Patent US2956636A successfully refreshed from Google Patents.
US2956636A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Loudspeaker
Assignee: Individual
•
Filing: 1956-06-11
•
Granted: 1960-10-18
•
Expires: 1976-06-11
Abstract
No abstract record available.
Inventors
- 👤 Sipko L Boersma
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 11:15
CPC Classifications
H; H04; H04R; H04R7/00; H04R7/02; H04R7/12; H04R1/00; H04R1/20; H04R1/22; H04R1/30
Claims Analysis
Total Claims: 0
No claims parsed yet. Click Sync Now above to re-index claims from Google Patents.
References Cited (Backward Citations)
US1624357A
Cited
US1608845A
Cited
US1759556A
Cited
US1756838A
Cited
US1821529A
Cited
DE539993C
Cited
US1844605A
Cited
GB382868A
Cited
GB451754A
Cited
US2269284A
Cited
US2717047A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1963-10-18 | 1964-04-18 | 1964-10-18 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1967-10-18 | 1968-04-18 | 1968-10-18 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1971-10-18 | 1972-04-18 | 1972-10-18 | $7700.00 | Window Closed / Lapsed |