Abstract: A preform production apparatus for precision press molding, which is downsized but can produce preforms at a lower cost, and a production method thereof using the apparatus are provided. The production method of a preform for precision press molding includes forming a molten glass body C by way of receiving and cutting molten glass A, being flowed continuously from a discharge nozzle 2, by a support member 1 or by way of allowing molten glass to fall in drops from a discharge nozzle 2 and receiving thereof by a support member 1, and transferring the molten glass body C from the support member 1 to a mold 5 by way of displacing the support member to near the mold 5, disposed not to be beneath the discharge nozzle 2, while increasing the viscosity of the molten glass body C on the support member 1.

Abstract: A preform production apparatus for precision press molding, which is downsized but can produce preforms at a lower cost, and a production method thereof using the apparatus are provided. The production method of a preform for precision press molding includes forming a molten glass body C by way of receiving and cutting molten glass A, being flowed continuously from a discharge nozzle 2, by a support member 1 or by way of allowing molten glass to fall in drops from a discharge nozzle 2 and receiving thereof by a support member 1, and transferring the molten glass body C from the support member 1 to a mold 5 by way of displacing the support member to near the mold 5, disposed not to be beneath the discharge nozzle 2, while increasing the viscosity of the molten glass body C on the support member 1.

Abstract: The present invention aims to provide a heating apparatus that can sufficiently suppress the occurrence of striae and the deterioration of optical properties, and that can reduce the maintenance burden. A heating apparatus 10 that is used for heating a flow path 90 for flowing out the molten glass includes an inner wall 21 which forms an entry hole 29 that a tip 91 of the flow path 90 can enter, heating portions 30 for heating the inner wall 21, and a high radiation portion 40 that is made of a high emissivity material. The high radiation portion 40 is arranged so as to face the tip 91 of the flow path 90 as well as a lower part thereof with a space therebetween when the heating apparatus 10 is used.

Abstract: A preform production apparatus for precision press molding, which is downsized but can produce preforms at a lower cost, and a production method thereof using the apparatus are provided. The production method of a preform for precision press molding includes forming a molten glass body C by way of receiving and cutting molten glass A, being flowed continuously from a discharge nozzle 2, by a support member 1 or by way of allowing molten glass to fall in drops from a discharge nozzle 2 and receiving thereof by a support member 1, and transferring the molten glass body C from the support member 1 to a mold 5 by way of displacing the support member to near the mold 5, disposed not to be beneath the discharge nozzle 2, while increasing the viscosity of the molten glass body C on the support member 1.

Abstract: The present invention is that, in a glass passage where it is usual that the flow rate near the center tends to become high, stirring effect for the glass flow is enhanced whereby temperature distribution is made uniform and generation of stria and devitrification is reduced. As a result, there is provided a passage by which glass blocks of highly refractive glass or low-Tg glass in recent years where selection of molding conditions is very difficult are able to be obtained easily and in high quality. Another object is to provide a passage by which simple control in a short distance is made possible whereby miniaturization of the device is possible even in the conventional glass. A passage which is connected to a melted glass vessel and flows out the melted glass which is characterized in that, in the inner wall, the above-mentioned passage has a control board for controlling the flow of the melted glass.

Abstract: A preform producing apparatus, in which the apparatus is downsized and capable of producing preforms at a lower cost, and a molten glass-supporting member used for the preform producing apparatus are provided. A molten glass-supporting member 1 has an openable and closable receiving member 12, of which a receiving surface 13 for receiving molten glass is constructed from a plurality of members 11a and 11b, and a closed state-maintaining member 14 for maintaining the receiving member 12 in a closed state.

Abstract: A high-quality glass gob is easily obtained that is adapted to glass of recent years having higher refractive indices or lower Tg of which the molding temperature is close to or below the temperature of liquid phase. A nozzle, which is connected to a bath of molten glass to flow out the molten glass, has a site disposed where the center of gravity of a cross-section, which is perpendicular to the flow-out direction of the molten glass in the flow path within the nozzle, is shifted from the center of gravity of the cross-section of upstream side. A method for producing a glass shaped body includes steps of melting a raw material of glass within a bath of molten glass, flowing out the molten glass into a molding tool through a nozzle connected to the bath of molten glass, and molding the glass shaped body.