With Annealing, Tempering, Or Fire-polishing Patents (Class 65/104)
  • Patent number: 4609391
    Abstract: A method capable of accurately forming a heated glass sheet to a deep, abrupt, or complex curvature are disclosed as utilizing a first curved mold (42) that initially forms the glass sheet at a first forming station (20) preferably by the operation of gravity. The initially formed glass sheet is moved horizontally preferably by movement on the first curved mold (42) to a second forming station (22). A second curved mold (48) of the second forming station (22) engages the initially formed glass sheet to provide accurate forming preferably by downward movement of the second curved mold that provides the engagement thereof with the glass sheet. In the preferred construction disclosed, the heated glass sheet is transferred from a furnace conveyor (28) to a topside conveyor (32) for depositing onto the first curved mold (42), and a transfer conveyor (55) transfers the formed glass sheet from the second curved mold (48) to a quench station (24) for tempering.
    Type: Grant
    Filed: September 25, 1985
    Date of Patent: September 2, 1986
    Assignee: Glasstech, Inc.
    Inventor: Harold A. McMaster
  • Patent number: 4604124
    Abstract: The apparatus for manufacturing of tempered, bent glass sheets comprises bending means (5) receiving the heated glass sheet in a horizontal position, said bending means (5) including a bending die (8) which, as well as the base supporting the glass sheet, is provided with coolant connections (13).
    Type: Grant
    Filed: February 26, 1985
    Date of Patent: August 5, 1986
    Assignee: Glasstemp of Toledo, Inc.
    Inventor: Gottfried Strauss
  • Patent number: 4591373
    Abstract: A method is provided for molding high-precision glass products where a piece of glass is heated at least in its surface portion and pressed between a pair of molds. Relative movement of the molds toward each other during the pressing is caused to follow change in dimension of a heated interval control member provided between the pair of molds, the interval control member having a coefficient of thermal expansion which is equal to or larger than that of the glass piece and therefore being capable of thermal contraction in the pressing direction by an amount which is substantially equivalent to or larger than that of the glass piece in the pressing direction due to cooling of the glass piece, and the change in dimension of the interval control member being caused by thermal contraction due to cooling thereof.
    Type: Grant
    Filed: December 14, 1984
    Date of Patent: May 27, 1986
    Assignee: Kabushiki Kaisha Ohara Kogaku Garasu Seizosho
    Inventor: Bunryo Sato
  • Patent number: 4575390
    Abstract: An apparatus capable of accurately forming a heated glass sheet to a deep, abrupt, or complex curvature are disclosed as utilizing a first curved mold (42) that initially forms the glass sheet at a first forming station (20) preferably by the operation of gravity. The initially formed glass sheet is moved horizontally preferably by movement on the first curved mold (42) to a second forming station (22). A second curved mold (48) of the second forming station (22) engages the initially formed glass sheet to provide accurate forming preferably by downward movement of the second curved mold that provides the engagement thereof with the glass sheet. In the preferred construction disclosed, the heated glass sheet is transferred from a furnace conveyor (28) to a topside conveyor (32) for depositing onto the first curved mold (42), and a transfer conveyor (55) transfers the formed glass sheet from the second curved mold (48) to a quench station (24) for tempering.
    Type: Grant
    Filed: November 23, 1984
    Date of Patent: March 11, 1986
    Assignee: Glasstech, Inc.
    Inventor: Harold A. McMaster
  • Patent number: 4575389
    Abstract: The invention relates to bending of glass plates moving in a horizontal position, under the effect of their own weight, with a device comprising a shaping bed made of rotating shaping elements whose surfaces in contact with the glass plates, as they advance, define increasingly curved generatrices, these shaping elements being carried by a frame that can be inclined by pivoting around a transverse axis located at its upstream end. The frame is mounted on pivoting axes (XX', YY', ZZ') that are adjustable in height. Particular zones of the glass plates can be kept at a constant level during bending, which improves the optical quality of the glass plates thus bent.
    Type: Grant
    Filed: November 9, 1984
    Date of Patent: March 11, 1986
    Assignee: Saint-Gobain Vitrage
    Inventors: Friedrich Halberschmidt, Josef Audi, Gerhard Schubert
  • Patent number: 4563206
    Abstract: Apparatus is disclosed for tempering curved glass sheets suspended in a vertical orientation. The apparatus comprises a pair of opposed manifolds each having a plurality of nozzles and positional adjustment means to optimize the heat exchange effect between the tempering station and the sheet of glass. A first adjustment means adjusts the orientation of the manifold with respect to the surface of the glass by means of four independently adjustable screw jacks that mount the manifold on a frame. A second adjustment means adjusts the horizontal spacing between the manifold and the surface of the glass by means of four screw jacks that operate in unison. In addition, another displacement means permits the manifold to be displaced from its tempering position to facilitate the insertion and removal of the glass sheets between the two manifolds. Advantageously, the displacement means is mounted on the second adjustment means.
