Patent ID: 8726694

Claim:
A method for manufacturing glass tubes having a predetermined inner profile, in which method: molten glass emerges from an outlet orifice of a melt feed and is drawn over a shaping body so as to form a hollow drawing bulb, and the drawing bulb is drawn over a profile forming body positioned downstream of the shaping body so that an inner circumferential surface of the drawing bulb is deformed while abutting against an outer surface of the profile forming body to form a glass tube having the predetermined inner profile, and in which method said glass tube is severed in a region below the drawing bulb to provide a region with free access below said shaping body and said profile forming body is moved in an axial direction from below the shaping body via an inner space of the glass tube or said profile forming body is inserted in an inner bore of a shaft supporting said shaping body from above and moved in the axial direction via said inner bore until reaching an operational position in the inner space of said glass tube for positioning said profile forming body in said operational position for the first time or after replacement of a profile forming body previously used in said method.