Pressure molded powder metal milled tooth rock bit cone
AssigneeSmith International, Inc.
InventorZhigang Fang
Life of this patent
Estimating the term…
Abstract
A milled tooth shaped rotary cone drill bit for drilling oil wells and the like manufactured using a powder metallurgy process in which an alloy powder is pressure molded into the desired bit shape, sintered, and precision machined.
Claims26
A method of manufacturing a milled tooth rotary rock bit cone comprising:
- pulling a vacuum in a mold defining a milled tooth rotary cone shape having a plurality of teeth;
- injection molding at a pressure less than 100 psi a blend of an alloy powder and a binder into the mold to form a toothed rotary cone shaped green part having a plurality of teeth, said toothed cone green part being complementary to the mold;
- and
- heating the green part.
A method of manufacturing a milled tooth rotary cone rock bit comprising the steps of:
- fabricating a mold defining a milled tooth rotary cone shape having a plurality of teeth and at least one internal bearing surface;
- preparing an alloy powder;
- blending the alloy powder with a binder;
- injection molding the alloy powder and the binder into the mold at a pressure of less than 100 psi to form a toothed rotary cone shaped green part;
- removing the green part from the mold;
- thermally debinding the green part for at least 12 hours at temperature range from approximately 100.degree. F. to approximately 400.degree. F.;
- sintering the alloy powder;
- and
- machining the internal bearing surface.
A milled tooth rotary cone rock drill bit comprising a body including a plurality of teeth and at least one internal bearing surface, the body being formed by preparing an alloy powder, blending the alloy powder with a binder, injection molding the alloy powder and the binder into a mold, at a pressure less than 100 psi, sintering the blend and machining the bearing surface.
Dependencies are inferred from the claim text.