Abstract: An apparatus for forming glass tubes is provided. The apparatus includes a Danner-pipe, a heating device, and a heating chamber having the Danner-pipe and the heating device arranged therein. The Danner-pipe is inclined with respect to a horizontal plane by a Danner-angle. The heating device is inclined with respect to the horizontal plane by a heating-angle. The Danner-angle and/or the heating angle are in a range of 1° to 45°.

Abstract: An inlay for a sleeve shaft for collecting particles originating from a material of the sleeve shaft at least in part, at least one fluid being flowable through the sleeve shaft along an axial direction which is parallel to a main extension of the sleeve shaft, the inlay includes at least one first wall section and the inlay is inserted or insertable at least in part into the sleeve shaft such that at least one part of the first wall section has a radial distance from at least one first area of an inner surface of the sleeve shaft, and, hence, that the inlay together with the first area of the inner surface of the sleeve shaft encloses at least one volume domain, which volume domain is limited in the axial direction by a limiting element.

Abstract: A system for use in a glass drawing process includes: a tensioning element; a refractory tube having a tubular element and a surface element, the refractory tube being configured so molten glass runs onto a contact surface area of the refractory tube during a glass drawing process, the contact surface area of the refractory tube being allocated at least in part on the surface element, the surface element covering at least one surface of an end section of the tubular element, and the surface element projects at least in part over the end section of the tubular element, at least one portion of the part of the surface element projecting over the end section of the tubular element being connected at least in part to the tensioning element; and a carrier that carries the refractory tube and is connected with the refractory tube in a non-rotating manner.

Abstract: A method for producing thing glass strips is provided that avoids camber defects. The method includes using a glass strip forming device that has a drawing device; drawing, using the drawing device, the thin glass strip away from the glass strip forming device; measuring, using a measuring device, variables that are dependent on a differing length of edges of the thin glass strip at at least two measurement locations spaced apart transversely to a longitudinal extension of the thin glass strip; determining a difference or a quotient of the variables. The difference or the quotient is used to determine a control variable by which the glass strip forming device is controlled so as to counteract a difference in velocities of the thin glass strip between the two opposite edges.

Abstract: This sleeve for glass tube molding is provided with: a sleeve shaft; a refractory tube into which the sleeve shaft is inserted in a coaxial manner; and a metal tip that is fixed to the tip of the sleeve shaft, and regulates movement of the refractory tube in the axial direction and towards the tip. The sleeve for glass tube molding is capable of ensuring the coaxiality of the metal tip and the refractory tube on the sleeve shaft. The metal tip comprises: an annular collar member that has a tapered outer circumferential surface of which the cross-sectional area gradually increases towards the tip of the sleeve shaft, and that is coaxially fitted to the tip of the sleeve shaft; and a main body member that has a tapered outer circumferential through-hole of which the cross-sectional area gradually increases towards the tip so as to conform to the outer circumferential surface of the collar member, and that is fitted to the collar member via the through-hole.

Abstract: Provided is a sleeve for glass tube molding that, without reducing the mechanical strength of the sleeve shaft, can prevent foreign objects such as rust from generating off the sleeve shaft and can prevent foreign objects such as rust from adhering to molten glass. The sleeve for glass tube molding is equipped with a sleeve shaft having a through-hole, and is equipped with a pipe member comprising a material having superior rust resistance to the sleeve shaft. The pipe member is provided with a main body portion, and a tapered portion. The through-hole is provided with an insertion portion into which the main body portion is inserted, and a contact portion with a tapered shape whereat the outer peripheral surface of the tapered portion comes into contact with one end of the through-hole. A portion or all of the inner surface of the through-hole is covered by inserting the pipe member into the through-hole.

Abstract: A method for the production of glass components, an apparatus for carrying out the method, and a glass component that is obtainable through the method are provided. The method is a drawing method wherein a forming zone of a preform is heated to a temperature that allows drawing of the glass. The method includes a forming zone of the preform that is very small. Thereby the width of the preform is decreased to a smaller extent than its thickness. The glass components that can be obtained by this method have very smooth surfaces.

