Abstract: In the tin float bath process of flat glass production, proposed automatic recuperative natural gas burners will replace the existing electrical heating elements. The use of natural gas instead of electricity creates a more energy-efficient bath operation, amounting to an approximately seventy percent savings. Control of the burner zones is comparable to that utilized with the replaced electrically heated zones. Combustion air and natural gas are ignited and burned within a heat-radiating chamber. The residue from burnt gases is exhausted externally to the bath and has no contact whatever with the atmosphere inside the bath. Advantages comprise a less complicated installation with minimal maintenance and with little or no replacement parts, all of which contribute to longevity not attained by prior art. Additionally, shutdown of the process is not necessary to remove and replace a possible defective burner, as is required with defective electrical heaters. Only periodic visual inspection is required.

Abstract: The apparatus for molding an optical glass element is made up of relatively movable upper and lower molds for press molding a glass blank, and a plurality of infrared ray lamps encircling the upper and lower molds, temperature measuring devices for measuring the temperatures of the upper and lower molds, and a controller responsive to the outputs of the temperature measuring devices for controlling electric inputs to the infrared ray lamps thereby maintaining the temperatures of the upper and lower molds at predetermined values.

Abstract: An apparatus and method are provided for automatically inspecting and rejecting glass articles during the continuous manufacture thereof. In particular, an optical pyrometer is provided for measuring the top of each glass article and generating signals representative of the residual temperature thereof. A computer includes software which processes the temperature signals and generates actuating signals if the temperature does not fall within a range of predetermined temperature setpoints. Generation of such actuating signals actuates a hammer which removes each defective glass article.

Abstract: A glass blank is molded into a lens while being clamped between a pair of molds and heated by a heater. A mold clamping force is applied, substantially concurrently with the heating, to the molds to deform the lens blank. The mold clamping force is unable to deform the lens blank when the temperature of the lens blank is below a transition point of the lens blank and the mold clamping force is able to deform the lens blank when the temperature of the lens blank is above the transition point. The deformation starting point of the lens blank is detected based on a movement of the molds. A temperature of the molds at the deformation starting point is also detected. The temperature of the molds at the starting point is stored in a control device.

Abstract: A process and apparatus for controlling the manufacture of mineral fibers, in particular glass fibers, by use of a fiber-drawing process using internal centrifuging in a centrifuger. The peripheral strip is pierced by a large number of outlet orifices and the radiation emitted superficially by the peripheral strip is measured in order to determine the temperature of points of the peripheral strip and the vertical coordinate of each of the points measured.

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: As an optical fiber (12) is being drawn, air (14) is directed at a portion of the fiber as a succession of air pulses, the pulses having a frequency near the natural frequency of the fiber portion. The frequency of the air pulses is then varied over a range of frequencies that includes the natural frequency of the fiber portion. When the air pulse frequency equals the natural frequency of the fiber portion, a resonance occurs which greatly amplifies the amplitude of the vibration of the fiber portion. The large deflection of the fiber that occurs at resonance is easy to detect, and the air pulse frequency which causes such maximum deflection is taken as being equal to the resonant frequency and therefore to the natural frequency of the fiber portion. Changes of the detected resonant frequency can be interpreted in a straightforward manner as changes in optical fiber tension which, in turn, are used to make compensatory changes of the temperature of the furnace (10).

Abstract: A fiber optic polarization maintaining apparatus for use in fabrication of fused optical couplers, where the fused optical couplers include first and second optical fibers. The apparatus includes apparatus for holding the first and second optical fibers in a first predetermined alignment where the first and second fibers each include a stripped portion and where the stripped portions are held in contact along their length. Apparatus for heating the first and second optical fibers are located adjacent the holding apparatus wherein the heating apparatus is brushed across the length of the first and second fibers so as to oscillate across the fibers in an amplitude varied in an ever decreasing stepped manner until fusion of the fibers is complete.

