Classifications

• • C—CHEMISTRY; METALLURGY
  • C03—GLASS; MINERAL OR SLAG WOOL
  • C03B—MANUFACTURE, SHAPING, OR SUPPLEMENTARY PROCESSES
  • C03B17/00—Forming molten glass by flowing-out, pushing-out, extruding or drawing downwardly or laterally from forming slits or by overflowing over lips
  • C03B17/06—Forming glass sheets
  • C03B17/068—Means for providing the drawing force, e.g. traction or draw rollers

Definitions

• the present specification generally relates to pulling rolls for use in the manufacture of glass sheets and, more specifically, to pulling rolls comprising spring elements for applying a drawing force to glass sheets.
• Pulling rolls are used in the manufacture of sheet glass to apply tension to a ribbon or web of glass from which individual sheets of glass are formed.
• the amount of tension applied by the pulling rolls to the glass is utilized to control the nominal thickness of the glass as the glass is drawn from molten glass, such as in an overflow down-draw fusion process, as described in U.S. Patent Nos. 3,338,696 and 3,682,609, or in similar glass manufacturing processes.
• Pulling rolls are generally designed to contact the glass web at its outer edges, usually in an area just inboard of the thickened beads that form at the very edges of the glass web. Because the pulling rolls are in direct contact with the surface of the glass web, damage to the surface of the glass can occur due to the wear characteristics of the pulling roll material. For example, glass particles can become embedded in the surface of the pulling roll resulting in damage to the glass as the pulling rolls contact the glass.
• the pulling roll may shed particulate matter if the material of the pulling roll degrades with use at the elevated temperatures of the glass drawing process. This particulate matter may become embedded in the soft glass thereby fomiing defects in the glass.
• particulate matter generated from the glass drawing process e.g., debris, dust, glass shards and the like
• the embodiments described herein relate to pulling rolls for use in glass drawing processes that reduce the occurrence of premature and/or uncontrolled breakage of the glass sheets drawn with the pulling rolls. Also disclosed are methods for fomiing glass sheets utilizing pulling rolls that mitigate premature and/or uncontrolled breakage of the glass sheets during a glass drawing process.
• a pulling roll for reducing premature and/or uncontrolled breakage in glass sheets may include a shaft member and a compliant cover assembly positioned on the shaft member.
• the compliant cover assembly may include at least one traction disk positioned on the shaft member.
• the at least one traction disk may include an annular hub and a plurality of spring elements integrally formed with the annular hub.
• the plurality of spring elements may project outward from the annular hub such that a free end of each spring element of the plurality of spring elements is positioned radially outward from a base of each spring element of the plurality of spring elements.
• Each of the plurality of spring elements may 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).
• a pulling roll for reducing premature and/or uncontrolled breakage in glass sheets may include a shaft member and a compliant cover assembly positioned on the shaft member.
• the compliant cover assembly may include a plurality of traction disks positioned on the shaft member.
• Each traction disk of the plurality of traction disks may be rotationally offset from adjacent traction disks and each traction disk of the plurality of traction disks may include an annular hub and a plurality of spring elements integrally formed with the annular hub.
• the plurality of spring elements may project outward from the annular hub such that a free end of each spring element of the plurality of spring elements is positioned radially outward from a base of each spring element of the plurality of spring elements.
• Each spring element of the plurality of spring elements may be curved between the free end and the base in a direction opposite a down-draw rotational direction of the pulling roll.
• Each spring element of the plurality of spring elements may 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).
• a method for fomiing a glass sheet that reduces premature and/or uncontrolled breakage in the glass sheet may include melting glass batch materials to form molten glass and forming the molten glass into a glass sheet. Thereafter, at least a first surface of the glass sheet may be contacted with at least one pulling roll to convey the glass sheet in a downstream direction.
• the at least one pulling roll may include a shaft member and a compliant cover assembly positioned on the shaft member.
• the compliant cover assembly may include a plurality of traction disks 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 projecting outward from the annular hub such that a free end of each of the plurality of spring elements is located radially outward from a base of each of the plurality of spring elements.
• Each of the plurality of spring elements may include 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).
