US3266845A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Core and blast tunneling method
Assignee: Hughes Tool Co
•
Filing: 1963-08-05
•
Granted: 1966-08-16
•
Expires: 1983-08-05
Abstract
No abstract record available.
Inventors
- 👤 Thomas N Williamson
- 👤 Erwin A Morlan
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 20:58
CPC Classifications
E; E21; E21D; E21D9/00; E21D9/10; E21D9/1053; E21D19/00; E21D19/04
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
107 words
A METHOD OF TUNNEL DRILLING IN A ROCK FORMATIONS COMPRISING A FIRST STEP WHICH INCLUDES THE OPERATION OF DRILLING AN ANNULAR KERF WITH A CORE DRILL WHICH INCLUDES A BARREL SUPPORTING THE NECESSARY CUTTING STRUCTURE ON ITS FORWARD END, EXTENDING SUBSTANTIALLY THE LENGTH OF SUCH KERF AND DEFINING AN APPRECIABLE RADIAL GAP BETWEEN ITS INNER SURFACE AND THE CORE THEREBY FORMED, AND THE OPERATION OF DRILLING AT LEAST ONE BLAST HOLE IN THE CORE, A SECOND STEP OF EXPLODING A CHARGE IN SUCH BLAST HOLE PRIOR TO REMOVING THE CORE DRILL FROM SAID KERF, AND A THIRD STEP OF REMOVING THE ROCK FRAGMENTS RESULTING FROM SUCH EXPLOSION.
Claim 2
Independent Claim
107 words
A METHOD OF TUNNEL DRILLING IN A ROCK FORMATIONS COMPRISING A FIRST STEP WHICH INCLUDES THE OPERATION OF DRILLING AN ANNULAR KERF WITH A CORE DRILL WHICH INCLUDES A BARREL SUPPORTING THE NECESSARY CUTTING STRUCTURE ON ITS FORWARD END, EXTENDING SUBSTANTIALLY THE LENGTH OF SUCH KERF AND DEFINING AN APPRECIABLE RADIAL GAP BETWEEN ITS INNER SURFACE AND THE CORE THEREBY FORMED, AND THE OPERATION OF DRILLING AT LEAST ONE BLAST HOLE IN THE CORE, A SECOND STEP OF EXPLODING A CHARGE IN SUCH BLAST HOLE PRIOR TO REMOVING THE CORE DRILL FROM SAID KERF, AND A THIRD STEP OF REMOVING THE ROCK FRAGMENTS RESULTING FROM SUCH EXPLOSION.
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) | 1969-08-15 | 1970-02-14 | 1970-08-16 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1973-08-15 | 1974-02-14 | 1974-08-16 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1977-08-15 | 1978-02-14 | 1978-08-16 | $7700.00 | Window Closed / Lapsed |