Abstract: A system is described for forming accurately spherical and centered fluid-filled shells, especially of high melting temperature material. Material which is to form the shells is placed in a solid form in a container, and the material is rapidly heated to a molten temperature to avoid recrystallization and the possible generation of unwanted microbubbles in the melt. Immediately after the molten shells are formed, they drop through a drop tower whose upper end is heated along a distance of at least one foot to provide time for dissipation of surface waves on the shells while they cool to a highly viscous, or just above melting temperature so that the bubble within the shell will not rise and become off centered. The rest of the tower is cryogenically cooled to cool the shell to a solid state.

Abstract: A rotary heating apparatus, for example, for liquefying glass batch or the like, is provided with dynamic stability by isolating structural support elements from vessel elements that are subject to thermal distortion and by supporting the vessel so as to be self-centering. The preferred embodiment entails a support ring separate from the vessel, rotatably supported at an elevation above the center of gravity of the vessel, and attached to a lower portion of the vessel by way of a plurality of link rods. Horizontal force is applied to the support ring to damp oscillations of the vessel. Rotation of the ring may be on a conical track to aid self-centering.

Abstract: A method of making an optical fiber, comprising the steps of forming an optical preform having a core and a cladding with different refractive indices, the core being offset from the geometric center of the preform and having a non-circular cross-section defining two transverse orthogonal axes, the core having a longer transverse dimension along one of the orthogonal axes than along the other of the axes for guiding two fundamental modes, which, in combination with the different refractive indices, permits the de-coupling of waves polarized along the axes, the outer surface of the preform having a non-circular cross-section forming an indexing surface with a predetermined geometric relationship to the core and the orthogonal transverse axes so that the location of the core and the orientation of the axes can be ascertained from the geometry of the outer surface, and drawing an optical fiber from the preform with the drawing rate and the temperature of the preform being controlled to produce a fiber with a cro

Abstract: An apparatus for the manufacture of mineral fibers from a drawable material such as glass products, poured in the molten state onto a first centrifuging wheel before being conducted to a following wheel, each wheel transforming part of the molten material into fibers and dispatching the excess to the following wheel. A cooling water supply channel is arranged in the axis of each centrifuging wheel and is ridgidly coupled to the rotational movement of said wheel. Means of the helicoidal type, which are fixed to the channel, caused the water to advance to the end of the channel.

Abstract: A method of producing a highly pure glass tube having a smooth inner surface, said method comprising the steps ofdepositing by the flame hydrolysis of a glass-forming raw material, a first layer of glass soot particles having a bulk density no greater than 0.2 g/cm.sup.3 on a seed member having a smooth and clean outer surface,depositing on the surface of the first layer of glass soot particles, a second layer of glass soot particles having a bulk density greater than that of the first layer by at least 0.03 g/cm.sup.3,drawing the seed member from the deposited two-layered glass soot preform to form a tube of glass soot particles,removing the first inner layer of glass soot particles from the second layer, either simultaneously with or subsequent to the drawing of the seed member from the soot preform, andheating and vitrifying the tubular glass soot preform to form a transparent solid glass tube.

Abstract: In a rotating vessel for liquefying pulverulent material wherein the pulverulent material forms a lining on sidewall portions of the vessel, pressing means are provided for creating a flattened end portion at the top of the lining onto which additional pulverulent material is fed and subsequently pressed into the lining. The pressing means is preferably a rotationally driven wheel and the pulverulent material may be glass batch. A more stable feeding operation and reduction of dusting are attained.

Abstract: The etching of dielectric oxide ceramics and dielectric single crystal oxides, particularly perovskite ceramics, is executed by means of laser radiation in an atmosphere having a reducing effect.

Abstract: Apparatus for removing dust from the atmosphere around an externally heated tube (1) having a deposit being made on its inside surface from a vapor phase, said dust being removed by setting up a laminar flow of dust-free air around the tube. The apparatus includes members (7, 8, 9, 10) for setting up laminar air flows in planes parallel to the axis of the tube and on either side thereof, together with members (15, 16) for setting up flows of air perpendicularly to the axis of the tube and on either side thereof.

Abstract: A tapered fiber and method and apparatus for making is provided in which the fiber has an increasing cross-sectional dimension in one direction along a portion of its length, and a decreasing cross-sectional dimension in the same direction along the same portion of its length.

Abstract: Suction molds used in the suction removal process must first be prepared ore they can receive vitrified radioactive waste materials. A method is disclosed for preparing the suction mold which includes a suction pipe welded into the base of the mold with a desired-break location whereat the suction pipe is broken off during the suction removal process. An evacuation stub is mounted in the mouth of the suction pipe and communicates with the interior of the mold. The method of the invention includes evacuating the mold through the evacuation stub and then heating the mold to remove moisture and organic impurities. The mold is then filled with a dry inert gas and the evacuation stub is cleaned. The mold is then evacuated to a predetermined residual pressure. Thereafter, the evacuation stub is cold-press welded so as to close off the interior of the mold from the ambient.

