Abstract: The apparatus for molding an optical glass element is made up of relatively movable upper and lower molds for press molding a glass blank, and a plurality of infrared ray lamps encircling the upper and lower molds, temperature measuring devices for measuring the temperatures of the upper and lower molds, and a controller responsive to the outputs of the temperature measuring devices for controlling electric inputs to the infrared ray lamps thereby maintaining the temperatures of the upper and lower molds at predetermined values.

Abstract: For obtaining mineral fibers from a thermoplastic material having a high melting point, and more precisely for the regulation of the flow rate and temperature of the stream of molten material distributed on the fiber-drawing machine, the molten material is conveyed via a reservoir where the flow rate is regulated and the height of the molten material at the base of the tapping aperture is controlled by inclining the reservoir. Preferably the molten material is subject to a basic heating process which raises its temperature close to the fiber-drawing temperature and, in the vicinity of the tapping aperture, it is subject to additional heating in order to adjust the temperature precisely.

Abstract: A mass production method and apparatus of hermetic coating optical fiber where a bare fiber drawn from a preform is hermetically coated by CVD method in a reactor vessel, wherein a liquid flushes solid particles or by-products sticking to the reactor inner wall. The liquid may be supplied continuously or intermittently, to flush carbon particles generated during carbon coating process. The invention enables to produce a long hermetic coating optical fiber without choking the reactor, and improves a yield rate and productivity.

Abstract: A glass preform for an optical fiber is flame abrased with an oxyhydrogen flame while vertically suspending and rotating the glass preform and relatively moving one or both of the glass preform and the oxyhydrogen flame, whereby a surface of the glass preform is smoothened.

Abstract: A method for producing an optical fibre which has been treated with titanium dioxide to improve its corrosion resistance includes stretching an assembly consisting of an outer sleeve having engaged therein a bar which is partially or entirely made of synthetic silica. When treating said fibre, the outside of the coupling sleeve is coated, prior to assembling the components, with a deposit of vitrified synthetic silica containing titanium dioxide.

Abstract: Gob-shearing apparatus for providing a predetermined amount of a molten glass article vertically transferred from a feeder bowl which is capable of performing two cutting strokes when a pair of hydraulic cylinders having a rack gear reciprocates, thus obtaining an improved sheared surface of the gob. The apparatus includes a driving pinion engaged with and rotated by the reciprocation, a pair of driven pinion engaged with the driving pinion and rotated by the rotation of the driving pinion, a pair of first links having a blade on its free end, a pair of second, third and fourth links which are linked between the first link and driven pinion for link motion, and a guide rail for guiding the circular movement of the first links.

Abstract: The invention relates to a nozzle assembly for a flat-glass tempering machine. A nozzle cover (2) includes two types of orifices side by side. A number of orifices (7, 8) are linked to the pressure of a compressor (11) and another number of orifices (6) are linked to the pressure of a blower (12). Thus, the different orifices supply air of different pressures.

Abstract: A transparent glass preform for an optical fiber is produced by heating a glass soot preform to remove gas from the soot preform at a temperature at which the soot preform is not vitrified under reduced pressure, and then heating the preform at a temperature at which the preform is vitrified under reduced pressure, whereby the transparent glass preform containing no or little bubbles and having a uniform outer diameter is produced.

Abstract: Method for regulating a weight related parameter in a mineral fibre felt, in mineral fibre production. The speed of the fibre felt is regulated by a feed-forward connected regulator (R.sub.1) based on the power consumption of the fiberizing unit (2). The regulator (R.sub.1) is corrected with a feed-back connected regulator (R.sub.2) wherein the measured signal is a weight related parameter measured at a location in the beginning of the felt forming line. The regulator (R.sub.2) in turn is corrected by a third feed-back connected regulator (R.sub.3) wherein the measured signal is a weight related parameter measured at a point at the end of the felt forming line.

Abstract: A method of collecting data to indicate certain internal conditions during the function of a glass container forming machine, and apparatus for the practice of the method including sensing devices within a plunger cycling mechanism of the machine for transmitting information from the mechanism during the operation of the machine.

Abstract: There is provided a process of melt drawing an optical fiber from a preform therefor in which a heating furnace comprising a muffle tube inside thereof through which the optical fiber is passed is provided immediately below a melt drawing furnace to further draw the optical fiber while heated, and an interior of the muffle tube is kept in an atmosphere selected from the group consisting of an inert atmosphere, an atmosphere comprising oxygen gas and an atmosphere comprising hydrogen gas.

Abstract: An optical fibre is manufactured by stretching a rod-shaped initial preform, after which a cladding tube is melted on the initial preform and the final preform thus obtained is drawn into an optical fibre. A narrow and hot softening zone is used to stretch the initial preform, which softening zone is obtained, for example, by means of a plasma torch 2. By virtue thereof, the stretching process can be controlled in a rapid and simple manner.

