Abstract: The invention relates to a method and apparatus for equalizing the temperature profile of glass sheets in a roller-equipped furnace included in a horizontal tempering plant. At least in the early stage of a heating cycle, the upper surface of a glass sheet is exposed to an intensified convection heat effect by blasting air into the furnace from blasting pipes (3) located close to the upper surface of a glass sheet. This blasting compensates for the vigorous heat transfer to the lower surface of a glass sheet in the early stage of a heating cycle, which is caused by hot rollers. The blasting range and spot is manoeuvred in the longitudinal direction of a furnace in a manner that, at any given time, the blasting is only applied to that longitudinal section of a furnace in which a movable glass sheet is located at a given time.

Abstract: The invention relates to a nozzle assembly for a flat-glass tempering machine. A nozzle cover (2) includes two types of orifices side by side. A number of orifices (7, 8) are linked to the pressure of a compressor (11) and another number of orifices (6) are linked to the pressure of a blower (12). Thus, the different orifices supply air of different pressures.

Abstract: The invention relates to a method and apparatus for bending and tempering a glass sheet. A glass sheet is supported by one and the same ring mould (3) throughout all its working operations. Following the preheating of a glass sheet from a temperature of about 500.degree. C., its heating to a final bending and tempering temperature is effected at a high output and rate of speed. For example, on 4 mm thick glass, this final heating is performed within a period of time of 15-25 s. Therefore, the temperature of bending station is 800.degree.-1000.degree. C. Since rapidly heating glass bends quickly, the bending flexure or temperature of glass is monitored and the glass is advanced to tempering as soon as a predetermined bending flexure or temperature is reached.

Abstract: In a cooling station in a tempering plant for glass sheets for chilling, heat-strengthening, or after-cooling, the cooling station including upper and lower cooling-air blast nozzles are positioned above and below the glass sheets to be cooled. Nozzle covers cover the upper and lower nozzles. The nozzle covers are covered with perforated plates having a reflection coefficient for more than 0.8 for heat radiation. The plates are detachable from the nozzle covers and are thus replaceable.

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: The invention relates to a method for bending and tempering a glass sheet. A glass sheet is supported on a ring mould during the course of heating, bending and tempering and the glass is heated for gravitational bending thereof. After a bending operation, the glass temperature is allowed to decrease to the range of 500.degree.-550.degree. C. throughout, followed by increasing the overall glass temperature to a tempering temperature by heating as quickly and uniformly as possible.

Abstract: The invention relates to a method for bending difficult bending shapes such as an S-shape in a glass sheet. The downward bending of an outline-mould supported, heated glass sheet is assisted by a non-engaging lower partial surface mould used for blowing to a bending line (BL) or its vicinity a gas having a temperature at least equal to that of glass, the gas serving simultaneously as a glass carrier preventing its falling or excessive downward sagging. Blasting orifices in the shaping surface are adapted to concentrate heating on the most problematic areas of a bending line.

Abstract: The invention relates to a glass sheet bending or supporting mould which is made primarily by casting of a ceramic material and which includes a curving or flat shaping surface, a number of orifices (10, 11) in a shaping surface (7, 8) as well as channels (16, 17) extending through the mould material and in communication with orifices (10, 11). Said channels (16, 17) are formed as distribution channels common to a plurality of orifices (10, 11) and connected to each other by means of transverse connecting channels (161, 171) for building a ladder-like or lattice-like distribution manifold (16, 161; 17, 171). The invention relates also to a mould manufacturing method, wherein a ceramic-based material is cast in a manufacturing mould which, prior to a casting operation, is fitted with a temporary filling matching a desired distribution manifold and having a ladder-like or lattice-like configuration.

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 relates to a method for bending difficult bending shapes such as an S-shape in a glass sheet. The downward bending of an outline-mould supported, heated glass sheet is assisted by a non-engaging lower partial surface mould used for blowing to a bending line (BL) or its vicinity a gas having a temperature at least equal to that of glass, the gas serving simultaneously as a glass carrier preventing its falling or excessive downward sagging. Blasting orifices in the shaping surface are adapted to concentrate heating on the most problematic areas of a bending line.

Abstract: The invention relates to a method and a mould assembly for bending complex shapes on a glass sheet. The invention relates also to a bending mould and its manufacturing method. A heated glass sheet placed upon a ring mould is bent to its final shape by means of an over-head non-contacting mould (6) whose curved lower surface (7, 8) is provided with blasting orifices (10) and suction orifices (11). Blasting orifices (10) are used to blow hot air for heating a glass sheet at least locally while building an air cushion between shaping surface and glass sheet. The hot air blown from blasting orifices (10) is used to apply a greater heat volume to those sections of the glass sheet surface in which the bending radius of a glass sheet is the smallest or deformation (elongation, bending) is the greatest.

Abstract: The invention relates to a method and apparatus for preventing the arching of glass sheets in the roller-equipped furnace of a horizontal tempering plant. In order to equalize the total thermal effect applied to the top and bottom surfaces of a glass sheet, the top surface of a glass sheet is subjected at least at the initial stage of a heating cycle to an intensified convection heat effect by blasting air into the furnace through blasting pipes (3) positioned adjacent to the top surface of a glass sheet. An object of this blasting is to compensate a vigorous heat transfer caused by hot rollers to the bottom surface of a glass sheet in the beginning of a heating cycle. In order to intensify a heat equalization between the opposite surfaces of a glass sheet, the furnace space below a glass sheet is cooled by passing the air to be blown into the furnace into a blasting manifold (3) through a heat-exchange manifold (6) positioned below a bearing surface formed by rollers (2).