Patent US4549820A successfully refreshed from Google Patents.
US4549820A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Opposed button thrust surfaces for earth boring bits
Assignee: Hughes Tool Co
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Filing: 1984-02-13
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Granted: 1985-10-29
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Expires: 2004-02-13
Abstract
Abstract An earth boring bit has thrust surfaces with enhanced cooling features. The bit has a body with three depending bearing pins. A cutter having an axial cavity is mounted on each bearing pin. The bearing pin and the cavity have mating thrust shoulders. Hard metal inserts or buttons are spaced around each of the shoulders and secured interferingly in mating holes. The buttons in one of the shoulders protrude slightly from the shoulder to allow air to flow past.
Inventors
- 👤 John M. Mullins
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 21:26
CPC Classifications
E; E21; E21B; E21B10/00; E21B10/08; E21B10/22; E21B10/23; F; F16; F16C; F16C33/00; F16C33/02; F16C33/04; F16C33/26; F16C2352/00
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
165 words
In an earth boring bit having a body with a depending bearing pin having a cylindrical outer section and a cylindrical inner section of lesser diameter, defining a bearing pin shoulder at the function of the inner and outer sections, the bit having a cutter with a cavity containing a cutter shoulder positioned opposite the bearing pin shoulder, the improvement comprising: a plurality of cylindrical wear resistant buttons interferingly pressed in a circular array into holes formed in each of the shoulders, the buttons in the cutter shoulder having flat ends that slidingly engage flat ends of the buttons in the bearing pin shoulder, the buttons in one of the shoulders being formed of tool steel and being longer than the holes in which they are secured, causing them to protrude from the shoulder within which they are secured; the buttons in the opposite shoulder being formed of tungsten carbide and having ends which are substantially flush with the shoulder in which they are secured.
Claim 2
Dependent Claim
165 words
In an earth boring bit having a body with a depending bearing pin having a cylindrical outer section and a cylindrical inner section of lesser diameter, defining a bearing pin shoulder at the function of the inner and outer sections, the bit having a cutter with a cavity containing a cutter shoulder positioned opposite the bearing pin shoulder, the improvement comprising: a plurality of cylindrical wear resistant buttons interferingly pressed in a circular array into holes formed in each of the shoulders, the buttons in the cutter shoulder having flat ends that slidingly engage flat ends of the buttons in the bearing pin shoulder, the buttons in one of the shoulders being formed of tool steel and being longer than the holes in which they are secured, causing them to protrude from the shoulder within which they are secured; the buttons in the opposite shoulder being formed of tungsten carbide and having ends which are substantially flush with the shoulder in which they are secured.
Claim 3
Dependent Claim
173 words
In an earth boring bit having a body with a depending bearing pin having a cylindrical outer section and a cylindrical inner section of lesser diameter, defining a bearing pin shoulder at the junction of the inner and outer sections, the bit having a cutter with a cavity containing a cutter shoulder positioned opposite the bearing pin shoulder, the improvement comprising: a plurality of cylindrical wear resistant buttons interferingly pressed in a circular array into holes formed in each of the shoulders, the buttons in the cutter shoulder having flat ends that slidingly engage flat ends of the buttons in the bearing pin shoulder, the buttons in one of the shoulders being longer than the holes in which they are secured, causing them to protrude from the shoulder within which they are secured; the buttons which protude from the holes in which they are secured being formed of tool steel, and having an annular inlay of metal alloy on the ends; and the buttons in the opposite shoulder being formed of tungsten carbide.
Claim 4
Dependent Claim
173 words
In an earth boring bit having a body with a depending bearing pin having a cylindrical outer section and a cylindrical inner section of lesser diameter, defining a bearing pin shoulder at the junction of the inner and outer sections, the bit having a cutter with a cavity containing a cutter shoulder positioned opposite the bearing pin shoulder, the improvement comprising: a plurality of cylindrical wear resistant buttons interferingly pressed in a circular array into holes formed in each of the shoulders, the buttons in the cutter shoulder having flat ends that slidingly engage flat ends of the buttons in the bearing pin shoulder, the buttons in one of the shoulders being longer than the holes in which they are secured, causing them to protrude from the shoulder within which they are secured; the buttons which protude from the holes in which they are secured being formed of tool steel, and having an annular inlay of metal alloy on the ends; and the buttons in the opposite shoulder being formed of tungsten carbide.
References Cited (Backward Citations)
US2086681A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1988-10-28 | 1989-04-29 | 1989-10-29 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1992-10-28 | 1993-04-29 | 1993-10-29 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1996-10-28 | 1997-04-29 | 1997-10-29 | $7700.00 | Window Closed / Lapsed |