Classifications

• • C—CHEMISTRY; METALLURGY
  • C03—GLASS; MINERAL OR SLAG WOOL
  • C03B—MANUFACTURE, SHAPING, OR SUPPLEMENTARY PROCESSES
  • C03B23/00—Re-forming shaped glass
  • C03B23/02—Re-forming glass sheets
  • C03B23/023—Re-forming glass sheets by bending
  • C03B23/025—Re-forming glass sheets by bending by gravity
  • C03B23/0252—Re-forming glass sheets by bending by gravity by gravity only, e.g. sagging
  • C03B23/0254—Re-forming glass sheets by bending by gravity by gravity only, e.g. sagging in a continuous way, e.g. gravity roll bending
• • C—CHEMISTRY; METALLURGY
  • C03—GLASS; MINERAL OR SLAG WOOL
  • C03B—MANUFACTURE, SHAPING, OR SUPPLEMENTARY PROCESSES
  • C03B23/00—Re-forming shaped glass
  • C03B23/02—Re-forming glass sheets
  • C03B23/023—Re-forming glass sheets by bending
  • C03B23/025—Re-forming glass sheets by bending by gravity
• • C—CHEMISTRY; METALLURGY
  • C03—GLASS; MINERAL OR SLAG WOOL
  • C03B—MANUFACTURE, SHAPING, OR SUPPLEMENTARY PROCESSES
  • C03B23/00—Re-forming shaped glass
  • C03B23/02—Re-forming glass sheets
  • C03B23/023—Re-forming glass sheets by bending
  • C03B23/03—Re-forming glass sheets by bending by press-bending between shaping moulds
  • C03B23/033—Re-forming glass sheets by bending by press-bending between shaping moulds in a continuous way, e.g. roll forming, or press-roll bending
• • C—CHEMISTRY; METALLURGY
  • C03—GLASS; MINERAL OR SLAG WOOL
  • C03B—MANUFACTURE, SHAPING, OR SUPPLEMENTARY PROCESSES
  • C03B25/00—Annealing glass products
  • C03B25/04—Annealing glass products in a continuous way
  • C03B25/06—Annealing glass products in a continuous way with horizontal displacement of the glass products
  • C03B25/08—Annealing glass products in a continuous way with horizontal displacement of the glass products of glass sheets
• • C—CHEMISTRY; METALLURGY
  • C03—GLASS; MINERAL OR SLAG WOOL
  • C03B—MANUFACTURE, SHAPING, OR SUPPLEMENTARY PROCESSES
  • C03B27/00—Tempering or quenching glass products
  • C03B27/04—Tempering or quenching glass products using gas
  • C03B27/0422—Tempering or quenching glass products using gas for flat or bent glass sheets starting in an horizontal position and ending in a non-horizontal position
  • C03B27/0426—Tempering or quenching glass products using gas for flat or bent glass sheets starting in an horizontal position and ending in a non-horizontal position for bent glass sheets
  • C03B27/0435—Tempering or quenching glass products using gas for flat or bent glass sheets starting in an horizontal position and ending in a non-horizontal position for bent glass sheets the quench unit being variably adaptable to the bend of the sheet
• • C—CHEMISTRY; METALLURGY
  • C03—GLASS; MINERAL OR SLAG WOOL
  • C03B—MANUFACTURE, SHAPING, OR SUPPLEMENTARY PROCESSES
  • C03B35/00—Transporting of glass products during their manufacture, e.g. hot glass lenses, prisms
  • C03B35/14—Transporting hot glass sheets or ribbons, e.g. by heat-resistant conveyor belts or bands
  • C03B35/16—Transporting hot glass sheets or ribbons, e.g. by heat-resistant conveyor belts or bands by roller conveyors
  • C03B35/161—Transporting hot glass sheets or ribbons, e.g. by heat-resistant conveyor belts or bands by roller conveyors specially adapted for bent sheets or ribbons
• • C—CHEMISTRY; METALLURGY
  • C03—GLASS; MINERAL OR SLAG WOOL
  • C03B—MANUFACTURE, SHAPING, OR SUPPLEMENTARY PROCESSES
  • C03B35/00—Transporting of glass products during their manufacture, e.g. hot glass lenses, prisms
  • C03B35/14—Transporting hot glass sheets or ribbons, e.g. by heat-resistant conveyor belts or bands
  • C03B35/16—Transporting hot glass sheets or ribbons, e.g. by heat-resistant conveyor belts or bands by roller conveyors
  • C03B35/163—Drive means, clutches, gearing or drive speed control means
• • C—CHEMISTRY; METALLURGY
  • C03—GLASS; MINERAL OR SLAG WOOL
  • C03B—MANUFACTURE, SHAPING, OR SUPPLEMENTARY PROCESSES
  • C03B35/00—Transporting of glass products during their manufacture, e.g. hot glass lenses, prisms
  • C03B35/14—Transporting hot glass sheets or ribbons, e.g. by heat-resistant conveyor belts or bands
  • C03B35/16—Transporting hot glass sheets or ribbons, e.g. by heat-resistant conveyor belts or bands by roller conveyors
  • C03B35/166—Transporting hot glass sheets or ribbons, e.g. by heat-resistant conveyor belts or bands by roller conveyors specially adapted for both flat and bent sheets or ribbons
• • C—CHEMISTRY; METALLURGY
  • C03—GLASS; MINERAL OR SLAG WOOL
  • C03B—MANUFACTURE, SHAPING, OR SUPPLEMENTARY PROCESSES
  • C03B35/00—Transporting of glass products during their manufacture, e.g. hot glass lenses, prisms
  • C03B35/14—Transporting hot glass sheets or ribbons, e.g. by heat-resistant conveyor belts or bands
  • C03B35/16—Transporting hot glass sheets or ribbons, e.g. by heat-resistant conveyor belts or bands by roller conveyors
  • C03B35/18—Construction of the conveyor rollers ; Materials, coatings or coverings thereof
  • C03B35/187—Rollers specially adapted for both flat and bent sheets or ribbons, i.e. rollers of adjustable curvature

