US3795501A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method of shaping glass sheets to sharp bends
Assignee: PPG Industries Inc
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Filing: 1972-03-29
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Granted: 1974-03-05
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Expires: 1992-03-29
Abstract
Abstract Simultaneously bending pair of glass sheets having a sharply bent portion extending across a portion of the sheet, using a combination of locally applied electrical resistance heating in said sharply bent portion in combination with general overall heating so that a pair of glass sheets bent simultaneously do not fuse together and can be separated after they are shaped, then assembled with a layer of plastic interlayer material therebetween and laminated.
Inventors
- 👤 R Jansson
- 👤 T Reese
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 17:26
CPC Classifications
C; C03; C03B; C03B23/00; C03B23/02; C03B23/023; C03B23/025; C03B23/0258; B; B32; B32B; B32B17/00; B32B17/06; B32B17/10; B32B17/10005; B32B17/1055; B32B17/10761
Claims Analysis
Total Claims: 17
Claim 1
Independent Claim
17 words
In the method according to claim 1, the improvement wherein said voltage does not exceed 220 volts.
Claim 2
Dependent Claim
33 words
In the method as in claim 1, the improvement wherein said treatment is applied simultaneously to two glass sheets while the latter are supported in bending relation to a glass sheet bending mold.
Claim 3
Dependent Claim
205 words
In a method of bending a pair of glass sheets simultaneously to a sharp bend wherein one portion of each said glass sheet is bent sharply with respect to another portion of said glass sheet along a line of sharp bending extending from edge to edge of said glass sheet and aligned with a corresponding line of sharp bending in said other glass sheet, by a combination of general heating supplemented by localized electric heating induced from a strip of electroconductive material disposed between the sheets in a region intersecting said lines of sharp bending and wherein said glass sheets are mounted in pairs in aligned relation to one another on a mold, the improvement comprising superimposing an additional strip of electroconductive material on the upper surface of the upper glass sheet of said pair in said region of sharp bending, each of said strips of electroconductive material being between about one-eighth inch wide and about one-fourth inch wide, simultaneously applying electrical power along the length of each of said strips of a magnitude such that the electrical power applied to each said strip does not exceed 50 watts per inch of length, and bending said pair of glass sheets in the heated region thereof.
Claim 4
Dependent Claim
32 words
In the method as in claim 4, the improvement wherein at least one of said strips is comprised of a flexible metal capable of reuse in bending additional pairs of glass sheets.
Claim 5
Dependent Claim
22 words
In the method as in claim 4, the improvement wherein at least one of said strips is comprised of a carbon tape.
Claim 6
Dependent Claim
24 words
In the method as in claim 4, the improvement wherein said electric power is applied at a voltage that does not exceed 220 volts.
Claim 7
Dependent Claim
33 words
In combination with the method as in claim 4, the additional steps of removing said bent sheets from said mold and laminating them to one another with a layer of plastic resin therebetween.
Claim 8
Dependent Claim
27 words
In the method as in claim 1, the improvement wherein said strip is comprised of a flexible metal capable of reuse in bending an additional glass sheet.
Claim 9
Dependent Claim
17 words
In the method as in claim 1, the improvement wherein said strip is comprised of carbon tape.
Claim 10
Dependent Claim
17 words
In the method as in claim 1, the improvement wherein said strip is comprised of nichrome ribbon.
Claim 11
Dependent Claim
21 words
In the method as in claim 4, the improvement wherein at least one of said strips is comprised of nichrome ribbon.
Claim 12
Dependent Claim
23 words
In the method as in claim 1, the improvement wherein said strip has a resistance of up to about 0.25 ohms per inch.
Claim 13
Dependent Claim
25 words
In the method as in claim 4, the improvement wherein each of said strips has a resistance of up to about 0.25 ohms per inch.
Claim 14
Dependent Claim
20 words
In the method as in claim 1, the improvement which comprises removing said strip after said glass sheet is bent.
Claim 15
Dependent Claim
20 words
In the method as in claim 4, the improvement which comprises removing said strips after said glass sheets are bent.
Claim 16
Dependent Claim
22 words
In the method as in claim 15, the improvement wheRein said strip is capable of reuse in bending an additional glass sheet.
Claim 17
Dependent Claim
23 words
In the method as in claim 16, the improvement wherein said strips are capable of reuse in bending additional pairs of glass sheets.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1977-03-04 | 1977-09-03 | 1978-03-05 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-03-04 | 1981-09-03 | 1982-03-05 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-03-04 | 1985-09-03 | 1986-03-05 | $7700.00 | Window Closed / Lapsed |