    Type: Grant
    Filed: March 7, 1984
    Date of Patent: January 7, 1986
    Assignee: Saint-Gobain Vitrage
    Inventor: Claude Benard
  • Patent number: 4557745
    Abstract: The invention relates to bending of glass sheets moving in a horizontal position. In a first phase glass sheets are bent on a shaping bed made up of rotating elements, then in a second phase these sheets are subjected to a complementary bending between two molds of a bending press. Air flow is used to help support the glass in the second phase.
    Type: Grant
    Filed: November 9, 1984
    Date of Patent: December 10, 1985
    Assignee: Saint-Gobain Vitrage
    Inventors: Friedrich Halberschmidt, Josef Audi, Herbert Radermacher, Norbert Schwarzenberg
  • Patent number: 4556406
    Abstract: A roll forming apparatus for shaping heat-softened glass sheets into a configuration having a longitudinal radius of curvature that varies in a direction transverse to the glass sheet. Opposing ends of each forming roll are mounted along continuous arcuate paths defining two different longitudinal radii. Quenching rolls are mounted downstream of the forming rolls with each opposing end mounted along a continuation of the corresponding longitudinal radii.
    Type: Grant
    Filed: October 25, 1984
    Date of Patent: December 3, 1985
    Assignee: PPG Industries, Inc.
    Inventor: Lisa M. Kahle
  • Patent number: 4553998
    Abstract: A method is provided for the manufacture of glass containers (10) of the type having a sidewall (12) and having a bottom (16) that is thicker than the sidewall (12). The method comprises a step in which a centered portion (44) of the bottom (16) is cooled subsequent to the molding step. Cooling the centered portion (44) is effective to develop a reverse strain in the transition portion (42a) of the sidewall (12) that is proximal to the bottom (16). This reverse strain corrects the strain that is induced by unequal cooling of a relatively thin sidewall (12) and a relatively thick bottom (16) and results in a reduction of annealing time.
    Type: Grant
    Filed: June 22, 1984
    Date of Patent: November 19, 1985
    Assignee: Ball Corporation
    Inventor: William E. Jones
  • Patent number: 4540426
    Abstract: An apparatus for bending or bending and tempering of thermoplastic sheets such as glass sheets heated to their softening temperature by passing the glass sheets over a bed of straight or curved supporting rollers placed along a profile with an upward concavity. The apparatus comprises a pivoting assembly which transfers the glass sheets from a supporting bed of rollers with one slope to a conveyor with a different slope. The last supporting roller of the bed of supporting rollers constitutes the first support roller of the conveyor. The apparatus permits the transfer of glass sheets from a transport system with one slope to another transport system with a different slope without damaging either the glass sheets themselves or any coatings that may have been applied to the glass sheets.
    Type: Grant
    Filed: July 20, 1984
    Date of Patent: September 10, 1985
    Assignee: Saint Gobain Vitrage
    Inventors: Aureliano Bocelli, Carlo Colombini
  • Patent number: 4526605
    Abstract: In apparatus for shaping sheets of heat-softenable material, such as glass and plastics, an upper vacuum mold is provided with an apertured wall member of low expansion refractory material to engage a heat-softened sheet during a portion of its shaping. In order to improve its durability, metal clamping devices that cause high local stresses in the refractory wall member are not used to secure the refractory wall member to metal structural elements of the vacuum mold. The present invention comprises novel mold structure to support a lower apertured wall member of refractory material on an inverted metal box member without metal attachment devices that induce high local stresses.
    Type: Grant
    Filed: September 15, 1983
    Date of Patent: July 2, 1985
    Assignee: PPG Industries, Inc.
    Inventors: Robert G. Frank, Michael T. Fecik, John J. Ewing
  • Patent number: 4525193
    Abstract: A method and apparatus are disclosed for operating an air supply system for a glass sheet quench including a D.C. drive system of a variable speed blower operated on a duty cycle. A quench cycle and a cooling cycle are carried out in the quench. In the preferred embodiment shown for thin glass (i.e. glass which is 5 mm or less in thickness) the drive system is sized to the RMS requirements of the complete cycle to minimize the initial and operating costs, size and power requirements of the D.C. drive system.
    Type: Grant
    Filed: November 14, 1983
    Date of Patent: June 25, 1985
    Assignee: Glasstech, Inc.
    Inventors: Ronald A. McMaster, John S. Nitschke
  • Patent number: 4525196
    Abstract: Glass sheet handling devices are provided with glass sheet engaging surfaces composed of a phenolic resin reinforced with fibers of an aromatic polyamide composition. In a specific embodiment of this invention, a sufficient number of said fibers extend to an exposed surface of said devices to develop a coefficient of friction sufficient to prevent relative sliding between the exposed surface of said glass sheet engaging member and said glass sheet.
    Type: Grant
    Filed: August 24, 1984
    Date of Patent: June 25, 1985
    Assignee: PPG Industries, Inc.