Definitions

• the invention relates to a method for bending and tempering a glass panel, said method comprising the steps of - heating a glass panel in a heating furnace for bending and tempering,
• patent publication FI- 101697 discloses a method, wherein a bending conveyor and a cooling conveyor are present separately as extensions of each other.
• the bending conveyor is in a previously arched configuration as it receives the glass. This is adverse for the reason that the glass is forced to bend at a single point of bending.
• a particular object of the invention is to alleviate the problem associated with the end portion flatness of glass panels This object is achieved by a method presented in the appended claim 1. Preferred embodiments of the invention are presented in the dependent claims.
• Figs. 1-3 show schematically an apparatus for carrying out a method of the invention in a side view during various working sequences.
• Fig. 4 shows more closely a bending conveyor and a tempering conveyor in a configuration arched to a desired radius of curvature, visualizing the arching of a bending conveyor 4, or at least its upstream end section, beyond a desired final curvature of the glass panel.
• Fig. 5 shows more closely a bending conveyor and a tempering conveyor in such a configuration that a tempering conveyor 5 has been arched to a radius of curvature R3 which is smaller in comparison with a radius of curvature Rl of the bending conveyor 4.
• Fig. 6 visualizes variations in the traveling speed of a glass panel as it emerges from the furnace onto a bending conveyor and passes from the bending conveyor onto a tempering conveyor, and
• Fig. 7 shows an even closer view of actuators used for arching the tempering conveyor.
• the apparatus includes a heating furnace 1 for heating glass panels G therein to a bending temperature.
• a heating furnace 1 for heating glass panels G therein to a bending temperature.
• From a furnace conveyor 2 the glass panel is passed by way of an intermediate conveyor 3 onto a bending conveyor 4, including horizontal conveyor rolls with press rolls thereabove.
• a gap between the conveyor rolls and the press rolls matches substantially the thickness of a glass panel.
• a tempering conveyor 5 which also consists of horizontal conveyor rolls and press rolls spaced from the conveyor rolls by a distance matching the thickness of a glass panel.
• the tempering conveyor 5 is covered over its entire length by upper and lower tempering air enclosures 7 and 8, tracing a curvilinear outline of the conveyor.
• the bending conveyor 4 may also have tempering air enclosures 7 and 8 along its downstream end section.
• Reference numeral 6 represents a vertical line, along which the bending conveyor 4 and the tempering conveyor 5 can be disengaged from each other.
• the tempering conveyor 5 is typically slightly longer than the bending conveyor 4. Both conveyors have their press rolls provided with a drive, i.e. rotated at a peripheral speed equal to that of the conveyor rolls, as a result of which the press rolls function also as conveyor rolls.
• Fig. 4 illustrates a power unit 10 and a lever system 11, by means of which the bending conveyor 4 is adjustable in terms of its radius of curvature.
• the power unit 10 can be a servomotor, which by way of a clutch operates a ball screw 10a, which in turn pushes and/or pivots the lever system 11 upon which rests a bridge established by the link bodies 9.
• a gap present in the link mechanism (not shown) controlling the pivoting action of the link bodies 9, allows for the upstream end section of the conveyor 4 to have a radius of curvature which is slightly smaller than that of the downstream end section.
• fig. 5 illustrates how the tempering conveyor 5 is maneuverable in vertical and horizontal directions (h and w) at the same time as the angle of its center axis CL changes.
• the tempering conveyor 5 can have its curvature varied regardless of the bending conveyor 4, with an articulation point 6a between the conveyors 4, 5 remaining nevertheless stationary.
• a curvature adjustment for the tempering conveyor 5 is performed independently of the bending conveyor. During a curvature adjustment for the tempering conveyor 5 performed while the process is ongoing, the end of said conveyor must not become disengaged from the articulation point 6a common to the conveyors 4, 5.
• the articulation point 6a for the conveyor 5 is set in position, e.g. by means of a photocell control.
• a curvature adjustment or immediately after the adjustment, is an interpolating position-setting for the ends of these conveyors.
• the ends of the conveyors 4 and 5 are mechanically separate from each other in order to enable a curvature adjustment of the tempering conveyor 5 and to enable, whenever necessary, a disengagement of the tempering conveyor 5 from the bending conveyor 4.
• the downstream end of the bending conveyor 4 remains stationary at all times.
• Indicated by arrows 15 are power units for bringing rollers 14 up and down (vertical action h).
• Fig. 7 illustrates an arching mechanism for the tempering conveyor 5, comprising a ball screw 12a, which is operated by a servomotor SMl and which, through the intermediary of arms 12b, arches a bridge established by the link bodies 9, and at the same time the entire conveyor resting upon the link bodies 9.
