Patent ID: 7383704

Claim:
An outside chemical vapor deposition apparatus for depositing porous glass-forming material onto a target rod to form a cylindrical body, comprising: a first burner array constructed and arranged to direct glass-forming material substantially only radially toward the target rod to form a cylindrical body, wherein the first burner array further is constructed and arranged for optimum deposition when the cylindrical body has a first diameter, and wherein the first burner array further is constructed and arranged to be selectively movable between a deposition position, in which the burner array is substantially radially aligned with the cylindrical body, and an idle position, in which the burner array is not aligned with the cylindrical body; and a second burner array constructed and arranged to direct glass-forming material substantially only radially toward the cylindrical body, wherein the second burner array is constructed and arranged for optimum deposition when the cylindrical body has a second diameter, larger than the first diameter, and wherein the second burner array further is constructed and arranged to be selectively movable between a deposition position, in which the burner array is substantially radially aligned with the cylindrical body, and an idle position, in which the burner array is not aligned with the cylindrical body; wherein the first and second burner arrays are constructed and arranged to deposit porous glass-forming material onto the cylindrical body separately and at successive times.