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AssigneeOwens-Illinois Glass Container Inc.
InventorsMarvin L. Barkhau, Frank J. DiFrank, Paul W. L. Graham, Harry N. Mills
Estimating the term…
A glass bottle forming system is described in which a main glass melter is connected to a forehearth with a fairly conventional feeder provided at the delivery end of the forehearth. The feeder opening in the bottom of the forehearth is closed by a first orifice member through which a molten core glass will flow. Beneath the first orifice there is positioned a second orifice member that has an orifice that is slightly larger than the orifice in the first orifice member. A small melter contains a glass of essentially the same composition as that in the main melter, but with a coefficient of expansion slightly less than that of the core glass. This lower expansion glass is fed to the second orifice member so that it can flow out of the orifice with the core glass in surrounding relationship with respect thereto. The skin glass melter is connected to the second orifice member by a gravity feed system in which the connection is thermally controlled so that the viscosity of the two glasses are maintained essentially the same. Two embodiments of the skin melter and the second orifice are disclosed. In one embodiment the second orifice is vertically adjustable so as to vary the volume of skin glass flow relative to the core glass flow. The second embodiment has the second orifice supporting an annular bushing that is vertically adjustable and it cooperates with the bottom of the upper orifice member to regulate the flow of glass into surrounding relationship to the core glass coming through the first orifice member.
A multiple gob glass feeder for feeding plural gobs of a molten core glass that are encased in molten skin glass of a composition that has a lower coefficient of expansion comprising, a generally horizontal forehearth which has a feeder bowl closing one end and a supply of molten soda-limesilica, core forming glass connected to the other end of said forehearth;
The method of forming plural, laminated glass articles from discrete composite charges of molten soda-lime-silica glass having a core of molten glass surrounded by a thin layer of molten skin glass comprising, continuously flowing molten core glass through a forehearth to a feeder bowl having a plurality of downwardly opening flow orifices in the bottom thereof, with rotating tube and plunger means for controlling the flow of core glass through said orifices, continuously flowing the molten skin glass into surrounding relationship to the core glass as it passes downwardly out of said orifices, said core glass and skin glass having log viscosity differences no greater than 00.5% and the skin glass being essentially of the same composition as the core glass with the exception that it has a coefficient of expansion of 3-12.times.10.sup.-7 in/in..degree.C. less, severing said flow of core and skin glass into composite charges and forming said charges into articles (bottles) by the usual forming technique of pressing, pressing and blowing or blowing and blowing.
A strengthened, lightweight, blown glass container formed from a composite glass gob having a soda. lime, silica glass core surrounded by a soda, lime silica skin glass with the skin glass layer in the blown container being 0.003"-0.010" thick and having an expansion coefficient of 3-12.times.10.sup.-7 in/in. .degree. C. less than that of the core glass.
Dependencies are inferred from the claim text.