• the arms 12a engage the conveyor 5 at a small distance from its ends.
• a second servomotor SM2 operates, by way of a herringbone gear 16, ball screws 17 which engage the conveyor 5 at its opposite outer ends.
• the servomotors SMl and SM2 are matched (position synchronized) with each other, such that various sections of the conveyor 5 become arched to the same extent.
• the servomotors can be provided e.g. with a control-designed electrical gearbox.
• the arching could be carried out with just one actuator, but the use of two actuators makes it possible to avoid inaccuracies in the curvature of a conveyor caused by gaps resulting from the wearing of links. Specifically, the curvatures along the mid-section and end sections can be retained the same.
• a glass panel G is heated in a furnace 1 to a temperature appropriate for bending and tempering.
• the flat glass panel G is delivered from the furnace 1 onto a bending conveyor 4 while the latter is in a straight configuration (fig. 1).
• a tempering conveyor 5 has been previously arched to a desired curve as early as or even prior to having the flat glass panel received by the straight bending conveyor 4.
• the glass panel's exit speed from the furnace is e.g. 700 mm/s (fig. 6) and the speed is decelerated over the period of e.g. 1 second to a speed of 400 mm/s at the same time as the glass panel passes onto the bending conveyor 4.
• the exit speed from the furnace can also be lower, e.g. 550 mm/s, and the deceleration proceeds to a speed of less than 300 mm/s.
• Arching of the bending conveyor 4 to a desired curve Rl is initiated even before the glass panel's trailing end section has completely reached the bending conveyor 4.
• Arching of the bending conveyor 4 is performed very quickly, typically within 1-2 seconds. That period is enough for the glass panel's leading edge to reach a position in line with tempering air enclosures 7, 8 present at the downstream end of the bending conveyor 4.
• Tempering blast may be continuously ongoing and the speed of a bent glass panel is increased to some degree, as can be seen from fig. 6.
• the increase of speed can be e.g. 10-40%.
• the deceleration of speed in the preceding stage is typically at least 30%, preferably more than 40%.
• On the bending conveyor 4, the glass panel is carried in one direction only.
• the conveyor 4, or at least its upstream end section is arched beyond what is the desired final curvature Rl of a glass panel.
• R2 is several percent, even up to 5-10%, smaller than Rl. If desired, the upstream end section of the conveyor 4 can be adapted to separate arching.
• the gaps in link mechanisms are generally enough to provide a sufficient over-arching for the conveyor's 4 upstream end section.
• the entire bending conveyor 4 can be arched, proceeding from its stationary downstream end, slightly beyond the desired final curvature of a glass panel.
• Fig. 5 illustrates, in an overstated manner for clearer visualization, the way how the tempering conveyor 5 can also be arched during the process to a radius of curvature R3 slightly smaller or larger than the desired radius of curvature Rl.
• This arching of the tempering conveyor 5 to the smaller or larger radius R3 is first of all enabled by virtue of the previously mentioned freedoms of movement (h, w and an angle ⁇ ), as well as by virtue of the mentioned interpolating position-setting, while the articulation point 6a between the conveyor 4, 5 remains stationary.
• the glass panel can be discharged from the tempering conveyor 5 at quite a low angle with respect to the horizontal plane, without having to move the glass panel in vertical direction.
• a glass panel can be oscillated back and forth.
• the curvature of the tempering conveyor 5 is retained the same at all times, except for said very slight increase of curvature during the process.
• the only time that the curvature of the tempering conveyor 5 needs changing is when the desired curvature Rl changes.
• the method according to the invention is also particularly apt for the production of bidirectionally curved glass panels.
• the rolls are also subjected to deflection, as described e.g. in the Applicant's patent publication EP-1597208 (Bl).

Landscapes

• Chemical & Material Sciences (AREA)
• Engineering & Computer Science (AREA)
• Materials Engineering (AREA)
• Organic Chemistry (AREA)
• Physics & Mathematics (AREA)
• Thermal Sciences (AREA)
• Re-Forming, After-Treatment, Cutting And Transporting Of Glass Products (AREA)

Priority Applications (1)

Applications Claiming Priority (2)

Publications (1)

Family

ID=38212431

Family Applications (1)

Country Status (4)

Cited By (2)

Citations (4)

• 2007
  • 2007-06-18 FI FI20075460A patent/FI120033B/fi active IP Right Grant
• 2008
  • 2008-05-29 TW TW097119895A patent/TW200909365A/zh unknown
  • 2008-06-13 CA CA002688354A patent/CA2688354A1/en not_active Abandoned
  • 2008-06-13 WO PCT/FI2008/050356 patent/WO2008155455A1/en active Application Filing

Patent Citations (4)

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