Abstract: A glass product manufacturing method that includes a step of disposing a workpiece configured of a glass material between two mutually-opposing punches, a step of starting to apply a pulsed current to the workpiece, and a step of starting to apply pressure to the workpiece using the two punches. The glass product is obtained from the workpiece through a discharge plasma process that causes the workpiece to deform in a state where the temperature of the workpiece has been increased by the application of the pulsed current.

Abstract: The invention relates to a device for marking the inside of a hollow glass item having at least one plunger comprising at least one raised and/or hollow pattern and a support assembly for said at least one plunger that can be moved between a first position in which the plunger is outside the item, and a second position in which the plunger is inside the item, and having radial movement means for moving said at least one plunger in a passive position spaced away from the inner surface of the side wall of the item and an active position pressed against said inner surface to imprint said at least one raised and/or hollow pattern.

Abstract: A method and device for bending superposed sheets of glass. The sheets are picked up by a top form furnished with a suction creating an upward airflow blowing over the rim of the sheets, the suction being sufficient to lift and hold the superposed sheets against the top form, then the sheets are pressed between the top form and a full surface solid concave bottom form furnished with openings, the pressing beginning conducted while the suction is not yet finished or is finishing, then the superposed sheets are formed, by suction of the main face of the bottom sheet through the openings of the bottom concave mold, the forming by suction beginning while the pressing is not yet finished, and then the sheets are cooled. Windshields free of optical defects may thus be produced.

Abstract: Provided is an optical element manufacturing method by which optical elements, such as a beam shaping element having a molded side surface, are highly efficiently and accurately manufactured by pressure-molding a molten glass drop. After supplying a lower molding die with the molten glass drop of a prescribed volume at a temperature higher than that of the molding die, the molten glass drop is pressure-molded by the molding die, and a free surface solidified without being in contact with the molding die is formed between a molded upper surface and the molded side surface. The volume of the molten glass drop to be supplied is 0.8 times or more but not more than 0.97 times the volume of a space configured by an extended molded upper surface, an extended molded side surface and the molded lower surface when the molded upper surface and the molded side surface are extended.

Abstract: The present invention provides an optical element manufacturing method including a first step of fixing an optical material by exerting a first weight different from a self weight of an upper die on the optical material positioned in a cavity between the upper die and a lower die, a second step of thereafter heating and softening the optical material by introducing a heated gas to an inside of the cavity, and a third step of thereafter molding an optical element by exerting a second weight larger than the first weight on the optical material within the cavity.

Abstract: A method and device for bending superposed sheets of glass. The sheets are picked up by a top form furnished with a suction creating an upward airflow blowing over the rim of the sheets, the suction being sufficient to lift and hold the superposed sheets against the top form, then the sheets are pressed between the top form and a full surface solid concave bottom form furnished with openings, the pressing beginning conducted while the suction is not yet finished or is finishing, then the superposed sheets are formed, by suction of the main face of the bottom sheet through the openings of the bottom concave mold, the forming by suction beginning while the pressing is not yet finished, and then the sheets are cooled. Windshields free of optical defects may thus be produced.

Abstract: An object of the invention is to provide a process for producing a synthetic quartz glass while taking account of a refractive index distribution remaining in the synthetic quartz glass; a jig for use in the synthetic-quartz-glass production process; and a synthetic quartz glass for an optical member, produced by the process.

Abstract: A first sleeve 30 regulates the horizontal relative position between an upper mold 10 and a lower mold 20 that are insertable into the first sleeve 30 from its both end sides. A second sleeve 40 provided inside the first sleeve 30 and surrounding the outer periphery of a molding surface 21 of the lower mold 20 supports at least part of an outer peripheral portion of a molding material 50 placed on the molding surface 21 of the lower mold 20, thereby preventing position offset and slip-off of the molding material 50. In this state, the molding material 50 is press-molded between the upper mold 10 and the lower mold 20.

Abstract: A heating process of molding a glass is provided. First, a first heat source is provided to heat up a glass preform in a mold directly and a second heat source is provided to heat up the mold directly. In the heating period using the first heat source, the glass preform is softened by heat and pressed with the mold, and in the pressing period using the mold, the glass preform is cooled down and formed as an optical lens.