• FIG. 1A schematically depicts a glass drawing apparatus for forming glass sheets according to one or more embodiments shown and described herein;
• FIG. IB schematically depicts a cross section of a draw assembly comprising a pair of opposed pulling rolls for use in drawing a glass sheet;
• FIG. 2 schematically depicts a partially exploded view of a pulling roll formed from a plurality of traction disks according to one or more embodiments shown and described herein;
• FIG. 3 schematically depicts a traction disk of the pulling roll of FIG. 2 according to one or more embodiments shown and described herein;
• FIG. 4 schematically depicts the annular hub and a single spring element of the traction disk of FIG. 3 for purposes of illustration;
• FIG. 5 schematically depicts a traction disk for a pulling roll in which the spring elements of the traction disk have complex curvatures
• FIG. 6 schematically depicts a traction disk for a pulling roll in which the spring elements of the traction disk include a contact foot
• FIG. 7 schematically depicts a traction disk for a pulling roll in which the spring elements of the traction disk are joined by a rim
• FIG. 8 schematically depicts a traction disk for a pulling roll in which the spring elements have an upper portion that is angled with respect to a lower portion;
• FIG. 9 schematically depicts the annular hub and a single spring element of the traction disk of FIG. 8 for purposes of illustration;
• FIG. 10 schematically depicts another embodiment of a traction disk for a pulling roll according to one or more embodiments described herein;
• FIG. 11 schematically depicts a portion of a traction disk of a pulling roll engaged with the surface of a glass sheet.
• the pulling roll generally comprises a shaft member and a compliant cover assembly positioned on the shaft member.
• the compliant cover assembly is formed from a plurality of traction disks having spring elements that extend radially outward from an annular hub.
• the spring elements generally have a 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).
• Glass sheet materials may generally be formed by melting glass batch materials to form molten glass and thereafter forming the molten glass into a glass sheet.
• Exemplary processes include the float glass process, the slot draw process and the tusion down-draw process. In each of these processes, one or more pulling rolls may be utilized to contact the glass sheet and convey the glass sheet in a downstream direction.
• an exemplary glass manufacturing apparatus 100 for fomiing glass sheet material from molten glass is schematically depicted in which a fusion draw machine is used to form the molten glass into glass sheets.
• the glass manufacturing apparatus 100 includes a melting vessel 101, a fining vessel 103, a mixing vessel 104, a delivery vessel 108, and a fusion draw machine (FDM) 120.
• Glass batch materials are introduced into the melting vessel 101 as indicated by arrow 102.
• the batch materials are melted to form molten glass 106.
• the fining vessel 103 has a high temperature processing area that receives the molten glass 106 from the melting vessel 101 and in which bubbles are removed from the molten glass 106.
• the fining vessel 103 is coupled to the mixing vessel 104 by a connecting tube 105. That is, molten glass flowing from the fining vessel 103 to the mixing vessel 104 flows through the connecting tube 105.
• the mixing vessel 104 is, in turn, coupled to the delivery vessel 108 by a connecting tube 107 such that molten glass flowing from the mixing vessel 104 to the delivery vessel 108 flows through the connecting tube 107.
• the delivery vessel 108 supplies the molten glass 106 through a downcomer 109 into the FDM 120.
• the FDM 120 comprises an enclosure 122 in which an inlet 110, a fomiing vessel 111 and at least one draw assembly 150 are positioned. As shown in FIG. 1A, the molten glass 106 from the downcomer 109 flows into an inlet 110 that leads to the fomiing vessel 111.
• the forming vessel 111 includes an opening 112 that receives the molten glass 106 that flows into a trough 113 and then overflows and runs down two converging sides 114a and 114b before fusing together at a root, where the two sides join, before being contacted and drawn in a downstream direction 151 by the draw assembly 150 to form a continuous glass sheet 148.
• the draw assembly 150 generally comprises a pair of opposed pulling rolls 200a, 200b that contact the glass sheet 148 on opposite sides. Accordingly, it should be understood that the glass sheet 148 is impinged between the pulling rolls 200a, 200b.
• the pulling rolls 200a, 200b may be powered (i.e., the pulling rolls 200a, 200b are actively rotated and thus impart a drawing force that conveys the glass sheet 148 in the downstream direction 151) or passive (i.e., the pulling rolls 200a, 200b contact the glass sheet 148 and stabilize the glass sheet as it is drawn in the downstream direction 151 by other pulling rolls).
• pulling rolls 200a, 200b have been described herein as being used in conjunction with an apparatus that utilizes a fusion draw machine to form the glass sheet, it should be understood that the pulling rolls may be used with similar processes in which glass batch materials are melted to form molten glass and the molten glass is then formed into a glass sheet and drawn with pulling rolls.