Abstract: In a known process for drawing a quartz glass strand, SiO2 particles are fed to a melting crucible and softened therein to form a quartz glass mass, and the softened quartz glass mass is pulled vertically downward as a quartz glass strand via a drawing nozzle which is provided in the bottom region of the melting crucible and has a gap-like drawing nozzle opening.

Abstract: The method produces glass tubes having a predetermined inner profile according to a Vello-method or Down-Draw method, wherein molten glass emerges from an outlet orifice of a melt feed and is drawn over a shaping body to form a hollow drawing bulb, and the drawing bulb is drawn over a profile forming body downstream of the shaping body to form the predetermined inner profile. To enable a reliable, risk-free positioning of the profile forming body within the drawing bulb, the profile forming body is axially moved either from below the shaping body via an inner space of the glass tube or via an inner bore of a shaft supporting the shaping body until reaching an operational position in the inner space of the glass tube. An apparatus for performing the method is also described.

Abstract: The invention relates to a method and apparatus for shaping an elongated glass body 81, which is a glass tube or glass rod and has an initial profile, to an elongated glass body having a different profile. In order to be properly shaped, an elongated glass body 81 passes through, in a hot malleable state, a nip, which is formed by squeezing rollers 1 and which has a nip width which is less than an outer dimension of the initial profile. In order to accomplish an enhanced precision of the shaping process, according to the invention the position of at least one of the squeezing rollers is varied continuously so that a contact area between the respective squeezing roller and the hot glass body is varied cyclic reciprocating movement. Disturbing effects such as local overheating of the squeezing rollers or an accumulation of dirt or glass particles on the surface of the squeezing rollers can thus be effectively prevented.

Abstract: In a known method for drawing a tubular quartz glass strand, SiO2-containing starting material is fed to a melting crucible, softened therein into a viscous quartz glass mass (27), and said mass is pulled vertically downward as a cylindrical quartz glass strand (5; 33) through a die (4; 34) provided in the bottom region of the melting crucible (1), said die having a gap-shaped outlet (25; 36), which is defined by a bottom opening and a die inside part, and thereafter the quartz glass cylinder is cut to length.

Abstract: A precious metal structure which has an internal gas permeable membrane is described herein for a glass manufacturing vessel configured to have molten glass flow therein. The internal gas permeable membrane can be supplied with an atmosphere of gas (or gases) to control the flux of hydrogen into our out of the molten glass or otherwise improve the production of the molten glass. In this manner, the undesirable detrimental reactions that can occur at the interface of the molten glass and precious metal interface which can cause defects in the molten glass such as bubbles or solid inclusions can be stopped or at least substantially reduced.

Abstract: The invention relates to a method and apparatus for manufacturing glass tubes having a predetermined inner profile according to a Vello-method or Down-Draw-method, wherein molten glass 6 emerges from an outlet orifice 12 of a melt feed 2 and is drawn over a shaping body 3 so as to form a hollow drawing bulb 50, and the drawing bulb 50 is drawn over a profile forming body 4 positioned downstream of the shaping body 3 to form the predetermined inner profile. In order to enable a reliable and riskless positioning of the profile forming body 4 in an operational position within the drawing bulb 50, according to the invention the profile forming body 4 is moved in axial direction either from below the shaping body 3 via the inner space of the glass tube 5; 5? or via an inner bore 31 of a shaft 30 supporting said shaping body until reaching an operational position in the inner space of said glass tube 5; 5?.

Abstract: The invention relates to a known method for drawing a quartz glass cylinder from a melt crucible comprising an inner crucible chamber extending in the direction of a center crucible axis and bounded by a side wall and a floor, wherein SiO2 granulate is fed into the melt crucible and therein softened into a quartz glass mass, and said mass is drawn vertically downward as a cylindrical quartz glass strand by means of a first draw-off device through a first draw nozzle provided in the floor of the melt crucible, and the quartz glass cylinder is cut off therefrom.

Abstract: An apparatus for stabilizing a flow of a viscous material, such as a molten glass or glass ceramic material in a tube or rod forming process is disclosed. The apparatus comprises a stabilization member through which the molten glass is passed after leaving the nozzle of a forming vessel. The stabilization member is positioned a finite distance below the nozzle. The column of viscous material is supported by a wall of the stabilization member, or by a gaseous film disposed between the column and the stabilization member. A method of stabilizing the flow of viscous material after it leaves the nozzle during a drawing process is also disclosed.

