US3682258A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Rotary-percussion gang drill with circumferentially floating offset bits
Assignee: Hughes Tool Co
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Filing: 1970-06-22
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Granted: 1972-08-08
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Expires: 1990-06-22
Abstract
Abstract A big hole drill in which a multiplicity of parallel downhole percussion drills are secured to a common framework for joint rotation therewith. The drills may be supplied with operating fluid from a common manifold, but each drill hammers independently of the others. The individual drill has a percussion bit secured to and depending from its forward end, the bit being mounted for limited axial movement relative to the drill so that the hammering action of the drill on the bit drives it forward into a rock formation. The improvement lies in mounting those bits which are offset from the axis of rotation of the assembly so that each bit is circumferentially floating with respect to its associated drill. In operation each such offset bit is rotated relative to its drill to bring different portions of its peripheral cutting structure into contact with the sidewall of the kerf formed by the row of bits in which it is located. The inventors have discovered that the offset bits thus mounted are rotated by contact with the formation as the entire assembly is rotated, distributing the wear on the bits and causing them to drill a full size hole.
Inventors
- 👤 Joseph L Kelly Jr
- 👤 Henry B Woods
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 09:47
CPC Classifications
E; E21; E21B; E21B4/00; E21B4/16; E21B10/00; E21B10/46; E21B10/56
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
99 words
A gang percussion drill assembly which comprises: a framework adapted to be secured to and rotated by a drill string member; a plurality of percussion drill means supported by the framework, and having reciprocating hammer elements driven by an operating fluid at a frequency independent of the rotational speed of the assembly; an anvil bit connected with each percussion drill means to communicate periodically with a hammer element; one end of the outermost of said bits including a wheel-like circumferential cutting edge that contains a plurality of wear resistant inserts; said bit being free to rotate circumferentially and freely.
Claim 2
Dependent Claim
99 words
A gang percussion drill assembly which comprises: a framework adapted to be secured to and rotated by a drill string member; a plurality of percussion drill means supported by the framework, and having reciprocating hammer elements driven by an operating fluid at a frequency independent of the rotational speed of the assembly; an anvil bit connected with each percussion drill means to communicate periodically with a hammer element; one end of the outermost of said bits including a wheel-like circumferential cutting edge that contains a plurality of wear resistant inserts; said bit being free to rotate circumferentially and freely.
Claim 3
Dependent Claim
31 words
The percussion drill assembly of claim 1 wherein the freely rotatable bit includes a shank end formed of a surface of revolution secured by retainer means inside the percussion drill means.
Claim 4
Dependent Claim
128 words
A gang percussion drill assembly which comprises: a framework adapted to be secured to and rotated by a drill string member; a plurality of percussion drill means supported by the framework, and having reciprocating hammer elements driven by an operating fluid at a frequency independent of the rotational speed Of the assembly; an anvil bit connected with each percussion drill means to communicate periodically with a hammer element; one end of the outermost of said bits including a wheel-like, circumferential cutting edge that contains a plurality of wear resistant inserts; said bit being rotatable circumferentially during drilling by frictional engagement with a borehole surface; retainer means securing said bit to the associated percussion drill means to enable unrestricted engagement of the bit against a borehole bottom during drilling.
Claim 5
Dependent Claim
128 words
A gang percussion drill assembly which comprises: a framework adapted to be secured to and rotated by a drill string member; a plurality of percussion drill means supported by the framework, and having reciprocating hammer elements driven by an operating fluid at a frequency independent of the rotational speed Of the assembly; an anvil bit connected with each percussion drill means to communicate periodically with a hammer element; one end of the outermost of said bits including a wheel-like, circumferential cutting edge that contains a plurality of wear resistant inserts; said bit being rotatable circumferentially during drilling by frictional engagement with a borehole surface; retainer means securing said bit to the associated percussion drill means to enable unrestricted engagement of the bit against a borehole bottom during drilling.
Claim 6
Dependent Claim
35 words
The percussion drill assembly of claim 3 wherein said retainer means comprises a ring secured in the percussion drill means to protrude into an elongated, circumferential slot to permit selected axial movement of said bit.
Claim 7
Dependent Claim
162 words
A gang percussion drill assembly which comprises: a framework adapted to be secured to and rotated by a drill string member; a plurality of percussion drill means supported by the framework, and having reciprocating hammer elements driven by an operating fluid at a frequency independent of the rotational speed of the assembly; an anvil bit connected with each percussion drill means to communicate periodically with a hammer element; one end of the outermost of said bits including a wheel-like, circumferential cutting edge that contains a multiplicity of wear resistant inserts having cylindrical bodies received in apertures in said bit, and additional such apertures spaced across the end of the bit; said bit being rotatable circumferentially during drilling by frictional engagement with a borehole surface, the rotation thus being independent of the rotational speed of the drill assembly; and retainer means securing said bit to the associated percussion drill means to enable unrestricted engagement of the bit against a borehole bottom during drilling.
Claim 8
Dependent Claim
162 words
A gang percussion drill assembly which comprises: a framework adapted to be secured to and rotated by a drill string member; a plurality of percussion drill means supported by the framework, and having reciprocating hammer elements driven by an operating fluid at a frequency independent of the rotational speed of the assembly; an anvil bit connected with each percussion drill means to communicate periodically with a hammer element; one end of the outermost of said bits including a wheel-like, circumferential cutting edge that contains a multiplicity of wear resistant inserts having cylindrical bodies received in apertures in said bit, and additional such apertures spaced across the end of the bit; said bit being rotatable circumferentially during drilling by frictional engagement with a borehole surface, the rotation thus being independent of the rotational speed of the drill assembly; and retainer means securing said bit to the associated percussion drill means to enable unrestricted engagement of the bit against a borehole bottom during drilling.
References Cited (Backward Citations)
US836494A
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US2942850A
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US3144086A
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FR1338995A
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US3346299A
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US3387673A
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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) | 1975-08-08 | 1976-02-07 | 1976-08-08 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-08-08 | 1980-02-07 | 1980-08-08 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-08-08 | 1984-02-07 | 1984-08-08 | $7700.00 | Window Closed / Lapsed |