Rock bit with reaming rows

Claim 2

An improved roller cone rock drill bit comprising: a plurality of cone cutters; each cone cutter being rotatably mounted on journals with sliding bearing surfaces and being sealed by an elastomeric cone/journal seal; each cone cutter being further adapted to drill the bottom of a borehole and being characterized by the cooperative operation of primary and secondary cutting structures; the primary and secondary cutting structures being functionally effective to maintain a full gage borehole during rotary drilling; the primary cutting structure comprising a circumferential heel row of wear resistant inserts for cutting the corner of a borehole at substantially gage diameter; a gage surface adjacent to the heel row; a circumferential groove in the gage surface, the groove being functionally effective for chip formation, chip removal and heat dissipation; and the secondary cutting structure comprising a plurality of wear resistant gage inserts for cutting the gage diameter in the sidewall of the borehole, the inserts being rigidly secured in apertures in the circumferential groove and protruding to substantially gage diameter.

Claim 3

The improved roller cone rock drill bit of claim 1 wherein the wear resistant gage inserts protrude 0.04 inches or more above the adjacent surface and have a cross sectional area of 0.08 square inches or less per insert for rock bits having a gage diameter of 63/4 inches or less with the cross sectional area measured perpendicular to the centerline of the insert and 0.04 inches from the outermost limit of the insert.

Claim 4

The improved roller cone rock drill bit of claim 1 wherein the wear resistant gage inserts protrude 0.05 inches or more above the adjacent surface and have a cross sectional area of 0.11 square inches or less per insert for rock bits having a gage diameter greater than 63/4 inches but less than 121/4 inches with the cross sectional area measured perpendicular to the centerline of the insert and 0.04 inches from the outermost limit of the insert.

Claim 5

The improved roller cone rock drill bit of claim 1 wherein the wear resistant gage inserts protrude 0.06 inches or more above the adjacent surface and have a cross sectional area of 0.20 square inches or less per insert for rock bits having a gage diameter of 121/4 inches or above with the cross sectional area measured perpendicular to the centerline of the insert and 0.04 inches from the outermost limit of the insert.

Claim 6

The improved roller cone rock drill bit of claims 2, 3, or 4 wherein there are more gage inserts in the circumferential groove than heel row inserts.

Claim 7

An improved roller cone rock drill bit comprising: a plurality of cone cutters; each cone cutter being rotatably mounted on journals with sliding bearing surfaces and being sealed by an elastomeric cone/journal seal; each cone cutter being further adapted to drill the bottom of a borehole and being characterized by the cooperative operation of primary and secondary cutting structures; the primary and secondary cutting structures being functionally effective to maintain a full gage borehole during rotary drilling; the primary cutting structure comprising a circumferential heel row of steel teeth for cutting the corner of a borehole at substantially gage diameter; a gage surface adjacent to the heel row; a circumferential groove in the gage surface, the groove being functionally effective for chip formation, chip removal and heat dissipation; and the secondary cutting structure comprising a plurality of wear resistant gage inserts for cutting the gage diameter in the sidewall of the borehole, the inserts being rigidly secured in apertures in the circumferential groove and protruding to substantially gage diameter.

Claim 8

An improved roller cone rock drill bit comprising: a plurality of cone cutters; each cone cutter being rotatably mounted on journals with sliding bearing surfaces and being sealed by an elastomeric cone/journal seal; each cone cutter being further adapted to drill the bottom of a borehole and being characterized by the cooperative operation of primary and secondary cutting structures; the primary and secondary cutting structures being functionally effective to maintain a full gage borehole during rotary drilling; the primary cutting structure comprising a circumferential heel row of steel teeth for cutting the corner of a borehole at substantially gage diameter; a gage surface adjacent to the heel row; a circumferential groove in the gage surface, the groove being functionally effective for chip formation, chip removal and heat dissipation; and the secondary cutting structure comprising a plurality of wear resistant gage inserts for cutting the gage diameter in the sidewall of the borehole, the inserts being rigidly secured in apertures in the circumferential groove and protruding to substantially gage diameter.

