Patent US3881559A successfully refreshed from Google Patents.
US3881559A
Expired / Lapsed
US
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Method for stress wave drilling
Assignee: United States Department of the Navy
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Filing: 1974-07-10
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Granted: 1975-05-06
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Expires: 1994-07-10
Abstract
Abstract A method and apparatus for drilling a hole in rock. An openended, hardened, drilling head containing a means for creating high-intensity stress waves capable of spalling rock is utilized to drill the hole. A fluid is passed through the drilling head which removes the spalled rock from the drilling head.
Inventors
- 👤 Jay R Allgood
- 👤 Robert J Odello
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 06:40
CPC Classifications
E; E21; E21B; E21B7/00; E21B7/18; E21B7/14; E21B7/15
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
130 words
A method of drilling a bore hole in a rock comprising the steps of: a. moving a bifurcated drill stem downwardly into the bore hole at a controlled rate of movement; b. generating adjacent the bottom of said bore hole stress waves, said stress waves being created by placing a set of three electrodes in said drill stem adjacent to said rock and energizing said electrodes with electrical energy; c. controlling the magnitude and duration of the generated stress waves such that said stess waves spall the rock at the bottom of said bore hole in the vicinity of said electrodes; and d. circulating a flow of drilling liquid downward through one section of said bifurcated drill stem and upwards through the the other section of said bifurcated drill stem.
Claim 2
Independent Claim
130 words
A method of drilling a bore hole in a rock comprising the steps of: a. moving a bifurcated drill stem downwardly into the bore hole at a controlled rate of movement; b. generating adjacent the bottom of said bore hole stress waves, said stress waves being created by placing a set of three electrodes in said drill stem adjacent to said rock and energizing said electrodes with electrical energy; c. controlling the magnitude and duration of the generated stress waves such that said stess waves spall the rock at the bottom of said bore hole in the vicinity of said electrodes; and d. circulating a flow of drilling liquid downward through one section of said bifurcated drill stem and upwards through the the other section of said bifurcated drill stem.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1978-05-05 | 1978-11-04 | 1979-05-06 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-05-05 | 1982-11-04 | 1983-05-06 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-05-05 | 1986-11-04 | 1987-05-06 | $7700.00 | Window Closed / Lapsed |