Method of supplying fluid to a rotating tube

DETAILED DESCRIPTION Referring now in more detail to the drawing, there is shown in FIG.
1 a lathe for forming an optical fiber preform by a vapor deposition process wherein chemical reaction products are deposited on the interior surface of a glass preform tube 10.
The lathe includes a frame 11 atop which a headstock 12 and a tailstock 13 are mounted.
The headstock 12 and its internal mechanisms rotatably support and drive a chuck 15 while the tailstock 13 and its internal mechanisms similarly rotatably support and drive chuck 16 about a common axis with that of chuck 15.
Each of the chucks is comprised of radially spaced jaws 18 which are adapted to be moved into and out of gripping engagement with the preform tube or with a tubular extension thereof.
Centrally apertured heat shields 20 are mounted by pendants 21 to both stocks closely adjacent the rotatable chucks.
A hydrogen-oxygen torch 23 is mounted atop a carriage 24 for reciprocal movement between the two heat shields 20 as indicated by arrows 25.
The torch 23 is reciprocated by an unshown automated drive mechanism which can be manually over-ridden and positioned by a handwheel 26.
Similarly, the lateral position of the headstock 12 may be adjusted by a handwheel 27 atop a rail 30 while the position of the tailstock may be manually adjusted over the rail by movement of handwheel 28.
A rotary conduit 32 projects laterally from the headstock 12 to a rotary seal 33 and junction with a stationary conduit 34.
The conduit 34 extends to an unshown vapor stream supply source.
An exhaust hose 37 extends from the tailstock while a scrapper rod 48 extends into the tailstock for cleaning.
FIG.
2 provides a detailed illustration of the rotary seal or joint 33.
The seal includes a tubular member 50 which is rigidly mounted to the rotatable conduit 32 by a compression fit about two O-rings 51 sandwiched between the tubular member and conduit.
Here the conduit 32 is an extension of the preform tube 10.
Alternatively, the seal 33 may be positioned within the headstock 12 with the end of the glass preform tube 10 itself mounted within the rotatable member 50