US3645570A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Coupling thread for percussion drill rods
Assignee: Sandvik AB
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Filing: 1970-08-12
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Granted: 1972-02-29
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Expires: 1990-08-12
Abstract
Abstract In a connection between two threaded sections of percussion drill rods held together by a threaded coupling sleeve, the rod threads and sleeve threads have- in longitudinal sectionstraight flank portions and straight (or only slightly curved) top and bottom portions, the flank portions being connected by curved portions. In coupled state, there is abutting contact (between rod and sleeve threads) only as regards the straight flank portions.
Inventors
- 👤 Ernst Lennart Johansson
- 👤 Karl Lennart Gosta Lumen
- 👤 Hans Per Olof Lundstrom
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 15:55
CPC Classifications
E; E21; E21B; E21B17/00; E21B17/02; E21B17/04; E21B17/042; E21B17/0426; Y; Y10; Y10T; Y10T403/00; Y10T403/57; Y10T403/5746
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
123 words
Thread joint for percussion drill rods comprising a rod thread and a coupling sleeve thread, the threads having one start and both the rod and sleeve thread having in longitudinal section substantially straight tops and bottoms, the improvement according to which both threads are cylindrical and have flanks that along their whole abutting contact portion are straight and adjoin straight top and bottom portions by portions that are curved in longitudinal section, the abutting flanks being inclined 35* to the drill axis, and the pitch angle of the thread being 6.5*-9*, the curved portion at the bottom of the abutting flank of the rod thread having a smaller radius than that of the adjoining curved portion of the top of the sleeve thread.
Claim 2
Dependent Claim
123 words
Thread joint for percussion drill rods comprising a rod thread and a coupling sleeve thread, the threads having one start and both the rod and sleeve thread having in longitudinal section substantially straight tops and bottoms, the improvement according to which both threads are cylindrical and have flanks that along their whole abutting contact portion are straight and adjoin straight top and bottom portions by portions that are curved in longitudinal section, the abutting flanks being inclined 35* to the drill axis, and the pitch angle of the thread being 6.5*-9*, the curved portion at the bottom of the abutting flank of the rod thread having a smaller radius than that of the adjoining curved portion of the top of the sleeve thread.
Claim 3
Dependent Claim
128 words
Thread joint for percussion drill rods comprising a rod thread and a coupling sleeve thread, the threads having one start and both the rod and sleeve thread having in longitudinal section substantially straight tops and bottoms, the improvement according to which both threads are cylindrical and have flanks that along their whole abutting contact portion are straight and adjoin straight top and bottom portions by portions that are curved in longitudinal section, the abutting flanks being inclined 35* to the drill axis, and the pitch angle of the thread being 6.5*-9*, the curved portion at the top of the nonabutting flank of the sleeve thread having a greater radius of curvature than that of the curved portion at the top of the abutting flank of the sleeve thread.
Claim 4
Dependent Claim
128 words
Thread joint for percussion drill rods comprising a rod thread and a coupling sleeve thread, the threads having one start and both the rod and sleeve thread having in longitudinal section substantially straight tops and bottoms, the improvement according to which both threads are cylindrical and have flanks that along their whole abutting contact portion are straight and adjoin straight top and bottom portions by portions that are curved in longitudinal section, the abutting flanks being inclined 35* to the drill axis, and the pitch angle of the thread being 6.5*-9*, the curved portion at the top of the nonabutting flank of the sleeve thread having a greater radius of curvature than that of the curved portion at the top of the abutting flank of the sleeve thread.
Claim 5
Dependent Claim
126 words
Thread joint for percussion drill rods comprising a rod thread and a coupling sleeve thread, the threads having one start and both the rod and sleeve thread having in longitudinal section substantially straight tops and bottoms, the improvement according to which both threads are cylindrical and have flanks that along their whole abutting contact portion are straight and adjoin straight top and bottom portions by portions that are curved in longitudinal section, the curved portion at the bottom of the abutting flank of the rod thread having a greater radius of curvature than that of the curved portion at the top of the same flank, the abutting flanks being inclined 35* to the drill axis, and the pitch angle of the thread being 6.5*- 9* .
Claim 6
Dependent Claim
126 words
Thread joint for percussion drill rods comprising a rod thread and a coupling sleeve thread, the threads having one start and both the rod and sleeve thread having in longitudinal section substantially straight tops and bottoms, the improvement according to which both threads are cylindrical and have flanks that along their whole abutting contact portion are straight and adjoin straight top and bottom portions by portions that are curved in longitudinal section, the curved portion at the bottom of the abutting flank of the rod thread having a greater radius of curvature than that of the curved portion at the top of the same flank, the abutting flanks being inclined 35* to the drill axis, and the pitch angle of the thread being 6.5*- 9* .
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) | 1975-02-28 | 1975-08-30 | 1976-02-29 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-02-28 | 1979-08-30 | 1980-02-29 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-02-28 | 1983-08-30 | 1984-02-29 | $7700.00 | Window Closed / Lapsed |