Patent ID: 11247929

Abstract:
Provided is a sleeve for glass tube molding, the sleeve being capable of: preventing the weakening of clamping force between a metal tip and a metal holding fixture even if the distance between the metal tip and the metal holding fixture increases due to the thermal expansion of a sleeve shaft; and ensuring the coaxiality, on the sleeve shaft, of the metal tip, the metal holding fixture and a refractory tube. This sleeve for glass tube molding comprises: a sleeve shaft; a refractory tube into which the sleeve shaft is inserted in a coaxial manner; a metal tip which is at one end of the refractory tube, and is fixed to the tip of the sleeve shaft; and a metal holding fixture which, at the other end of the refractory tube, is slidably inserted in the sleeve shaft, and clamps and holds the sleeve shaft together with the metal tip. A part of the inner circumferential surface of a through-hole, which is in the metal holding fixture and through which the sleeve shaft is inserted, is in close contact with the outer circumferential surface of the sleeve shaft.