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: The invention relates to a method and apparatus for bending a glass sheet. A glass sheet (5) is supported on a bending mould (6) in a heating furnace and heated close to a softening temperature by means of a heating field generated by heating elements (4). Glass sheet (5) is placed adjacent to the heating field whose energy distribution is adjusted as desired. Glass sheet (5) is controllably pulled away from the heating field as the glass heats up and begins to bend.

Abstract: A glass melting tank has a melting chamber, a shallow uniflow conditioning chamber, a shallow refining chamber and a riser chamber between the melting chamber and refining chamber. Heat is input to glass in the riser chamber by electrodes located centrally in the riser chamber near the base of the riser chamber. Temperature sensors sense the temperature entering the riser chamber through a throat and near the base of a downstream wall of the riser chamber and the heat input is controlled to produce torroidal flow in the riser chamber.

Abstract: A cylindrical piece of glass (4) is subjected to heating passes on a glassmaker's lathe. Possible opto-geometrical defects of said piece of glass are detected and measured and then said defects are corrected by machining the outside surface thereof during a correction pass performed on the same glassmaker's lathe.

Abstract: A machine is provided for molding an optical element by using a molding block having upper and lower molding dies, a sleeve die and a glass blank combined integrally with each other. The machine includes a chamber which accommodates a heating zone having a plurality of sections for heating the molding block from above and below, a deformation zone for pressing the molding dies and a cooling zone having a plurality of sections for cooling the molding block. The chamber is formed with an inlet and an outlet for the molding block. The sections of the heating zone, the deformation zone and the sections of the cooling zone are provided independently of one another. A transport member is provided for sequentially transporting the molding block through the heating zone, the deformation zone and the cooling zone, and first and second shutters are provided for opening gas supply member is provided for introducing nonoxidizing gas into the chamber.

Abstract: The present invention relates to a female press bending ring for use in the press bending of glass sheets outside of a furnace, and more particularly to a female press bending ring which is suitably heated during the bending cycle to regulate the transfer of heat between the peripheral margin of the glass and the female bending ring with which it is in contact. By so doing, near-edge tension and edge stresses are greatly reduced, thereby reducing chill cracking and glass breakage during and after production. The female ring may be covered by a layer of fiberglass cloth or the like to provide a smooth resilient surface for engaging the glass sheet.

Abstract: A glass treating apparatus suitable for heating glass sheets, such as in a process of forming motor vehicle windshields, comprises a heater suppoted by a modular support structure. The heater comprises a non-monoplanar heating surface subdivided into heating zones. The heating zones are individually controlled. The heating surface can approximate the configuration of the glass sheet. The invention allows preferential heating of selected zones of the glass sheet. One or more such modular radiant heater assemblies can be used in a glass forming process.

Abstract: A curving furnace has at least one curving station, of which the walls are equipped with resistors. The series of upper resistors are subdivided into one or more axial zones in which the resistors are oriented parallel to the height of the glass sheets, and into one or more transverse zones in which the resistors are oriented perpendicularly. The heating power of a given zone is regulated independently of the heating powers associated with the other zones.

Abstract: First and second glass sheets, which are to be combined together into a single laminated glass sheet, are heated in a heating furnace so that the temperature of the first glass sheet at the exit of the heating furnace and the temperature of the second glass sheet at the exit of the heating furnace are substantially equal to each other.

Abstract: A mold cooling arrangement includes a plurality of closed bores vertically disposed in the mold between the molding surface and the mold exterior. A manifold positioned vertically above the mold communicates with the interior of each bore and a condenser is disposed vertically above and communicates with the manifold. The bores and manifold are at least partially filled with a phase change liquid such as distilled water which during operation of the mold is partially vaporized. The vapor rises to the condenser where it is converted back to liquid and returns by gravity to the manifold and mold bores. The rate of heat transfer from the mold to the liquid is controlled by developing an electrical signal proportional to mold temperature and using the difference between that signal and a set reference temperature signal to control the rate of flow of a secondary coolant into the condenser of the system in order to vary the pressure in the system, in turn, to control the rate of mold cooling.

