Patent US3343369A successfully refreshed from Google Patents.
US3343369A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method of inhibiting earth subsidence over a cavity
Assignee: PPG Industries Inc
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Filing: 1963-11-14
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Granted: 1967-09-26
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Expires: 1983-11-14
Abstract
No abstract record available.
Inventors
- 👤 John R Polhamus
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 04:29
CPC Classifications
E; E21; E21F; E21F15/00
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
55 words
A METHOD OF PROVIDING AGAINST SUBSIDENCE OF THE EARTH OVER AN INACTIVATED FLUID CONTAINING CAVITY WHICH COMPRISES SEALING SAID CAVITY AGAINST FLOW OF FLUID THEREFROM AND ADDING FLUID TO SAID SEALED CAVITY TO ESTABLISH AND MAINTAIN A FLUID PRESSURE AGAINST THE ROOF OF THE CAVITY SUFFICIENT TO INHIBIT SUBSIDENCE OF THE EARTH OVER SAID CAVITY.
Claim 2
Independent Claim
55 words
A METHOD OF PROVIDING AGAINST SUBSIDENCE OF THE EARTH OVER AN INACTIVATED FLUID CONTAINING CAVITY WHICH COMPRISES SEALING SAID CAVITY AGAINST FLOW OF FLUID THEREFROM AND ADDING FLUID TO SAID SEALED CAVITY TO ESTABLISH AND MAINTAIN A FLUID PRESSURE AGAINST THE ROOF OF THE CAVITY SUFFICIENT TO INHIBIT SUBSIDENCE OF THE EARTH OVER SAID CAVITY.
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) | 1970-09-25 | 1971-03-27 | 1971-09-26 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1974-09-25 | 1975-03-27 | 1975-09-26 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1978-09-25 | 1979-03-27 | 1979-09-26 | $7700.00 | Window Closed / Lapsed |