Abstract: A roller conveyor furnace (12) for heating flat glass sheets has top and bottom heating arrays (28,30) respectively located above and below the plane of conveyance with each heating array including a plurality of elongated heaters (32,34) extending parallel to the direction of conveyance and spaced laterally from each other with respect to the direction of conveyance. The top heating array (28) has one more heater (32) than the number of heaters (34) of the bottom heating array (30) and the bottom heaters (34) are located in a laterally staggered relationship with respect to the top heaters such that each bottom heater is located laterally between a pair of top heaters. A control (36) energizes the top and bottom heating arrays (28,30) to heat each bottom heater (34) only when the two top heaters 32 on opposite lateral sides thereof are heated to thereby prevent excessive lateral edge heating of the conveyed glass sheet.

Abstract: The invention relates to a hardening furnace, in particular for sheets of glass (2) and the like. In the furnace, the glass sheets (2) are sustained and transported by a conveyor plane (1) of the roller type above and beneath which plane an upper radiating surface (3) and a lower radiating surface (4) are arranged. The upper radiating surface (3) is composed of a plurality of longitudinal strips (31) arranged side-by-side and parallel to the movement direction of the plane (1), while the lower radiating surface (4) is constituted by a plurality of transversal strips (41) arranged transversally to the said movement direction. Each of the strips (31 and 41) is separated from the contiguous strips and represents the lower and upper walls of chambers (32 and 42) separated one from the other. In each said chamber (32 and 42) there is a device which confers regulatable thermal energy, for example, a radiating tube (15).

Abstract: A continuous furnace (straight-through furnace) for heating glass panes to their curving and/or toughening temperature is constructed as a circular furnace and comprises an annular, horizontal hot gas support bed (3). On this annular hot gas support bed (3) the glass panes are carried, each by means of a template (56) of heat-resistant metal plate, also floating on the hot gas support bed (3), in a circuit from the feed station (6) to the discharge station (7). The templates (56) are each mounted on the arms (17) of a star-type turntable (16) concentrically to the support bed (3). At the discharge station (7) the glass panes, heated to bending and/or toughening temperature, are removed from the furnace by means of a radially traversable suction plate (42) and transferred into a bending and/or toughening device disposed laterally alongside the furnace.

Abstract: The invention relates to a method and apparatus for heat-strengthening glass sheets. A glass sheet heated close to a softening temperature is heat strengthened by cooling it at a certain controlled cooling rate. The cooling is effected in a space between cooling panels and the cooling panels are cooled by a gas jet which is applied to the surfaces of cooling panels facing away from the glass sheet. A cooling space temperature measurement can be used for controlling the power of a cooling jet.

Abstract: A longitudinally extending row of closely spaced elongated flexible springs extend over an elongated slot of a furnace to prevent heat loss. The springs are deflected in turn as an arm moves along the length of the slot and the springs return to their original state after the arm passes by. The arm holds a glass handling device which holds a glass sheet within the furnace. The arm moves along the length of the slot so as to transport the glass sheet through the sections of the heat treating furnace.

Abstract: The invention relates to an apparatus for heat-strengthening glass sheets. In a heat-strengthening station (3) down-stream of a heating furnace the cooling rate of a glass sheet is retarded by means of plates (9, 11), which are set above and below a glass sheet and return some of the thermal radiation back to a glass sheet and slow down convection. Thus, a glass sheet can be heat-strengthened by chilling it at a certain controlled cooling rate. In order to make also the lower plate effectively return some of the termal radiation applied thereto despite the rolls fitted in between, the top surface of lower plate (11) is made highly reflective to thermal radiation and further corrugated in a manner that the ribs of corrugations extend between the rolls close to a glass sheet.

Abstract: The invention comprises a tunnel-type heating furnace of modular construction for heating glass sheets carried therethrough in succession on a series of aligned rollers. The furnace enclosure includes a lower section of generally rectangular cross-section beneath the rollers and an upper section, which is of generally elliptical configuration in cross-section, above the rollers. The upper enclosure section is vertically retractable by means of a jack mechanism to facilitate maintenance and changing of the rollers. The rollers include shafts at their opposite ends having bearings adapted to be received and supported in upwardly opening recesses in roll support plates extending along either side of the furnace. A toothed gear or sprocket is affixed to the end shaft at one end of each roller. The rollers are driven in groups by timing belts whose upper flights extend over and engage the toothed gears.

