Glass manufacturing – Press molding machine
Patent
1996-12-06
1998-10-20
Griffin, Steven P.
Glass manufacturing
Press molding machine
65 68, 65 85, 65226, 65308, 65318, 65321, 65322, 65362, C03B 1100, C03B 1116
Patent
active
058230114
DESCRIPTION:
BRIEF SUMMARY
The invention relates to a method of producing molded glass bodies in accordance with a press molding method, in which molten glass is pressed into a mold with the specified external shape. A molding plug, that determines the internal shape of the molded glass body, is used to press the molten glass at a pressing station. An apparatus particularly suited for executing this method, a glass molding apparatus for producing molded glass bodies using a press molding method.
BACKGROUND OF THE INVENTION
Generally, the methods used for molding glass bodies are those which involve a plurality of press molds disposed with constant angular spacing on a rotatable machine table. After the press mold that is located under a filling apparatus, the so-called feeder, has been filled with a predetermined quantity of molten glass, the table is turned by the angular distance of two adjacent press molds, so that the one now containing the molten glass is positioned under a molding plug. The molding plug, which determines the interior shape of the molded glass body, is lowered into the mold and presses the molten glass into its actual exterior shape. During this procedure, the adjacent mold, which is now located under the feeder, is filled with molten glass. After the minimum time required to complete the forming of the glass body, which is usually in a range of a few seconds, the molding plug is withdrawn from the mold, the machine table is rotated again by the angular distance of two adjacent molds, and the cycle starts over.
The molded glass body remains in its press mold until it has cooled, through radiant emission and in particular through heat dissipation via the press mold, to the point at which it has solidified into a dimensionally-stable body. Typically, the time required for cooling significantly exceeds the pressing time for completing the molding procedure, so the molded glass body has to be cooled in the mold for the duration of several cycles. Therefore, the machine table must be equipped with at least enough molds that the time required for transport from the pressing station to an unmolding station at least corresponds to the time required for cooling. The formula for the cooling time t.sub.k is: is the time the rotating table requires to turn by an angular distance corresponding to the spacing between two adjacent molds. U.S. Pat. No. 3,337,325 discloses a glass-molding machine in which, following the actual forming process, the molding plug remains in the press mold, without considerable pressure, until the molded glass body has completely solidifies. Along with a device the covers the press mold during the solidification process, this measure prevents the formation of internal tension in the molded glass body. The capability of such methods, therefore, does not merely depend on the minimum pressing time required for molding the glass body, but is substantially limited by the time required to cool the molded glass body until it solidifies.
Hence, a significant disadvantage these methods is that the capability of the methods cannot be increased significantly, even with the use of more expensive and more efficient pressing drives, which allow for faster molding of the glass body.
Generally, for lowering the molding plug into the mold, apparatuses are used in which the plug is attached to the front end of a pressing rod, which can be acted upon by the force of a pressure cylinder. The molding plug is either pushed into the mold until the entire volume remaining between the plug and the mold has been filled with molten glass (so-called "stop-free pressing") or until the mold and the plug are in a position clearly defined by contact with a stop ("press to stop") at the end of the pressing process. Usually the pressure cylinder is hydraulically operated.
The disadvantage of this hydraulic drive is that the hydraulic assembly required to control the pressure in the hydraulic cylinder is made relatively complicated by a number of necessary control valves, hydraulic lines, pressure pumps, etc., and is therefore ex
REFERENCES:
patent: 653523 (1900-07-01), O'Neill
patent: 799332 (1905-09-01), Hartman
patent: 1340366 (1920-05-01), Bingham
patent: 1560062 (1925-11-01), Kucera
patent: 1590481 (1926-06-01), Stenhouse et al.
patent: 1611363 (1926-12-01), O'Neill
patent: 1655917 (1928-01-01), Obiol
patent: 1843175 (1932-02-01), Sears
patent: 1909778 (1933-05-01), Marsden
patent: 2053402 (1936-09-01), Le Mare
patent: 2244809 (1941-06-01), Sloan
patent: 2490450 (1949-12-01), Lysle et al.
patent: 2598564 (1952-05-01), Kucera
patent: 2783591 (1957-03-01), Johnson
patent: 3224497 (1965-12-01), Copeland
patent: 3291588 (1966-12-01), Lippmann et al.
patent: 3337325 (1967-08-01), Bittner et al.
patent: 3471281 (1969-10-01), Bittner et al.
patent: 3582303 (1971-06-01), Stutske
patent: 3595637 (1971-07-01), Eldred et al.
patent: 4094657 (1978-06-01), Carmi et al.
patent: 4459147 (1984-07-01), Messina et al.
International Search Report For PCT/DE95/00381, dated Jul. 26, 1995.
International Preliminary Exam Report For PCT/DE95/00381, dated Sep. 4, 1996.
Article from Sprechsaal, vol. 123, No. 9, 1990, p. 885.
Griffin Steven P.
Poting GmbH & Co. KG
LandOfFree
Apparatus for press molding glass bodies does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Apparatus for press molding glass bodies, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Apparatus for press molding glass bodies will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-233065