Abstract: A method and apparatus for electrically melting solidified glass in difficult to reach regions of a glass melting furnace not readily accessible with fossil fuel heating means and, more particularly, to an electrode arrangement for electrically heating solidified glass in difficult to melt regions such as a submerged outlet throat between a furnace melter section and the riser through which the glass is supplied in production.

Abstract: A forehearth supplied with molten glass from a tank furnace, with bottom passages overlying bushings for the extrusion of vitreous filaments, forms an elongate chamber whose sidewalls are penetrated by heating electrodes spaced apart in the longitudinal direction and arrayed in two relatively staggered tiers. The electrodes of the lower tier are more numerous in the vicinity of the bottom passages than between these passages. The heating effect of the electrodes can be supplemented by top burners disposed above the glass level.

Abstract: A forechamber or reservoir to which molten glass is fed, is provided with burners for heating the surface of the glass mass. The molten glass is conducted from the forechamber via at least one opening in its bottom wall into a vertically disposed intermediate chamber which is provided at its lower end with a nozzle heating plate having a plurality of orifices through which the mass is extruded. The intermediate chamber is provided with electrode heating elements so that the glass mass may be heated within the chamber. The height of the chamber is greater than its longitudinal length or diameter so that a laminar flow, caused by the head of the molten glass through the forechamber and intermediate chamber, is effected.

Abstract: A method and apparatus for feeding pulverant raw material to an arc furnace having a plurality of arcing locations defined by vertical electrodes. A vertical feed tube gravitationally conveys the raw material to a central location inside the furnace which is above the arcing locations. A rotatable deflector is located at the bottom of the feed tube and is rotated in step-wise fashion to direct raw material from the feed tube to each of the arcing locations. A fixed deflector is located at each arcing location to confine the raw material fed into the furnace predominantly to the arcing locations. By locating most of the raw material at the arcing locations, the feeding mechanism of the present invention improves the stability of the arc and the melting efficiency of the furnace.

Abstract: A glass edge multiple glazed unit having fillets of substantially uniform thickness is produced by the application of heat to marginal edge portions of adjacent sheets, followed by a delay sufficient to establish a substantially uniform, greater than fusing temperature condition in the body of fillet-forming glass. The fused sheets are thereafter drawn apart a preselected distance to a spaced-apart face-to-face relation to form a glass-edge multiple glazed unit.

Abstract: A method for imparting increased mechanical strength to a glass object having imperfections in a surface thereof. The glass object is heated to a temperature above the strain point of the glass. A laser beam is generated having a wavelength absorbable by the glass and impinged on all portions of the surface containing the imperfections. The power density at which the beam is impinged is sufficient to rapidly heat a surface stratum of the glass to establish a thermal gradient therein whereby the viscosity at a depth from the surface sufficient to encompass the imperfections is low enough that the stress induced by the surface tension of the glass at the sites of the imperfections is sufficient to cause flow of glass and effect a reforming of the glass surface at said sites.

Abstract: A method and a system for uniformly heating a glass stream flowing in the feeder of a glass melting furnace wherein power or energy is supplied through the electrodes immersed in the glass melt and wherein the temperature of the glass stream is continuously detected, has the current flowing between cooperating electrodes maintained constant independently of the resistance defined by the glass melt by controlling the voltage as long as the temperature of the glass stream does not deviate from predetermined limits and the current flow of at least a number of electrodes positioned at the inlet of the feeder are controlled to compensate for temperature variations when the tolerable deviation limit has been exceeded.

Abstract: A method of bonding a cover glass to a semiconductor substrate having conductors thereon. The cover glass and the semiconductor substrate are placed in a relatively high voltage field and heated to induce ion drift in the glass and improved conductivity in the substrate. Additional localized heating softens the cover glass in the vicinity of the conductors permitting the cover glass to flow around the conductors and to be drawn into contact and bonded with the substrate.

Abstract: Apparatus for producing glass fibres by flowing a plurality of streams of molten glass through an electrically-heated bushing comprising a metal plate having a plurality of orifices therein, together with means for flowing an electric current through said plate to heat it, and the bushing is provided with at least two spaced apart electrical terminals at each end thereof, together with adjustable connector means for each of said terminals, whereby in use, the current flowing through each of said terminals is independently adjustable.