Abstract: In a method for ceramising glass plates, in which the plates to be ceramised are hung vertically, a plurality of plates are hung transversely of the transport direction so that they form a plate package. This plate package is passed through a plurality of chambers of an oven in which it is subjected to a direct succession of different temperatures.

Abstract: Improved burner constructions for gas-fired infra-red generators having ceramic fiber matrix through the thickness of which gaseous combustion mixture is passed and as it emerges it is burned to heat emerging surface to incandescene. Burner matrix can be loaded with silicon carbide particles to improve its emissivity, can be made water repellent and its uniformity can be improved. Burner body can be casting, with sheet metal addition to form a baffle and air seal and to grip matrix edges. Combustion mixture plenum can have movable partition assembly separating it from air seals, to adjust portion of matrix at which incandescene is generated. Metal screen can be stretched in front of incandescent surface to assist with low-temperature operation. Large size matrix can have central support fitted and secured to back of burner body. Air seal can be provided by narrow curtain of air extending around internal faces of burner body.

Abstract: A device and a process for heating glass sheets in horizontal position, to bend them or temper them, by means of two series of resistors, the series being distributed on both sides of the path followed by the glass sheet and on a portion of the length of this path. Each resistor group is distributed in longitudinal zones or in crosswise subzones of various widths along the longitudinal zones, the power furnished to each longitudinal zone being regulated independently of the power furnished to the other longitudinal zones and being distributed in a controlled way between the crosswise zones and the longitudinal zones.

Abstract: The invention relates to a flow barrier in the annealing section of a glass tempering apparatus, said annealing section being provided with glass sheet supporting rollers (7) and cooling air blow boxes (1, 3) are disposed above and below a glass sheet, in addition to which there are, above the glass sheets, "false rolls" (8) in the form of a downward open trough, extending crosswise to the traveling direction of said glass sheets. The purpose of "false rolls" (8) is to increase a pressure applied to the top surface of a glass sheet in order to reduce the risk of a glass sheet becoming afloat. A flow along the trough, which increases towards the ends of the trough, results in a non-uniform tempering. The flow is cut off by fitting the trough with partitions (9) spaced from each other.

Abstract: An apparatus for synchronizing the movement of glass sheets through a furnace includes a stop for holding the sheets at the entrance to the furnace. An actuator is responsive to a synchronizing signal for moving the stop and releasing the sheet into the furnace. A reference point sensor detects a reference point associated with a rotating conveyor roller adjacent the entrance to the furnace when the reference point is in a predetermined spatial relationship to the glass sheet which is being held at the entrance. Thus, each glass sheet enters the furnace and engages the conveyor rollers in the same position such that any roller corrugation pattern is reproduced in the same position on each glass sheet. When two such glass sheets are laminated together to form a windshield, the roller corrugation patterns can be matched to reduce the optical distortion produced by the corrugation.

Abstract: A glass sheet tempering method and system (10) disclosed utilizes a heating chamber (22) and a quenching chamber (26) which contain ambients at superatmospheric pressure during both the heating and quenching. Forced convection heating is preferably performed in an improved furnace (14"). In one embodiment, heated gas flow is provided by centrifugal blowers which blow air across a plurality of spaced heat tubes. The heated gas flow is directed toward a glass sheet positioned within the heating chamber to provide rapid heating of the glass sheet. In a second embodiment, the heated gas flow is provided by upper and lower sets of opposed gas jet pumps connected to a gas supply. A pressure gas supply including a compressor maintains the superatmospheric pressure of the heating and quenching chambers (22,26). A recirculating gas supply (32) feeds compressed quenching gas to opposed blastheads (28,30) to perform the tempering.