Abstract: A feeder for the production of glass filaments is provided with a mechanical valve means to render the operation dripless or non-dripless as desired. Preferably, the feeder is rendered non-dripless when the restart of filament formation from idle orifices is desired.

Abstract: A method and apparatus for rapidly cooling optical fiber comprising passing optical fiber through an enclosure having a flat black internal surface, the walls of said enclosure having symmetrically oriented perforations or other symmetrically oriented means of passing cryogenic gas through the walls to contact optical fiber within the enclosure, the enclosure surrounded by a gas plenum to which gas is supplied to facilitate the symmetrical passage of cryogenic gas through the walls, whereby the cryogenic gas symmetrically contacts and cools the optical fiber and also serves to cool the walls of the enclosure.

Abstract: In a surface processing apparatus, the LTE (Local Thermal Equilibrium) plasma is produced, instead of the glow discharge, in the discharge chamber. Then the LTE plasma is conducted into the reaction chamber. The surface of the substrate positioned in the reaction chamber is exposed to at least one of the radiation and the active species generated from the LTE plasma for performing the surface processing.

Abstract: A method for producing a glass preform for an optical fiber comprising flame hydrolyzing a glass raw material in an oxyhydrogen flame to form glass fine particles, depositing the glass fine particles on a seed member to produce a solid or hollow cylindrical soot preform, dehydrating by holding the whole soot preform in an atmosphere containing a dehydrating agent kept at such temperature for such period of time that the diameter of the soot preform shrinks by at least 20%, and heating and sintering the dehydrated soot preform by introducing it from its one end in an atmosphere of a pure inert gas to produce a glass preform having a uniform distribution of refractive index along its length, from which glass preform, an optical fiber having attenuation of light transmission as low as 1 dB/km or less at a wavelength of 1.30 micrometer is fabricated.

Abstract: The invention relates to the production of mineral fibers from a material melted in a cupola. To regularize the supply of material to the fiber-forming apparatus, the material emanating from the cupola and conveyed to the apparatus passes through a reserve.

Abstract: An photoresist deposited by sputtering or evaporation on an insulation layer to be smoothed out is etched by an ion beam applied at a first angle of ion bombardment which is smaller than an angle of ion bombardment at which the photoresist can be etched at a maximum etching rate. Thereafter, the photoresist and the insulation layer are etched at a second angle of ion bombardment at which the photoresist and the insulation layer are etched at the same rate. The first angle is larger than 30.degree. and smaller than 45.degree., and the second angle is 75.degree..

Abstract: An apparatus for producing a polyacetylene film by contacting acetylene gas with Ziegler-Natta catalyst to polymerize the acetylene gas in a vessel which comprises a catalyst introduction conduit to be introduced with the Ziegler-Natta catalyst provided at a cap provided at the top of the vessel and having an end opening disposed in the vicinity of the inner surface of the side wall of the vessel in such a manner that the conduit and the vessel are relatively moved in rotation, and a rotary transmission mechanism for driving to rotatably coat the catalyst flowed out from the end opening of the conduit on the inner surface of the bottom from the inner surface of the side wall of the vessel. Thus, the polyacetylene film can be produced in a uniform thickness and in a relatively large area by introducing the Ziegler-Natta catalyst of the suitable quantity, and the catalyst can be spread over the entire surface rapidly by the relative rotation between the conduit and the vessel.

Abstract: A continuous glass fiber forming system incorporates a high energy stream of fluid to establish and control induced air flow from around the feeder to (1) substantially simulate the induction of air into the filament forming region in the absence of filament attenuation like that induced during attenuation and/or (2) increase the amount of heat removal effected during attenuation of the filaments.

Abstract: A method and an apparatus in a plant for fibrating molten mineral material which in the form of a stream of molten material (4) is discharged to the peripheral surface of a primary spinner wheel (1) and which is formed to mineral fibres by being thrown out from the spinner wheel or from several cooperating spinner wheels. The distribution of the stream of molten material (4) over the width or length of the primary spinner wheel is improved in that a force is applied to the incoming stream of molten material (4), especially from rear side thereof as seen in the rotation direction of the spinner wheel, which force is acting in a plane substantially perpendicular to a generatrix to the peripheral surface of the spinner wheel (1) and in a blunt angle to the stream of molten material (4).

Abstract: A gas reaction apparatus for manufacturing base material of optical fiber and a multi-wall pipe type burner for the gas reaction apparatus. The gas reaction apparatus includes a mechanism which heats or heat insulates at least one of gas passages of the burner for gaseous raw material of optical fiber so as to set a saturated vapor pressure of whole kinds of the gaseous raw material higher than a partial pressure of raw material of optical fiber in the gaseous raw material when the gaseous raw material is fed through the one of the gas passages.