Apparatus for inhibiting checks and cracks in the moil or yoke area of TV funnels
AssigneeCorning Glass Works
InventorsStuart M. Dockerty, deceased, by Robert C. Dockerty, executor
Life of this patent
Estimating the term…
Abstract
In the hot forming of TV funnels from molten glass, heat is extracted from the glass in the moil area at a lesser rate than that in adjacent areas by providing relatively thin mold portions in such area and thereby producing more fluid glass which may be formed with lower pressing forces. Further, by reducing the wall thickness of the nose portion of a pressing plunger, internal cooling may be applied to such nose portion during the pressing cycle to cool such nose portion and contract it away from the moil area, and thereby prevent the formation of checks and cracks during plunger withdrawal.
Claims5
Molding apparatus for forming funnel-shaped articles from molten glass having an open upper wide mouth portion and a lower narrow yoke portion while inhibiting the formation of cracks and checks in such yoke area of said articles by minimizing the extraction of heat therefrom during forming to promote the fluidity of the molten glass in such area, said molding apparatus having standard wall portions of conventional thickness extending from about said yoke portion up to said wide mouth portion, said molding apparatus having means adjacent said yoke portion for reducing heat transfer from molten glass supplied to such portion to thereby facilitate glass flow in the area of such yoke portion, said means including relatively thin-wall portions adjacent said yoke portion compared with the thickness of the remaining standard wall portions, and said thin-wall portions being of the same material as that of the remaining wall portions whereby said thin-wall portions extract less heat from the molten glass in contact therewith than the remaining wall portions extract from the molten glass in contact therewith and thereby facilitating the fluidity of the molten glass in the yoke area so as to inhibit the formation of cracks or checks in the yoke portion of the formed funnel-shaped articles.
Dependencies are inferred from the claim text.