Abstract: A sheet of glass is bent with a system including a feed mechanism for feeding the sheet of glass along a predetermined path, a heating furnace disposed along the path, for heating the sheet of glass, and a shaping device disposed along the path for bending the sheet of glass heated by the heating furnace. Before the sheet of glass is bent by the shaping device, the sheet of glass is thermally processed to different degrees at leading and trailing end portions thereof along the path, thereby uniformizing temperatures of the sheet of glass from the leading end portion to the trailing end portion thereof.

Abstract: This invention contemplates a near net-shape method of making thin glass-ceramic articles possessing substantially uniform thickness and parallel opposing surfaces comprising the steps of: (a) heating the receiving and opposing molding surfaces of a mold to predetermined different temperatures; (b) bringing the receiving and opposing molding surfaces of the mold into close proximity to each other to press a delivered charge of molten glass to fill said mold, while thermally providing and maintaining a substantially parallel fit between the receiving and opposing surfaces of the mold, to achieve substantially uniform thickness in the pressed charge, (c) pressing the glass charge for a time sufficient to remove enough heat from the glass charge that the temperatures of the molding surfaces and the glass article surfaces are all nearly at equilibrium, wherein the press time and mold temperature differential combine to result in symmetric heat removal thereby causing all the aforementioned temperatures to reach e

Abstract: A method of collecting data to indicate certain internal conditions during the function of a glass container forming machine, and apparatus for the practice of the method including sensing devices within a plunger cycling mechanism of the machine for transmitting information from the mechanism during the operation of the machine.

Abstract: The invention relates to a heat conditioning chamber for controlled cooling following a high-temperature treatment of plane thin glass sheets, transported in horizontal position by a continuously driven roller conveyor. According to the invention, in the hottest zone in the chamber, the cooling is performed solely by absorption of radiation and continues in other zones by convection.

Abstract: A furnace for heating glass sheets moving along the axis of the furnace has at least one differentiated heating cell, the heating elements of which disposed at the vault side are constituted of sets of electrical resistors controlled in temperature or in power and adjustable in height independently for each set. A portion of the electrical resistors are mounted parallel to the axis of the furnace, the other heating cells each constituting a longitudinal heating zone independent of the other longitudinal zones and having, at the vault side, heating elements composed of sets of electrical resistors subdivided into several independent transverse sub-zones, in which the electrical resistors are mounted perpendicularly to the axis of the furnace. The invention is applicable to the manufacture of curved and toughened panes.

Abstract: A bushing balance controller controls the overall average temperature of a multiple segment glass fiber forming bushing and the temperature of each individual bushing segment. Current shunting loops divert current away from each bushing segment as required to provide the proper bushing segment temperature profile as well as the desired average bushing temperature.

Abstract: A process and device for controlling heating of a furnace by means of electrical resistors using switching devices, particularly thyristors, associated with the electrical resistors, and whose operation is to be controlled. The switching devices are controlled in syncopated mode by an industrial computer, a programmable industrial robot or equivalent which performs a set of functions which make it possible to compute the power to be dissipated in the resistors, and control directly the switching devices so as to dissipate the previously coputed power. The invention applies particularly to controlling industrial furnaces and more particularly of glassmaking furnaces, particularly furnaces for heating of glass for the tempering and/or bending of the glass.

Abstract: The present invention provides a method of controlling the temperature of a multiple segment fiber glass bushing. Sensors monitor the temperature of each individual segment and the current delivered to the bushing is adjusted so as to maintain the average bushing temperature at a predetermined value. In addition, the temperature of each individual segment is compared to a set point reference value and bushing current is shunted around each segment based on this comparison.

Abstract: An apparatus for heating and bending quenching glass sheets (10) is disclosed as including a first platen (14) and a second platen (22). Both platens (14,22) are deformable for heating and bending a heated glass sheet (12) therebetween. First heat source (18) is integral with the first platen (14) and provides heat in close proximity to the heated glass sheet (12) during the bending to maintain an optimal glass bending temperature.