    Inventors: Michael T. Fecik, John J. Ewing, Edward I. Mates
  • Patent number: 4519829
    Abstract: A method of quench-tempering a hot shaped glass sheet comprises supporting the sheet in a quenching station underneath a downwardly directed upper nozzle array and above an upwardly directed lower nozzle array by engagement of only a portion of the lower surface of the sheet. The portion engaged for support is interrupted by a generally uniformly distributed array of unsupported regions. An air stream is directed from the lower nozzle array up toward the lower surface of the glass sheet while an opposite air stream is directed down from the upper nozzle array toward the upper surface of the sheet. Generally all of the lower surface of the sheet is shielded except at the unsupported regions from the air stream of the lower nozzle array. A prestress field is thus formed in the sheet which corresponds to the distribution of the unsupported regions. The sheet is supported on and shielded by a plate having the same shape as the sheet but formed with holes at the unsupported regions.
    Type: Grant
    Filed: October 13, 1983
    Date of Patent: May 28, 1985
    Assignee: Flachglas Aktiengesellschaft
    Inventors: Horst Spittka, Rudolf Eckardt, Cristoph Neuendorf
  • Patent number: 4517001
    Abstract: Sheet glass is heated during conveyance on a conveyor within a furnace. A vacuum holder is horizontally movable within the furnace immediately above the conveyor in close proximity to the heated glass sheet. The holder has a downwardly facing surface with spaced openings in which a vacuum is drawn to receive the heated glass sheet from the conveyor, support the sheet above the conveyor, move the heated glass sheet horizontally along the longitudinal axis of the furnace and drop the heated glass sheet onto a carrier mold ring positioned within the furnace by removing the vacuum so that the glass sheet bends under the force of gravity in a manner that allows the heated glass sheet to be accurately bent. In a preferred embodiment the mold ring subsequently is removed from the furnace to a quench unit that tempers the bent glass.
    Type: Grant
    Filed: March 19, 1984
    Date of Patent: May 14, 1985
    Assignee: Glasstech, Inc.
    Inventor: Ronald A. McMaster
  • Patent number: 4511386
    Abstract: A deformable vacuum holder having a glass facing wall of flexible sheet material subject to local distortion for shaping heat-softened material, such as glass sheets, has a deformable sheet of insulator material attached mechanically to said glass facing wall for engaging the flexible glass facing sheet wall of the vacuum holder. The deformable sheet has a smooth surface less subject to distortion than said glass facing wall facing the engaged glass sheet surface to avoid having scratches and other surface irregularities of the glass facing wall mar the vision area of the shaped glass sheet and is mechanically supported against the flexible sheet wall beyond the margin of the engaged glass sheet instead of being adhered to said flexible sheet wall.
    Type: Grant
    Filed: May 24, 1983
    Date of Patent: April 16, 1985
    Assignee: PPG Industries, Inc.
    Inventors: John D. Kellar, Gordon F. Pereman
  • Patent number: 4511387
    Abstract: A vacuum holder for holding sheets of heat-softenable material such as glass thereagainst by vacuum during their fabrication into shaped sheets comprising a lower sheet wall that has flanking portions slit longitudinally to provide strips extending longitudinally from a central portion, the width of the strips being limited to limit transverse bulging as the holder becomes hot during a sheet shaping campaign. Longitudinal slots of increasing length from a selected transverse line, preferably one traversing the geometric center of the sheet, control longitudinal bulging of the holder.
    Type: Grant
    Filed: May 24, 1983
    Date of Patent: April 16, 1985
    Assignee: PPG Industries, Inc.
    Inventors: John D. Kellar, Gordon F. Pereman
  • Patent number: 4510005
    Abstract: The end face of an optical fiber is urged against the highly polished surface of a disk as a laser beam is directed toward the disk to heat the end face above its softening temperature and cause it to conform to the contour and finish of the highly polished surface. A termination ferrule may be simultaneously mounted on the fiber optic cable with a heat bonding agent, using as a heat source either the laser beam or an auxiliary heat source. A hand-held, gun-type unit with a built-in disk and triggered laser can be used to polish and terminate optical fibers in the field.
    Type: Grant
    Filed: September 28, 1982
    Date of Patent: April 9, 1985
    Assignee: Allied Corporation
    Inventor: John P. Nijman
  • Patent number: 4501603
    Abstract: Bending a glass sheet to a complicated shape that comprises one portion bent sharply relative to a main portion of the sheet involving the use of a vacuum holder, an auxiliary shaping rail and means to correlate the movement of the shaping rail with that of the glass sheet during a bending cycle to insure that the glass sheet is clear of the auxiliary shaping rail except for such time in the glass sheet bending cycle that requires the auxiliary shaping rail to engage the glass sheet portion to be sharply bent against the corresponding portion of the vacuum holder. Another feature incorporated in a preferred embodiment of the present invention facilitates ready removal of glass fragments whenever a flawed glass sheet fractures at or beyond a shaping station outside a furnace where the glass sheet is heated to its deformation temperature.
    Type: Grant
    Filed: March 30, 1983
    Date of Patent: February 26, 1985
    Assignee: PPG Industries, Inc.