Abstract: The invention relates to an apparatus for equalizing the temperature of conveyor rolls in a glass-tempering furnace, said furnace comprising a thermally insulated housing (1) confining a heating chamber (8), conveyor rolls (4), extending horizontally between the side walls of chamber (8) and lying one after the other in the lengthwise direction of the chamber, heating resistors (5 and 6) in the chamber above and below the array of conveyor rolls, as well as means for driving the conveyor rolls unidirectionally during a first cycle and reciprocally during a second cycle. Since the reciprocating movement means that a glass sheet remains longer in contact with the midsection rolls, these rolls cool more rapidly. In order to equalize the temperature of the rolls, the end sections of the furnace are provided with screen plates (7) mounted between heating resistors (6) below the array of conveyor rolls and the rolls (4) themselves.

Abstract: A metal or metal compound coating 6 is deposited on a face of a hot, freshly formed ribbon 1 of glass during the ribbon's forward travel through a coating station 5 between a forming installation 3 and an annealing lehr 4 by contacting the ribbon face with fluid coating precursor material e.g. sprayed from nozzle 17.Preparatory to the coating step, the ribbon 1 is passed through successive thermal conditioning zones comprising a zone 19 in which temperature gradients across the ribbon are reduced and a following zone in which heat is supplied substantially entirely to a surface layer of the glass at the face to be coated by exposing that face to one or more radiant heaters 22 having a black body temperature below 1100.degree. C. to compensate at least partially for the cooling effect of the coating step on the ribbon 1.

Abstract: Hot glass panes are displaced without sagging through a treatment station, such as an oven, on a roller grate which is linearly reciprocated while the rollers of the grate receive a translatory angular velocity component and an angular oscillation so that the velocity at a glass pane relative to the traveling grate is R.multidot..omega..sub.osc +R.multidot..omega..sub.trans, where R is the radius of the rollers at a point of contact with the pane, .omega..sub.osc is the angular oscillation velocity component of the roller displacement and .omega..sub.trans is the angular translatory component.

Abstract: In order to control the thickness of a metal or metal compound coating which is formed on a face of a freshly formed ribbon of hot glass during its travel from a flat glass forming installation by contacting such face at a coating station with a fluid medium or fluid media comprising a substance or substances from which the coating is formed, preparatory to being coated, the glass (4) is thermally conditioned (e.g. selectively or differentially heated) at a thermal conditioning station between the flat glass forming installation and the coating station, so as to eliminate or reduce temperature gradients across the ribbon width to be coated.

Abstract: An end cap (18) for use with a conveyor roll (12) of the thermally low expansive ceramic type used to convey hot glass sheets includes a metal sleeve (20) that receives an end (16) of the roll to provide rotational support and/or driving and also includes a retention spring (22) interposed between and engaged with both the roll end and the sleeve in order to retain the sleeve on the roll. The retention spring (22) preferably includes a plurality of leaf springs (44) that are sufficiently deflected at room temperature so as to remain partially deflected upon heating in order to provide the end cap retention.

Abstract: A traveling grate for hot glass prevents sagging of the glass by displacing the grate at a velocity different from the angular velocity imparted to the grate rollers in the opposite direction so that the translatory velocity imparted to the glass is an algebraic summation of the grate velocity and .omega.R where .omega. is the angular velocity of the rollers and R is the radius thereof.

Abstract: The present invention was developed to provide an improved process for retaining the substantially pristine state of glass articles, particularly thin-walled, lightweight glass containers.

Abstract: The invention relates to a process for regulating the temperature of a glass sheet in a furnace as the glass sheet is moved at a determined rate and heated according to a preestablished program. The furnace is characterized by only slight thermal inertia thereby to provide rapid adjustment of the internal temperature within each of several cells. The physical presence of the glass sheet is checked in synchronization with its step-by-step advance at least at one location upstream of one furnace cell to correct the regulation of the radiation heating output should these be a variance from that of the preestablished program. The process may be carried out with limited fabrication rejects by virtue of the capability of regulation of variations of the conveying rate or as required due to gaps in the succession of glass sheets being treated.

Abstract: Controlling the exit temperature of heated glass sheets of different thicknesses within a predetermined thickness range and/or different heat absorbing characteristics e.g. color, so that each sheet arrives at the furnace exit at substantially the same elevated temperature required for subsequent treatment that is substantially equal from sheet to sheet.

