Patent US2432276A successfully refreshed from Google Patents.
US2432276A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Frequency determining circuit for telephone ringing current and the like
Assignee: LEICH ELECTRIC CO
•
Filing: 1944-07-24
•
Granted: 1947-12-09
•
Expires: 1964-07-24
Abstract
No abstract record available.
Inventors
- 👤 Hans P Boswau
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 03:09
CPC Classifications
H; H02; H02M; H02M7/00; H02M7/42; H02M7/54; H02M7/58; H02M7/62; H04; H04M; H04M19/00; H04M19/02
Claims Analysis
Total Claims: 0
No claims parsed yet. Click Sync Now above to re-index claims from Google Patents.
References Cited (Backward Citations)
US1307517A
Cited
US1292815A
Cited
US1296269A
Cited
US2035875A
Cited
US2129747A
Cited
US2258303A
Cited
US2313527A
Cited
US2298003A
Cited
US2210211A
Cited
US2265717A
Cited
US2352299A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1950-12-08 | 1951-06-09 | 1951-12-09 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1954-12-08 | 1955-06-09 | 1955-12-09 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1958-12-08 | 1959-06-09 | 1959-12-09 | $7700.00 | Window Closed / Lapsed |