    Inventors: Robert G. Frank, Michael T. Fecik, John J. Ewing
  • Patent number: 4497645
    Abstract: A method of and a furnace assembly for bending glass sheets. Glass sheets (6) are conveyed in bending moulds (5) supported by cars (4) along an upper transport run (2) periodically from one heating section (10) to another. In the final heating section, temperature is risen so high that a glass sheet bends by the action of heat and gravity to conform with the surface of the mould. Thereafter, a car (4) together with a bent glass sheet is lowered onto a lower run (3) and returned to the outset of a furnace (1). On cooling, the glass sheets on said lower run emit heat to the glass sheets on said upper run through the open bottom structures of cars (4). The weight and heat capacity of the cars have been made as low as possible by removing the side and back walls thereof, whereby only the front or leading walls (8) provide locking walls between sections (10) successive in the longitudinal direction of the furnace.
    Type: Grant
    Filed: April 16, 1984
    Date of Patent: February 5, 1985
    Assignee: O/Y KYRO A/B Tamglass
    Inventor: Esko J. Peltonen
  • Patent number: 4496386
    Abstract: A method of and apparatus for press bending sheets into complex shapes wherein the apparatus includes at least one press member of outline or ring-type construction having an array of spaced apart shaping rail elements mounted in a composite array and adapted to pass upwardly between adjacent conveying rolls to contact and support the undersurface of a sheet of heat-softened glass. Another array of shaping rail extensions is disposed above the conveying rolls mounted for movement into and out of association with the spaces between the spaced apart shaping rail elements of the first mentioned array.
    Type: Grant
    Filed: January 16, 1984
    Date of Patent: January 29, 1985
    Assignee: Libbey-Owens-Ford Company
    Inventors: Frank J. Hymore, Paul H. Kreinbrink
  • Patent number: 4487623
    Abstract: Vacuum is applied to help separate a press bent glass sheet from between a pair of complementary press bending molds during the separation of said molds after completing said press bending.
    Type: Grant
    Filed: July 18, 1983
    Date of Patent: December 11, 1984
    Assignee: PPG Industries, Inc.
    Inventors: George R. Claassen, John J. Ewing
  • Patent number: 4483701
    Abstract: In the art of shaping sheets of glass and other deformable materials comprising engagement of said sheets while hot by a vacuum holder in a relatively hot atmosphere and removing the holder into a cooler atmosphere to cool the holder between successive shaping cycles, production of shaped sheets was limited by the time necessary for the holder to cool during its exposure to said cooler atmosphere to a temperature suitable for beginning a subsequent sheet shaping cycle. The present invention lessens this necessary time by drawing cold air by suction from said cooler atmosphere between successive shaping cycles, thereby increasing the maximum production rate possible.
    Type: Grant
    Filed: May 24, 1983
    Date of Patent: November 20, 1984
    Assignee: PPG Industries, Inc.
    Inventors: John D. Kellar, Gordon F. Pereman
  • Patent number: 4483702
    Abstract: Multiple chamber vacuum holders for use in shaping sheets of glass or other heat-softenable material to complex shapes require a different level of vacuum in adjacent vacuum chambers. A porous fiber glass cover used with such vacuum holders provide passages for residual air in adjacent passages to tend to equalize when a sheet is held against the porous cover. The present invention helps maintain a difference in level of vacuum between adjacent vacuum chambers by interposing a narrow space vented to atmosphere between adjacent vacuum chambers of the multiple chamber vacuum holder.
    Type: Grant
    Filed: May 24, 1983
    Date of Patent: November 20, 1984
    Assignee: PPG Industries, Inc.
    Inventors: Robert G. Frank, John J. Ewing
  • Patent number: 4481023
    Abstract: The present invention is directed to a four-step process for molding glass articles of high precision and excellent surface figure. A glass preform having an overall geometry closely approximating that of the desired final product is placed into a mold, the mold and preform are brought to a temperature at which the glass exhibits a viscosity between 10.sup.8 -10.sup.12 poises, a load is applied to shape the glass into conformity with the mold, and thereafter the glass shape is removed from the mold at a temperature above the transformation range of the glass and annealed.
    Type: Grant
    Filed: July 20, 1983
    Date of Patent: November 6, 1984
    Assignee: Corning Glass Works
    Inventors: Jean-Pierre Marechal, Richard O. Maschmeyer
  • Patent number: 4474831
    Abstract: In a method for reflow of a phosphosilicate glass (PSG) layer applied to a semiconductor wafer, the wafer is placed in a processing chamber in parallel alignment with a planar blackbody source. The chamber is evacuated, and the source rapidly and uniformly heats the PSG layer to a temperature at which plastic flow occurs. The blackbody source provides significant radiation in the 7-10 micron portion of the infrared spectrum. The thermal treatment is typically completed in 8-15 seconds, thereby avoiding impurity redistribution in the semiconductor device.
    Type: Grant
    Filed: August 27, 1982
    Date of Patent: October 2, 1984
    Assignee: Varian Associates, Inc.
