Patent US3521029A successfully refreshed from Google Patents.
US3521029A
Expired / Lapsed
US
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Planar heater for melting snow
Assignee: Panasonic Holdings Corp
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Filing: 1968-06-17
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Granted: 1970-07-21
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Expires: 1988-06-17
Abstract
No abstract record available.
Inventors
- 👤 Tadao Toyooka
- 👤 Hiromutsu Ueda
- 👤 Akira Kobayashi
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 18:09
CPC Classifications
H; H05; H05B; H05B3/00; H05B3/20; H05B3/34; H05B3/342; E; E04; E04D; E04D13/00; E04D13/10; E04D13/103; H05B3/10; H05B3/12; H05B3/14; H05B3/145; H05B2203/00; H05B2203/002; H05B2203/003; H05B2203/011; H05B2203/014; H05B2203/016; H05B2203/017; H05B2203/037
Claims Analysis
Total Claims: 0
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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) | 1973-07-20 | 1974-01-19 | 1974-07-21 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1977-07-20 | 1978-01-19 | 1978-07-21 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1981-07-20 | 1982-01-19 | 1982-07-21 | $7700.00 | Window Closed / Lapsed |