Abstract: For producing large volume optical components of high optical quality from synthetic quartz glass blanks, the latter are heated in a component mold in a furnace with a protective gas atmosphere to a temperature 50° to 170° K above the softening point, this temperature being held for 20 to 90 minutes and, during this holding time, the quartz glass blank being pressed into the component mold. By these means, a gentle treatment of the quartz glass, a good yield, a decrease in the energy input and a complete filling up of the component mold are achieved.

Abstract: A method of manufacturing a glass substrate for a storage medium by pressing a glass material between an upper and a lower dies. The method includes a heating step of heating the glass material arranged between the upper and lower dies, a pressing step of pressing the heated glass material via the upper and lower dies, and a cooling step of having, after the pressing step, a cooling member contact the upper and lower dies to cool them together with the molded glass material arranged between the upper and lower dies. During the heating step and the pressing step, a vacuum atmosphere is maintained in a space containing the dies and the glass material. When the pressing step has completed, an inert gas is filled in the space to set a pressure in the space equal to an ambient pressure.

Abstract: A glass sheet forming system (20) provides continuous roll conveyed forming of heated flat glass sheets to formed shapes having a major axis of curvature and a minor axis of curvature perpendicular to each other. The forming is performed by a roll station (30) having a shape retaining quench (36) associated with a lower deformable roll bed (32) and an upper deformable roll former (34). An adjustment mechanism (78) provides adjustment of the extent of the minor curvature and an actuating mechanism (56) is operable to provide the major curvature.

Abstract: Rolls for generally conveying sheets, such as of steel or glass over a roller typically have a steel mandrel and fiber-containing roll cover, with the fiber roll cover pressed between end plates. In a roll end assembly including the end plates there is now provided an axial shaft beyond the end plate. The shaft incorporates a roll compression means. The compression means includes a compression element which element engages the end plate. Pressure from the compression means, which may be exerted from beyond the shaft, can thereby be transmitted to the fiber roll.

Abstract: In a press molding apparatus for press molding a plurality of glass materials into a plurality of glass optical elements by the use of a pressing mold including upper and lower molds each of which has a plurality of molding surfaces, at least one of the upper and the lower molds is a heat generator within which heat is generated when the heat generator is subjected to a high-frequency induction heating by an induction heating coil. The heat generator having a plurality of shape-processed portions (130) produced by partially processing a shape of the heat generator in order that a temperature distribution of the heat generator is adjusted. The apparatus simultaneously press forms, into the glass optical elements, the glass materials supplied between the molding surfaces of the upper and the lower molds which are subjected to the high-frequency induction heating.

Abstract: A glass material (4) is placed in a forming die including a pair of upper and lower dies (1, 2) and a control member (3) for controlling the space between the upper and the lower die, and then heated, softened, and molded by pressure into a glass substrate in the shape of a parallel plate. The amount of thermal contraction of the control member is smaller than that of the glass material. Therefore, the glass substrate is released from the die when cooled after molding. The present invention can provide a glass substrate that is excellent in smoothness and form accuracy of the surface, and that is suitable for recording media such as magnetic disks that are inexpensive and suitable for mass production.

Abstract: For producing large volume optical components of high optical quality from synthetic quartz glass blanks, the latter are heated in a component mold in a furnace with a protective gas atmosphere to a temperature 50° to 170° K above the softening point, this temperature being held for 20 to 90 minutes and, during this holding time, the quartz glass blank being pressed into the component mold. By these means, a gentle treatment of the quartz glass, a good yield, a decrease in the energy input and a complete filling up of the component mold are achieved.

Abstract: A glass tube is positioned over a heater and stretched until drawn apart into two drawn portions. A controlled pulling force is applied to the tube by a powered driver such as a linear motor. After separation, one of the drawn glass portions is repositioned over the heater and reciprocated in a controlled fashion by the driver to refine the geometry of the fine tip formed on the resulting pipette.

Abstract: There is provided a glass substrate having a V-groove portion for arranging an optical fiber core and a countersunk portion for containing an optical fiber coated portion, formed on the extension of the V-groove portion, on the surface thereof. The surface roughness of an inside side face of the countersunk portion is 1 &mgr;m or less in Rmax, or 0.2 &mgr;m or less in Ra at least at the connecting portion of the V-groove portion and the countersunk portion. The glass substrate is manufactured by a two-stage molding method in which a first molding step for forming a concave portion in the surface of a glass substrate molded body by grinding or pressing, and a second molding step for pressing the glass substrate molded body obtained by the first molding step from the top and bottom surfaces while reheating the molded body are performed.