    Inventor: Daniel F. Downey
  • Patent number: 4470835
    Abstract: A deformable vacuum mold for shaping glass sheets to complicated shapes includes mold stiffening structure engaging the central portion of the mold, mold lifting means engaging the longitudinal end portions of the vacuum mold to lift the latter relative to the mold stiffening structure and optional bar means adjustable in position and orientation to provide local control imparted to the shape of the vacuum mold when the longitudinal end portions of the mold are lifted. The deformable vacuum mold may also include a pair of lifting means providing different amounts of lift to the longitudinal end portions on opposite sides of the longitudinal center line of the mold and approximately equal amounts of lift to the longitudinal end portions on opposite sides of the transverse center line of the mold.
    Type: Grant
    Filed: November 15, 1982
    Date of Patent: September 11, 1984
    Assignee: PPG Industries, Inc.
    Inventors: Michael T. Fecik, Robert G. Frank, John J. Ewing, George R. Claassen
  • Patent number: 4455325
    Abstract: Phosphorus-doped silicon oxide glass is flowed on an integrated circuit by raising the pressure in which that integrated circuit is placed above atmospheric for a selected period of time and heating said phosphosilicate glass to a selected temperature sufficient to cause said glass to flow at said pressure. The atmosphere in which the device is placed includes moisture to enhance the flow of the glass at temperatures substantially beneath those at which dopants in the underlying integrated circuit move. The result is that the electrical characteristics of the integrated circuit are not substantially altered during glass flow.
    Type: Grant
    Filed: January 7, 1983
    Date of Patent: June 19, 1984
    Assignee: Fairchild Camera and Instrument Corporation
    Inventor: Reda Razouk
  • Patent number: 4447252
    Abstract: An apparatus is provided for curving and tempering or heat toughening thin glass sheets, with thickness less than 4 mm and with camber over 60 mm, regardless of the type of curve described by their profile (cylindrical, parabolic, etc.). A continuous feed system is provided for curving rings, such system including a horizontal carrousel which permits individual curving rings to pass under a forming station every 3 seconds. Rolls are provided in the curve forming station designed to pass across the curving ring or forming mould, regardless of the camber of the latter, even if it exceeds 60 mm, as the rolls are not secured to the rings. The carrousel includes the combination of two racks or horizontal chain conveyors with two pairs of roller conveyors.
    Type: Grant
    Filed: March 26, 1982
    Date of Patent: May 8, 1984
    Assignee: Societa Italiana Vetro - SIV - S.p.A.
    Inventors: Dino Di Nocco, Nicola Delle Donne
  • Patent number: 4445921
    Abstract: In tempering a glass sheet to a high temper by heating the sheet to approximately its softening point followed by rapid chilling using a quenching composition that comprises a tempering medium having high heat transfer characterisitcs, the heat-softened glass sheets are protected from breakage during fabrication and resulting optical distortion by applying the tempering medium through exit orifices of a delivery system toward the heated glass in a novel cycle. The initially applied tempering medium has a low heat transfer rate and is mixed with a second tempering medium having a higher heat transfer rate to gradually increase the heat transfer rate of the mixed tempering medium. In a specific embodiment, dry air is the first tempering medium and a sublimable material, such as carbon dioxide, is the second tempering medium. The delivery system has an uninsulated portion that assures that initially the sublimable material is applied as a gas.
    Type: Grant
    Filed: January 24, 1983
    Date of Patent: May 1, 1984
    Assignee: PPG Industries, Inc.
    Inventors: Terry A. Bennett, Herbert W. Eilenfeld, Dewitt W. Lampman
  • Patent number: 4444579
    Abstract: Apparatus capable of tempering bent glass sheets of different sizes and shapes including sharp bends about axes oblique to the length and width of the glass sheets is made possible by supporting end nozzle boxes of tempering apparatus in such a manner that they can be moved relative to center nozzle boxes and also permitting limited pivotal adjustment of the end nozzle boxes about both essentially horizontal and essentially vertical axes to permit the end nozzle boxes to move into positions conforming to the shape of corresponding end portions bent to different orientations relative to the length and/or width of the central portion of the bent glass sheets having different glass sheet patterns, including flat patterns.
    Type: Grant
    Filed: November 10, 1982
    Date of Patent: April 24, 1984
    Assignee: PPG Industries, Inc.
    Inventors: Robert E. Dunn, Samuel L. Seymour
  • Patent number: 4441907
    Abstract: An improved apparatus including a localized heater that moves along the direction of conveyance with conveyed glass sheets to provide localized heating of a portion of each glass sheet to be bent without heating the rest of the glass sheet prior to its subsequent treatment. This invention is especially suitable for locally heating designated portions of glass sheets as they are heated while being conveyed through a furnace on a horizontal roller conveyor where the designated portion of glass sheets are to be formed with bends having relatively short radii of curvature at a bending station. The apparatus includes a pair of elongated localized gas heaters, each of which is positioned above the portion of the glass sheet which requires significant bending. These heaters are mounted on a carriage driven by a drive mechanism.
    Type: Grant
    Filed: August 20, 1982
    Date of Patent: April 10, 1984
    Assignee: Glasstech, Inc.
