Abstract: Disclosed are processes for manufacturing glass optical elements by press molding a heated and softened glass material in preheated molds. In the process, the glass material is heated while it is floated by a gas blow and the heated and softened glass material is transferred to the preheated molds and then subjected to press molding. Alternatively, the process comprises: heating a glass material at a temperature at which the glass material has a viscosity of lower than 109 poises, preheating molds at a temperature at which the glass material has a viscosity of from 109 to 1012 poises, subjecting the heated and softened glass material to initial press in the preheated molds for 3 to 60 seconds, starting to cool the vicinity of molding surfaces of the molds at a rate of 20° C.

Abstract: A method for forming glass sheets is performed by a system (10) that includes a furnace (12) having a heating chamber (14) in which a topside transfer device (20) has a downwardly facing surface (22) to which vacuum and pressurized air are supplied to receive and support a heated glass sheet from a conveyor (16) without any direct contact. A forming station (24) located externally of the furnace has a vertically movable upper mold (28) whose temperature is not greater than 500° C. The upper mold (28) cooperates with a horizontally movable lower ring (34) that transfers the heated glass sheet from the topside transfer device (20) to the forming station under the control of a first actuator (40). A second actuator (42) moves the upper mold (28) downwardly to cooperate with the lower ring (34) in forming the glass sheet. The external forming station (24) includes heat loss reducing apparatus (43) for reducing heat loss of the hot glass sheet during the forming.

Abstract: An apparatus for bend-shaping a glass sheet is disclosed, which comprises a heating furnace, a plurality of in-furnace beds disposed within the heating furnace, at least one out-furnace bed disposed externally of the heating furnace proximately to an outlet of the heating furnace, and an elevating mechanism disposed below that one of the in-furnace beds which is positioned proximately to the outlet and the out-furnace bed. The in- and out-furnace beds have upper surfaces curved transversely and capable of jetting air to floatingly support a glass sheet. For producing a dual curved glass sheet, the elevating mechanism is operated to elevate opposed ends of the one in-furnace bed and the out-furnace bed so that these beds jointly form a hill For producing a single-curved glass sheet, the elevating mechanism is operated to lower the opposed ends of those beds to their original flat positions.

Abstract: A method for forming glass sheets is performed by a system (10) that includes a furnace (12) having a heating chamber (14) in which a vacuum platen (20) has a downwardly facing surface (22) to which a vacuum is supplied to support a heated glass sheet received from a conveyor (16). A forming station (24) located externally of the furnace has a vertically movable upper mold (28) whose temperature is not greater than 500° C. The upper mold (28) cooperates with a horizontally movable lower ring (34). A first actuator (39) moves the vacuum platen (20) vertically to transfer a heated glass sheet from the conveyor (16) to the lower ring (34) which is then moved by a second actuator (40) to the forming station (24). A third actuator (42) then moves the upper mold (28) downwardly to cooperate with the lower ring (34) in forming the glass sheet. The forming station (24) includes apparatus (43) for reducing heat loss of the glass sheet during the forming.

Abstract: A device for manufacturing glass gobs includes a membrane body of a porous gas transmitting material. Channels for introducing compressed gas into the membrane body extend through the membrane body material and are spaced at a distance from the gas outlet surface of the membrane body. The channels run parallel to or are at an acute angle to the outlet surface. In an alternate embodiment, the channels are open channels at the opposite surface from the outlet surface.

Abstract: In a method of producing a glass gob by continuously dropping a molten glass 9 from a nozzle 2 in a dropping direction, a gas flow 20 is caused to continuously flow in the dropping direction along an outer peripheral surface of the nozzle 2 at a predetermined flow rate. The gas flow 20 applies a wind pressure to the molten glass 9 appearing from a nozzle end 2a of the nozzle 2 to drop the molten glass 9.

Abstract: In a method of manufacturing a glass gob, a down-flowing molten glass is received on a molding die. The molding die is moved down at a speed higher than a down-flowing speed of the molten glass so as to cut the molten glass. The molten glass is remained with a predetermined weight on the molding die. The molten glass is sprayed with gas in order to form the glass gob under such a condition that the molten glass is floated or slightly floated. The receiving step is carried out by spraying the molten glass with gas having a flow rate lower than the gas used in the spraying step, or the receiving step is carried out without performing the gas spraying.

Abstract: An inclined trough assembly (10) or gob scoop (20, 40) for conveying, by gravity, formable gobs of glass at an elevated temperature to a section of a glass container forming machine of the I.S. type. The trough assembly has a trough member (12) configured, in cross-section, generally corresponding to that of an upwardly facing V and a manifold (14) at least partly underlying the trough member and having a configuration, in cross-section, generally corresponding to that of an upwardly facing U. The trough member is inserted into the manifold partly to the bottom thereof, and the manifold has a compressed air inlet (14a) for receiving compressed or fan air to flow along the manifold in cooling contact with the trough member.