Abstract: A machine for processing hollow glass objects (8) is described. The machine includes a sequence of like processing units (1) to (15) and (A, B) on which a small number of processing steps can be carried out on the workpiece (8). The workpieces (8) are brought to the processing unit on a clock-driven loading belt (4) and taken therefrom. A workpiece, which is being processed in a unit, is held during the entire sequence by one and the same workpiece holder. Each processing unit includes two separate handling units with which two workpieces run through the workstations time displaced. The machine arrangement permits processing units to be taken out or switched into the line without a production standstill.

Abstract: Disclosed are a molding apparatus for glass optical elements a plurality of molds each constituted of an upper mold and a lower mold, a matrix supporting the molds, and heating means wound around the matrix for heating the molds, wherein the matrix extends in a longitudinal form and has a constant width, wherein the plurality of the molds are arranged in the matrix in a line so that the center of each mold is located on a center line of the matrix, and wherein a distance between the heating means and the matrix is constant at least at an edge of the matrix in a transverse direction, and a molding method for optical elements comprising the steps of: softening a plurality of glass material pieces by heat; and making a simultaneous press molding of the glass material pieces with a plurality of molds, constituted of upper and lower molds, arranged in a longitudinal form matrix, in a line extending in a longitudinal direction, wherein each mold is heated by thermal conductance from the matrix heated by heating mea

Abstract: Disclosed is a manufacturing method for molded glass articles including glass optical elements such as high precision lenses not requiring grinding and polishing after press molding. The manufacturing method according to the invention is a method for manufacturing the molded glass articles having a higher surface precision with a high productivity by pressing a glass material in a stepwise manner constituted of some steps depending on a temperature condition of the glass material.

Abstract: A molding die assembly includes an upper molding die and a lower molding die facing the upper molding die with provision for their alignment. The upper molding die includes an upper core, while the lower molding die includes a hollow cylinder and a lower core. The upper core has one of the molding surfaces that corresponds to a molding, while the lower core has the other molding surface corresponding to the molding. The lower core slides in the cylinder and defines a cavity in cooperation with the upper core. A clamping device applies a clamping force to the upper molding die and the lower molding die, and a compression device applies a compressive force between the upper core and the lower core. The clamping force is generated between the upper molding die and the lower molding die but not between the upper core and the lower core so that no clamping force is applied to the preform.

Abstract: A molding method for optical element is disclosed in which a glass material prepared for weight is introduced into a mold and then heated to soften, and subsequently pressed with the mold to mold an optical element. The glass material is heated to have a viscosity of 10.sup.5 to 10.sup.7 dPaS and press-molded with the mold having a temperature equivalent to a viscosity of 10.sup.9 to 10.sup.11 dPaS of the glass material.

Abstract: The invention relates to lenses such as aspherical lenses and to a process for their manufacture. According to the invention, the lens is composed of a glass matrix including the constituents below in the following weight proportions:______________________________________ SiO.sub.2 65-85% Al.sub.2 O.sub.3 0-10% B.sub.2 O.sub.3 0-20% Li.sub.2 O + Na.sub.2 O + K.sub.2 O 3-20% CaO + MgO + BaO 1-15% FeO + Fe.sub.2 O.sub.3 0-0.1%, ______________________________________wherein the K.sub.2 O content is equal to or less than 1% and the BaO content is equal to or less than 1%.

Abstract: A manufacturing method for molded glass articles including glass optical elements such as high precision lenses not requiring grinding and polishing after press molding. The manufacturing method according to the invention is a method for manufacturing the molded glass articles having a higher surface precision with a high productivity by pressing a glass material in a stepwise manner constituted of some steps depending on a temperature condition of the glass material.