• the pulling rolls described herein may also be utilized in conjunction with up-draw processes, slot-draw processes, float-draw processes and other, similar glass drawing processes.
• the pulling rolls used in the aforementioned processes are in direct contact with the glass sheet and, as such, damage to the surface of the glass can occur due to the wear characteristics of conventional pulling rolls. For example, glass particles can become embedded in the surface of conventional pulling rolls resulting in damage to the glass as the pulling rolls contact the glass. Similarly, conventional pulling rolls may degrade with prolonged use at elevated temperatures and shed particulate matter. This particulate matter may become embedded in the soft glass, thereby fomiing defects in the glass. Regardless of the source, such defects and/or damage may lead to premature and/or uncontrolled breakage of the glass sheet during the glass drawing process thereby reducing manufacturing efficiencies and increasing costs.
• the pulling rolls described herein utilize spring elements to contact the glass sheet.
• the spring elements are formed from materials that are stable at elevated temperatures and, therefore, the pulling rolls do not readily degrade after prolonged use or shed particulate matter. Moreover, the pulling rolls are formed with an open structure between the spring elements such that particulate matter can be readily enveloped in the body of the pulling roll rather than embedded into the surface of the pulling roll.
• the pulling roll 200 generally includes a shaft member 202 and a compliant cover assembly 208 that is positioned on the shaft member 202.
• the compliant cover assembly 208 comprises a plurality of traction disks 210 positioned on the shaft member 202 and forming a contact surface 209 of the compliant cover assembly. While the embodiment of the pulling roll 200 depicted in FIG. 2 includes a plurality of traction disks, it should be understood that the compliant cover assembly 208 may be formed from a single traction disk.
• the shaft member 202 may include threads 224 on one end while the opposing end is formed with a shoulder 222.
• the traction disks 210 may be positioned against the shoulder and secured on the shaft member with a nut or another suitable fastener such as, for example, a taper pin.
• the shoulder 203 may also facilitate securing the pulling roll 200 to a frame or a mechanism for actively rotating the pulling roll 200.
• the shaft member 202 further comprises a key 225 for engaging with a corresponding keyway 250 formed in the traction disks 210 of the compliant cover assembly 208, as shown in FIG. 2.
• the shaft member is formed with a keyway for engaging with a corresponding key formed in the traction disks. The interaction between the key and keyway prevents the traction disks 210 from rotating on the shaft member 202 as the pulling roll 200 is rotated.
• the traction disks 210 generally comprise an annular hub 206 and a plurality of spring elements 204.
• the plurality of spring elements 204 are integrally formed with the annular hub 206 and project radially outward from the annular hub 206 as depicted in FIG 3.
• each spring element 204 extends between a base 214 and a free end 212.
• each spring element 204 is integrally attached to the annular hub 206 at the base 214 such that a free end 212 of the spring element is positioned radially outward from the base 214 and the annular hub 206.
• the annular hub 206 and the plurality of spring elements 204 are substantially co-coplanar.
• the spring elements 204 of each traction disk 210 are designed to elastically Ilex with respect to the annular hub 206 such that, when the pulling rolls are pressed into contact with the surface of a glass sheet to apply a drawing force to the glass sheet, the spring elements 204 elastically displace with respect to the annular hub 206. As a result, the spring elements 204 do not damage the glass sheet while providing a drawing force to the glass sheet.
• each traction disk generally have a radial spring constant (i.e., a spring constant along a radial projection from the annular hub 206) in a range from about 2 lbf/mm to about 2000 lbf/mm (about 8.9 N/mm to about 8896.4 N/mm) or even from about 5 lbf/mm to about 1500 lbf/mm (22.2 N/mm to about 6672.3 N/mm).
• Spring constants falling within these ranges produce a pulling roll that is sufficiently compliant so as not to damage the glass sheet while, at the same time, being firm enough to provide an adequate traction force against the surface of the glass sheet to facilitate drawing the glass sheet with the pulling roll.
• the spring elements 204 of the traction disk 210 are sufficiently compliant in the axial and tangential directions such that, when debris is impinged between the contact surface of the compliant cover assembly, the spring elements displace tangentially and/or axially such that the debris passes between the spring elements allowing the debris to completely pass through the pulling roll or become enveloped in the compliant cover assembly, away from the surface of the compliant cover assembly, thereby mitigating damage to the glass sheet.