    Inventor: John S. Nitschke
  • Patent number: 4437871
    Abstract: Sheet glass is heated during conveyance within a furance housing having a fixed roof and vertically movable side doors that define side slots through which ends of conveyor rolls project outwardly to be supported and frictionally driven by continuous drive loops slidably driven over external support surfaces that extend alongside the side slots. A vacuum holder of the apparatus is positioned within the furnace housing above the conveyor and has a downwardly facing surface with spaced openings in which a vacuum is drawn to receive a glass sheet from the conveyor and support the sheet above the conveyor. The holder surface is disclosed as being both planar and curved and as having a porous cover of ceramic fibers so as to distribute the vacuum and prevent marring of the glass as it is supported. A greater vacuum is drawn to initially support the glass and a lesser vacuum is subsequently drawn to prevent glass deformation at the spaced openings.
    Type: Grant
    Filed: May 14, 1981
    Date of Patent: March 20, 1984
    Inventors: Harold A. McMaster, Norman C. Nitschke, John S. Nitschke
  • Patent number: 4437872
    Abstract: Sheet glass is heated during conveyance within a furnace housing having a fixed roof and vertically movable side doors that define side slots through which ends of conveyor rolls project outwardly to be supported and frictionally driven by continuous drive loops slidably driven over external support surfaces that extend alongside the side slots. A vacuum holder of the apparatus is positioned within the furnace housing above the conveyor and has a downwardly facing surface with spaced openings in which a vacuum is drawn to receive a glass sheet from the conveyor and support the sheet above the conveyor. The holder surface is disclosed as being both planar and curved and as having a porous cover of ceramic fibers so as to distribute the vacuum and prevent marring of the glass as it is supported. A greater vacuum is drawn to initially support the glass and a lesser vacuum is subsequently drawn to prevent glass deformation at the spaced openings.
    Type: Grant
    Filed: May 29, 1981
    Date of Patent: March 20, 1984
    Inventors: Harold A. McMaster, Norman C. Nitschke, John S. Nitschke
  • Patent number: 4433993
    Abstract: The present invention relates to shaping and tempering glass sheets using a pair of cooling stations and an access area with a common tunnel-like furnace and a common shaping station. The cooling stations are located near the common glass sheet shaping station along angularly diverging paths of movement from said shaping station so that a first cooling station for chilling a glass sheet bent about an axis of curvature approximately parallel to its initial path of movement through the furnace is located along an extension of the path and a second cooling station for chilling a glass sheet bent about an axis substantially normal to the path of glass sheet movement through the furnace is located to one side of said shaping station and said access area is located to the other side of said shaping station. The access area permits ready change of shaping molds at the shaping station.
    Type: Grant
    Filed: May 5, 1982
    Date of Patent: February 28, 1984
    Assignee: PPG Industries, Inc.
    Inventor: Robert G. Frank
  • Patent number: 4432782
    Abstract: A flat glass sheet of a given outline configuration is supported in a shaping station by a combination of a gas hearth bed portion and readily replaceable flat plate means comprising spaced plates having spaced edges of conforming shape that define an elongated slot conforming to the outline shape of at least a portion of the periphery of the flat glass sheet. The gas support bed portion provides hot gas under pressure to float the flat glass, and the flat plate means is located in close proximity to an end of the gas hearth bed portion to provide a narrow space at the level of the gas hearth bed portion for escaping gas between the flat plate means and the extending glass sheet portion to limit sag of the extending glass sheet portion. The flat plate means may be covered by material that does not mar hot glass, such as boron nitride, in case the glass sheet portion sags a limited distance to slide in contact with the flat plate means before it is lifted on a shaped, ring-like member.
    Type: Grant
    Filed: June 17, 1982
    Date of Patent: February 21, 1984
    Assignee: PPG Industries, Inc.
    Inventor: Samuel L. Seymour
  • Patent number: 4430111
    Abstract: In the bending and tempering of sharply bent glass sheets supported on a ring-like member for conveyance of the bent glass sheet through a cooling station, a transfer device for unloading the sharply bent, tempered glass sheet is provided. The transfer device is so constructed and arranged that it does not cause a bottleneck in high speed, mass production of sharply bent, tempered glass sheets, avoids uncontrolled departures from the desired shape of the bent, tempered glass sheets, particularly those that develop in the marginal edge portion of the glass sheets that must fit exactly into glass sheet receiving frames of installation structures or vehicles, provides clearance for the sharply bent glass sheets and enables the glass sheet to transfer so gently as to inhibit the likelihood of breakage resulting from uncontrolled dropping of bent, tempered glass sheets during their handling.
    Type: Grant
    Filed: July 28, 1982
    Date of Patent: February 7, 1984
    Assignee: PPG Industries, Inc.
    Inventors: George R. Claassen, John J. Ewing
  • Patent number: 4430110
    Abstract: This invention concerns shaping sheets of glass or other deformable material to compound shapes. A sheet having a desired transverse component of curvature engages the downward facing surface of a deformable vacuum mold having a lower transversely curved wall and is held thereagainst by vacuum while still hot enough to be distorted as the vacuum mold deforms to apply the longitudinal bending component to the sheet to be shaped.
    Type: Grant
    Filed: July 28, 1982
    Date of Patent: February 7, 1984
    Assignee: PPG Industries, Inc.
