Abstract: A silicon surface oxidation device utilizes a steam generator in which heated water is barely in contact with the members of the device, steam with no contamination is efficiently generated, and the silicon surface can be oxidized through relatively large thickness by using a steam oxidation method which is simple and high in safety. The steam generator has a feed port for pure water which flows along a surface in a chamber, an oscillator for oscillating a microwave toward the surface, a steam exit port for sending out the steam of the pure water generated from the surface by the microwave, and a discharge port for the pure water flowing along the surface. A heating furnace is connected to the steam exit port, and silicon placed in the heating furnace is oxidized by the steam generated by the microwave.

Abstract: A supplemental controller for a fiber glass bushing actively performs heating and cooling of a connected segment of the bushing which is otherwise controlled by a primary controller. In one embodiment, the supplemental controller performs heating by means of current injection into a connected bushing segment and cooling by means of current diversion from or around the connected bushing segment. Initial start-up and balancing operations can be performed without activation of the supplemental controller. In another embodiment of the invention, the supplemental controller heats a bushing segment by injecting current in-phase with current from the primary bushing controller and cools the bushing segment by injecting current out-of-phase with current from the primary bushing controller.

Abstract: A supplemental controller for a fiber glass bushing actively performs heating and cooling of a connected segment of the bushing which is otherwise controlled by a primary controller. In one embodiment, the supplemental controller performs heating by means of current injection into a connected bushing segment and cooling by means of current diversion from or around the connected bushing segment. Initial start-up and balancing operations can be performed without activation of the supplemental controller. In another embodiment of the invention, the supplemental controller heats a bushing segment by injecting current in-phase with current from the primary bushing controller and cools the bushing segment by injecting current out-of-phase with current from the primary bushing controller.

Abstract: A method for drawing a glass ingot into a rod having a given outer diameter is described. The method is characterized in that when the glass ingot is fed into a heating zone at a final tapered portion thereof, a temperature in the heating zone is decreased so that the final tapered portion is prevented from being drawn in excess owing to the heat from the heating zone.

Abstract: The transmission properties of an optical fiber are enhanced by cooling the fiber gradually to temperatures of at least -300.degree. Fahrenheit, maintaining the fiber at such reduced temperature for a time suitable to stabilize the transmission properties of the fiber, and then allowing the fiber gradually to return to normal room temperature. The heating of the fiber to restore it to room temperature in part is accomplished by transmitting through the fiber optical pulses of the frequency and repetition rate the fiber will experience in normal use.

Abstract: A glass-fiber bushing including a bottom tip-plate and side walls surrounding the bottom tip-plate forming a container for molten glass. The bottom tip-plate including a plurality of tips arranged to permit molten glass to flow there through to produce a multiplicity of individual molten glass streams from which glass fibers may be formed. The glass-fiber bushing includes at least one tip-plate thermocouple having a platinum tube housing, a pair of thermocouple wires transversing the tube housing and terminating in a weld junction. The tube housing, thermocouple wires and the weld are attached directly to the tip-plate such that the thermocouple junction is formed directly at the tip-plate surface.

Abstract: This invention relates to a high throughput glass fiber production system and process to provide optimum glass delivery to the glass fiberizing bushing and enhanced glass production of textile fibers or filaments of glass. The fiberizing system includes dual melters which feed the molten glass through various screens within a high throughput feed bushing positioned below the melters to reduce seeds and condition the glass. The feed bushing directs the molten glass into a dual flow diverter for supplying the molten glass into the optimum location of the glass fiberizing bushings placed below the dual flow diverter.

Abstract: The material is in a fluid state at a predetermined temperature above the ambient temperature. According to the invention: a) at least two different compositions of this material in the fluid state are prepared; b) simultaneously and concentrically both the core of the rod with the aid of one of the compositions and a sheath enveloping this core with the aid of another composition are cast; and c) the casting is then taken to a temperature at which it solidifies to constitute the rod. Advantageously, the section of the casting is made to grow by its passing through a cylindrical mold shaped to define the final section of the rod. Application to the manufacture of a glass rod presenting a cross-sectional refractive index gradient.

Abstract: A method of drawing an optical fiber preform to manufacture an optical fiber, includes the steps of heating an optical fiber preform to temperatures at which the heated preform can be drawn, drawing the heated optical fiber preform by applying tension to the preform, and making the tension substantially constant during the drawing step. The particular method permits manufacturing an optical fiber exhibiting uniform transmitting characteristics, particularly uniform transmission loss, over the entire lengthwise region of the optical fiber, even if the optical fiber is manufactured by drawing an optical fiber preform having a large diameter.

Abstract: A heat-absorbing finshield assembly, which is located adjacent the discharge area of a furnace for producing glass fibers, includes fins spaced along a fluid-cooled manifold such that the fins extend between, but not in contact with, the molten glass fibers emerging from the furnace. The fins may have microfins in their bases which are in contact with the cooling fluid. The fins also may be of variable thicknesses relative to each other along the manifold to absorb different quantities of heat from the emerging fibers.

Abstract: During the fire-polishing of a lengthwise extended glass body (3), for example a preform for drawing optical fibers, the glass body (3) is held by a holding device (5, 7), and is heated by a burner (23) moving at a variable advancing speed parallel to the lengthwise axis (19). The surface temperature of the glass body (3) is determined with a temperature measuring device (25). The mechanical stress condition of the glass body (3) is detected with an optical device (29) and can be controlled by varying the burner temperature and/or the advancing speed of the burner. The invention makes it possible to counteract the occurrence of high mechanical stresses in the glass body (3).

Abstract: A supplemental controller for a fiber glass bushing actively performs heating and cooling of a connected segment of the bushing which is otherwise controlled by a primary controller. In one embodiment, the supplemental controller performs heating by means of current injection into a connected bushing segment and cooling by means of current diversion from or around the connected bushing segment. Initial start-up and balancing operations can be performed without activation of the supplemental controller. In another embodiment of the invention, the supplemental controller heats a bushing segment by injecting current in-phase with current from the primary bushing controller and cools the bushing segment by injecting current out-of-phase with current from the primary bushing controller.

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.