Patent US2825319A successfully refreshed from Google Patents.
US2825319A
Expired / Lapsed
US
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Free piston engine-compressor apparatus
Assignee: Individual
•
Filing: 1955-04-21
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Granted: 1958-03-04
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Expires: 1975-04-21
Abstract
No abstract record available.
Inventors
- 👤 Herbert W Harrer
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 14:02
CPC Classifications
F; F02; F02B; F02B71/00; F02B71/04
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
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US1416210A
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US1128917A
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GB143319A
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US1620565A
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GB369149A
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US2075133A
Cited
US2115921A
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US2112368A
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US2303794A
Cited
US2473204A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1961-03-03 | 1961-09-02 | 1962-03-04 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1965-03-03 | 1965-09-02 | 1966-03-04 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1969-03-03 | 1969-09-02 | 1970-03-04 | $7700.00 | Window Closed / Lapsed |