Patent US2921676A successfully refreshed from Google Patents.
Patent US3822952A successfully refreshed from Google Patents.
US3822952A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Drill rod coupling
Assignee: Sandvik AB
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Filing: 1972-07-18
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Granted: 1974-07-09
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Expires: 1992-07-18
Abstract
Abstract A drill rod coupling assembly in which each of two rods has at least two spaced sets of threads, the outer of which are coupled by a sleeve so that percussive force is transmitted through the abutting ends of the rods The threads at the end of each rod are designed for surface to surface contact with matching surfaces on a stop in the sleeve. Whenever the outer set of threads is worn or broken they may be cut off and a new end similar to the original end is provided and may be coupled by the sleeve.
Inventors
- 👤 E Johansson
- 👤 K Lumen
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 17:48
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: 3
Claim 1
Independent Claim
308 words
A drill rod coupling assembly comprising two drill rods and a coupling sleeve therefor, each rod being provided with at least two sets of threads, each set intersecting at the lead end thereof with a tapered contact surface and spaced from each other axially along the axis of said rod, the end of each rod being provided with a tapered contact surface for abutting a stop in the sleeve and a transverse end surface for abutting the transverse end surface of the second rod when coupled by said sleeve, said sleeve being provided with two sets of internal threads for engagement with the threads of the outer set of threads of each rod and a stop between said Two sets of internal threads for limiting the movement of a rod into said sleeve, said stop forming a ridge having on both sides tapered contact surfaces spaced axially from the adjacent end of each set of internal threads and matching the tapered contact surface on the two meeting rods, said tapered contact surfaces having an average inclination of 20* to 45* in relation to the drill axis, the space between said at least two sets of threads of each rod being formed by an unthreaded portion representing a tapered reduction in cross-sectional area which develops, when cut transversely therethrough to remove worn threads at the outer end of the rod, a tapered contact surface which matches a tapered contact surface on the sleeve, and which has an axial projection that at least partly extends between the top and the bottom of the thread, all the said tapered contact surfaces being rotation surfaces coaxial with the drill rods, and not more than one of the tapered end portions of said rods, when the transverse end surfaces thereof are in abutment, engaging the stop in said sleeve in surface contact therewith.
Claim 2
Dependent Claim
308 words
A drill rod coupling assembly comprising two drill rods and a coupling sleeve therefor, each rod being provided with at least two sets of threads, each set intersecting at the lead end thereof with a tapered contact surface and spaced from each other axially along the axis of said rod, the end of each rod being provided with a tapered contact surface for abutting a stop in the sleeve and a transverse end surface for abutting the transverse end surface of the second rod when coupled by said sleeve, said sleeve being provided with two sets of internal threads for engagement with the threads of the outer set of threads of each rod and a stop between said Two sets of internal threads for limiting the movement of a rod into said sleeve, said stop forming a ridge having on both sides tapered contact surfaces spaced axially from the adjacent end of each set of internal threads and matching the tapered contact surface on the two meeting rods, said tapered contact surfaces having an average inclination of 20* to 45* in relation to the drill axis, the space between said at least two sets of threads of each rod being formed by an unthreaded portion representing a tapered reduction in cross-sectional area which develops, when cut transversely therethrough to remove worn threads at the outer end of the rod, a tapered contact surface which matches a tapered contact surface on the sleeve, and which has an axial projection that at least partly extends between the top and the bottom of the thread, all the said tapered contact surfaces being rotation surfaces coaxial with the drill rods, and not more than one of the tapered end portions of said rods, when the transverse end surfaces thereof are in abutment, engaging the stop in said sleeve in surface contact therewith.
Claim 3
Dependent Claim
33 words
A drill rod coupling assembly as claimed in claim 1 in which the space between the sets of rod threads has a slightly smaller diameter than the bottom diameter of the rod thread.
References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1977-07-08 | 1978-01-07 | 1978-07-09 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-07-08 | 1982-01-07 | 1982-07-09 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-07-08 | 1986-01-07 | 1986-07-09 | $7700.00 | Window Closed / Lapsed |