Abstract: Apparatus for treating fragile vitreous articles such as glass sheets which are apt to break when the treatment involves thermal conditioning. The apparatus includes spaced conveyor members for conveying the articles in a predetermined direction over a treatment area. To assist in the easy removal of any broken fragments of said vitreous articles, the treatment area is located beneath the conveyor members and has a plurality of heads for treating the underside of the articles. The treatment heads are retractable from a treating position, where they project into the spaces between the conveyor members, into a retracted position, where they are spaced beneath the conveyor members. A sweepable fragment collecting surface is spaced beneath said conveyor members. A sweeper is provided for cleaning the collecting surface when the treatment heads are retracted.

Abstract: A method and an apparatus for the heat treatment of a float glass ribbon in which a tunnel lehr is provided with arrays of parallel heat-exchange tubes above and below the path of the ribbon and for each of the longitudinally divided zones of these arrays, the tubes are grouped and provided with respective heaters at the upstream end of the zone while all of the tubes at the zone are connected to a flow at the downstream end for drawing the heated air through the tubes. The temperature of the glass ribbon is measured at the upstream end and the throughflow of the individual groups is controlled selectively to ensure a homogeneous temperature distribution in the glass ribbon.

Abstract: A process for strengthening a glass object by chemical reaction at the glass surface of the object between the glass and a chemical strengthening agent reactive with the glass to alter its composition and thereby either directly generate compressive stress therein or reduce the thermal expansion coefficient thereof. The object is kinetically contacted with the chemical strengthening agent in a bed comprising gas-fluidized particulate solid material under conditions of temperature and active fluidization such that the reaction proceeds but the formation of either stress-concentrating surface defects or an adherent coating of solid material on the surface of the object is substantially avoided. The object is maintained in the bed for a time sufficient for the reaction to alter the composition of a marginal stratum of the object adjacent the surface. The object is thereafter cooled, producing an object of increased strength and toughness having the marginal stratum under compressive stress.

Abstract: A method for reducing roll marking of glass sheets is disclosed whereby metal rolls are coated in situ with a boron nitride film.

Abstract: A rotatable roll for conveying glass sheets during thermal treatment comprising a frangible ceramic roll of cylindrical configuration engaged in compression stress between a pair of metal spindles, one of which is coupled to drive means for rotation and both of which spindles are provided with heads approximately coextensive in cross-section with the end surfaces of the frangible ceramic roll. The interfacial surfaces between the end surfaces of the rolls and the heads of the spindles are provided with friction material. The other of said pair of metal spindles is biased in compression to apply axial compression stress to the ceramic roll while the latter rotates in unison with the spindles. A method of using a conveyor comprising at least some of said ceramic rolls for the thermal treatment of glass sheets is also described.

Abstract: A gas-fluidized bed of particulate material is operated by extracting gas from a localized region of the bed to produce an unfluidized static condition of the material in that region. The region may be in the upper part of the fluidized bed, or may be a region adjacent a side opening into the bed where the unfluidized static material obturates the opening. There may be a plurality of unfluidized static regions in the bed.The invention is applicable to the thermal toughening of glass quenched in the fluidized bed.

Abstract: An article, for example a glass sheet, is treated in a gas-fluidized particulate material by advancing the article along a path leading into the gas-fluidized particulate material and extracting gas from a region of the path at a rate sufficient to pack the particulate material in that region and thereby obturate the path. An opening leading into a container for a gas-fluidized bed of particulate material may be obturated in this way. The packed state of the material obturating the opening is such that an article can pass through the opening.

Abstract: Glass containers received on a machine conveyor which passes a plurality of forming machine sections and receives the ware from the sections is coordinated in its relationship to the machine sweepouts, such that a gap is provided periodically in the row of ware carried by the machine conveyor. A bottle-transfer device which transfers the ware from the machine conveyor to a cross-conveyor is operated so that it also will maintain the gap that is provided in the line of ware. The ware on the cross-conveyor moves in line across the open-receiving end of the lehr and is pushed from the cross-conveyor onto the moving lehr mat. By providing a gap in the line of ware, the lehr loader pusher bar may be operated more slowly than in the past and to thereby provide a more stable transfer of ware from the cross-conveyor to the lehr.

