Rock bit with load stabilizing cutting structure
First Claim
1. A roller cone drill bit comprising:
- a bit body having three legs depending therefrom, each leg having a journal, a roller cone rotatably mounted on each journal, each roller cone having a plurality of cutting elements thereon, the cutting elements arranged in rows on each cone, the rows including at least a gage row and a first row interior of the gage row, the first interior row staggered with respect to the gage row on each of the three cones, wherein a maximum distance between the cutting elements on the gage row and the first interior row on any one of the cones is about zero to 350 percent greater than a minimum distance between the cutting elements on the gage row and the first interior row on any other one of the cones.
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Accused Products
Abstract
One aspect of the invention is a roller cone drill bit including a bit body having three legs depending therefrom, each leg having a journal, a roller cone rotatably mounted on each journal, and each roller cone having a plurality of cutting elements thereon. The cutting elements are arranged in rows on each cone. The rows include at least a gage row and a first row interior of the gage row. The first interior row is staggered with respect to the gage row on each of the three cones. Another aspect of the invention is a roller cone drill bit including a bit body having three legs depending therefrom. Each leg has a journal, a roller cone rotatably mounted on each journal, and each roller cone has a plurality of cutting elements thereon. The cutting elements are arranged in rows on each cone. The rows include at least a gage row and a first row interior of the gage row. The first interior row is staggered with respect to the gage row on at least two of the three cones. The cutting elements have an extension to diameter ratio of at least 0.829.
30 Citations
39 Claims
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1. A roller cone drill bit comprising:
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a bit body having three legs depending therefrom, each leg having a journal, a roller cone rotatably mounted on each journal, each roller cone having a plurality of cutting elements thereon, the cutting elements arranged in rows on each cone, the rows including at least a gage row and a first row interior of the gage row, the first interior row staggered with respect to the gage row on each of the three cones, wherein a maximum distance between the cutting elements on the gage row and the first interior row on any one of the cones is about zero to 350 percent greater than a minimum distance between the cutting elements on the gage row and the first interior row on any other one of the cones. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11)
greater than 0.799, about 20 to 60 percent;
0.709 to 0.799, about 20 to 53 percent;
0.440 to 0.710, about 20 to 43 percent; and
less than 0.440, about 20 to 35 percent.
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11. The roller cone drill bit as defined in claim 1 wherein an area of a hole bottom surface cut by the ones of the cutting elements on the gage row and the first interior row on the three roller cones forms a fraction of a total area of the hole bottom cut by all the cutting elements on all the roller cones defined according to a ratio of cutting element extension to diameter, the ratio and corresponding fraction of the total area being at least one of:
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greater than 0.799, about 30 to 55 percent;
0.709 to 0.799, about 20 to 45 percent;
0.440 to 0.710, about 20 to 33 percent; and
less than 0.440, about 10 to 25 percent.
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12. A roller cone drill bit comprising:
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a bit body having three legs depending therefrom, each leg having a journal, a roller cone rotatably mounted on each journal, each roller cone having a plurality of cutting elements thereon, the cutting elements arranged in rows on each cone, the rows including at least a gage row and a first row interior of the gage row, the first interior row staggered with respect to the gage row on at least two of the three cones, the cutting elements having an extension to diameter ratio of at least 0.829. - View Dependent Claims (13, 14, 15, 16, 17, 18, 19, 20)
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21. A roller cone drill bit, comprising:
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a bit body having three legs depending therefrom, each leg having a journal, a roller cone rotatably mounted on each journal, each roller cone having a plurality of cutting elements thereon, the cutting elements arranged in rows on each cone, the rows including at least a gage row and a first row interior of the gage row;
wherein a fractional amount of a hole bottom area defined by the cutting elements in the gage row and the first interior row is less than a boundary amount defined with respect to a cutting element extension to diameter ratio, the boundary amount substantially conforming to values of the ratio 0.330, 0.436, 0.49, 0.52, 0.56, 0.658, 0.688, 0.747, 0.769, 0.8, 0.875, 1.04 and corresponding fractional amounts of 42.30, 36.44, 48.32, 50.67, 50.65, 51.80, 45.3, 49.53, 54.45, 58.08, 60.88, 61.81, and 65.57 percent. - View Dependent Claims (22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 39)
greater than 0.799, about 30 to 55 percent;
0.709 to 0.799, about 20 to 45 percent;
0.440 to 0.710, about 20 to 33 percent; and
less than 0.440, about 10 to 25 percent.
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32. A roller cone drill bit, comprising:
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a bit body having three legs depending therefrom, each leg having a journal, a roller cone rotatably mounted on each journal, each roller cone having a plurality of cutting elements thereon, the cutting elements arranged in rows on each cone, the rows including at least a gage row and a first row interior of the gage row;
wherein a bottom hole area cut by the cutting elements in the gage row and the first interior row on all the roller cones forms a fractional amount of the total area cut by all the cutting elements on all the roller cones defined with respect to a cutting element extension to diameter ratio, the ratio and corresponding fractional amount of the total area being at least one of;
greater than 0.799, about 20 to 60 percent;
0.709 to 0.799, about 20 to 53 percent;
0.440 to 0.710, about 20 to 43 percent; and
less than 0.440, about 20 to 35 percent. - View Dependent Claims (33, 34, 35, 36, 37, 38)
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Specification