Claim 9

The improved roller cone rock drill bit of claim 6 wherein the wear resistant gage inserts protrude 0.04 inches or more above the adjacent surface and have a cross sectional area of 0.08 square inches or less per insert for rock bits having a gage diameter of 63/4 inches or less with the cross sectional area measured perpendicular to the centerline of the insert and 0.04 inches from the outermost limit of the insert.

Claim 10

The improved roller cone rock drill bit of claim 6 wherein the wear resistant gage inserts protrude 0.05 inches or more above the adjacent surface and have a cross sectional area of 0.11 square inches or less per insert for rock bits having a gage diameter greater than 63/4 inches but less than 121/4 inches with the cross sectional area measured perpendicular to the centerline of the insert and 0.04 inches from the outermost limit of the insert.

Claim 11

The improved roller cone rock drill bit of claim 6 wherein the wear resistant gage inserts protrude 0.06 inches or more above the adjacent surface and have a cross sectional area of 0.20 square inches or less per insert for rock bits having a gage diameter of 121/4 inches or above with the cross sectional area measured perpendicular to the centerline of the insert and 0.04 inches from the outermost limit of the insert.

Claim 12

The improved roller cone rock drill bit of claims 7, 8 or 9 wherein there are more gage inserts in the circumferential groove than heel row steel teeth.

Claim 13

An improved roller cone rock drill bit comprising: a plurality of cone cutters; each cone cutter being rotatably mounted on journals with sliding bearing surfaces and being sealed by an elastomeric cone/journal seal; each cone cutter being further adapted to drill the bottom of a borehole and being characterized by the cooperative operation of primary and secondary cutting structures; the primary and secondary cutting structures being functionally effective to maintain a full gage borehole during rotary drilling; the primary cutting structure comprising a circumferential heel row of wear resistant inserts for cutting the corner of a borehole at substantially gage diameter; a gage surface adjacent to the heel row; the secondary cutting structure comprising a circumferential gage row of wear resistant gage inserts for cutting the gage diameter in the sidewall of the borehole, the inserts being rigidly secured in apertures in the adjacent gage surface and protruding from the gage surface; and a clearance area between the gage surface and the gage inserts being functionally effective for chip formation, chip removal and heat dissipation.

Claim 14

An improved roller cone rock drill bit comprising: a plurality of cone cutters; each cone cutter being rotatably mounted on journals with sliding bearing surfaces and being sealed by an elastomeric cone/journal seal; each cone cutter being further adapted to drill the bottom of a borehole and being characterized by the cooperative operation of primary and secondary cutting structures; the primary and secondary cutting structures being functionally effective to maintain a full gage borehole during rotary drilling; the primary cutting structure comprising a circumferential heel row of wear resistant inserts for cutting the corner of a borehole at substantially gage diameter; a gage surface adjacent to the heel row; the secondary cutting structure comprising a circumferential gage row of wear resistant gage inserts for cutting the gage diameter in the sidewall of the borehole, the inserts being rigidly secured in apertures in the adjacent gage surface and protruding from the gage surface; and a clearance area between the gage surface and the gage inserts being functionally effective for chip formation, chip removal and heat dissipation.

Claim 15

The improved roller cone rock drill bit of claim 11 wherein the wear resistant gage inserts protrude 0.04 inches or more above the adjacent surface and have a cross sectional area of 0.08 square inches or less per insert for rock bits having a gage diameter of 63/4 inches or less with the cross sectional area measured perpendicular to the centerline of the insert and 0.04 inches from the outermost limit of the insert.