    Inventors: Robert G. Frank, George R. Claassen, John J. Ewing, Michael T. Fecik
  • Patent number: 4402723
    Abstract: Nozzles are arranged in different densities transverse to a path of travel for glass sheets moving through a pass-through quench to facilitate removal of spent tempering medium to both lateral sides of said path of travel.
    Type: Grant
    Filed: January 28, 1982
    Date of Patent: September 6, 1983
    Assignee: PPG Industries, Inc.
    Inventor: Stephen J. Schultz
  • Patent number: 4400193
    Abstract: Glass is heated to a temperature above its strain point and is thermally toughened by chilling with a quiescent gas-filuidized particulate material which has gas-generating properties and a mean particle size in the range 30 .mu.m to 120 .mu.m, a particle size distribution in the range 1.15 to 2.78, a flowability in the range 69.5 to 92, and a thermal capacity per unit volume at minimum fluidization in the range 0.7 to 1.59 MJ/m.sup.3 K.The invention is particularly suitable for thermally toughening glass sheets for vehicle windscreens.
    Type: Grant
    Filed: October 19, 1979
    Date of Patent: August 23, 1983
    Assignee: Pilkington Brothers Limited
    Inventors: Raymond P. Cross, Gordon T. Simpkin
  • Patent number: 4390359
    Abstract: A method for the prevention of the curving of glass sheets in the roller-equipped furnace of a horizontal tempering plant utilizes a substantially turbulent air flow over the upper surface of the glass sheet for intensifying the convection heat action applied to the upper surface of the glass sheet. The furnace is fitted with perforated pipes which are connected to a source of compressed air for blowing horizontal air jets above the upper surface of the glass sheet.
    Type: Grant
    Filed: September 8, 1981
    Date of Patent: June 28, 1983
    Assignee: Tamglass Oy
    Inventor: Pauli Reunamaki
  • Patent number: 4386952
    Abstract: A glass sheet bending system (10) is disclosed as including a compressed gas bending unit (28) located above a horizontal conveyor (22) on which glass sheets are heated within a furnace (12) of the system. A downwardly facing curved surface (26) of a holder (24) above conveyor (22) receives a heated glass sheet from the conveyor for bending. Compressed gas fed through outlets (34) of the bending unit (28) provides inclined gas jets directed in a generally perpendicular relationship to the holder surface (26) with a sufficient intensity to bend the glass sheet on the holder (24) to the curved shape of its surface. The conveyor (22) of the system is preferably of the roller type including spaced rolls (36) and the bending unit (28) is disclosed as including a pair of supply conduits (48) extending upwardly between the rolls to supply compressed gas to a pair of delivery conduits (52) which define the outlets (34).
    Type: Grant
    Filed: March 31, 1982
    Date of Patent: June 7, 1983
    Inventor: David B. Nitschke
  • Patent number: 4372772
    Abstract: The geometric pattern for the support framework is obtained by projecting a subdivided icosahedron onto a parabolic surface. The resulting framework has forty primary planar triangular faces or sections, each of which are, in the embodiment shown, subdivided equally into 4 secondary planar triangular sections. At the dead center of the framework pattern is the outline of a pentagon, formed of five equal-size triangular sections. The framework terminates in a rim which lies completely in a single plane. Triangular reflecting members, which comprise the reflecting surface portion of the apparatus, are supported interiorly of the framework by standoff elements. Intermediate along each edge of the reflecting members is a tensioning element which bends the reflecting member so that the intermediate edge points, as well as the vertices of each reflecting member, lie on the surface of an imaginary paraboloid, the reflecting members thus approximating a parabolic curve.
    Type: Grant
    Filed: June 11, 1981
    Date of Patent: February 8, 1983
    Inventor: Douglas E. Wood
  • Patent number: 4372774
    Abstract: The thermal treatment of glass is effected by contacting the glass, when it is hot, with a gas-fluidized mixture of particulate materials, at least one of which is selected to have gas-generating properties when heated by the hot glass. The materials are mixed in selected pre-determined proportions which impart to the mixture a thermal capacity and flowability which are such that a required thermal treatment is achieved.The method is particularly suitable for the thermal toughening of glass sheets for vehicle windscreens.
    Type: Grant
    Filed: July 21, 1981
    Date of Patent: February 8, 1983
    Assignee: Pilkington Brothers Limited
    Inventors: Raymond P. Cross, Gordon T. Simpkin
  • Patent number: 4364765
    Abstract: Sheet glass is heated during conveyance within a furnace housing having a fixed roof and vertically movable side doors that define side slots through which ends of conveyor rolls project outwardly to be supported and frictionally driven by continuous drive loops slidably driven over external support surfaces that extend alongside the side slots. A vacuum holder of the apparatus is positioned within the furnace housing above the conveyor and has a downwardly facing surface with spaced openings in which a vacuum is drawn to receive a glass sheet from the conveyor and support the sheet above the conveyor. The holder surface is disclosed as being both planar and curved and as having a porous cover of ceramic fibers so as to distribute the vacuum and prevent marring of the glass as it is supported. A greater vacuum is drawn to initially support the glass and a lesser vacuum is subsequently drawn to prevent glass deformation at the spaced openings.
