Patent US3686374A successfully refreshed from Google Patents.
US3686374A
Expired / Lapsed
US
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Gas assisted electrostatic pinning
Assignee: EIDP Inc
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Filing: 1970-03-23
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Granted: 1972-08-22
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Expires: 1990-03-23
Abstract
Abstract In the electrostatic pinning of dielectric film onto a moving surface, the improvement comprising surrounding the electrostatic source with a gas in which a specific minimum current can be generated.
Inventors
- 👤 William E Hawkins
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 23:10
CPC Classifications
B; B29; B29C; B29C48/00; B29C48/25; B29C48/88; B29C48/911; B29C48/9135; B29C48/915; B29C48/9165; B29C48/03; B29C48/07; B29C48/08; B29C48/914
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
35 words
A process of claim 1 wherein the difference between voltage at threshold current and the voltage at spark breakdown of the gas is at least about 2 kilovolts, as determined by the current generation test.
Claim 2
Dependent Claim
10 words
A process of claim 1 wherein the gas is oxygen.
Claim 3
Dependent Claim
10 words
A process of claim 1 wherein the gas is nitrogen.
Claim 4
Dependent Claim
10 words
A process of claim 1 wherein the gas is helium.
Claim 5
Dependent Claim
23 words
A process of claim 1 wherein the gas is a halocarbon selected from at least one of tetrachloroethane, dichlorodifluoromethane, carbon tetrachloride and dichlorotetrafluoroethane.
Claim 6
Dependent Claim
12 words
A process of claim 1 wherein the film is thermoplastIc polymeric film.
Claim 7
Dependent Claim
21 words
A process of claim 7 wherein the film is a freshly extruded web and the moving surface is a quenching surface.
Claim 8
Dependent Claim
13 words
A process of claim 8 wherein the film consists essentially of polyethylene terephthalate.
Claim 9
Dependent Claim
19 words
A process of claim 1 wherein the electrostatic charge is applied across substantially the full width of the film.
Claim 10
Dependent Claim
18 words
A process of claim 1 wherein the electrostatic charge is applied at the edges of the thermoplastic sheet.
References Cited (Backward Citations)
US3470274A
Cited
US3520959A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1975-08-22 | 1976-02-21 | 1976-08-22 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-08-22 | 1980-02-21 | 1980-08-22 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-08-22 | 1984-02-21 | 1984-08-22 | $7700.00 | Window Closed / Lapsed |