Method controlling the draw rate in the drawing of a glass feedstock
AssigneeCorning Incorporated
InventorsDavid M. Koening, Peter J. Majestic, Richard O. Maschmeyer
Life of this patent
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Abstract
A method for drawing glass objects from glass feedstock, wherein a dimension of the glass object is measured on-line and controlled by a control structure which compensates for the deadtime between a change to the drawing speed and the measurement of the effect of that change to the measured dimension. The model which compensates for the deadtime is preferably nonlinear, and the control gains and model parameters are preferably continuously calculated during the drawing process. The invention is particularly applicable to drawing optical waveguide cane from optical waveguide preforms.
Claims19
A method for drawing a glass object from a glass feedstock, comprising,
- a. providing a glass feedstock,
- b. heating said glass feedstock to its softening temperature,
- c. drawing said glass feedstock into a glass object at a drawing speed which is adjustable, and
- d. adjusting the drawing speed to control a dimension of said glass object,
- wherein said step of adjusting the drawing speed comprises comparing an on-line measurement of said dimension to a predetermined target value and compensating for an inherent deadtime which exists between a change in the drawing speed and the detection of the effect of said change in the drawing speed on said dimension.
A method for manufacturing a cane for optical fiber, comprising
- a. providing a preform,
- b. heating an end of said preform to its softening temperature, and
- c. drawing said cane from said softened end of said preform,
- wherein the diameter of said cane is controlled by adjusting the drawing speed at which said cane is drawn from said preform by comparing an on-line measurement of the diameter of said cane to a predetermined target value and compensating for an inherent deadtime which exists between a change in the drawing speed and the detection of the effect of said change in the drawing speed on the diameter and wherein said step of compensating occurs substantially continuously during said step of drawing said cane.
Dependencies are inferred from the claim text.