Abstract: The invention relates to apparatus and method for producing fibers from heat-softened mineral material, such as glass. More specifically, this invention relates to method of, and apparatus for, producing glass fibers from an electrically heated bushing having a bottom wall with an orifice section for delivery of glass streams for attenuation into fibers comprising sensing the temperature at the orifice section, supplying a signal that varies in response to the sensed temperature and indicating that a disruption in fiber production has occurred when the supplied signal is outside a predetermined range.

Abstract: The present invention embraces apparatus for the production of mineral fibers. An electrically heated bushing for the maufacture of glass fiber comprises an electrically conductive bottom wall having orifices for the passage of streams of molten glass therethrough for attenuation into fibers and upwardly extending, electrically conductive, sidewalls. Each sidewall has an outwardly extending, electrically conductive flange. The bushing further comprises an electrically conductive material added to a portion of each flange to lower the electrical resistance of said portion to establish desired electrical current flow distribution in the bottom wall.

Abstract: The invention provides a method and apparatus for the manufacture of glass film having a thickness not in excess of 0.003 inches and accomplished by drawing the film through a narrow slot-like orifice. The walls of the orifice are defined by an electrically conductive, hot glass resistant metal and electrical currents are introduced into the metal walls of the orifice to effectively maintain the central portions of the orifice walls at a higher temperature than each of the two lateral end walls of the orifice, thereby producing a temperature differential in the drawn film on the order of 40.degree. F. between the edges of the film and the central portions of the film.

Abstract: The molten glass feeding bowl has two parallel sides with a third side being generally perpendicular thereto. Electrodes for heating glass within the bowl extend through aligned holes in the side walls of the refractory bowl and metal housing. The bowl can accommodate electrodes along its parallel side walls and along a front wall depending upon the operative position of the shear mechanism which may extend along the center line of the bowl or to either side of the center line.

Abstract: A large plurality of fiber optic preforms are manufactured by chemically vapor depositing the fiber optic glass constituents on the exterior surface of electrically heatable mandrels. A corresponding plurality of mandrels are located relative to a common source of materials for chemical vapor deposition thereon. A substantial savings in materials cost, manufacturing time and greater uniformity between the individual preforms is thereby accomplished.

Abstract: Double-glazed window units made by electrically heating the margins of two glass sheets to form a continuous peripheral weld are disclosed wherein an electroconductive stripe is deposited on the margins of one of the glass sheets from an aqueous composition comprising colloidal graphite, a perfluoroalkyl surfactant and optionally a water-soluble thixotropic agent.

Abstract: In a gas hearth furnace having a gas hearth block provided with gas supply passages and exhaust passages for the circulation of hot gas that produces a gaseous support bed for glass sheets during thermal treatment, electric heating wire is supported within certain of said passages in position to heat gas passing therethrough with minimum interference to the movement of said gas through said passages to improve the thermal efficiency of said gas hearth block.

Abstract: Corrosion-resistant, hermetic glassceramic-to-metal seals are made in a single rapid heating step by inserting a glass preform made of 25-35% by weight ZnO, 2.5-10% by weight Al.sub.2 O.sub.3 and 30-60% SiO.sub.2 together with optional nucleating and/or fluxing agents, between a metal pin and surrounding metal collar. Heating is rapid in a single step to first fluidize the glass, while avoiding excessive oxidation of the metal pin and the metal collar and to prevent excessive interaction of the glass composition at the glass/collar interface, then to ceram the seal. The resulting seals exhibit good corrosion resistance to potassium hydroxide solutions and are useful in Ni-Cd batteries.

Abstract: Apparatus for bending one or more glass sheets to a sharp bend by a combination of overall heating and localized heating using an outline glass sheet bending mold comprising one or more electroconductive heating elements in the form of a ribbon. Means is provided to tension the ribbon so that it does not wrinkle when the ribbon expands thermally due to the application of electrical energy thereacross. The ribbon is tensioned by one or more electrodes. Means is provided to maintain the electrodes attached to the mold in case the ribbon breaks.

Abstract: Disclosed is a method and apparatus for forming hollow and cylindrical ingots of amorphous or fused silica and other ingot materials. The ingot is formed from a melt on a deposition surface which is lowered as the ingot is formed at a rate which maintains a constant distance between the deposition surface and a heat source vertically positioned above same. The melt is shaped into a vertical cylinder by at least one forming tool which is a roller member rotatable about a vertical axis. In a preferred embodiment the fixed distance from the heat source is maintained with the aid of the laser beam.