Abstract: In a known method for drawing a tubular quartz glass strand, a crucible is fed with SiO2-containing start material, the start material is softened in the crucible and, as a softened quartz glass mass, is drawn vertically downwards as a tubular quartz glass strand along a drawing axis through an annular gap between an outer member and an inner member, which is arranged in a through hole of the outer member, of a drawing nozzle provided in the bottom area of the crucible.

Abstract: The apparatus for continuously manufacturing a calibrated round or profiled glass tube with a predetermined inner profile has a melt feed with an outlet opening for molten glass, a shaping body for forming a hollow drawing bulb from the molten glass, a profile forming body positioned downstream of the shaping body, and a device for changing a distance between the shaping body and the profile forming body to vary a wall thickness of the glass tube. The molten glass from the outlet opening is drawn over the shaping body to form the drawing bulb and the drawing bulb is drawn over the profile forming body so that inner circumferential surfaces of the drawing bulb are deformed while bearing on outer surfaces of the profile forming body to form the predetermined inner profile of the glass tube.

Abstract: In the method molten glass emerges from an outlet opening of a melt feed. The molten glass is drawn over a shaping body so as to form a hollow drawing bulb. According to the invention, the drawing bulb is drawn over a profile forming body positioned downstream of the shaping body so that inner circumferential surfaces of the drawing bulb are deformed while abutting against outer surfaces of the profile forming body to form the predetermined inner profile. The distance between the shaping body and the profile forming body can be changed to vary the wall thickness of the glass tube.

Abstract: A device for the production of a glass rod is provided. The device has a Danner blowpipe constructed to avoid problems attributed to different heat expansion coefficients of the participating materials. The Danner blowpipe has an outer metal jacket surrounding a ceramic body and defines a supply end and a discharge end of the blowpipe. A clamping plate is provided at both the supply and discharge ends. The clamping plate on the discharge end is rigidly joined with a shaft and engages the outer metal jacket at the discharge end. The clamping plate on the supply end is joined in an axially displaceable manner on the shaft, which is rigidly joined with a pressure plate against displacement in an axial direction. A pressure spring is disposed between the pressure plate and the clamping plate on the supply end to urge the plates away from one another.

Abstract: The invention provides a method for manufacturing a large scale quartz glass slab ingot in a flame hydrolysis reaction in a furnace, including the steps of rotating the furnace, depositing a fused silica on a furnace bed, and extending the deposit outwardly by heating and rotation of the furnace, thereby a quartz glass slab ingot is obtained. A quartz glass burner is installed at the ceiling of the furnace, hydrogen gas supplied to the burner flows down along the tapered wall of the oxygen chamber and is ejected into the outer casing. Part of the hydrogen gas is deflected to the center of the burner and mixed with the oxygen just after the ejection from the oxygen gas nozzles. Thereby, the flame is formed smoothly and the thermal efficiency is improved. The flame becomes wide enough and the silica powder transported by the hydrogen gas is uniformly fused by the flame and heat capacity of the fused silica.

Abstract: A method and apparatus for the manufacture of synthetic vitreous silica ingots involves the production of a melt of synthetic vitreous silica in a crucible (35) within a refractory furnace (31), and the continuous withdrawal of an ingot (43) through an orifice (40) in the wall of the crucible. The silica may be deposited in the crucible by a synthesis burner (33), which may also serve to maintain the silica above its sintering temperature. The emerging ingot is supported by an arrangement of moveable clamps (44).

Abstract: The invention relates to a device for producing a glass rod. The device comprises a Danner blowpipe (1); a nozzle for applying stream of glass to the surface of the Danner blowpipe (1) at one end of said blowpipe (supply end) at a relatively high temperature in order to form a glass film, which is removed at the other end (discharge end) in the form of a bulb at low speed. According to the invention, the device is characterised as follows: the Danner blowpipe (1) is constructed as follows: the peripheral wall consists of an external metal jacket (2) and a ceramic body (3) surrounded by said jacket; a respective clamping plate (6.1, 6.2) is provided at the supply end and at the discharge end; the discharge-end clamping plate (6.2) is connected in a fixed manner to the shaft (6); the supply-end clamping plate (6.

