Abstract: The present invention relates to a mandrel for producing glass tubes or rods, particularly for the Vello process, the A-drawing process and preferably for the Danner process. The mandrel comprises a body (1) of a ceramic composite material, and an external metal material jacket (2) surrounding at least a portion of said body, wherein the ceramic composite material has a substantially similar thermal expansion coefficient as the metal material of said jacket. Alternatively the mandrel comprises a self-supporting metal material jacket (22).
Abstract: The invention relates to an apparatus for heat-strengthening glass sheets. In a heat-strengthening station (3) down-stream of a heating furnace the cooling rate of a glass sheet is retarded by means of plates (9, 11), which are set above and below a glass sheet and return some of the thermal radiation back to a glass sheet and slow down convection. Thus, a glass sheet can be heat-strengthened by chilling it at a certain controlled cooling rate. In order to make also the lower plate effectively return some of the termal radiation applied thereto despite the rolls fitted in between, the top surface of lower plate (11) is made highly reflective to thermal radiation and further corrugated in a manner that the ribs of corrugations extend between the rolls close to a glass sheet.
Abstract: In an apparatus for removing molten glass from a bath through a taphole in the wall of a vessel containing the bath, and transporting the molten glass to a processing station, a lance can be moved through the taphole and dipped into the molten glass to pick up glass with the tip portion of the lance. The lance is connected to a connecting element of an operating arrangement by first pivot means and the connecting element is mounted on a support of the operating arrangement by a second pivot spaced from the first pivot. The two pivots have mutually parallel horizontal axes and, to provide for unimpeded pivotal movement of the lance about the first pivot and of the connecting element about the second pivot, the pivots are displaced relative to each other such that the lance is pivotable in a first vertical plane and the connecting element is pivotable in a second vertical plane which is spaced from the first vertical plane.