Abstract: The contacted edge portions of plate glasses to be joined are locally heated to a temperature higher than in the other portions of the plate glasses, after the whole of the plate glasses is heated. Electric current is then passed to the edge portions in order to further heat the edge portions so that the edges of the plate glasses are molten and welded together.

Abstract: As a first step to bend a glass along a line traversing the plate, external heat is applied to the glass plate such that a narrow zone containing the entire length of the bending line is heated more intensely than the remaining area to reach a temperature at which the glass does not yet soften but exhibits an appreciable lowering of its electrical resistivity. Then an electric current is caused to flow through the glass in the intensely heated zone from one terminal of the bending line to the other terminal, until the glass is softened only in this zone, i.e. along the bending line by the Joule effect of the current. In this state, desired manner of bending is achieved by the use of a suitably shaped bending die.

Abstract: The edge portion of a plate glass is locally heated to a temperature higher than that in the other portion of the plate glass, after the whole of the plate glass is heated. Electric current is thereafter applied to the edge portion of the plate glass in order to further heat the edge portion so that the edge of the plate glass is slightly melted.

Abstract: This invention relates to a method and apparatus for shaping glass sheets to V-bends along a curved line of bending.

Abstract: Method and apparatus for forming glass fiber strand directly and continuously from raw batch glass-forming material, which includes means for continuously electrically melting raw batch, glass-forming materials, forehearth and fiber forming means for continuously receiving said melted glass, means for continuously attenuating said glass from said fiber forming means in the form of a multiplicity of fiberglass filaments, and means for converging and winding said filaments in the form of a fiberglass strand.

Abstract: Improved construction for bushings used to produce glass fibers is provided. Such bushings commonly have thin side and end walls of precious metal defining a glass-melting chamber, with a bottom in which fiber-forming tips are located. Refractory material is located around the side and end walls. When the bushings are heated to operating temperatures, the metal walls tend to expand more than the refractory material and, particularly with larger bushings, the walls can buckle and crack since full expansion of the walls is prevented by the refractory material. To overcome this, it has been found that the bushings can be constructed with space between the metal walls and the refractory, with the space equalling the difference in expansion of the two materials. The space is formed by layers of heat-removable material, such as wax which melts out as the bushings are heated.

Abstract: A process for welding two glass members together to form a weld bead through which connecting wires extend. The glass members are first brought into intimate contact with metal parts which can be heated by a high frequency current. The glass members are held close to one another with the wires disposed in the space between them, and the glass is then melted until it welds by heating the metal parts with the aid of high-frequency heating coil windings surrounding the metal parts.

Abstract: A laser beam (FIG. 1; 28) is reflected from a first oscillating galvanometer controlled mirror (14) onto a second oscillating galvanometer controlled mirror (15). The laser beam is reflected from the second mirror as a pattern (29) having an annular cross section by individually controlling the amplitude and phase relationships of the oscillations of the mirrors. The annular beam is directed at a frustoconical reflector (21) which reflects the annular beam radially inward to heat a portion of a glass preform (25) positioned along the axis of the reflector to form a melt zone therein from which an optical fiber (36) is drawn.Additionally, the amplitude of the mirror oscillations are modulated to vary the diameter of the annular beam to cause the beam to reciprocate along a portion of the length of the preform to expand the size of the melt zone.

Abstract: Marginal edge portions of a pair of glass sheets are welded together to make a multiple glazed unit by sequentially imposing a voltage on marginal edge portions of a sheet followed by alternately imposing a voltage on opposed corners of the sheet.

Abstract: Marginal edge portions of a pair of glass sheets are welded together to make a multiple glazed unit by sequentially imposing a voltage on marginal edge portions of a sheet during side heating cycles followed by alternately imposing a voltage on opposed corners of the sheet during diagonal heating cycles. During the last side heating cycle, the voltage applied to the next to last marginal edge heated is for a shorter time period than the time period in which the first marginal edge was heated. In this manner, the average resistance of the electrical paths during the first diagonal heating cycle is substantially equal.

