Patent US3377020A successfully refreshed from Google Patents.
US3377020A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Calcium sulphate centrifuging
Assignee: Bird Machine Co Inc
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Filing: 1966-03-16
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Granted: 1968-04-09
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Expires: 1986-03-16
Abstract
No abstract record available.
Inventors
- 👤 Eric G Piper
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 20:09
CPC Classifications
C; C01; C01F; C01F11/00; C01F11/46; C04; C04B; C04B11/00; C04B11/26
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
70 words
A PROCESS OF DELIQUORING A SLURRY OF CALCIUM SULPHATE HEMI-HYDRATE WHICH COMPRISES SUBJECTING THE SLURRY AT A TEMPERATUE BELOW ITS CRITICAL INVERSION TEMPERARTURE TO A CENTRIFUGING OPERATION IN WHICH A PARTIALLY DRY SOLIDS FRACTION IS CONTINUOUSLY SEPARATED FRM THE LIQUID FRACTION AND DISCHARGED TO A SOLIDS RECEIVING COMPARTMENT AND SUPPLYING HEAT TO SAID COMPARTMENT SUFFICIENT TO MAINTAIN THE INTERIOR WALL SURFACES THEREOF AT A TEMPERATURE ABOVE SAID CRITICAL INVERSION TEMPERATURE.
Claim 2
Dependent Claim
70 words
A PROCESS OF DELIQUORING A SLURRY OF CALCIUM SULPHATE HEMI-HYDRATE WHICH COMPRISES SUBJECTING THE SLURRY AT A TEMPERATUE BELOW ITS CRITICAL INVERSION TEMPERARTURE TO A CENTRIFUGING OPERATION IN WHICH A PARTIALLY DRY SOLIDS FRACTION IS CONTINUOUSLY SEPARATED FRM THE LIQUID FRACTION AND DISCHARGED TO A SOLIDS RECEIVING COMPARTMENT AND SUPPLYING HEAT TO SAID COMPARTMENT SUFFICIENT TO MAINTAIN THE INTERIOR WALL SURFACES THEREOF AT A TEMPERATURE ABOVE SAID CRITICAL INVERSION TEMPERATURE.
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) | 1971-04-09 | 1971-10-09 | 1972-04-09 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1975-04-09 | 1975-10-09 | 1976-04-09 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1979-04-09 | 1979-10-09 | 1980-04-09 | $7700.00 | Window Closed / Lapsed |