US4958689A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method of providing a high pressure surge of working fluid to an underground percussive mole
Assignee: Gas Technology Institute
•
Filing: 1989-11-17
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Granted: 1990-09-25
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Expires: 2009-11-17
Abstract
Abstract A manually operated downhole for an underground earth boring apparatus having a pneumatically operated earth boring tool. A drill pipe is connected to the tool and to a source of pneumatic fluid. A valve is positioned in the drill pipe substantially adjacent to the tool between the tool and the source of pneumatic fluid. This downhole valve controls the flow of pneumatic fluid to the tool. The valve is operable in response to pushing or pulling on the drill pipe.
Inventors
- 👤 Douglas W. Lee
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 16:50
CPC Classifications
E; E21; E21B; E21B4/00; E21B4/06; E21B4/14; E21B4/145; E21B34/00; E21B34/06; E21B34/12
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
100 words
A method of providing a high pressure surge of working fluid to an underground percussive mole connected to a rigid drill string having a downhole end and a surface end, the method comprising the steps of: connecting a downhole valve between the percussive mole and the downhole end of the drill string; pulling on the rigid drill string to close the downhole valve; charging the drill string with working fluid until a desired pressure is reached; pushing on the rigid drill string to open the downhole valve and release a high pressure surge of working fluid to the percussive mole.
Claim 2
Independent Claim
100 words
A method of providing a high pressure surge of working fluid to an underground percussive mole connected to a rigid drill string having a downhole end and a surface end, the method comprising the steps of: connecting a downhole valve between the percussive mole and the downhole end of the drill string; pulling on the rigid drill string to close the downhole valve; charging the drill string with working fluid until a desired pressure is reached; pushing on the rigid drill string to open the downhole valve and release a high pressure surge of working fluid to the percussive mole.
References Cited (Backward Citations)
CA563083A
Cited
CA723453A
Cited
US1706072A
Cited
US1807837A
Cited
FR696828A
Cited
US2276979A
Cited
US2311212A
Cited
US2509671A
Cited
US2844166A
Cited
US2858099A
Cited
US2848014A
Cited
US2856009A
Cited
US3148732A
Cited
US3180433A
Cited
US3277922A
Cited
US3425664A
Cited
US3525405A
Cited
US3593786A
Cited
US3642249A
Cited
US3731716A
Cited
US3794128A
Cited
US4022427A
Cited
US3952813A
Cited
US4019592A
Cited
SU611988A1
Cited
US4214638A
Cited
US4249611A
Cited
DE2840564A1
Cited
US4714200A
Cited
US4632191A
Cited
US4596292A
Cited
US4693316A
Cited
US4694913A
Cited
US4834193A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1993-09-24 | 1994-03-26 | 1994-09-25 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1997-09-24 | 1998-03-26 | 1998-09-25 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2001-09-24 | 2002-03-26 | 2002-09-25 | $7700.00 | Window Closed / Lapsed |