US3792989A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Thermally directed glass cutting
Assignee: PPG Industries Inc
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Filing: 1972-06-21
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Granted: 1974-02-19
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Expires: 1992-06-21
Abstract
Abstract This invention relates to a method and apparatus for cutting glass wherein glass is thermally scored along an intended path of cut, using a non-radiant, surface heating means. A fracture is then directed along the intended path by applying a bending moment about the thermal score.
Inventors
- 👤 J Dahlberg
- 👤 J Oravitz
- 👤 E Michalik
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 21:56
CPC Classifications
C; C03; C03B; C03B33/00; C03B33/09; Y; Y10; Y10T; Y10T225/00; Y10T225/10; Y10T225/12; Y10T225/30; Y10T225/304; Y10T225/307; Y10T225/321; Y10T225/325
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
118 words
A method of thermally scoring a piece of glass along an intended path of cut so as to permit the severance thereof along said path comprising the steps of: aligning at least one hot-gas heater with said path, convectively heating a narrow zone on a surface of said piece along said path by activating said heater, said convective heating being at a temperature and for a time sufficient to introduce a thermal stress throughout the glass beneath said zone without, however, introducing sufficient thermal stress to fracture said glass, contemporaneously therewith providing relative movement between said heater and said glass and maintaining said thermal stress in said glass until it is severed along said intended path of cut.
Claim 2
Independent Claim
118 words
A method of thermally scoring a piece of glass along an intended path of cut so as to permit the severance thereof along said path comprising the steps of: aligning at least one hot-gas heater with said path, convectively heating a narrow zone on a surface of said piece along said path by activating said heater, said convective heating being at a temperature and for a time sufficient to introduce a thermal stress throughout the glass beneath said zone without, however, introducing sufficient thermal stress to fracture said glass, contemporaneously therewith providing relative movement between said heater and said glass and maintaining said thermal stress in said glass until it is severed along said intended path of cut.
Claim 3
Dependent Claim
11 words
A method according to claim 1 wherein said gas is air.
Claim 4
Dependent Claim
36 words
A method according to claim 1 wherein there is provided an in-line array oF hot-gas heaters aligned with said path and said piece is moved relative to said array of heaters while said piece is heated.
Claim 5
Dependent Claim
17 words
A method according to claim 1 wherein said piece is at least about 0.50 inch in thickness.
Claim 6
Dependent Claim
17 words
A method according to claim 1 wherein said piece is at least about 0.75 inch in thickness.
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) | 1977-02-18 | 1977-08-20 | 1978-02-19 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-02-18 | 1981-08-20 | 1982-02-19 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-02-18 | 1985-08-20 | 1986-02-19 | $7700.00 | Window Closed / Lapsed |