Abstract: A device for the production of a glass rod is provided. The device has a Danner blowpipe constructed to avoid problems attributed to different heat expansion coefficients of the participating materials. The Danner blowpipe has an outer metal jacket surrounding a ceramic body and defines a supply end and a discharge end of the blowpipe. A clamping plate is provided at both the supply and discharge ends. The clamping plate on the discharge end is rigidly joined with a shaft and engages the outer metal jacket at the discharge end. The clamping plate on the supply end is joined in an axially displaceable manner on the shaft, which is rigidly joined with a pressure plate against displacement in an axial direction. A pressure spring is disposed between the pressure plate and the clamping plate on the supply end to urge the plates away from one another.

Abstract: The suction feeder for glass processing includes a housing containing a material; a heatable noble metal or noble metal alloy feed line embedded in the housing in a thermally insulated fashion; a connection element at one end of the feed line for connection with a molten glass supply device and an outlet element for operative engagement with a suction device at the other end of the feed line. To prevent aspiration of bubbles through the feed line the material together with the housing surrounds the heatable feed line and has a composition and/or structure such that in operation a negative pressure can be produced on an outer side of the feed line. Preferably this negative pressure is lower than a minimum internal pressure within the feed line that is established during a suction process.

Abstract: The invention relates to a device for producing a glass rod. The device comprises a Danner blowpipe (1); a nozzle for applying stream of glass to the surface of the Danner blowpipe (1) at one end of said blowpipe (supply end) at a relatively high temperature in order to form a glass film, which is removed at the other end (discharge end) in the form of a bulb at low speed. According to the invention, the device is characterised as follows: the Danner blowpipe (1) is constructed as follows: the peripheral wall consists of an external metal jacket (2) and a ceramic body (3) surrounded by said jacket; a respective clamping plate (6.1, 6.2) is provided at the supply end and at the discharge end; the discharge-end clamping plate (6.2) is connected in a fixed manner to the shaft (6); the supply-end clamping plate (6.

Abstract: Suction feeders of this type are used in the processing of glass and have a heatable feed line (1) consisting of noble metal. Said feed line is embedded in a heat-insulated manner in a housing (4a) with a refractory material (3a). Said housing has a connecting flange (5) for connection to a molten glass supply device and an exit flange (6) for operational engagement with a suction ball (7) which removes the gob from the feed line (1). According to the invention, the material (3a, 4a) surrounding the feed line (1) is configured in such a way in terms of the construction and/or substance that a negative pressure can be produced on the outer periphery of the feed line (1), so that the mechanical compression of the feed line (1) is minimised and air bubbles are not drawn up.