from the shaft member to be imparted to the glass sheet, and thus down-draw In order to mitigate the potential damage of the glass sheet during the process, the down-draw force applied on the glass sheet is increased without decreasing the elasticity of the spring member 204.

As described above, the traction disc may be provided with a key groove that prevents the traction disc from rotating in the shaft member. In the traction disc 230 of the embodiment shown in FIG. 6, the keyway 250 may be an opening formed in the annular hub 206. The keyway 250 may be formed to receive a corresponding key (not shown) secured to the shaft member to prevent rotation of the traction disc 230 on the shaft member.

Referring to FIG. 7, there is schematically shown a tow disk 232 of another embodiment in the figure. In this embodiment, the traction disc 232 includes a rim 218. Rim 218 connects the free end of each spring member of the plurality of spring members to the free end of the adjacent spring member on the same traction disk. In this embodiment, the rim 218 increases the contact area between the spring members and the surface of the glass sheet drawn into the traction disk 232. Increasing the contact area between the spring members 204 and increasing the surface of the glass sheet with the rim 218 increases the friction between the traction disc and the glass sheet to produce greater torque to be applied to the glass sheet by the shaft member. Allow, thereby increasing the down-draw force applied on the glass sheet. Moreover, the curved spring member 204 of the traction disc 232 may displace the rim relative to the annular hub 206 to mitigate potential damage of the glass sheet during the down-draw process.

It will be appreciated that while a tension roll is described herein as constructed of a traction disc with a curved spring member, other embodiments of traction discs may be considered. For example, in FIGS. 8 and 9, a traction disc 236 formed from an inclined spring member 204 is shown. In particular, the traction disc 236 includes an annular hub 206 integrally formed with a plurality of spring members 204 extending radially outward from the annular hub 206 as described above. Each spring member includes an upper portion 226 and a lower portion 227, wherein the lower portion 227 is an upper portion of the spring member 204 inclined at an angle α with respect to the lower portion 227. 226. The inclination of the upper portion 226 of the spring member 204 relative to the lower portion 227 provides a flexible point at the intersection of the lower portion 227 and the upper portion 226 and provides a predetermined spring constant. It is easy to form the spring member having. In particular, the angle α as well as the position of the flexible point can be selected to achieve a certain spring constant for the spring member. The angle α between the upper portion 226 and the lower portion 227 may be, for example, approximately 10 degrees or approximately 30 degrees. In various other embodiments, the angle α may be approximately 45 degrees or approximately 60 degrees.

The traction discs shown in FIGS. 3-9 can be made from a material that retains its mechanical properties at elevated temperatures encountered during a glass down-draw process that can reach approximately 900 ° C. Suitable materials include, by way of example only, metals, ceramics, matrix composites, and mineral-based materials. For example, the traction disc may be formed from a nickel-based alloy, which includes only Rene 41, Haynes 282, or similar nickel-based alloys, for example. Suitable ceramic materials of embodiments of the present invention include by way of example only silicon nitride, silicon carbide, alumina, boron carbide, SIALONs, or similar ceramic materials. Suitable mineral materials only include bulk bulk mica materials such as, for example, phlogopite mica. The traction discs shown in FIGS. 3-9 may be fabricated using conventional machining techniques such as, for example, electro-discharge machining (EDM) or water jet machining techniques. Can be formed.

An alternative embodiment pull disk 238 is schematically illustrated in FIG. 10. Traction disc 238 includes an annular hub 206 and a plurality of spring members 204. In this embodiment, the spring member 204 is formed and brittle to achieve a predetermined spring constant (ie, a spring constant in the range of 60 lbf / mm to 2000 lbf / mm). However, in this embodiment, the spring member 204 is formed by selectively etching the hub material to form individual spring members. The towing disk 238 of this embodiment may be formed of the same material described above for the towing disk of the embodiment shown in FIGS.

