The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Jul. 22, 1986
Filed:
Dec. 18, 1984
Brian Lynch, Norcross, GA (US);
William D O'Brien, Jr, Lilburn, GA (US);
AT&T Technologies, Inc., Berkeley Heights, NJ (US);
Abstract
A preform from which lightguide fiber is drawn is made by depositing optically suitable layers of doped silicon dioxide on an inner wall of a rotating glass tube (31) which is exposed to a moving zone of heat (56) which is provided by a torch assembly (50) during a deposition mode and during a collapse mode. After the deposition mode and generally prior to the collapse mode, one end portion of the tube is at least partially closed in order to allow pressurizing of the tube during collapse. This is accomplished with a pivotally mounted tool (70) which straddles the torch assembly to cause an internally water cooled contact device (92) to be disposed within the confines of the torch. Further, the contact device is configured to provide a curved lead-in from the tube to the at least partially closed portion. The use of separate apparatus for initially closing the tube provides control of the sealed-off portion and prevents an irregular cross-section from being propagated along the length of the tube.