Claim 16

The improved roller cone rock drill bit of claim 11 wherein the wear resistant gage inserts protrude 0.05 inches or more above the adjacent surface and have a cross sectional area of 0.11 square inches or less per insert for rock bits having a gage diameter greater than 63/4 inches but less than 121/4 inches with the cross sectional area measured perpendicular to the centerline of the insert and 0.04 inches from the outermost limit of the insert.

Claim 17

The improved roller cone rock drill bit of claim 11 wherein the wear resistant gage inserts protrude 0.06 inches or more above the adjacent surface and have a cross sectional area of 0.20 square inches or less per insert for rock bits having a gage diameter of 121/4 inches or above with the cross sectional area measured perpendicular to the centerline of the insert and 0.04 inches from the outermost limit of the insert.

Claim 18

The improved roller rock drill bits of claims 12, 13, or 14 wherein there are more gage inserts in the circumferential gage row than heel row inserts.

Claim 19

An improved roller cone rock drill bit comprising: a plurality of cone cutters; each cone cutter being rotatably mounted on journals with sliding bearing surfaces and being sealed by an elastomeric cone/journal seal; each cone cutter being further adapted to drill the bottom of a borehole and being characterized by the cooperative operation of primary and secondary cutting structures; the primary and secondary cutting structures being functionally effective to maintain a full gage borehole during rotary drilling; the primary cutting structure comprising a circumferential heel row of steel teeth for cutting the corner of a borehole at substantially gage diameter; a gage surface adjacent to the heel row; the secondary cutting structure comprising a circumferential gage row of wear resistant gage inserts for cutting the gage diameter in the sidewall of the borehole, the inserts being rigidly secured in apertures in the adjacent gage surface and protruding from the gage surface; and a clearance area between the gage surface and the gage inserts being functionally effective for chip formation, chip removal and heat dissipation.

Claim 20

An improved roller cone rock drill bit comprising: a plurality of cone cutters; each cone cutter being rotatably mounted on journals with sliding bearing surfaces and being sealed by an elastomeric cone/journal seal; each cone cutter being further adapted to drill the bottom of a borehole and being characterized by the cooperative operation of primary and secondary cutting structures; the primary and secondary cutting structures being functionally effective to maintain a full gage borehole during rotary drilling; the primary cutting structure comprising a circumferential heel row of steel teeth for cutting the corner of a borehole at substantially gage diameter; a gage surface adjacent to the heel row; the secondary cutting structure comprising a circumferential gage row of wear resistant gage inserts for cutting the gage diameter in the sidewall of the borehole, the inserts being rigidly secured in apertures in the adjacent gage surface and protruding from the gage surface; and a clearance area between the gage surface and the gage inserts being functionally effective for chip formation, chip removal and heat dissipation.

Claim 21

The improved roller cone rock drill bit of claim 16 wherein the wear resistant gage inserts protrude 0.04 inches or more above the adjacent surface and have a cross sectional area of 0.08 square inches or less per insert for rock bits having a gage diameter of 63/4 inches or less with the cross sectional area measured perpendicular to the centerline of the insert and 0.04 inches from the outermost limit of the insert.

Claim 22

The improved roller cone rock drill bit of claim 16 wherein the wear resistant gage inserts protrude 0.05 inches or more above the adjacent surface and have a cross sectional area of 0.11 square inches or less per insert for rock bits having a gage diameter greater than 63/4 inches but less than 121/4 inches with the cross sectional area measured perpendicular to the centerline of the insert and 0.04 inches from the outermost limit of the insert.

Claim 23

The improved roller cone rock drill bit of claim 16 wherein the wear resistant gage inserts protrude 0.06 inches or more above the adjacent surface and have a cross sectional area of 0.20 square inches or less per insert for rock bits having a gage diameter of 121/4 inches or above with the cross sectional area measured perpendicular to the centerline of the insert and 0.04 inches from the outermost limit of the insert.

Claim 24

The improved roller rock drill bit of claims 17, 18, or 19 wherein there are more gage inserts in the circumferential gage row than heel row steel teeth.