Abstract: A device used for the bending of plate glass sections (3) includes an oven (1), a bending chamber (6), an upper bending mold installed in the bending chamber (6) in such a manner as to be able to be raised and lowered, a duct producing a flow of hot gas in order to raise the plate glass sections (3) against the upper bending mold, a lower bending mold in the form of a frame that works together with the upper bending mold to ensure bending by compression of the plate glass that is held by the flow of hot gas against the upper bending mold, as well as a movable transport frame (20) which is used to pick up the bent plate glass from the upper bending mold and to transport it to a cooling station located downstream.

Abstract: In press molding, a shaft (metal mold 13) is moved by positional or torque control to cause upper and lower molds to reach a set position slightly before a position where the upper and lower molds are set in a final mold closed state. As soon as the upper and lower molds reaches the set position, the control is switched to torque control using a small force which does not deform a glass material to perform feedback control. For this reason, when the cooling process is started, the mobile shaft is moved by the same amount as a contraction amount of the shaft, the actual position of the shaft is moved. However, a tight contact state between the molds and the glass material is kept without changing the thickness of the glass material, and positional control and torque control can be apparently performed at once. Thereafter, when temperature reaches an almost glass transition point, final pressing is performed.

Abstract: An apparatus for bending and tempering glass sheets includes a roll conveyor for supporting a glass sheet, the glass sheet having a top and a bottom surface. The roll conveyor includes a plurality of vertically movable rolls for arching the conveyor to a curvature corresponding to a desired degree of bending in the glass sheet. The rolls each have two opposed ends, and at least some of the rolls being deflectable such that at least mid-sections thereof are movable relative to a vertical position of ends thereof. The apparatus further includes a plurality of movable press rollers disposed above the rolls. The press rollers are movable in a vertical direction to apply a pressing force to the top surface of the glass sheet.

Abstract: When heating and bending glass sheets in a furnace, it has been found to be desirable to raise the glass sheets towards the furnace heat sources to increase obtainable temperature differentials and reduce heating power. An apparatus for bending the glass sheets includes an elongate furnace divided along its length into a plurality of heating zones, each heating zone having an upper part. A plurality of heat sources are arranged in the upper part of such heating zone and a plurality of carriages are arranged in succession along the length of the furnace below the furnace heat sources. A drive device propels the carriages through the zones of the furnace in intermittent steps, and a mould lift raises the bending mould towards the furnace heat sources. The bent glass sheet may be used in the manufacture of a vehicle glazing.

Abstract: A furnace for molding glass blanks includes a housing having a series of electrical heating stations and a rotary door adapted to receive glass blanks for processing. The furnace also includes a rotary turntable for receiving the glass blanks and a steering coil positioned to direct the glass blanks in a spiral pattern as they are heated at the electrical stations, a paddling platform for manual shaping, and a pressing station for pressing the glass blanks into a predetermined configuration.

Abstract: The present invention provides a shaping mold for shaping heat softenable sheet material which includes a flexible rail having a sheet shaping surface to support a marginal edge portion of a sheet to be shaped and a plurality of controllable actuators secured to the rail and capable of deforming the rail to provide its surface with configurations each having a desired elevational contour. In one particular embodiment of the invention, the shaping rail is a shaping ring having a peripheral configuration which provides generally continuous support about the marginal edge portion of the sheet. A controller is used to control each actuator and deform the sheet shaping surface of the ring from a first configuration having a generally flat elevational contour to a second configuration having an elevational contour that generally corresponds to the final desired contour of the marginal edge portion of the sheet.

Abstract: In forming a piano-convex lens from a column-like lens blank by heating the blank to a temperature higher than the transition temperature thereof and by pressurizing an upper die with a closed space formed between the blank and the upper die, there are alternately repeated operations of pressurizing the upper die and stopping the application of pressure thereto. Through the control of the amount of displacement of the upper die, the maximum pressure of gas in the closed space at each pressurizing step is so controlled: as to be low according to the surface viscosity of the blank to the extent that no local concave deformation in the surface of the blank is produced; and as to be high to the extent that gas caught in the closed space is discharged at each step of stopping the application of pressure.

Abstract: In press molding, a shaft (metal mold 13) is moved by positional or torque control to cause upper and lower molds to reach a set position slightly before a position where the upper and lower molds are set in a final mold closed state. As soon as the upper and lower molds reaches the set position, the control is switched to torque control using a small force which does not deform a glass material to perform feedback control. For this reason, when the cooling process is started, the mobile shaft is moved by the same amount as a contraction amount of the shaft, the actual position of the shaft is moved. However, a tight contact state between the molds and the glass material is kept without changing the thickness of the glass material, and positional control and torque control can be apparently performed at once. Thereafter, when temperature reaches an almost glass transition point, final pressing is performed.