• the spring elements 204 generally have an axial spring constant (i.e., a spring constant in the +/- z-direction of the coordinate axes depicted in FIG. 3) that is sufficiently low to facilitate setting the roll tilt angle (i.e., the angle of long axis of the roll with respect to horizontal).
• the axial spring constant may be 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 about 333.6 N/mm).
• the tangential spring constant (i.e., a spring constant in the direction of arrow 240) should be high enough to prevent excessive deflection at the free ends of the spring elements that may interfere with maintaining constant sheet velocity.
• the tangential spring constant may be 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).
• the spring elements 204 of the traction disks 210 are formed on the annular hub such that a spacing G between the bases of adjacent spring elements 204 in the circumferential direction is greater than or equal to about 0.01 mm. This spacing is sufficient to permit debris to pass between circumferentially adjacent spring elements 204 rather than embedded in the contact surface 209 of the compliant cover assembly 208. In some embodiments, the spacing G may be greater than or equal to about 0.05 mm.
• the thickness T of the spring elements 204 in the circumferential direction generally depends on the type of material from which the traction disks 210 are formed as well as the desired spring constants of the spring elements. In the embodiments described herein, the thickness T of the spring elements 204 is generally in the range from about 0.25 mm to about 3.00 mm. In some embodiments, the thickness T of the spring elements may be from about 0.25 mm to about 1.5 mm. However, it should be understood that the spring elements 204 may have other thicknesses depending on the type of material from which the traction disks 210 are made and/or the desired spring constants of the spring elements.
• the thickness T of the spring elements 204 may by non-uniform between the base 214 and the free end, as shown in FIG. 4 while, in other embodiments (not shown), the thickness of the spring elements 204 may be uniform between the base 214 and the free end 212.
• the annular hub 206 of the traction disks 210 generally has an outer diameter d in a range from about 18 mm to about 75 mm while an outer diameter D of the traction disk is in a range from about 60 mm to about 200 mm. Accordingly, it should be understood that the compliant cover assembly of the pulling roll 200 also has an outer diameter in a range from about 60 mm to about 200 mm.
• the axial thickness t of the spring elements 204 (i.e., the thickness in the +/- z- direction of the coordinate axes depicted in FIG. 3) and the thickness of the annular hub 206 is generally in the range from about 0.50 mm to about 105 mm. Moreover, for a given material, the axial thickness t of the spring elements 204 may be increased or reduced in order to adjust the axial spring constant of the spring elements 204. In some embodiments, the axial thickness of the annular hub 206 may be greater than the axial thickness of the spring elements 204.
• the annular hub 206 is utilized to achieve a desired spacing between axially adjacent spring elements 204 when the traction disks 210 are secured on the shaft member 202. Accordingly, it should be understood that the traction disks 210 may be formed with annular hubs having different thicknesses in order to achieve the desired spacing between axially adjacent spring elements.
• the spring elements 204 may be formed with a specific contour to achieve the desired mechanical response (i.e., the desired elastic deformation and stress) when the pulling rolls are pressed against a planar surface of a glass substrate.
• FIGS. 2-4 depict one embodiment of a pulling roll 200 constructed from traction disks 210 with spring elements that are curved between the free end 212 and the base 214 such that, when the free ends of the spring elements are engaged with a planar surface of the glass sheet, the spring elements elastically deflect radially inward toward the center of the annular hub.
• the radius of curvature R of the spring elements 204 is constant between the free end 212 and the base 214.
• the radius of curvature R may 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 curved in a direction opposite the down-draw rotational direction of the pulling roll such that the spring elements 204 readily flex when they contact the surface of the glass sheet.
• the pulling roll 200a of FIG. IB has a down-draw rotational direction in the clockwise direction while the spring elements 204 are curved in the counter-clockwise direction.
• the spring elements 204 may have a complex curvature.
• the radius of curvature of each spring element may increase from the base 214 of the spring element 204 to the free end 212 of the spring element 204.
• the radius of curvature of each spring element may decrease from the base 214 of the spring element to the free end 212 of the spring element 204.
• the spring elements 204 may be formed with a complex curvature in which different segments of the spring element have different radii and/or are curved in different directions. For example, FIG.
