Verfahren und Vorrichtung zum Ummanteln einer primären Vorform für eine optische Faser

摘要

A method and device provide an optical fibre secondary preform by collapsing an over-cladding tube 24 on an optical fibre primary preform 22. A hand bar 18 is provided as a first supporter for the optical fibre primary preform 22, which hand bar 18 has a sealing-up part 20 for sealing the over-cladding tube 24. A supporting handle tube 14 is provided as a second supporter for the over-cladding tube 24, the purity of the supporting handle tube 14 being different to that of the over-cladding tube 24. Also the supporting handle tube 14 includes a ring 16 to align the centres of the optical fibre primary preform 22 and the over-cladding tube 24. A vacuum pump 12 evacuates the space between the optical fibre primary preform 22 and the over-cladding tube 24 as the latter is heated by a burner 26, to collapse the over-cladding tube 24 onto the preform 22 as it is rotated on a lathe being held by chucks 10 of the lathe. <IMAGE>