Method of controlling an upper portion of an optical fiber draw furnace
US6810692B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | May 28, 2003 |
| Grant date | Nov 2, 2004 |
| Priority date | — |
| Expiry date | May 28, 2023 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC03B2205/98
- WIPO fieldOther special machines
- WIPO sectorMechanical engineering
Abstract
A furnace for drawing an optical fiber provided with a muffle tube (10) and inner tubes (5,5′) connected to the upper end of the core tube, wherein a preform (1) supported by a dummy rod (2) at the upper part thereof is disposed inside the muffle tube (10) and inner tubes (5,5′) so as to be movable downward together with dummy rod (2), the preform (1) is heated and melted by a heater (11) from the outside of the muffle tube (10) and an optical fiber (1a) is pulled out from the lower end of the preform (1); the furnace is further provided with one or a plurality of sets of separating plates (4, 17) adapted to partition a space in the inner tubes (5,5′) above the preform (1) into a plurality of portions in the advance direction of the preform and disposed in the space, and with gas blowing inlets (8) disposed in the parts of wall surfaces of the inner tubes (5,5′) which are below the separating plates (4, 17) and adapted to blow an inert gas into the inner tubes (5,5′) and the muffle tube (10), thereby preventing variations in diameter of the optical fiber (1a).
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.