Patent US3507486A successfully refreshed from Google Patents.
US3507486A
Expired / Lapsed
US
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Dual stage compressor spring
Assignee: BERNARD L SCHWALLER
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Filing: 1967-11-13
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Granted: 1970-04-21
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Expires: 1987-11-13
Abstract
No abstract record available.
Inventors
- 👤 Bernard L Schwaller
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-06 04:00
CPC Classifications
F; F04; F04B; F04B39/00; F04B39/10; F04B39/1053; F16; F16F; F16F3/00; F16F3/02; F16F3/04
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) | 1973-04-20 | 1973-10-20 | 1974-04-21 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1977-04-20 | 1977-10-20 | 1978-04-21 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1981-04-20 | 1981-10-20 | 1982-04-21 | $7700.00 | Window Closed / Lapsed |