US3830540A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Treating glass sheets
Assignee: PPG Industries Inc
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Filing: 1973-01-05
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Granted: 1974-08-20
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Expires: 1993-01-05
Abstract
Abstract Thermal treatment of glass sheets, particularly to impart a controlled temper that is approximately unchanging from sheet to sheet, on a high speed, mass production basis in such a manner that each glass sheet so treated has acceptable optical properties a so-called flood quenching, which comprises applying a plurality of continuous or approximately continuous flows of a liquid selected for its heat exchange properties across the entire surface of the sheet and removing the flows of liquid from contact with the sheet after the liquid has moved across the surface of the sheet and has cooled the sheet sufficiently to impart a temper of the desired magnitude. A novel type of glass gripping tongs is provided to minimize any interference with free movement of the liquid flows that would be expected from using tongs. Means is provided to avoid top edge breakage and means is provided to minimize bubbles entrapped within the tempering liquid when the latter is applied to a glass surface.
Inventors
- 👤 L Sperry
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 11:54
CPC Classifications
C; C03; C03B; C03B27/00; C03B27/02; C03B27/022; C03B27/024; B; B66; B66C; B66C1/00; B66C1/10; B66C1/42; B66C1/44; B66C1/48; C03B35/00; C03B35/14; C03B35/20
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
200 words
In combination, a self closing tong for suspending a glass sheet during thermal treatment having an apertured member, a pair of upper tong arms pivoted to one another and to said apertured member at the upper ends of said upper tong arms, a pair of lower tong arms, each pivoted at its upper end to the lower end of one or the other of said upper tong arms, a common hinge pin pivotally interconnecting said lower tong arms together between their upper and lower ends, and a thin, vertically oriented member attached to the lower end of each of said lower tong arms and aligned with a thin, vertically oriented member attached to the lower end of the other tong arm, each of said vertically oriented members having a thin, convexly shaped edge surface extending vertically and arranged in such a manner that when said tong hangs freely, said thin edge surface of said vertically oriented members engage the opposite major surfaces of said glass sheet near the upper edge thereof, and screen means having a minimum length equal to the entire length of the upper edge of said glass sheet positioned in closely spaced relation to said upper edge.
Claim 2
Dependent Claim
200 words
In combination, a self closing tong for suspending a glass sheet during thermal treatment having an apertured member, a pair of upper tong arms pivoted to one another and to said apertured member at the upper ends of said upper tong arms, a pair of lower tong arms, each pivoted at its upper end to the lower end of one or the other of said upper tong arms, a common hinge pin pivotally interconnecting said lower tong arms together between their upper and lower ends, and a thin, vertically oriented member attached to the lower end of each of said lower tong arms and aligned with a thin, vertically oriented member attached to the lower end of the other tong arm, each of said vertically oriented members having a thin, convexly shaped edge surface extending vertically and arranged in such a manner that when said tong hangs freely, said thin edge surface of said vertically oriented members engage the opposite major surfaces of said glass sheet near the upper edge thereof, and screen means having a minimum length equal to the entire length of the upper edge of said glass sheet positioned in closely spaced relation to said upper edge.
Claim 3
Dependent Claim
14 words
The combination as in claim 1, wherein said screen means is channel-shaped in cross-section.
Claim 4
Dependent Claim
71 words
The combination as in claim 2, wherein said channel-shaped screen means comprises an inverTed channel-shaped screen comprising a web portion adapted to be spaced vertically a short distance from the upper edge of said glass sheet and a pair of walls extending downward from the longitudinal side edges of said web portion and having their lower edge portions adapted to engage said glass sheet near the upper edge of the latter.
Claim 5
Dependent Claim
17 words
The combination as in claim 1, wherein said vertically oriented members of said tong are disc shaped.
Claim 6
Dependent Claim
18 words
The combination as in claim 1, wherein said edge surfaces have a horizontal dimension of approximately 1/16 inch.
Claim 7
Dependent Claim
27 words
The combination as in claim 1, wherein said glass engaging elements of said tong are composed of curved segments of wire of a rigid, refractory, non-sticking material.
References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1977-08-19 | 1978-02-18 | 1978-08-20 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-08-19 | 1982-02-18 | 1982-08-20 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-08-19 | 1986-02-18 | 1986-08-20 | $7700.00 | Window Closed / Lapsed |