Apparatus for manufacturing glass fibers

Glass filaments with a narrow range of diameters for use in method of glass fiber production are prepared by discharging the molten glass under gravity flow through a novel multi-orifice bushing plate having a first, or inner, bushing plate adapted to support a charge of molten glass and provided with a plurality of tubular discharge orifices extending downwardly therefrom, and a second or outer, bushing plate spaced from said first plate approximately at the outlet tips of the discharge orifices, said outer plate being electrically conductive and adapted to be heated by the controlled flow of electricity therethrough to regulate the temperature of glass streams discharging through the orifices and a third plate located between and parallel to the inner and outer plates in heat conductive relation to the tubes extending therethrough. If desired, water-cooled heat-absorbing fins may be provided at selected locations on the outer bushing for further control of the temperature of the glass streams.