Abstract: A method of controlling the temperature in a tunnel open at both ends and along which objects are displaced by conveyor means, the tunnel including heating or cooling means disposed along its two side walls between which the conveyed objects pass. According to the invention, the temperature is sensed in a particular zone of the tunnel in which a predetermined temperature is desired, and in organizing transverse displacement of the heating or cooling means (104) is organized in a direction essentially perpendicular to the direction in which the objects (103) are conveyed by means of a servo-control system causing the heating or cooling means to be displaced automatically mutually towards each other or away from each other whenever the sensed temperature differs from the predetermined temperature, thereby having the effect of permanently ensuring a constant temperature environment for the objects concerned in the above-mentioned zone of the tunnel.

Abstract: The subject matter of this invention relates to an improved method for controlling an industrial glass fiber-forming process. More particularly, it involves a method for controlling the thermal environment of several fiber glass bushing assemblies by the utilization of fin cooler assemblies in which a coolant is passed through the fins as part of a closed-loop pressurized system to remove heat radiated to the fins by the molten glass that emerges from the bushing. In the preferred embodiment, this liquid coolant is demineralized water operating at a pressure of somewhere between 18 and 100 psi.The use of a programmable logic controller to monitor various system parameters such a pressure, temperature and flow rate is also disclosed. The controller is programmed to take corrective action automatically upon the detection of certain triggering events in order to maintain a constant flow of coolant throughout the entire system.

Abstract: An apparatus for processing glass sheets includes a furnace and a bending station traversed by a conveyor for carrying the glass sheets. A plurality of heaters mounted in the furnace each heat associated areas of the glass sheets in accordance with setpoint temperature signals representing desired values of temperatures for heating associated areas of the glass sheets. One or more parameters of the glass sheets, such as thickness and color, are sensed and the setpoint signal values are changed accordingly. The parameter values are also utilized to change the spacing between the upper and lower mold members in the bending station to adjust the bending pressure applied to the glass sheets. Furthermore, the parameters are utilized to change the speed of the conveyor sections in order to vary the time that the glass sheets are in the furnace and thus the amount of heat imparted to the glass sheets.

Abstract: An improved bushing controller is shown which utilizes an auxiliary transformer in each of the variable impedance circuits in the controller and the bushing tha the controller is connected to increase the current capability of the controller by a significant percentage. Improved performance of fiber glass bushings producing multiple forming packages is realized.

Abstract: Disclosed is a glass press molding method which comprises a step of heating glass material and a mold die composed at least of an upper mold die and a lower mold die for molding the glass material;a step of pressing the glass material by means of the mold die;plural pallets for supporting the glass material and the mold die, each of the pallet supporting the glass material and the mold die in independent manner;a step of transporting, in succession, the pallets each supporting the glass material and the mold die; anda step of transferring the glass material, prior to the pressing step, in such a manner as to place the glass material, heated to a predetermined temperature in the heating step, between the lower mold die and the upper mold die, and to transfer the pallet with the glass material inserted in the mold die to the pressing step.

Abstract: A local heater is arranged in a heating furnace in which glass plates are continuously conveyed, and a bending line on each glass plate is forcibly heated. The local heater is elongated, and positions of both ends of the local heater are independently and digitally controlled in a widthwise (X-axis) direction of the heating furnace. Control point data along the bending line is obtained by interpolating coordinate values of both ends of the bending line. X-axis velocity control is performed such that the local heater is located on the glass bending line in synchronism with conveyance of the glass plate. A heating locus is linear, and the operation of the local heater is not stepwise. An offset of the actual heating locus from the bending line can be minimized.

Abstract: A heating oven is provided for processing glass materials, e.g., porous glass preforms, from which optical waveguide fibers are prepared. The oven includes a stationary elongated chamber, e.g., a silica muffle, for receiving the glass material which is to be processed. At least a portion of the chamber is surrounded by a stationary susceptor. The chamber is heated by moving an energized induction heating coil along a path parallel to the longitudinal axes of the susceptor and the chamber.

