Method of manufacturing glass optical elements

• Main Authors: TAKAHARA; HIROAKI, HIROTA; SHIN-ICHIRO, FUJIMOTO; TADAYUKI
• Format: Patent
• Language: English
• Published: 09.06.1998
• Edition: 6
• Subjects: CHEMISTRY; GLASS; MANUFACTURE, SHAPING, OR SUPPLEMENTARY PROCESSES; METALLURGY; MINERAL OR SLAG WOOL

In a method of manufacturing glass optical elements at high operational efficiency, a mass of molten glass which is dropped down is cut at a first step by a wind blast into a sequence of glass gobs each of which is received by a gas stream spouted from a lower portion. Each glass gob is kept afloat with a gas stream spouted to be adjusted to a temperature corresponding to a glass viscosity between 105.5 and 109 poises. Thereafter, the glass gob is pressed in a third step by the use of a pair of forming dies kept at a temperature which corresponds to a glass viscosity between 108 and 1012 poises and which is lower than the temperature of the glass gob. During the third step, the forming dies are cooled to a temperature lower than the temperature corresponding to a glass viscosity of 1013.4 poises with the glass gob kept within the forming dies and are thereafter opened to release a shaped article from the forming dies. A plurality of the glass gobs may be simultaneously processed in parallel through the second and the third steps so that a gob supply pace at the first step is matched with each pace of the second and the third steps.