Abstract: The invention relates to a process for the production of internally-hardened glass tubes, in which in a tube-drawing process for the production of glass tubes that is known in the art, a coated drawing tool, for example in the process according to Danner a coated mandrel or in the process according to Vello or in A-drawing process a coated needle, is used, whose coating releases coating material upon contact with the inside surface of the tube that is produced and accumulates on the inside glass surface. The chemical resistance is increased by this internal hardening. The invention also relates to devices for implementing this process and uses of the tubes that are produced according to these processes.

Abstract: The sleeve-type glass melt agitator has a rotatable cylindrical sleeve provided with openings or small loops in its outer surface. The sleeve type agitator is arranged vertically in a glass melt feed channel in a glass melt feed system for making glass tubes or pipes according to the Vello or down-drawn process. During formation of glass tubes or pipes from the glass melt the sleeve-type agitator is rotated as the glass melt flows downward to prevent formation of schlieren in the glass melt, which causes glass material losses.

Abstract: A drawing apparatus 1 has a drawing furnace 11, a heating furnace 21, and a resin curing section 31. The drawing furnace 11 has a muffle tube 13 to which an He gas supply passage 15 from an He gas supply section 14 is connected so as to supply He gas. The optical fiber 3 drawn upon heating by the drawing furnace 11 is fed to the heating furnace 21, whereby a predetermined part of the optical fiber 3 is annealed at a predetermined cooling rate. The heating furnace 21 has a muffle tube 23 to which an N2 gas supply passage 25 from an N2 gas supply section 24 is connected so as to supply N2 gas. Thereafter, the optical fiber 3 is coated with a UV resin 39 by a coating die 38, and the UV resin 39 is cured in the resin curing section 31, whereby a coated optical fiber 4 is formed.

Abstract: A partition member having partition walls arranged in a lattice is disposed in the vicinity of an upper surface of a molten metal mass. The upper surface is divided by the partition walls into a multiplicity of segmental surfaces. A forming starter member is brought into contact with the partition member so that the molten material adheres to a starter surface of the forming starter member, and is then separated from the partition member. The molten metal is drawn from each of the segmental surfaces, and the drawn metal is solidified to form a piece which has a cross sectional shape corresponding to the shape of the starter surface. With the use of forming starter members having respective starter surfaces which are different in shape from each other, it is possible to form pieces having various cross sectional shapes which correspond to the shapes of the starter surfaces.

Abstract: A hollow high temperature ceramic superconducting fiber (10, 100), a process for making the hollow fibers and an apparatus for carrying out the process are provided. The apparatus functions to simultaneously draw a molten superconducting material (16) and a molten glass material (18) into a hollow preform (25) which is heat treated to form a hollow superconducting fiber (10, 100) which is flexible and has a high electrical current carrying capacity. The glass cladding layer (14, 14') surrounds the hollow superconducting core (12).

Abstract: A runway for conveying glass tubing, as the tubing is drawn from a source of molten glass, embodies support assemblies having rotating sleeves mounted on guide shafts to contact the tubing. A circulating humid atmosphere is maintained in an enclosure during an initial portion of the tube draw to reduce frictive damage to the tubing.

Abstract: A method for manufacturing a glass fiber having a polygonal cross section is provided. According to the method, a glass fiber having an orbicular cross section is manufactured by drawing molten glass supplied into a crucible heated at higher temperatures than a softening point of glass out of a nozzle having an orbicular cross section heated at lower temperatures than the heating temperature of the crucible and at higher temperatures than the softening point of glass. Then, the glass fiber is passed through a slit of a twin roller, having a predetermined shape, whereby glass fibers having a polygonal cross section are successively manufactured. The twin roller is heated at slightly higher temperatures than the softening point of the glass.

Abstract: Methods of an apparatus for producing profiled glass tubing utilizing the Danner process comprise flowing the molten glass over profiled blowpipe heads which are "super-profiled" in that the angles of ridges and grooves are more acute than the ridges and grooves resulting in the glass tubing. The particular profiles of the glass tubing are controlled by selecting the necessary drawing speed, viscosity of the glass, internal air pressure at the blowpipe head and throughput rate of the glass melt.