Claim 25

An improved roller cone rock drill bit comprising: a plurality of cone cutters; each cone cutter being rotatably mounted on journals with sliding bearing surfaces and being sealed by an elastomeric cone/journal seal; each cone cutter being further adapted to drill the bottom of a borehole and being characterized by the cooperative operation of primary and secondary cutting structures; the primary and secondary cutting structures being functionally effective to maintain a full gage borehole during rotary drilling; the primary cutting structure comprising a circumferential heel row of wear resistant inserts for cutting the corner of a borehole at substantially gage diameter; a gage surface adjacent to the heel row; the secondary cutting structure comprising a circumferential gage row of wear resistant gage inserts for cutting the gage diameter in the sidewall of the borehole, the inserts being rigidly secured in apertures in the gage surface; the gage inserts having a length substantially equal to or longer than the diameter of the gage inserts; and the gage inserts being secured such that 11% or more of the insert length protrudes beyond the gage surface adjacent to the insert.

Claim 26

An improved roller cone rock drill bit comprising: a plurality of cone cutters; each cone cutter being rotatably mounted on journals with sliding bearing surfaces and being sealed by an elastomeric cone/journal seal; each cone cutter being further adapted to drill the bottom of a borehole and being characterized by the cooperative operation of primary and secondary cutting structures; the primary and secondary cutting structures being functionally effective to maintain a full gage borehole during rotary drilling; the primary cutting structure comprising a circumferential heel row of wear resistant inserts for cutting the corner of a borehole at substantially gage diameter; a gage surface adjacent to the heel row; the secondary cutting structure comprising a circumferential gage row of wear resistant gage inserts for cutting the gage diameter in the sidewall of the borehole, the inserts being rigidly secured in apertures in the gage surface; the gage inserts having a length substantially equal to or longer than the diameter of the gage inserts; and the gage inserts being secured such that 11% or more of the insert length protrudes beyond the gage surface adjacent to the insert.

Claim 27

An improved roller cone rock drill bit comprising: a plurality of cone cutters; each cone cutter being rotatably mounted on journals with sliding bearing surfaces and being sealed by an elastomeric cone/journal seal; each cone cutter being further adapted to drill the bottom of a borehole and being characterized by the cooperative operation of primary and secondary cutting structures; the primary and secondary cutting structures being functionally effective to maintain a full gage borehole during rotary drilling; the primary cutting structure comprising a circumferential heel row of steel teeth for cutting the corner of a borehole at substantially gage diameter; a gage surface adjacent to the heel row; the secondary cutting structure comprising a circumferential gage row of wear resistant gage inserts for cutting the gage diameter in the sidewall of the borehole, the inserts being rigidly secured in apertures in the gage surface; the gage inserts having a length substantially equal to or longer than the diameter of the gage inserts; and the gage inserts being secured such that 11% or more of the insert length protrudes beyond the gage surface adjacent to the insert.

Claim 28

An improved roller cone rock drill bit comprising: a plurality of cone cutters; each cone cutter being rotatably mounted on journals with sliding bearing surfaces and being sealed by an elastomeric cone/journal seal; each cone cutter being further adapted to drill the bottom of a borehole and being characterized by the cooperative operation of primary and secondary cutting structures; the primary and secondary cutting structures being functionally effective to maintain a full gage borehole during rotary drilling; the primary cutting structure comprising a circumferential heel row of steel teeth for cutting the corner of a borehole at substantially gage diameter; a gage surface adjacent to the heel row; the secondary cutting structure comprising a circumferential gage row of wear resistant gage inserts for cutting the gage diameter in the sidewall of the borehole, the inserts being rigidly secured in apertures in the gage surface; the gage inserts having a length substantially equal to or longer than the diameter of the gage inserts; and the gage inserts being secured such that 11% or more of the insert length protrudes beyond the gage surface adjacent to the insert.