Abstract: A method and an apparatus for producing an optical element capable of performing a molding temperature control required for a plurality of independent molding blocks in a short period of time, and continuously and simultaneously producing a plurality of different optical elements having a high degree of accuracy at a low cost is provided.

Abstract: The invention relates to the press bending and tempering of glass sheets, especially for use as glazings in vehicles. When the press bending system is not located in a heated environment such as a furnace, it is important to maintain the glass sheets at a sufficiently high temperature for an adequate degree of temper to be achieved on quenching the sheet. The present invention provides a method of bending and tempering a thin glass sheet comprising pressing the substantially horizontal sheet between moulds having opposed complementary shaping surfaces, at least one of the surfaces being heated, and subsequently quenching the surfaces of the sheet characterised in that the heated shaping surface is maintained at a temperature in the range from 200.degree. C. to 350.degree. C.

Abstract: When blank-molded optical glass bodies are manufactured according to known methods based on blank-molding technology, the product exhibits rings in the glass and folds as well as an impression that precisely coincides with the contact surface of the parison inside the pressing die before the pressing operation. These defects are not permissible in blank-molded lenses, however, because they cause an undesirable optical effect such as changing the glare value in automobile headlights. Such defects are process-dependent and are caused by the fact that the transfer of the parison to the pressing die and the pressing itself are two separate operations that are performed with different tools.

Abstract: An apparatus for press bending glass sheets carried on a mold, the apparatus including a die having a lower surface shape to mold a glass sheet positioned thereunder to a desired curved shape, a first counterbalance assembly connected to the die for providing the die with a selected net weight, a frame mounted above the die, a plurality of flexible members connecting the die to the frame for suspending the die below the frame whereby the die is capable of unconstrained lateral and tilting movement relative to the frame and die moving device connected to the frame for vertically moving the die.

Abstract: When heating and bending glass sheets in a furnace, it is desirable to raise the sheets towards the furnace heat sources to increase obtainable temperature differentials and reduce heating power.

Abstract: An apparatus for press bending glass sheets, the apparatus comprising an upper die, a suspension system for the upper die for suspending and vertically moving the upper die, a lower gravity bending mould and a plurality of spacer devices for spacing the upper die and the lower mould a selected distance from each other when the upper die presses a glass sheet on the lower mould, the suspension system being adapted and the spacer devices being configured to permit lateral movement of the die relative to the mould. There is also provided a method of press bending glass sheets.

Abstract: In forming a plano-convex lens from a column-like lens blank by heating the blank to a temperature higher than the transition temperature thereof and by pressurizing an upper die with a closed space formed between the blank and the upper die, there are alternately repeated operations of pressurizing the upper die and stopping the application of pressure thereto. Through the control of the amount of displacement of the upper die, the maximum pressure of gas in the closed space at each pressurizing step is so controlled: as to be low according to the surface viscosity of the blank to the extent that no local concave deformation in the surface of the blank is produced; and as to be high to the extent that gas caught in the closed space is discharged at each step of stopping the application of pressure.

Abstract: A machining chamber encloses a glass molding apparatus including a molding die assembly composed of upper and lower molding dies cooperating to define a mold therebetween. The glass molding apparatus, contained within the sealed machining chamber, further includes a clamping/heating/compressing station, a cooling station and a preform-loading/molding-ejecting station. A shutter is provided in the casing for selectively opening the casing to the ambient atmosphere. An annular nozzle surrounds a molding surface provided on one of the upper and lower molding dies and is used to supply a first inactive-gas to the region between the two dies. A second, independent inactive-gas supply provides inactive-gas directly into the sealed casing, whereby the region between the dies is maintained at a lower oxygen level than that within the remainder of the sealed casing.