Abstract: Methods of an apparatus for producing profiled glass tubing utilizing the Danner process comprise flowing the molten glass over profiled blowpipe heads which are "super-profiled" in that the angles of ridges and grooves are more acute than the ridges and grooves resulting in the glass tubing. The particular profiles of the glass tubing are controlled by selecting the necessary drawing speed, viscosity of the glass, internal air pressure at the blowpipe head and throughput rate of the glass melt.

Abstract: A method of manufacturing shaped bodies from ceramic or glass, in which a green body is formed from the starting material for the shaped body in the form of a plastic mass consisting of microdispersed solid particles and water as a dispersing liquid and, if necessary, a binder, after which said green body is dried and sintered, the still wet green body being immersed in water miscible organic liquid having a lower surface tension and a lower enthalphy of vaporization than water, until the water in the green has at least largely been replaced by the organic liquid due to diffusion.

Abstract: An apparatus and method for the continuous production of glass articles characterized by the ability to form a single sheet of glass having two layers of different compositions, double glass panels having an air space between the panels or to produce tubes having either circular or eliptical cross-sections. The apparatus and method utilizes a molding body having a trough means which may be used to divide the glass mass into two cooperating flows over the working surfaces of an upper and lower molding body portions. The glass mass flows downwardly along an outer working surface of the upper body portion onto the inner working surfaces of the lower portion. A nozzle means provided with a ceramic shell or other refractory material may be disposed in an opening provided in the bottom portion of the molding body to provide a means for forming a closed double panel of sheet glass or a tube shaped article.

Abstract: A fused silica glass tube (26) is extruded from a melt (21) in a chamber (11) pressurized with an inert gas. A shield is placed in close, spaced, relation to the melt (21) surface during the gas pressure extrusion process to substantially eliminate losses from the melt due to vaporization.

Abstract: A glass tube extrusion apparatus (50) is comprised of a chamber (52) having a crucible (72) therein mounted within and spaced from an inductive heating coil (77). As a glass tube (170) is extruded from an annular opening (74) in the bottom of the crucible (72) the tube is monitored for bending. When a bend starts to occur an X-Y motion apparatus (54) is activated to move the crucible (72) laterally within the coil (77) in a direction opposite to the bend to straighten the tube (170).

Abstract: A process and apparatus for producing glass foil is disclosed in which a thin glass foil is produced by conveying a glass melt from a rotatable crucible of a smelting furnace through an annular distribution reservoir and a distributing disk having flow-through slots. Jets of glass emerge from the flow-through slots and are combined at a funnel-shaped wall into a hollow, cylindrical glass mass. Due to its weight and to heating by pressurized, gas-heated heating and cooling zones, the cylindrical glass mass flows downward, and is stretched until it reaches a pre-determined wall thickness by auxiliary conveyor belts. The hollow cylinder of glass is then split on one side by a separating device, flattened, conveyed to a bath of liquids, and then drawn-off at full width in the form of a glass foil by a draw-off guide roller. After the glass foil is drawn-off, the auxiliary conveyor belts are moved laterally so that they are no longer in physical contact with the glass cylinder.

Abstract: In the drawing of glass, steam or water vapor is introduced into the atmosphere surrounding the glass while the same is being formed to reduce or inhibit breakage of the glass during the drawing operation.

Abstract: There is disclosed a method of making composite glass tubing, and a molten glass feeding apparatus uniquely designed to carry out such method. The feeder apparatus comprises concentrically-arranged cylindrical containers, a blow tube located within the central container, and a plug member mounted on the base of the blow tube. The bottom portion of each cylindrical wall is downwardly and inwardly directed to provide restricted annular bottom openings. The bottom edges of the cylindrical walls and of the plug are positioned in such relation to each other that orifices are provided through which annular streams of molten glass may flow and contact adjacent streams in the fluid state, thereby forming composite glass tubing having at least three layers.

Abstract: An extrusion die for forming hollow bodies has a flow-adjusting ring which also defines the outer periphery of the flow gap for the outer portion of the body.