Abstract: This invention relates to a process and an apparatus for the manufacture of fused glass, suitable for molding, wherein the total time of manufacture is reduced to about one hour. The process accelerates the homogenization and refining of glass by eliminating unfused particles and gas bubbles which are the main factors limiting the production rate of industrial glass. This is accomplished by increasing the temperature of the molten glass to produce foaming throughout its mass while maintaining its viscosity below 1,000 poises.

Abstract: This invention relates to a bushing for processing molten glass. The bushing has a bottom wall provided with orifices to deliver downwardly flowing streams of molten glass, side walls and end walls. The bushing is provided with oppositely arranged terminals to receive electrical conductors for heating the bushing. The end walls of the bushing and the terminal means are moulded integrally from rhodium or platinum/rhodium alloy.

Abstract: An optical fibre is manufactured by forming a layer of fused silica, which may or may not be doped, on the inner wall of a fused silica tube by producing a plasma in the reactant gases flowing through the tube. By this means a higher temperature can be maintained inside the tube than at the tubes outer wall. The plasma is produced at substantially atmospheric pressure. Cooling gas is passed along the outer wall of the tube.

Abstract: A method of making glass beads for current leading-in wires of lamps by internal and external high-frequency heating of a glass tube which surrounds a metal rod.

Abstract: An apparatus for forming relatively sharp angled bends in a flat sheet of glass including a sectionalized gravity mold structure having electrical conducting means terminating in improved contact assemblies engageable with electrically conducting frit lines or paths formed on a glass sheet. The contact assemblies are mounted on the mold structure for movement along with the glass sheet relative to the mold during bending and offer continuous positive clamping contact with the electro-frit circuitry at all times.

Abstract: A suspended mass is shaped by melting all or a selected portion of the mass and applying acoustic energy in varying amounts to different portions of the mass. In one technique for forming an optical waveguide slug, a mass of oval section is suspended and only a portion along the middle of the cross-section is heated to a largely fluid consistency. Acoustic energy is applied to opposite edges of the oval mass to press the unheated opposite edge portions together so as to form bulges at the middle of the mass. In another technique for forming a ribbon of silicon for constructing solar cells, a cylindrical thread of silicon is drawn from a molten mass of silicon, and acoustic energy is applied to opposite sides of the molten thread to flatten it into a ribbon.

Abstract: Method of and apparatus for supplying streams of molten glass including: a feeder with a chamber having an opening for supply of glass marbles for conversion to a molten body; a bottom wall for the chamber having orifices for discharging the molten glass as streams; means for heating the feeder; and a surface above the molten glass effective to reflect radiation so that reflected radiation is concentrated in a chamber where unmelted glass is present during melting.

Abstract: A microchannel plate for secondary electron emission intensification, having channel walls which are rounded so as to increase the interception of secondary electrons formed due to the incidence of primary electrons on the ends of the said channel walls.According to the invention, the method of manufacturing such a channel plate consists of softening the channel wall material and by bombardment of the glass of the input surface by means of an energy-carrying beam of high power for a very short period of time. The glass of the walls at the input surface side then assumes a rounded shape under the influence of gravity and the surface stress of the glass.

Abstract: A material is selected which is capable of propagating light energy and is lso highly absorptive of light energy within a determinable wavelength region. A laser beam which includes such wavelength region in its output energy is focused on the surface of the selected material in a sufficent concentration to cause partial evaporation of its surface and relative linear movement is given effect between the laser beam focal point and the selected material in a focal plane of the laser beam. The rate of such relative linear movement is controlled to produce grooves in the surface of the selector material by absorption of laser energy, thereby defining optical waveguide guiding paths immediately beneath the grooves due to localized change of index of refraction.

Abstract: Apparatus for forming fibers of refractory materials. A melt volume is continuously formed on a feed rod of the material to be fiberized and a fiber drawn therefrom. The melt volume is formed by introducing the feed rod at a predetermined velocity into a heating zone. The fiber diameter is determined by the relative velocities at which the feed rod is moved and the fiber drawn, and by the fractional density of the feed rod material.

Abstract: A heating unit for converting batch mineral material to molten glass is disclosed. The unit includes a receptacle for the flowable material, heating elements for supplying heat to the flowable material, and movably mounted bus bars for supplying electrical energy to the heating elements, where the bus bars are movable to accommodate the expansion and contraction of the heating elements.