Once the traction disc is formed, the traction disc may be coated with a material that enhances the oxidation and abrasion resistance of the traction disc. For example, the traction disc may be coated with Stellite 6, Stellite 12 or various similar coating materials that enhance the oxidation and / or abrasion resistance of the traction disc.

Referring again to FIG. 2, an individual traction disc 210 is assembled on the shaft member 202 such that the keyway 250 of each traction disk 210 engages with the key 225 formed in the shaft member 202. do. In the tension roll 200 of the embodiment shown in FIG. 2, the traction disc 210 is positioned relative to the shoulder 222 and a nut (not shown) is screwed onto the threaded portion 225 of the shaft member to secure the traction disc. It is fixed on the shaft member 202 to form the compliant cover assembly 208 of the tension roll. In various embodiments, each traction disk is located on the shaft member such that the extent of the axial gap S (ie, the gap in the z-direction of the coordinate axis shown in FIG. 2) between adjacent traction discs is approximately. From 0.0 mm (substantially slightly greater than 0) to approximately 25 mm, or from about 0.0 mm (substantially slightly greater than 0) to approximately 25 mm. In various embodiments, the range of the axial gap S between adjacent traction discs may be between about 0.75 mm and about 6 mm. The axial gap S between adjacent traction discs allows debris to pass into the compliant cover assembly 208 with respect to the gap G between the spring members on the single traction disc (shown in FIG. 3). And pass through the compliant cover assembly rather than being inserted into the surface of the compliant cover assembly to prevent damage to the glass sheet during the down-draw process.

In the tension roll 200 of the embodiment shown in FIG. 2, the individual traction discs 210 are keyed so that each traction disc rotates from the adjacent traction disc when the traction disc is positioned on the key 225. FIG. Direction, and as such, the spring members of the traction discs adjacent to each other are not aligned with each other. However, in various embodiments, the individual traction discs 210 may be keyed identically such that the spring members of the traction discs adjacent to each other are aligned with each other.

1B and 11, during the down-draw glass forming process, the tension rolls 200a, 200b of the draw assembly 150 are formed of a glass sheet (1) on the first flat surface 149 and the second flat surface 152, respectively. In contact with 148, at least the free end 212 of the spring member 204 is in contact with the glass sheet. As each spring member contacts the surface of the glass sheet, the spring member deflects radially inwards, towards the center of the annular hub 206 (ie, in the direction of arrow 350), from the shaft member to the glass sheet 148. Torque is delivered to and thus the glass sheet is drawn in the downstream direction 151. For example, as shown in FIG. 11, the tension roll rotates in the counter-clockwise direction 153. The spring members 204a and 204c do not contact the surface 149 of the glass sheet 148, and as such, the spring members 204a and 204c are not deflected. However, as the spring member 204b rotates in contact with the surface 149 of the glass sheet 148, the spring member causes the rotating shaft member to apply torque through the tension roll on the glass sheet to downstream the glass. As it draws in the direction 151, it deflects radially inward, towards the center of the annular hub 206.

11, where debris or various particulate matter, such as particle 300, is present on surface 149 of glass sheet 148, as spring member 204 contacts particle 300 The glass sheet 148 drawn in the downstream direction 151 is deflected radially inward by the particles 300 such that a point load of the particle 300 is directed against the surface 149 of the glass sheet 148. loading), and as a result, damage to the glass sheet is reduced. Moreover, the load at any point of the particle 300 on the surface of the glass sheet 148 is not limited to a single spring member or immediately adjacent spring member of a local group according to the size of the particle. As a result, the rest of the spring member remains in contact with the glass sheet and continues to impart tensile force to the glass sheet.

