Abstract: An objective of the invention is to provide a glass-substrate manufacturing method that is capable of increasing the amount of production of glass substrates and improving warpage quality. A glass-substrate manufacturing method according to an aspect of the invention is a method for manufacturing glass substrates by employing a down-draw process. In down-draw processing, a molten glass is made to overflow from a forming member and formed into a sheet glass and the sheet glass is then cooled while being drawn in a downward-flow direction. In this glass-substrate manufacturing method, after the sheet glass has separated from the forming member and when the temperature of the sheet glass is within a temperature region ranging from a temperature higher than the softening point to a temperature near the annealing point, the sheet glass is cooled by maintaining the viscosity of side sections of the sheet glass within a range of 109.0-1014.5 poise while applying a tension toward the side sections.

Abstract: One embodiment of the present invention is an improved sheet glass forming apparatus. In another embodiment, a precise thermal control system redistributes the flow of molten glass at the weirs to counteract the degradation of the sheet forming apparatus which inevitably occurs during manufacturing. In yet another embodiment, the invention introduces a counteracting force to the stresses on the trough in a manner such that the thermal creep which inevitably occurs has a minimum impact on the glass flow characteristics of the forming trough. Another embodiment creates a variable external cross-section which provides hydraulic stresses that are in opposition to the surface tension and body force stresses and thus, reduces the influence of surface tension and body forces.

Abstract: A quenching method and apparatus for tempering a glass sheet. The method includes a step of transferring a heated glass sheet between quenching boxes which are provided with nozzles opposingly arranged near upper and lower surfaces of the glass sheet to blow air streams of cooling air supplied from the quenching boxes to the glass sheet. The method also includes the step of arranging the nozzles extending from the quenching boxes so as to face at least one of the upper and lower surfaces of the glass sheet so that openings on the end of the nozzles blow the air streams of the cooling air in different directions simultaneously so as to intersect and thus be substantially uniformly arranged with respect to the glass sheet. The number of intersections is approximately 30 or more in any 10 cm square area of the glass sheet. The end portions of the nozzles have a semi-spherical shape.

Abstract: In situ lehr-roll cleaning apparatus includes a carriage supported within the space between first and second adjacent rolls, the carriage having a first set of elements contacting the surface of the first roll and a second set of elements contacting the surface of the second roll, whereby the carriage is movable back and forth along a path parallel to the rolls. A mechanism such as a rotating wire wheel disposed on the carriage is used to clean at least one of the first and second rolls as the carriage moves along the path and in between the adjacent rolls. The invention further including means for forcing the carriage away from an adjacent roll toward the one being cleaned so that the elements contacting the surface of the roll being cleaned are forced thereagainst to precisely position the cleaning mechanism relative to the surface. Means are preferably further provided for fine-adjusting the distance of the cleaning mechanism relative to the surface of the roll being cleaned.

Abstract: In a quenching apparatus for quenching a glass sheet that has been heated and bent in a heating furnace, a cooling gas blows onto the glass sheet to provide a distribution of a temperature and/or a distribution of a static pressure in at least one section in the quenching apparatus. The distribution of a temperature provides different temperatures between the both surfaces of the glass sheet, while the distribution of a static pressure is nonuniform in a part of at least one surface of the glass sheet. The distributions can modify a shape of the glass sheet given in the heating furnace so that a degree of freedom in shape for manufacturing a bent and tempered glass sheet by utilizing its self-weight can be improved.

Abstract: A mesh belt is stretched in an annealing lehr and a plurality of fine mesh elements, which constitute a fine mesh having gas-permeability and elasticity, formed by weaving a heat-resistant wire, are fixed onto the mesh belt so as to be arranged along the moving direction of the mesh belt with predetermined spaces in the direction of the width of the mesh belt whereby a flaw which may be produced in a glass product to be annealed when it is placed on the mesh belt in the annealing lehr, is prevented.

Abstract: A glass sheet strip annealing lehr (16) is disclosed as including a housing (18) along which a conveyor (26) including a gas support (28) supports a glass sheet strip G by pressurized gas for movement between entry and exit ends (22,24) of the housing before a conveyor drive (32) engages the strip after the surfaces thereof are cooled below the strain point. Best results are achieved when the glass sheet strip is supported only by the gas support (28) until its surfaces are placed in compression. Lower and upper manifolds (34,36) respectively support and convey the glass sheet strip within the housing (18) preferably by a recirculating gas flow supplied by gas burner (76) and associated gas jet pumps (78).

Abstract: A glass ribbon conveying roll includes cylindrical outer tubular end portions having a plurality of high temperature thermal insulating discs secured thereon and an intermediate tubular portion. The hollow interior of the roll is filled with thermal insulating material. The thermal insulating material within the roll reduces heat transfer through the center of the ribbon and the discs prevent heat loss from the ribbon edges to maintain a relatively flat temperature profile across the ribbon as it advances through an annealing lehr.

Abstract: A leer for the cooling and annealing of glass includes, at the entering, hot end thereof, a plurality of smooth-surfaced glass-supporting rollers of stainless steel and, at the cool or exit end a plurality of glass-supporting rollers of stainless steel having circumferential or helical ridges on which the glass rests.

Abstract: Method and apparatus for continually monitoring the surface temperature of a moving glass ribbon at a given distance from the edge of the ribbon where the ribbon moves through a critical portion of an annealing lehr where the rate of cooling determines whether the ribbon may be cut easily after annealing and whether the ribbon is subjected to spontaneous breakage during annealing.