Claim 29

The improved roller cone rock drill bit of claim 1, 6, 11, 16, 21 or 22 wherein each cutter is rotatably mounted on a journal bearing and sealed by an o-ring seal.

Claim 30

An improved roller cone rock drill bit comprising: a plurality of cone cutters; each cone cutter being rotatably mounted on journals with sliding bearing surfaces and being sealed by an elastomeric cone/journal seal; each cone cutter being further adapted to drill the bottom of a borehole; each cone cutter having a circumferential heel row of steel teeth which do not cut the borehole to full gage diameter; each cone cutter having a gage surface adjacent to the heel row; each cone cutter having a circumferential gage row of wear resistant gage inserts for reaming the sidewall of the borehole to substantially gage diameter; the wear resistant gage inserts being rigidly secured in apertures in gage surface and protruding from the gage surface; and a clearance area between the gage surface and the gage inserts being functionally effective for chip formation, chip removal and heat dissipation.

Claim 31

An improved roller cone rock drill bit comprising: a plurality of cone cutters; each cone cutter being rotatably mounted on journals with sliding bearing surfaces and being sealed by an elastomeric cone/journal seal; each cone cutter being further adapted to drill the bottom of a borehole; each cone cutter having a circumferential heel row of steel teeth which do not cut the borehole to full gage diameter; each cone cutter having a gage surface adjacent to the heel row; each cone cutter having a circumferential gage row of wear resistant gage inserts for reaming the sidewall of the borehole to substantially gage diameter; the wear resistant gage inserts being rigidly secured in apertures in gage surface and protruding from the gage surface; and a clearance area between the gage surface and the gage inserts being functionally effective for chip formation, chip removal and heat dissipation.

Claim 32

The improved roller cone rock drill bit of claim 24 wherein each cone cutter is rotatably mounted on a journal bearing and sealed by an o-ring seal.

Claim 33

An improved roller cone rock drill bit comprising: a plurality of cone cutters; each cone cutter being rotatably mounted on journals with sliding bearing surfaces and being sealed by an elastomeric cone/journal seal; each cone cutter being further adapted to drill the bottom of a borehole; each cone cutter having a circumferential heel row of wear resistant inserts which do not cut the borehole to full gage diameter; each cone cutter having a gage surface adjacent to the heel row; each cone cutter having a circumferential gage row of wear resistant gage inserts for reaming the sidewall of the borehole to substantially gage diameter; the wear resistant gage inserts being rigidly secured in apertures in gage surface and protruding from the gage surface; and a clearance area between the gage surface and the gage inserts being functionally effective for chip formation, chip removal and heat dissipation.

Claim 34

An improved roller cone rock drill bit comprising: a plurality of cone cutters; each cone cutter being rotatably mounted on journals with sliding bearing surfaces and being sealed by an elastomeric cone/journal seal; each cone cutter being further adapted to drill the bottom of a borehole; each cone cutter having a circumferential heel row of wear resistant inserts which do not cut the borehole to full gage diameter; each cone cutter having a gage surface adjacent to the heel row; each cone cutter having a circumferential gage row of wear resistant gage inserts for reaming the sidewall of the borehole to substantially gage diameter; the wear resistant gage inserts being rigidly secured in apertures in gage surface and protruding from the gage surface; and a clearance area between the gage surface and the gage inserts being functionally effective for chip formation, chip removal and heat dissipation.

Claim 35

The improved roller cone rock drill bit of claim 26 wherein each cone cutter is rotatably mounted on a journal bearing and sealed by an o-ring seal.

Claim 36

The improved roller cone rock drill bit of claim 1, 6, 11, 16, 21, 22, 24, 25, 26, or 27 further comprising: a plurality of journal segment arms; a stabilizer pad on each journal segment arm, protruding to nominal gage diameter and functionally effective as an additional gage maintaining structure; and a plurality of wear resistant inserts in each stabilizer pad.