It will be appreciated that the tension rolls disclosed herein can be used in glass manufacturing processes to draw and / or guide glass sheets. In particular, the spring member of the traction disc is on a smooth, elastic contact surface and the contact surface allows the glass sheet to be contacted without damaging the surface of the glass sheet. Since the tension rolls are composed of a material suitable for use at elevated temperatures, the tension rolls are particulate matter and / or which may not readily degrade with prolonged use at elevated temperatures or may contaminate the glass drawing process. Do not drop debris. Moreover, the spring member of the traction disc can be easily surrounded in the axial direction, the radial direction and the tangential direction so as to easily surround the particulate matter between the spring members, which reduces the damage of the glass sheet.

The spring members of the tension rolls disclosed herein increase the radial compliance of the rolls to provide a more constant tensile force on the glass sheet. Moreover, the spring member also provides increased contact area of the roll surface, while reducing the contact pressure and shear force applied to the glass sheet. In particular, the spring member mitigates or eliminates particle-induced point loads on the surface of the glass sheet and, as a result, reduces cracking and / or catastrophic failure of the glass sheet.

Those skilled in the art will appreciate that various changes and modifications can be made to the embodiments disclosed herein without departing from the scope and spirit of the appended claims. Accordingly, it will be appreciated that various changes and modifications to the various embodiments disclosed herein may be made within the scope of the appended claims.

Claims (10)

A tension roll for drawing a glass sheet in a down-draw process,
Shaft member; And
A compliant cover assembly positioned on the shaft member;
The compliant cover assembly includes at least one towing disk positioned on the shaft member,
The at least one towing disc is:
Cyclic hub; And
A plurality of spring members integrally formed with the annular member,
The plurality of spring members project outwardly from the annular hub such that a free end of each spring member of the plurality of spring members is located radially outward from a base of each spring member of the plurality of spring members. Each spring member of the spring member has a radial spring constant in the range of approximately 2 lbf / mm to approximately 2000 lbf / mm, when the compliant cover assembly is engaged with the flat surface of the glass sheet. At least a portion of the member is radially inwardly deflected toward the center of the annular hub, thereby pulling the glass sheet in a down-draw process to prevent damage to the glass sheet. The method according to claim 1,
Wherein each spring member of said plurality of spring members is curved between said free end and said base, wherein said spring member is curved. The method according to claim 1,
Wherein each spring member of said plurality of spring members has a radius of curvature of approximately 10 mm to approximately 80 mm. The method according to claim 1,
Wherein each spring member of the plurality of spring members has a constant radius of curvature, wherein the tension roll is for drawing the glass sheet in a down-draw process. The method according to claim 1,
And said at least one towing disk comprises a plurality of towing disks. The method according to claim 1,
And the annular hub comprises a keyway or a keyway or keyway corresponding to the key, respectively, formed in the shaft member. 10. A tension roll for drawing a glass sheet in a down-draw process. The method according to claim 1,
Further comprising a rim connecting said free end of each spring member of said plurality of spring members to said free end of an adjacent spring member on a single traction disk. Tensile roll. As a molding method of the glass sheet,
Melting the glass batch material to form molten glass;
Forming the molten glass into the glass sheet;
Contacting at least one tension roll with a first surface of the glass sheet to transport the glass sheet in a downstream direction,
The at least one tension roll is:
Shaft member; And
A compliant cover assembly positioned on the shaft member;
The compliant cover assembly is:
A plurality of towing disks positioned on the shaft member, each of the plurality of towing disks including an annular hub, wherein the annular hub includes a plurality of free ends of each spring member of the plurality of spring members; Integrally formed with a plurality of spring members projecting outwardly of the annular hub so as to be located radially outward from the base of each spring member of the spring members of each spring member, wherein each spring member is approximately 2 lbf / mm Having a radial spring constant in the range of from about 2000 lbf / mm, when the compliant cover assembly is in contact with the first surface of the glass sheet, the spring member deflects radially inward, towards the center of the annular hub; And forming method of glass sheet which prevents damage of said glass sheet. The method according to claim 8,
Wherein each spring member of the plurality of spring members is curved between the free end and the base. The method according to claim 8 or 9,
Wherein each spring member of said plurality of spring members has a constant radius of curvature.

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