Abstract: A method for supplying a glass molding material by dropping it from a higher level onto a molding surface of a lower mold of a mold constituted of an upper mold and the lower mold, in which a guide means is used for dropping the glass molding material and is disposed at a position such that the glass molding material drops onto the molding surface of the lower mold, and the guide means used for this method are disclosed. Moreover, a method for supplying a glass molding material to a molding surface of a lower mold of a mold constituted of an upper mold and the lower mold, in which after the glass molding material is supplied to the molding surface of the lower mold the position of the glass molding material is corrected so that the vertical center of the glass molding material substantially coincides with the center point of the molding surface of the lower mold, and a position correcting means used for this method are disclosed.

Abstract: An optical glass having a high refractive index and high dispersion characteristics that is suited to application to precision press molding to precisely mold the shape of final products for objectives not requiring grinding or polishing. An optical glass exhibiting a refractive index in the range of from 1.75 to 2.0, an Abbé number in the range of from 20 to 28.5. Optical parts comprised of this glass; press-molding materials comprised of this glass; methods of manufacturing the same; and methods of manufacturing molded glass products employing these materials.

Abstract: The invention relates to a method for heating up and shaping a preform consisting of glass or glass ceramic.

Abstract: A process for shaping glass sheets with a surface-shaping mould, against which the glass sheets are pressed using a pressure drop produced by sucking out the air from the space lying between the moulding face and that face of the glass sheet on the opposite side from the glass sheet, in which the pressure drop is a maximum at the edge of the glass sheet and decreases towards the center of the glass sheet, because of fact that air is introduced via air-inlet apertures opening into the moulding face, the air is again extracted by subjecting suction apertures made in the moulding face inside the region covered by the respective glass sheet to a vacuum. Furthermore, pressure between the glass sheet and the moulding face also in the region where the air is introduced is set to a value at most equal to the pressure beyond the glass sheet, in order to avoid any formation of bulging. A shaping mould suitable in particular for implementing this process is also described.

Abstract: A process for forming a glass sheet, which is a process for continuously forming a glass sheet, and which comprises a step of introducing a vapor film-forming agent, which is not vapor at least around room temperature and which is vapor at a temperature above the glass transition point of the glass, into a support composed of a structure or a material capable of internally containing liquid, and a step of sliding the support and the glass of which temperature is above the glass transition point against each other via a thin layer of a vaporized vapor film-forming agent.

Abstract: A glass sheet quench unit (22) and method for quenching formed glass sheets by quench gas jets (40) that define a uniformly repeating gas jet impingement pattern (44) that is an equilateral triangular pattern providing uniformly repeating quench cells (46) distributed over the formed glass sheet to be quenched as equilateral hexagonal quench cells. The resultant product is a formed and quenched glass sheet (G) that has oppositely facing surfaces between which glass stresses are uniformly distributed. A method for making the quench unit (22) is performed by initially forming nozzle openings (38) in an elongated nozzle strip (36′), thereafter forming the nozzle strip with a curved cross section, thereafter forming the nozzle strip with a curved shape along its elongated length to provide a curved nozzle cap, subsequently securing the curved nozzle cap to planar sides (30) of an associated nozzle feed row (28), and securing the sides (30) of the nozzle feed row to a plenum housing (24).

Abstract: A block assembly for a lehr includes a plurality of blocks extending longitudinally, each of the blocks having a seal surface for mating and overlapping with an adjacent one of the blocks.

Abstract: A method disclosed can mold glass optical elements having a good surface precision with a relatively short cycle time even where glass optical elements are manufactured in largely transforming a glass material. This method is, for example, a molding method for glass optical elements including the step of pressing a glass molding material softened by heat until the center thickness of the glass molded article becomes 70% of the center thickness of the glass molding material to produce the glass molded article. The preheat temperature of the mold is set to a temperature that the average of the temperatures around molding surfaces of upper and lower molds constituting the mold is a temperature that the glass molding material indicates a viscosity of X poises; the heating temperature of the glass molding material is set to a temperature that the glass molding material indicates a viscosity of Y poises; the viscosity X and the viscosity Y satisfy the following formulas. log X<10 log Y≧6.

Abstract: A method of manufacturing a hollow cone having an open side and a cone tip. The method utilizing the steps of introducing a viscous material in a first mold portion, introducing a second mold portion and contacting the viscous material therewith, providing a force in an escape space so as to prevent the viscous material from flowing into the escape space, forming the open side of the hollow cone while preventing the viscous material from entering the escape space and causing the viscous material to enter the escape space to form the cone tip.