US 12,441,649 B2
Optical fiber draw furnace system and method
Erling Richard Anderson, Wilmington, NC (US); Tammy Michelle Hoffmann, Wilmington, NC (US); Nikolaos Pantelis Kladias, Horseheads, NY (US); Kenneth William Roberts, Wilmington, NC (US); Eric Wade Thornton, Wilmington, NC (US); and Chunfeng Zhou, Painted Post, NY (US)
Assigned to Corning Incorporated, Corning, NY (US)
Filed by CORNING INCORPORATED, Corning, NY (US)
Filed on Mar. 29, 2022, as Appl. No. 17/706,976.
Claims priority of provisional application 63/171,302, filed on Apr. 6, 2021.
Prior Publication US 2022/0315473 A1, Oct. 6, 2022
Int. Cl. C03B 37/029 (2006.01); C03B 37/025 (2006.01)
CPC C03B 37/029 (2013.01) [C03B 37/0253 (2013.01); C03B 2205/98 (2013.01)] 16 Claims
OG exemplary drawing
 
1. An optical fiber draw furnace system comprising:
a muffle forming an inner cavity;
a downfeed handle moveably disposed within the inner cavity and comprising an inner handle and an outer handle, and
a downfeed handle extension portion connected to the downfeed handle and moveably disposed within the inner cavity,
the downfeed handle extension portion being moveable with the outer handle with respect to the inner handle,
a length of the downfeed handle extension portion being in a range from about 2 inches to about 25 inches,
the downfeed handle extension portion formin a first gap between an outer surface of the downfeed handle extension portion and an inner surface of the muffle, the first gap having a length in a range of about 0.001 m to about 0.2 m, and
the downfeed handle extension portion configured to form a second gap between a lower surface of the downfeed handle extension portion and a shoulder of a preform attached to the downfeed handle extension portion, the second gap having a length in a range from about 0.001 m to about 0.2 m.