Wear resistant material at the shirttail edge and leading edge of a rotary cone drill bit
View Patent ↗A rotary cone drill bit includes: a body, a leg depending from the body, a bearing shaft extending from the leg and a cone mounted to the bearing shaft. The leg includes a surface edge that is subject to wear during operation of the bit. A bottom surface of a hard material plate having an edge is attached to a conforming surface of the leg in a position where the edge of the hard material plate defines at least a portion of the surface edge of the leg. The attachment of the surfaces is made using a flowable material such as a brazing material.
1. A rotary cone drill bit, comprising:
a body;
a leg depending from the body;
a bearing shaft extending from the leg;
a cone mounted to the bearing shaft;
wherein the leg terminates at a shirttail edge adjacent a base of the cone;
a preformed hard material plate having an edge and a bottom surface; and
an adhesive material attaching the bottom surface of the hard material plate to a substantially conforming surface of the leg, wherein the edge of the hard material plate defines at least a portion of the shirttail edge.
2. The bit of claim 1 wherein the leg includes an outer surface, and the bottom surface of the hard material plate is attached by the adhesive material to a conforming floor surface formed in or by the outer surface of the leg.
3. The bit of claim 2 wherein the adhesive material attaching the bottom surface of the hard material plate to the floor surface of the leg comprises a flowable adhesive material interposed between the bottom surface of the hard material plate and the floor surface of the leg.
4. The bit of claim 3 wherein the flowable adhesive material is a brazing material.
5. The bit of claim 1 wherein the leg includes an outer surface, and a slot is provided in the outer surface extending inwardly from the shirttail edge, the slot being open at the shirttail edge and including a floor surface, and wherein the bottom surface of the hard material plate is attached by the adhesive material to the floor surface provided by the slot in the outer surface of the leg.
6. The bit of claim 5 wherein the adhesive material attaching the bottom surface of the hard material plate to the floor surface of the slot comprises a flowable adhesive material interposed between the bottom surface of the hard material plate and the floor surface of the slot.
7. The bit of claim 6 wherein the flowable adhesive material is a brazing material.
8. The bit of claim 1 wherein the hard material plate has width w and a thickness t, wherein a ratio t/w<0.5.
9. The bit of claim 1 wherein the hard material plate is made of solid tungsten carbide.
10. The bit of claim 1 wherein the hard material plate is one of a polycrystalline diamond compact or an impregnated diamond segment.
11. The bit of claim 1 wherein the hard material plate is a polycrystalline cubic boron nitride compact.
12. The bit of claim 1 wherein the hard material plate is thin and includes a substantially flat top surface.
13. The bit of claim 1 wherein a top surface of the hard material plate is substantially flush with an outer surface of the leg.
14. The bit of claim 1 wherein the preformed hard material plate is at least one preformed hard material plate and at least a portion of the shirttail edge comprises a majority of the shirttail edge.
15. The bit of claim 1 wherein the hard material plate is a tile.
16. The bit of claim 15 further comprising a plurality of adjacent tiles.
17. The bit of claim 16 wherein the plurality of adjacent tiles is a plurality of spaced apart, adjacent tiles.
18. A rotary cone drill bit, comprising:
a body;
a leg depending from the body;
a bearing shaft extending from the leg;
a cone mounted to the bearing shaft;
wherein the leg includes a lateral leading edge;
a preformed hard material plate having an edge and a bottom surface; and
an adhesive material attaching the bottom surface of the hard material plate to a substantially conforming surface of the leg, wherein the edge of the hard material plate defines at least a portion of the lateral leading edge.
19. The bit of claim 18 wherein the leg includes a leading side surface and an outer surface adjacent thereto at the lateral leading edge, and the bottom surface of the hard material plate is attached by the adhesive material to a conforming floor surface formed in or by the outer surface of the leg.
20. The bit of claim 19 wherein the adhesive material attaching the bottom surface of the hard material plate to the floor surface of the leg comprises a flowable adhesive material interposed between the bottom surface of the hard material plate and the floor surface of the leg.
21. The bit of claim 20 wherein the flowable adhesive material is a brazing material.
22. The bit of claim 18 wherein the leg includes a leading side surface and an outer surface adjacent thereto at the lateral leading edge, and a slot is provided in the outer surface extending inwardly from the lateral leading edge, the slot being open at the lateral leading edge and including a floor surface of the leg, and wherein the bottom surface of the hard material plate is attached by the adhesive material to the floor surface provided by the slot in the outer surface of the leg.