Abstract: A method for consolidating a porous glass preform is provided in which a preform is placed in a stationary elongated chamber and selected portions of the chamber, distributed along the chamber's length, are sequentially heated above the preform's sintering temperature. In certain preferred embodiments, the chamber is surrounded by an elongated susceptor and the heating is performed by moving an induction heating coil along a path parallel to the longitudinal axes of the susceptor and the chamber.

Abstract: A method for heating thick-walled glass tubes, particularly quartz tubes, in the manufacture of optical fibres while using microwave energy. According to the invention, the tube (5) is pre-heated to a temperature of about 1000.degree. C.-1500.degree. C., preferably in a known manner with the aid of a gas flame, whereafter the tube is further heated by means of microwave energy, generated by a microwave generator, by inserting the tube (5) axially into a microwave cavity (2) incorporating in both end walls (6,7) or end surfaces openings (3,4) for the tube (5), the electrical field strength being given a field image which includes only one tangential component, according to TE-01n-mode, preferably according to the mode TE-011, whereby the electrical field is so formed as to be tangential to the surfaces of the tube (5), and so formed that the electrical field strength is zero adjacent the surfaces of the cavity (2). The invention also relates to apparatus for carrying out the method.

Abstract: A mold cooling arrangement includes a plurality of closed bores vertically disposed in the mold between the molding surface and the mold exterior. A manifold positioned vertically above the mold communicates with the interior of each bore and a condenser is disposed vertically above and communicates with the manifold. The bores and manifold are at least partially filled with a liquid such as distilled water which partially evaporized during operation of the mold and the vapor rinse to the condenser is converted back to liquid and return by gravity to the manifold and mold bores.

Abstract: According to the invention, ventilating air blown around and/or in the walls of a mould is cooled so as to maintain substantially constant, at least during predetermined periods of time, the temperature of the air around and/or in the walls of the mould, irrespective of the ambient temperature.

Abstract: A method for manufacturing mineral fibers comprises forming mineral fibers from molten mineral material, continuously discharging an auxiliary stream of molten mineral material, continuously measuring the temperature and the mass flow rate of the auxiliary stream, calculating the viscosity of the material using the measured mass flow rate and modifying a process parameter in response to the measured temperature and calculated viscosity of the auxiliary stream.

Abstract: A temperature monitoring and control system for a glass sheet processing system includes a temperature sensor mounted at a preselected location in the system, a display, and a computer connected to the temperture sensor for periodically receiving a series of signals corresponding to temperature values transmitted by the sensor. The computer includes memory for storing selected values received from the temperature sensor and memory for storing one or more preselected threshold values. The computer also includes control logic for comparing the temperature values with one or more of the preselected threshold values, selecting and storing a set of those temperature values which satisfy a predetermined criteria, and displaying the set of temperature values as a profile taken along the length of the glass sheet in the direction of conveyance of the sheet through a glass processing system.

Abstract: For sure sealing of the evacuation tips of vacuum tubes, the electric power supplied to the heating resistor of the sealing furnace is regulated for each treatment stage, the set value is pre-selected and laid down by a computer for the corresponding power generator.

Abstract: A digitally controlled apparatus for varying the temperature of a glass fiber forming bushing over a period of time is disclosed. A clock generates timing pulses at a predetermined frequency to a BCD counter. The output signals from the BCD counter are fed to a comparator means. BCD output signals generated by a plurality of manually operable switch assemblies are also fed to the comparator means. The switch assemblies are set by an operator to generate a predetermined number related to the amount of time required to wind a strand of glass fibers upon a tube. The comparator means generates an output pulse when the count of the BCD counter equals the number set by the switch assemblies, then resets the BCD counter to zero. The output pulses from the comparator means are fed to a binary counter. The output lines from the binary counter are connected to a digital to analog converter. The converter generates an analog output signal which is proportional to the magnitude of the number from the binary counter.