• FIG. 5 depicts one embodiment of a traction disk 234 in which the spring elements have a lower portion 227 (i.e., the portion of the spring element closest to the annular hub 206) and an upper portion 226.
• the lower portion 227 of each spring element 204 has a first radius of curvature and is curved in the counterclockwise direction while the upper portion 226 of the spring element 204 has a second, different radius of curvature and is curved in the clockwise direction.
• the upper portion 226 of the spring element is generally curved in a direction opposite the down-draw direction of rotation of the pulling roll. Accordingly, in the embodiment of the traction disk 234 depicted in FIG. 5, the down-draw direction of the pulling roll would be in the counterclockwise direction.
• the traction disk 230 is formed with spring elements 204 that include a contact foot 216 formed on the free end 212 of each spring element 204.
• the contact foot 216 increases the contact area between the spring element 204 and the surface of a glass sheet drawn with the traction disk 230.
• Increasing the contact area between the spring elements 204 and the surface of the glass sheet increases the friction between the traction disk and the glass sheet that allows for a greater torque from the shaft member to be imparted to the glass sheet thereby increasing the down-draw force exerted on the glass sheet without decreasing the elasticity of the spring elements 204 thereby mitigating the potential tor damage to the glass sheet during the down-draw process.
• the traction disks may be formed with keyways that prevent the traction disks from rotating on the shaft member.
• the keyway 250 is an aperture formed in the annular hub 206.
• the keyway 250 is shaped to receive a corresponding key (not shown) that is affixed to the shaft member thereby preventing rotation of the traction disk 230 on the shaft member.
• the traction disk 232 includes a rim 218.
• the rim 218 joins the free end of each spring element of the plurality of spring elements to the free end of an adjacent spring element on the same traction disk.
• the rim 218 increases the contact area between the spring elements and the surface of a glass sheet drawn with the traction disk 232.
• Increasing the contact area between the spring elements 204 and the surface of the glass sheet with the rim 218 increases the friction between the traction disk and the glass sheet allowing for a greater torque to be applied to the glass sheet with the shaft member thereby increasing the down-draw force exerted on the glass sheet.
• the curved spring elements 204 of the traction disk 232 allow the rim to be displaced with respect to the annular hub 206 thereby mitigating the potential for damage to the glass sheet during the down-draw process.
• FIGS. 8 and 9 depict a traction disk 236 that is formed with angular spring elements 204.
• 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 with the upper portion 226 of the spring element 204 oriented at an angle a with respect to the lower portion 227.
• Angling the upper portion 226 of the spring element 204 with respect to the lower portion 227 provides a flexure point at the intersection of the lower portion 227 and the upper portion 226 and facilitates the formation of spring elements with the desired spring constants.
• the position of the flexure point as well as the angle a may be chosen to achieve the desired spring constant for the spring element.
• the angle a between the upper portion 226 and the lower portion 227 may be, without limitation, about 10 degrees or even about 30 degrees. In some other embodiments, the angle a may be about 45 degrees or even about 60 degrees.
• the traction disks depicted in FIGS. 3-9 may be formed from materials that retain their mechanical characteristics at the elevated temperatures encountered during a glass down- draw process that may reach up to about 900°C. Suitable materials include, without limitation, metals, ceramics, metal matrix composites, and mineral-based materials. For example, the traction disks may be formed from nickel-based alloys including, without limitation, Rene 41, Haynes 282, or similar nickel-based alloys. Examples of suitable ceramic materials include, without limitation, silicon nitride, silicon carbide, alumina, boron carbide, SIALONs, or similar ceramic materials. Suitable mineral materials include, without limitation, bulk mica materials such as phlogopite mica. The traction disks depicted in FIGS. 3-9 may be formed using conventional machining techniques such as, for example, electro -discharge machining (EDM) or water jet machining techniques.
• EDM electro -discharge machining
• FIG. 10 An alternative embodiment of a traction disk 238 is schematically depicted in FIG. 10.
• the traction disk 238 includes an annular hub 206 and a plurality of spring elements 204.
• the spring elements 204 are bristles that are shaped to achieve the desired spring constant (i.e., a spring constant in the range from 60 lbf/mm to 2000 lbf/mm).
• the spring elements 204 are formed by selectively etching away the hub material thereby fomiing the individual spring elements.
• the traction disks 238 of this embodiment may be formed from the same materials described hereinabove with respect to the embodiments of the traction disks depicted in FIGS. 3-9.
