US2730706A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Apparatus for indicating age of insulation
Assignee: McGraw Electric Co
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Filing: 1954-10-05
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Granted: 1956-01-10
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Expires: 1974-10-05
Abstract
No abstract record available.
Inventors
- 👤 George H Manke
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 22:58
CPC Classifications
H; H01; H01F; H01F27/00; H01F27/40; H01F27/402; H01F27/404
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
85 words
IN ENCASED ELECTRICAL APPARATUS INSULATED WITH SOLID INSULATION AND IMMERSED WITHIN A DIELECTRIC LIQUID WITHIN THE CASING OF SAID APPARATUS, THE RATE OF DETERIORATION OF SAID SOLID INSULATION INCREASING WITH TEMPERATURE RISE, IN COMBINATION, A THERMALLY RESPONSIVE ACTUATOR IMMERSED AT LEAST IN PART IN SAID DIELECTRIC LIQUID AND INCLUDING AN EXPANSIBLE BELLOWS PARTIALLY FILLED WITH AN EXPANSIBLE LIQUID MOVABLE IN RESPONSE TO HEATING CAUSED BY LOAD CURRENT IN SAID APPARATUS, A ROTATABLE INDICIA CARRYING DIAL, A RACK AND PINION CONNECTED TO SAID BELLOWS FOR DERIVING
Claim 2
Dependent Claim
85 words
IN ENCASED ELECTRICAL APPARATUS INSULATED WITH SOLID INSULATION AND IMMERSED WITHIN A DIELECTRIC LIQUID WITHIN THE CASING OF SAID APPARATUS, THE RATE OF DETERIORATION OF SAID SOLID INSULATION INCREASING WITH TEMPERATURE RISE, IN COMBINATION, A THERMALLY RESPONSIVE ACTUATOR IMMERSED AT LEAST IN PART IN SAID DIELECTRIC LIQUID AND INCLUDING AN EXPANSIBLE BELLOWS PARTIALLY FILLED WITH AN EXPANSIBLE LIQUID MOVABLE IN RESPONSE TO HEATING CAUSED BY LOAD CURRENT IN SAID APPARATUS, A ROTATABLE INDICIA CARRYING DIAL, A RACK AND PINION CONNECTED TO SAID BELLOWS FOR DERIVING
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) | 1959-01-09 | 1959-07-11 | 1960-01-10 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1963-01-09 | 1963-07-11 | 1964-01-10 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1967-01-09 | 1967-07-11 | 1968-01-10 | $7700.00 | Window Closed / Lapsed |