Abstract: There is disclosed an improved apparatus for locally heating selected portions of glass sheets conveyed through a tunnel type furnace on a roller conveyor. The apparatus comprises two localized heaters positioned within the furnace, supporting members for supporting the localized heaters, at least one portion of each of the supporting members extending into the furnace, and a drive mechanism positioned externally of the furnace and adapted to reciprocatingly moving the localized heaters in a direction transversely to the direction of conveyance of the glass sheets in a substantially synchronized relation to movement of the conveyed glass sheets so that the selected portions of the glass sheets are locally heated by the localized heaters and can thereafter be bent, at a bending station, to a much smaller radius of curvature than the rest of the glass sheet.

Abstract: A bushing balance controller senses the temperature of each section of a multiple section glass fiber forming bushing by thermocouples or resistance (voltage drop) measuring techniques and injects electrical energy to all but one of the individual bushing sections and adjusts the supply of electrical energy to the entire bushing assembly thereby controlling the temperature of each individual section of the bushing. When thermocouples sensors are utilized, standard thermocouple driven temperature controllers may be utilized to provide a signal to a plurality of power packs, a primary power pack providing electrical energy to the entire bushing and smaller power packs controlling the injection of electrical energy to all but one of the bushing segments. A similar power pack and bushing control scheme accompanies the use of resistance (voltage drop) measurement techniques.

Abstract: An improved fiber glass bushing control system. One aspect of the system has a weighing means for weighing complete collections of glass fiber strands produced from forming from a bushing through attenuation, a monitoring means for the time of attenuation at constant strand speed and a program computer means that receives signals from the weighing means and the monitoring means. The program computer means has a means for establishing a database of the weights and times, a means for determining the throughput of the glass from the bushing from the weights and times, a means for determining average throughputs and including these averages in the database, a means for comparing the average throughputs to a standard set throughput, and a means for initiating an adjustment to the main bushing temperature controller, when the average throughput deviates from the set point throughput by a value greater than the sensitivity factor of the bushing.

Abstract: A glassware production system includes an electropneumatic individual section glass forming machine having a multiplicity of operating mechanisms for converting a gob of molten glass into a hollow glass container. A glass forehearth feeds molten gobs at controlled temperature and weight to the forming machine. Electronic controllers individually and selectively control parameters of operation of the multiplicity of machine mechanisms and the forehearth. Glassware from the forming machine is inspected for manufacturing faults and for identifying each inspected container with its associated mold of origin. The glassware inspection devices provide fault signals indicative of a plurality of differing types of faults, which are thereafter associated not only with mold or section of origin but also with fault cause.

Abstract: A fiber glass bushing having a thermocouple embedded in the bottom thereof and a method of preparing the same is described. The thermocouple is carried in a plate member which is welded to the bushing bottom by a weld on the outside of the busing.

Abstract: A heating oven for processing glass materials from which optical waveguide fibers are prepared is provided which comprises:(a) an elongated chamber for receiving the glass material to be processed; and(b) means for heating the chamber, said means comprising an elongated susceptor, the longitudinal axis of the susceptor being parallel to the longitudinal axis of the chamber, an induction heating coil, means for moving the induction heating coil along a path parallel to the longitudinal axes of the susceptor and the chamber, and means for energizing the induction heating coil.

Abstract: The device comprises a three-dimensional grid of thermocouples which are immersed in a fluid, which is moving in a covered channel and has a temperature above that of its environment. Apertures in the sheathing of the channel can be progressively closed by shutters so as to control the cooling of the fluid through an outgoing radiation through the apertures. Burners with a variable intensity are placed within the channel and allow to heat up the fluid in the vicinity of each burner. The position of each shutter and the fuel flow to each burner are commanded severally, based on the values emitted by the ensemable of the thermocouples in order to obtain a homogeneous repartition of the temperature of the fluid, transversally with respect to the channel.

Abstract: An apparatus for more accurately measuring the temperature of a fiber glass forming bushing is described which includes the placing of sidewall and bottom thermocouples in locations on the bushing so that electrical signals representing noise are eliminated or reduced significantly.