• the traction disks may be coated with a material that improves the oxidation resistance and wear resistance of the traction disks.
• the traction disks may be coated with Stellite 6, Stellite 12 or other, similar coating materials that improve the oxidation and/or wear resistance of the traction disks.
• the individual traction disks 210 are assembled onto the shaft member 202 such that the keyway 250 of each traction disk 210 engages with the key 225 formed on the shaft member 202.
• each traction disk is positioned on the shaft member such that an axial spacing S between adjacent traction disks (i.e., the spacing in the z-direction of the coordinate axes shown in FIG. 2) is from about greater than 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 may be from about 0.75 mm to about 6 mm.
• the axial spacing S between the adjacent traction disks in conjunction with the spacing G (shown in FIG. 3) between spring elements on a single traction disk, allows debris to penetrate into the compliant cover assembly 208 and pass through the compliant cover assembly rather than embedded at the surface of the complaint cover assembly thereby preventing damage to the glass sheet during the down-draw process.
• the individual traction disks 210 are keyed such that each traction disk is rotationally offset from adjacent traction disks when the traction disks are positioned on the key 225 and, as such, the spring elements of axially adjacent traction disks are not aligned with one another.
• the individual traction disks 210 may be identically keyed such that the spring elements of axially adjacent traction disks are aligned with one another.
• the pulling rolls 200a, 200b of the draw assembly 150 contact the glass sheet 148 on a first planar surface 149 and a second planar surface 152, respectively, such that at least the free ends 212 of the spring elements 204 contact the glass sheet.
• the spring elements deflect radially inward, towards the center of the annular hub 206 (i.e., in the direction of arrow 350), communicating a torque from the shaft member to the glass sheet 148 thereby drawing the glass sheet in the downstream direction 151.
• the pulling roll is rotating in a counter-clockwise direction 153.
• Spring elements 204a and 204c are not in contact with the surface 149 of the glass sheet 148 and, as such, spring elements 204a and 204c are not deflected. However, as spring element 204b rotates into contact with the surface 149 of the glass sheet 148, the spring element deflects radially inward, towards the center of the annular hub 206, as the rotating shaft member exerts a torque on the glass sheet through the pulling roll thereby drawing the glass in the downstream direction 151.
• any point loading of the particle 300 against the surface of the glass sheet 148 is limited to a single spring element or a localized group of immediately adjacent spring elements depending on the size of the particle. As a result, the remainder of the spring elements remain in contact with the glass sheet and continue to impart the drawing force to the glass sheet.
• the pulling rolls described herein can be used in a glass manufacturing process to draw and/or guide glass sheets.
• spring elements of the traction disks present a smooth, resilient contact surface with which a glass sheet can be contacted without imparting damage to the surface of the glass sheet. Because the pulling roll is constructed from materials suitable for use at elevated temperatures, the pulling rolls do not readily degrade with prolonged use at elevated temperatures or shed particulate matter and/or debris that could contaminate the glass drawing process. Further, the spring elements of the traction disks are sufficiently resilient in the axial, radial and tangential directions to facilitate enveloping particulate matter in between the spring elements reducing damage to the glass sheet.
• the spring elements of the pulling rolls described herein increase the radial compliance of the roll thereby providing a more uniform drawing force to a glass sheet. Moreover, the spring elements also provide for an increased contact area of the roll surface while decreasing the contact pressure and shear forces imparted to the glass sheet. In particular, the spring elements mitigate or eliminate particle-derived point loading on the surface of the glass sheet that, in turn, reduces cracking and/or catastrophic failure of the glass sheet.

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• Chemical & Material Sciences (AREA)
• Engineering & Computer Science (AREA)
• Materials Engineering (AREA)
• Organic Chemistry (AREA)
• Re-Forming, After-Treatment, Cutting And Transporting Of Glass Products (AREA)
• Manufacturing Of Magnetic Record Carriers (AREA)

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• 2011
  • 2011-10-03 WO PCT/US2011/054525 patent/WO2013052026A1/en active Application Filing
• 2012
  • 2012-10-03 JP JP2012221133A patent/JP6027383B2/ja not_active Expired - Fee Related
  • 2012-10-03 TW TW101136571A patent/TW201318981A/zh unknown
  • 2012-10-08 CN CN201210535746.3A patent/CN103113018B/zh not_active Expired - Fee Related

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