Abstract: A glass rod used as a molding material is inserted into a cylinder, pressed and heated with a temperature gradient in which the tip side of the glass rod is at a higher temperature. The glass rod is melted on the tip side thereof, and it is solidified on the rear side in the vicinity of the inlet of the cylinder, the solid portion functioning as a plunger when the rear side is pushed. When the glass rod is forwardly moved, the molten glass on the tip side is injected from an injection nozzle and is filled in the cavity of a forming mold. Since the glass rod itself is made of a molding material and functions as a plunger, when the tip side is melted and consumed, the solid portion on the rear side is forwardly moved and melted. It is thus possible to perform continuous mold forming without complicating the mechanism and steps and to improve the quality of the molded product.

Abstract: A die for press-molding a glass optical element which includes a base material having a surface to press-mold glass and a tantalum(Ta)-containing alloy thin layer on the surface, the base material being heat-resistant and strong enough to withstand press-molding.

Abstract: An infrared transmitting chalcogenide glass lens having precision optical surfaces of different curvature radii is molded. A pair of molds having different curvature radiuses from each other, and a bushing which controls the thickness of the lens is provided. A block of chalcogenide glass is placed within the cavity. The upper mold, the lower mold and the block of glass are heated with the mold having a smaller curvature radius being at a higher temperature than the other mold. The glass is then pressed, cooled, and the resulting lens is removed from the mold assembly.

Abstract: An improved method of forming an optical element, wherein heated upper and lower molds are used in conjunction with radiation heating glass material placed in an optical forming surface of the lower mold. The molds are heated to a necessary temperature, then the glass material is heated by exposure to heat by radiation. The glass blank then is pressed between the upper and lower molds to transfer the optical forming surfaces of each mold to the glass material, and define the optically functional surfaces of an optical element.

Abstract: Disclosed is a glass molding process using an apparatus for manufacturing a glass preform into a glass molded product. In the process a mold is prepared for pressing the glass preform. The mold consists of a pair of molds having a cavity surface for forming the glass molded product, and a frame mold which is movable against the pair of molds and incorporates a heating source. A next step in the process involves introducing the glass preform, where the pair of molds are opened and the glass preform is placed on the cavity surface. The glass preform then undergoes heating, where the glass preform is moved so as to come near the heating source of the frame mold by closing the mold, thereby heating the glass preform. The glass preform is then pressed by moving the mold to mold a shape of a glass molded product. The resulting glass molded product is then separated from the heating source by moving the frame mold and taken out by opening the mold.

Abstract: A method for press-forming a glass preform includes the steps of applying positioning pressure to an upper mold as the temperature of the upper mold and a lower mold increase to set values, maintaining a first temperature difference between the upper and lower molds of at least 10.degree. C. and increasing the temperature of the glass preform to a value above its glass transition temperature. Additional steps include cooling the upper and lower molds at a rate of 30.degree. to 100.degree. C. per minute while maintaining a temperature difference between the upper and lower molds at at least the first temperature difference, applying pressure to the lower mold, and opening the upper and lower molds to release the formed optical element after the temperatures of the upper and lower molds decrease to below a set value and a temperature difference between the upper and lower molds becomes greater than the first temperature difference.

Abstract: A mold for use in producing a lens comprises a pair of first and second mold portions which are arranged in opposed relation to each other. At least one of the first and second mold portions is movable toward and away from the other. Molding surfaces of the respective first and second mold portions have their respective areas which are located radially outwardly of an effective aperture of the lens. A plurality of recesses are formed in the molding surface of at least one of the first and second mold portions and are located in the area of the molding surface of the at least one mold portion. These recesses separate the lens from the molds.

Abstract: A lens molding method where a lens material is set between an upper mold and a lower mold, and the molding pressure is reduced or made zero at least once during a heating & pressing step without the mold surfaces breaking contact with the lens materials, and during a cooling & pressing step.

Abstract: A mold assembly adapted for producing a molded glass in a relatively thin form has an upper mold and a lower mold. The lower mold carries thereon a glass to be molded during the heating, pressing and cooling of the glass to be molded. The lower mold has the maximal thickness below or equal to 1/10 of a diameter of the lower mold. A third ring-shaped mold having an annular recess along its interior surface receives the molded glass during pressing between the upper and lower molds to prevent sticking of the molded glass product to a mold surface when released from the mold assembly after pressing. Additionally, a stopper is used to contact the periphery of the ring-shaped mold to strip the molded glass product from the upper mold when the latter is moved upwardly during pressing the molded glass.