Roller cone disk with shaped compacts
View Patent ↗An earth boring drill bit that includes a cutting cone with a cutting disk. Compacts are inserted within the disk having a chisel shaped end set flush with the cutting disk periphery. The compact crests and cutting disk periphery form a generally seamless cutting surface. The cutting cone can further include cutting teeth thereon also having flush mounted compacts. The compacts can be made from a material such as cemented carbide, hardfacing, tungsten, tungsten alloys, tungsten carbide and the cutter made from steel.
1. An earth boring bit comprising:
a body;
a leg depending from the body;
a bearing shaft extending inward from the leg;
a cutting cone mounted on the hearing shaft,
a cutting disk on the cutting cone; and
compacts with the cutting disk that each have an axis oriented relative to an axis of the cutting disk at an angle that differs from an angle between the axis of the cutting disk and an axis of an adjacently located compacts, so that when a row of compacts is set in the cutting disk, the compacts avoid interference between adjacently disposed compacts.
2. The earth boring bit of claim 1 , wherein the compacts have crests arranged along a cutting surface defined by a path on the cutting disk surface.
3. The earth boring bit of claim 1 , wherein the cutting disk has an upper surface, a lower surface that join each other to define a peripheral edge, and wherein the compacts have crests aligned with the peripheral edge.
4. The earth boring bit of claim 3 , wherein the upper and lower surfaces converge towards one another proximate to the peripheral edge and wherein the compacts include flanks depending from the crests, so that when the compacts are disposed in the cutting disk the flanks are flash with the upper and lower surfaces.
5. The earth boring bit of claim 1 , wherein the cutting disk is coaxially disposed on the cutting cone.
6. The earth boring bit of claim 1 , wherein the compact comprises cemented carbide.
7. The earth boring bit of claim 1 , further comprising serrations provided on the cutting disk outer edge between adjacent ones of the compacts.
8. The earth boring bit of claim 7 , wherein the serrations have circumferential extents less than a distance between adjacent compacts.
9. The earth boring bit of claim 1 , further comprising teeth on the cutting cone having compacts flush within the teeth.
10. The earth boring bit of claim 1 , wherein each compact comprises a cylindrically shaped barrel section inserted into a bore in the cutting disk and a chisel shaped tip set flush with an outer surface of the cutting disk and on an axis that is earned at an angle with respect to an axis of the barrel section.
11. The earth boring bit of claim 1 , wherein the compact material hardness is at least from about 1.2 to about 3.3 times as hard as the cutting cone material.