Abstract: According to the invention, a hollow silica bar (2) is produced with a thick wall and high geometrical precision, the bar is then cleaned and an oven (24) is used able to heat the silica to its melting temperature and with respect to which the bar is moved so as to embody an external thermic glazing of the bar, an internal vapor phase depositing a vitreous coating in this bar by making circulate inside it a mixture of suitable gaseous constituents, this coating being intended for the subsequent formation of the core of the optical fibers, and an area contraction of the bar, the various temperatures of the bar required to embody these operations being obtained by varying the temperature of the oven or speed of the bar with respect to the oven.

Abstract: The present invention provides a fiber coupler manufacturing apparatus comprising a pair of fiber holding portions and a fiber clamp disposed on each of the fiber holding portions for holding at least two optical fibers. A weight and pulley system is arranged wherein a first weight is coupled to each of the fiber holding portions to pull the fiber holding portions away from each other to apply tension to the optical fibers. A heating unit is disposed between the fiber holding portions and proximate to the optical fibers to heat the optical fibers. A second weight is coupled to either the fiber holding portions or the first weight and rests on a movable platform. As the movable platform descends in a vertical direction, the second weight applies additional force to the fiber holding portions and thus applies additional tension to the optical fibers.

Abstract: An apparatus for forming a porous preform that is useable to an optical fiber by extruding a plastifiable material having silica powder as a main component thereof. The apparatus includes an extruding main body having a cylinder and a screw for extruding the plastifiable material from the cylinder and a material passage member connected to the cylinder so as to communicate therewith. The material passage member has a projection member which projects into the material passage member for preventing a lamination of the plastifiable material. The apparatus also includes a molding head connected to the material passage member so as to communicate therewith.

Abstract: Optical waveguide paths are formed under the surface of a glass substrate by a method comprising (a) forming by ion-exchange a dopant ion path on a first substrate surface, (b) applying an electrode to the second surface, (c) contacting the first surface with a molten salt bath, and (d) applying an electrical field across the substrate to drive the dopant ions deeper into the substrate. The current resulting from high fields can overheat the substrate, thereby causing substrate warping and burying of paths to uneven depths. One aspect of the invention involves cooling the substrate by flowing the molten salt along the first surface of the substrate at a sufficient rate of flow to adequately decrease its temperature and by rapidly flowing the furnace atmosphere over the surface of the substrate. A further aspect of the invention involves initially applying a voltage V.sub.i across the substrate, allowing the current to increase to a predetermined level I.sub.

Abstract: Low attenuation, low dispersion of optical waveguides are provided by a process initiating with axial deposition of a high velocity core soot stream impinging on a target at a high angle of incidence relative to the axis of rotation of the target. A core cylinder is built up axially by relative movement between the soot stream and target during deposition, the movement being non-constant in order to maintain a substantially constant diameter with a constant deposition rate. A cladding layer is then built up by deposition of soot radially on the core. Subsequent drying and sintering provides a vitreous preform which may be drawn directly into optical waveguides. Alternatively, the sintered product may be drawn down to smaller rods, which then are covered with further deposited soot cladding to a desired final thickness, and after further drying and sintering may be drawn to optical waveguides.

Abstract: As an optical fiber (12) is being drawn, air (14) is directed at a portion of the fiber as a succession of air pulses, the pulses having a frequency near the natural frequency of the fiber portion. The frequency of the air pulses is then varied over a range of frequencies that includes the natural frequency of the fiber portion. When the air pulse frequency equals the natural frequency of the fiber portion, a resonance occurs which greatly amplifies the amplitude of the vibration of the fiber portion. The large deflection of the fiber that occurs at resonance is easy to detect, and the air pulse frequency which causes such maximum deflection is taken as being equal to the resonant frequency and therefore to the natural frequency of the fiber portion. Changes of the detected resonant frequency can be interpreted in a straightforward manner as changes in optical fiber tension which, in turn, are used to make compensatory changes of the temperature of the furnace (10).

Abstract: A method and apparatus for producing glass fibers wherein molten glass is deposited onto a spinning cup structure. Centrifugal force urges the molten glass outwardly and upwardly along the inner surface of an upstanding wall of the cup structure. The glass is then extruded through small holes in the cup wall. A downflowing stream of hot gas passes downwardly along the outer surface of the cup wall to turn the fibers downwardly while producing an attenuation (reduction) of fiber diameter. The lower portion of the cup side wall is heated to achieve greater temperature uniformity of the fibers as they are formed. A cool gas curtain is formed about the downflowing hot gas stream to somewhat concentrate the hot gas stream for more uniform heating of the downflowing glass fibers.

Abstract: Short and long wavelength absorption losses contribute to loss at the operating wavelength of an optical fiber drawn from a preform. Excess losses over and above Rayleigh scattering losses have been attributed to conditions such as temperature and the speed during drawing. Typically, after optical fiber (21) is drawn from an optical preform in a furnace (23) wherein temperatures may be 2200.degree. C. or higher, the fiber is moved out of the furnace and immediately through ambient environment to other portions of a draw line such as, for example, measuring and coating apparatus. It has been found that these absorption losses may be reduced substantially by application of a magnetic field to the optical fiber after it has been drawn and prior to it being coated.