23. The bit of claim 22 wherein the adhesive material attaching the bottom surface of the hard material plate to the floor surface of the slot comprises a flowable adhesive material interposed between the bottom surface of the hard material plate and the floor surface of the slot.
24. The bit of claim 23 wherein the flowable adhesive material is a brazing material.
25. The bit of claim 18 wherein the leg includes a leading side surface and an outer surface adjacent thereto at the lateral leading edge, and the bottom surface of the hard material plate is attached by the adhesive material to a conforming floor surface formed in or by the leading side surface of the leg.
26. The bit of claim 25 wherein the adhesive material attaching the bottom surface of the hard material plate to the leading side surface of the leg comprises a flowable adhesive material interposed between the bottom surface of the hard material plate and the floor surface of the leg.
27. The bit of claim 26 wherein the flowable adhesive material is a brazing material.
28. The bit of claim 18 wherein the leg includes a leading side surface and an outer surface adjacent thereto at the lateral leading edge, and a slot is provided in the leading side surface extending inwardly from the lateral leading edge, the slot being open at the lateral leading edge and including a floor surface of the leg, and wherein the bottom surface of the hard material plate is attached by the adhesive material to the floor surface provided by the slot in the leading side surface of the leg.
29. The bit of claim 28 wherein the adhesive material attaching the bottom surface of the hard material plate to the floor surface of the slot comprises a flowable adhesive material interposed between the bottom surface of the hard material plate and the floor surface of the slot.
30. The bit of claim 29 wherein the flowable adhesive material is a brazing material.
31. The bit of claim 18 wherein the hard material plate has width w and a thickness t, wherein a ratio t/w<0.5.
32. The bit of claim 18 wherein the hard material plate is made of solid tungsten carbide.
33. The bit of claim 18 wherein the hard material plate is one of a polycrystalline diamond compact or an impregnated diamond segment.
34. The bit of claim 18 wherein the hard material plate is a polycrystalline cubic boron nitride compact.
35. The bit of claim 18 wherein the hard material plate is thin and includes a substantially flat top surface.
36. The bit of claim 18 wherein a top surface of the hard material plate is substantially flush with an outer surface of the leg.
37. A rotary cone drill bit, comprising:
a body;
a leg depending from the body;
a bearing shaft extending from the leg;
a cone mounted to the bearing shaft;
wherein the leg includes a surface edge;
a preformed hard material plate having an edge and a bottom surface;
an adhesive material attaching the bottom surface of the hard material plate to a substantially conforming surface of the leg, wherein the edge of the hard material plate defines at least a portion of the surface edge of the leg.
38. The bit of claim 37 wherein the surface edge is a leading edge of a shirttail, and the bottom surface of the hard material plate is attached by the adhesive material to the conforming surface of the leg.
39. The bit of claim 38 wherein the adhesive material attaching the bottom surface of the hard material plate to the surface of the leg comprises a flowable adhesive material interposed between the bottom surface of the hard material plate and the conforming surface of the leg.
40. The bit of claim 39 wherein the flowable adhesive material is a brazing material.
41. The bit of claim 38 further comprising a slot formed in the leg extending from the leading edge, the slot being open at the leading edge and wherein the conforming surface of the leg to which the bottom surface of the hard material plate is attached is a floor surface of the slot.
42. The bit of claim 37 wherein the surface edge is a shirttail edge at an end of the leg adjacent a base of the cone, and the bottom surface of the hard material plate is attached by the adhesive material to the conforming surface of the leg.
43. The bit of claim 42 wherein the adhesive material attaching the bottom surface of the hard material plate to the surface of the leg comprises a flowable adhesive material interposed between the bottom surface of the hard material plate and the conforming surface of the leg.
44. The bit of claim 43 wherein the flowable adhesive material is a brazing material.
45. The bit of claim 42 further comprising a slot formed in the leg extending from the shirttail edge, the slot being open at the shirttail edge and wherein the conforming surface of the leg to which the bottom surface of the hard material plate is attached is a floor surface of the slot.
46. The bit of claim 37 wherein the hard material plate has width w and a thickness t, wherein a ratio t/w<0.5.
47. The bit of claim 37 wherein the hard material plate has width w and a thickness t, wherein a ratio t/w<0.2.
48. The bit of claim 37 wherein the hard material plate has width w and a thickness t, wherein a ratio t/w<0.1.
49. The bit of claim 37 wherein the hard material plate is thin and includes a substantially flat top surface.
50. The bit of claim 37 wherein a top surface of the hard material plate is substantially flush with an outer surface of the leg.