Abstract: This invention relates to glass sheet conveyor rolls and, particularly, those that are useful in conveying glass sheets through a hot atmosphere. The gist of the invention resides in the manner of supporting rigid, unitary conveyor rolls on three bearing housings, a pair of which is located to one side of the conveyor path provided by a set of conveyor rolls. According to a specific embodiment of this invention, the outer bearing housing of the pair of bearing housings is supported slightly above the one horizontal plane of support for the other bearing housings supporting each conveyor roll so as to impart a stress causing each conveyor roll of cylindrical configuration to develop a slightly concave upper surface during rotation.

Abstract: An installation for the flame treatment of glass articles comprises a succession of rotatable turntables driven linearly and cyclically by a chain between a loading point, at which a supply means, comprising a moulding press provided with a rotatable plate, the movement of which is synchronized with that of the chain, loads articles onto the turntables and an unloading point, passing through a flame treatment zone; and means to transfer an article from the rotatable plate to the turntables of the chain by means of at least one intermediate point, one article being transported from the transfer point to the chain, while the following article is transported from the plate to the intermediate point.The installation may be used in the flame treatment of all glass articles.

Abstract: In the coating of glass containers with a plastic film, the curing of the applied plastic film to the container is an extremely important phase of the overall process. Generally, the most economical method of achieving cure is to carry a plurality of the bottles through an oven where the curing operation is accomplished, the bottles being carried on a moving belt. In order to allow such containers to be carried on the moving belt, the base must achieve a partial cure, prior to being placed on the conveying means for passage through the oven. In accordance with the present invention, means and a method are disclosed for providing a sufficient cure of the coated container base to allow for final curing in the oven.

Abstract: A glass sheet to be heated, for example to a bending or a quenching temperature, is supported on its lower edge in an upright disposition and is advanced along a horizontally disposed path through a furnace. Transient support is provided for the upper edge of the sheet which support is positioned to cause the sheet to lean at a near-vertical angle as it is advanced, and thermal conditions in the furnace as well as the time the sheet is within the furnace are set in dependence on the glass thickness so as to heat the glass to the required temperature while permitting the glass to relax as it is heated only by an amount less than a maximum acceptable deformation of the sheet which depends on the use to which the sheet is to be put.

Abstract: A glass tempering system including a roller hearth furnace that has a conveyor with elongated rollers extending through an elongated heating chamber of the furnace and outwardly through elongated slots in the sides of the furnace so as to be supported on drive belts which are slidably driven along support surfaces to thereby frictionally drive the rollers and convey glass sheets over the rollers through the heating chamber. The furnace is of a modular construction and includes upper and lower housing portions with inner layers of refractory material that define the heating chamber. Flanges of the refractory material cooperate to define the elongated slots at the sides of the furnace. Heat seal arrangements extend between the refractory flanges and the conveyor rollers to mitigate heat flow from the furnace during use. A first electric motor drive mechanism drives belt sheaves that receive the drive belt at the end of the furnace where glass enters the heating chamber.

Abstract: A glass annealing lehr to which newly formed glassware is passed under and over sprays of abrasion resistant material by transfer mechanism that engages the ware and suspends it to expose the bottom to spray, the transfer mechanism in one form being capable of transferring the ware from one conveyor to another moving in opposite directions out of contact with said conveyors during the transfer movement.

Abstract: A method and an apparatus for the heat treatment of a float glass ribbon in which a tunnel lehr is provided with arrays of parallel heat-exchange tubes above and below the path of the ribbon and for each of the longitudinally divided zones of these arrays, the tubes are grouped and provided with respective heaters at the upstream end of the zone while all of the tubes at the zone are connected to a flow at the downstream end for drawing the heated air through the tubes. The temperature of the glass ribbon is measured at the upstream end and the throughflow of the individual groups is controlled selectively to ensure a homogeneous temperature distribution in the glass ribbon.