Abstract: A vertically elongated glassmaking furnace is provided with two groups of electrodes: one group is positioned in the upper portion of the furnace and is operated to melt glass batch and to establish an upward flow of hot glass along the center of the furnace; a second group is positioned in the lower portion of the furnace and operated to slow the downward flow of molten glass through the furnace, particularly near the walls of the furnace so that all the molten glass in the lower portion of the furnace flows uniformly downwardly to discharge at a rate sufficiently slow to insure the upward escape of seeds or bubbles from the discharged glass.

Abstract: A method for preparing high purity laser and optical fiber glass by the controlled oxidation of metals initially purified by zone refining processes.

Abstract: A vertically elongated glassmaking furnace is provided with two groups of electrodes: one group comprises crossed pairs of electrodes positioned in the upper portion of the furnace and is operated to melt glass batch and to establish an upward flow of hot glass along the center of the furnace; a second group is positioned in the lower portion of the furnace and operated to slow the downward flow of molten glass through the furnace, particularly near the walls of the furnace so that all the molten glass in the lower portion of the furnace flows uniformly downwardly to discharge at a rate sufficiently slow to insure the upward escape of seeds or bubbles from the discharged glass. The crossed. pairs of electrodes are energized in such a way as to provide intersecting lines of current flow with the loci of intersection in the vicinity of the central vertical axis of the furnace.

Abstract: An electrically-heated, glass-melting furnace has an infrared-absorbing material located along the side walls to intercept energy from the heat source in the pool of molten glass in the furnace and thereby enable the side walls to be at a lower temperature. The furnace is heated electrically by means of electrodes immersed in the molten glass and with this arrangement, the glass and the side walls of the furnace tend to be at higher temperatures than furnaces utilizing fuel-fired burners firing above the molten glass. The higher wall temperatures result in a shorter life for the furnace, requiring more frequent, costly rebuilding. To overcome this, a material capable of absorbing infrared rays is supplied to the furnace along the side walls thereof. This material forms a curtain disposed between the side walls and the heat source to intercept the infrared rays and thereby reduce the operating temperatures of the side walls.

Abstract: A stream feeder for supply of streams of molten glass for attenuaton into fibers. The feeder is formed of metal and is electric-resistance heated. The bottom wall and sidewalls of the feeder are of varied thickness and are formed from a single sheet of metal. The disclosure also includes method and apparatus for forming the bottom wall and varied thickness sidewalls from a single sheet of metal.

Abstract: Apparatus is disclosed for automated mass production of precision transparent silica glass products in accordance with a unique process in which slip-cast fused silica articles are rapidly heated and sintered in a vacuum or in a helium or hydrogen atmosphere at high temperatures, such as 2950.degree. to 3150.degree.F. A heated graphite susceptor shaped to conform to the outer surface of the fused silica article is automatically moved between a cooling zone and an induction furnace chamber which is opened momentarily to admit the article. The furnace and the graphite susceptor are designed to cause the trapped gases in the article to move radially outwardly and to effect rapid heating so as to avoid substantial devitrification during sintering.

Abstract: Method of sealing glass objects to one another by means of comparatively low voltages, in which method the preheated seal joint is heated by passing current through it by means of a large number of electrodes which are in mechanical contact with the glass and belong to at least two current circuits which are periodically switched on and off and each comprise at least two series-connected current sources.

Abstract: A sealing method for a laser glass which provides a high bonding strength comprising applying a powder mixture of (1) a low melting glass containing an infrared absorbing component and (2) a low expansion high melting glass containing an infrared absorbing component to a laser glass and welding the powder mixture to the laser glass by heating.

Abstract: A sealing method for a laser glass which provides a high bonding strength comprising applying a powder mixture of (1) a low melting glass for sealing a glass laser and (2) a glass having a higher melting point and lower expansion coefficient than those of the low melting glass, to a laser glass and welding the powder mixture to the laser glass by heating.

Abstract: The invention provides a method and apparatus for the manufacture of glass film having a thickness not in excess of 0.003 inches and accomplished by drawing the film through a narrow slot-like orifice. The walls of the orifice are defined by an electrically conductive, hot glass resistant metal and electrical currents are introduced into the metal walls of the orifice to effectively maintain the central portions of the orifice walls at a higher temperature than each of the two lateral end walls of the orifice, thereby producing a temperature differential in the drawn film on the order of 40.degree. F. between the edges of the film and the central portions of the film.