US3562916A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Retrievable borehole extensometer
Assignee: United States Department of the Interior
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Filing: 1969-05-14
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Granted: 1971-02-16
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Expires: 1989-05-14
Abstract
Abstract EXPANDABLE MECHANICAL ANCHORS ARE LINKED TO A SENSORHEAD FOR MEASURING DEFORMATION OF A FORMATION SURROUNDING A BOREHOLD. THE AHCHORS ARE SIMILAR IN OPERATION TO SCISSOR-TYPE JACKS, AND HAVE RADIALLY EXTENDING SHOES FOR SECURING THEM TO THE WALL OF A BOREHOLE. THE SENSOR-HEAD IS DESIGNED FOR MOUNTING WITHIN THE COLLAR OF A BOREHOLE AND HAS A RADIAL ARRAY OF DISPLACEMENT SENSORS. WHEN PLACED FOR OPERATION, THE ANCHORS ARE MOUNTED SERIALLY BEHIND ONE ANOTHER WITHIN A BOREHOLE, WITH AN INDIVIDUAL MECHANICAL LINKAGE EXTENDING FROM EACH ANCHOR AND THROUGH PASSAGES IN INTERMEDIATE ANCHORS, TO JOIN WITH AN INDIVIDUAL DISPLACEMENT SENSOR IN THE SENSOR-HEAD.
Inventors
- 👤 Maynard Duckworth
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 12:19
CPC Classifications
E; E21; E21B; E21B49/00; E21B49/006
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1974-02-15 | 1974-08-17 | 1975-02-16 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-02-15 | 1978-08-17 | 1979-02-16 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-02-15 | 1982-08-17 | 1983-02-16 | $7700.00 | Window Closed / Lapsed |