Method and apparatus for shaping an elongated glass body

A method for producing an elongated glass body embodied as a glass tube or glass rod, comprising the step of:

• drawing the elongated glass body from a glass melt to a glass tube or glass rod having an initial profile;
• and
• forming said glass tube or glass rod in a hot, malleable state to a glass tube or glass rod having a different profile, comprising the step of:
• passing the elongated glass body, in a hot malleable state, through a nip formed by squeezing rollers, said nip having a nip width which is less than an outer dimension of the initial profile, wherein the position of at least one of the squeezing rollers is varied continuously so that a contact area between the respective squeezing roller and the hot glass body is varied continuously by a continuous axial adjustment of the respective squeezing roller performed in accordance with a predetermined function, wherein the predetermined function is a cyclic reciprocating movement of the respective squeezing roller in an axial direction of said respective squeezing roller.