Process and apparatus for the continuous production of elongate light conductors

Claim 1

A process for producing an elongate light conductor of indefinite length, comprising the steps of: (a) placing a vitreous seed rod in a vertical position with an exposed upper end extending into a vaccum chamber; (b) depositing successive amounts of a powdered glassy material in said vacuum chamber on the upper end of said rod while training a beam of ions of a refractivity-controlling doping substance, to be implanted in said glassy material, upon a limited area of said upper end; (c) fusing the deposited material with said doping substance onto said rod, thereby progressively extending same upwardly; (d) progressively lowering the upwardly growing rod at an average speed corresponding to its growth rate; (e) thermally softening the lower end of the descending rod sufficiently to enable its mechanical deformation; (f) drawing the softened lower end of said rod into a vitreous strand of reduced cross-section; and (g) continuously varying the relative position of said beam of ions and said upper end to distribute said substance in a predetermined pattern over the cross-section of said strand.

Claim 8

An apparatus for producing an elongate light conductor of indefinite length, comprising: a vacuum chamber; a holder at the bottom of said vacuum chamber for fricionally retaining a vitreous rod in vertical position; stationary hopper means above said holder at the top of said vacuum chamber for depositing successive amounts of a powdered glassy material on the upper end of the rod positioned in said holder; an emitter of an ion beam of a refractivity-controlling doping substance, to be implanted in said glassy material, trained in said vacuum chamber upon a limited area of the upper end of said rod; heating means for fusing the deposited material with said doping substance onto said rod, thereby progressively extending same upwardly; transport means below said holder for progressively lowering the upwardly growing rod at an average speed corresponding to its growth rate; a furnace disposed in the path of the descending rod for sufficiently softening its lower end to enable a mechanical deformation thereof; drawing means for extracting said lower end from said furnace as a vitreous strand of reduced cross-section; and mechanism for displacing said emitter relatively to said holder with resulting distribution of said substance in a predetermined pattern over the cross-section of said strand.

Claim 9

An apparatus for producing an elongate light conductor of indefinite length, comprising: a vacuum chamber; a holder at the bottom of said vacuum chamber for fricionally retaining a vitreous rod in vertical position; stationary hopper means above said holder at the top of said vacuum chamber for depositing successive amounts of a powdered glassy material on the upper end of the rod positioned in said holder; an emitter of an ion beam of a refractivity-controlling doping substance, to be implanted in said glassy material, trained in said vacuum chamber upon a limited area of the upper end of said rod; heating means for fusing the deposited material with said doping substance onto said rod, thereby progressively extending same upwardly; transport means below said holder for progressively lowering the upwardly growing rod at an average speed corresponding to its growth rate; a furnace disposed in the path of the descending rod for sufficiently softening its lower end to enable a mechanical deformation thereof; drawing means for extracting said lower end from said furnace as a vitreous strand of reduced cross-section; and mechanism for displacing said emitter relatively to said holder with resulting distribution of said substance in a predetermined pattern over the cross-section of said strand.