    Type: Grant
    Filed: May 14, 1981
    Date of Patent: December 21, 1982
    Inventors: Harold A. McMaster, Norman C. Nitschke, John S. Nitschke
  • Patent number: 4361433
    Abstract: A method of handling a glass part to be treated and shaped in a hot liquid bath of a composition having a melting point greater than ambient temperature comprises the steps of: placing at least one glass part on at least one flexible porous member suspended by its edges; immersing the glass part, flexible member and a form in the hot bath; drawing the immersed glass part against the form by pulling the edges of the flexible porous member over the form; removing the form, glass part and flexible member from the bath as a unit, whereupon the glass and a portion of the bath composition hardens, the bath composition clinging to the glass and porous member; removing the form from the glass; and, removing the flexible porous member, and essentially all of the bath composition clinging to the glass. Protection for the glass and further ease of handling are provided where a second flexible porous member is placed between the glass and the form.
    Type: Grant
    Filed: March 24, 1981
    Date of Patent: November 30, 1982
    Assignee: Advanced Glass Systems Corp.
    Inventors: W. Novis Smith, Jr., Nelson P. Bolton
  • Patent number: 4361432
    Abstract: Sheet glass is heated during conveyance within a furnace housing having a fixed roof and vertically movable side doors that define side slots through which ends of conveyor rolls project outwardly to be supported and frictionally driven by continuous drive loops slidably driven over external support surfaces that extend alongside the side slots. A vacuum holder of the apparatus is positioned within the furnace housing above the conveyor and has a downwardly facing surface with spaced openings in which a vacuum is drawn to receive a glass sheet from the conveyor and support the sheet above the conveyor. The holder surface is disclosed as being both planar and curved and as having a porous cover of ceramic fibers so as to distribute the vacuum and prevent marring of the glass as it is supported. A greater vacuum is drawn to initially support the glass and a lesser vacuum is subsequently drawn to prevent glass deformation at the spaced openings.
    Type: Grant
    Filed: May 14, 1981
    Date of Patent: November 30, 1982
    Inventors: Harold A. McMaster, Norman C. Nitschke, John S. Nitschke
  • Patent number: 4357156
    Abstract: This invention relates to heat treating glass sheets, and particularly relates to shaping and tempering a glass sheet comprising a step of supporting the sheet while heat softened with its upper surface against a glass sheet holder. In order to minimize surface distortion resulting from the heat-softened glass sheet replicating any surface deficiencies in the holder such as surface blemishes if the sheet is forced against a continuous surface by an upward flow of gas pressure, or those resulting from perforations through the bottom wall of the holder if the holder is of the vacuum type that holds the glass sheet thereagainst by suction, the present invention interposes a soft, fluffy, porous cover of fiber glass fabric, perferably knit fabric composed of texturized yarns between the upper surface of the glass sheet and the glass sheet holder.
    Type: Grant
    Filed: July 21, 1980
    Date of Patent: November 2, 1982
    Assignee: PPG Industries, Inc.
    Inventor: Samuel L. Seymour
  • Patent number: 4356018
    Abstract: An improved method and apparatus (12) for deep bending glass sheets disclosed provides minimal sliding of the glass sheet with respect to a curved bending mold (44) utilized, insures accurate positioning of the glass sheet on the mold for bending to the desired shape, and permits relatively abrupt end bends to be performed. A heated glass sheet (G) is initially supported against a downwardly facing surface (26) of a holder (24) above the curved bending mold (44) which has an upwardly concave shape. An upward gas flow (49) from a gas supply unit (48) at a central portion (50) of the glass sheet (G) is supplied and continued as opposite extremities (52) of the glass sheet are released and dropped downwardly onto the mold. Thereafter, termination of the upward gas flow (49) from the gas supply unit (48) releases the central portion (50) of the glass sheet (G) for bending on the mold (44). After the bending, a mold is moved to a quench unit (22) for tempering of the bent glass sheet.
    Type: Grant
    Filed: September 4, 1981
    Date of Patent: October 26, 1982
    Inventor: Harold A. McMaster
  • Patent number: 4349375
    Abstract: In the shaping of sheets of heat-softenable material such as glass and other deformable materials, a hot sheet engages an apertured lower sheet of a deformable vacuum box while the sheet and the box are flat and conforms to the changing shape of the box. Since the box intermittently engages a hot deformable sheet for shaping and releases the deformed sheet after shaping, its lower apertured sheet is exposed to a wide temperature cycle, which causes the lower apertured sheet to warp away from the shape desired for the deformable sheet. The present invention provides structure for the deformable box that avoids such warpage while retaining the ability of the box to maintain sufficient vacuum to hold and distort the hot sheet while the box changes shape into its desired configuration with minimum warpage therefrom so that the hot sheet develops a desired curved configuration while held thereagainst during deformation of the box.
    Type: Grant
    Filed: October 23, 1981
    Date of Patent: September 14, 1982
    Assignee: PPG Industries, Inc.
    Inventors: John D. Kellar, Gordon F. Pereman