Glasfaserspule

摘要

Glass strand 30, formed by collecting filamentary streams 26 emerging from a bushing 18 and sized by engagement with an applicator roller 34, is wound in a series of superposed parallel layers on a forming tube 28 carried on a collet 29. As each layer is completed and the next successive layer is commenced, either the bushing temperature is increased, thereby gradually decreasing the viscosity of the glass to permit more glass to be attenuated as the winding progresses, or the speed of rotation of the tube is decreased to compensate for the increased diameter of the package (see Division D1): the diameter of the attenuated filaments is thus maintained uniform. Apparatus whereby the temperature of bushing is increased stepwise, Figs. 8 and 9, is actuated by limit switches 203, 204, Figs. 3-6 (not shown), and 9, on the winder 45. As shown, a measuring and regulating unit 215 receives a signal corresponding to the temperature of bushing 18 from a thermocouple 216. An auxiliary signal from a variable resistance unit 218 causes a decrease in the total signal (falsely indicating that the temperature is falling from a pre-set value) so that unit 215 sends a signal to a saturable core reactor 206, the reactance of which is thereby reduced to permit more current to be supplied to transformer 208 and therefore more current to bushing 18. In the operation of the unit 218, closure of limit switches 203, 204 energizes solenoids 234, 240 to operate pawls 232, 236, which turn ratchet 230 and change the position of a potentiometer-connected rheostat 224 stepwise corresponding to each axial movement of collet 29. The variable voltage derived from rheostat 224 is used to pass current through resistance 233 in series with thermocouple 216 and unit 215. A conventional stepping switch and a series of fixed resistances may replace the ratchet, pawls and rheostat. Specifications 595,094, 909,154 and U.S.A. Specifications 2,607,197 and 2,873,718 are referred to.