Abstract: A rock bit for drilling subterranean formations is lubricated with a grease composition comprising molybdenum disulfide particles in the range of from 6 to 14% by weight, copper particles in the range of from 3 to 9% by weight, a metal soap thickener in the range of from 4 to 10% by weight, and a balance of primarily hydrocarbon oil.

Abstract: In conventional rock bits which utilize a lubrication system, a pressure venting function for a radial type O-ring bearing seal is accomplished by allowing the excessive lubricant pressure buildup within the rock bit to bulge the O-ring into a venting pocket or cavity located in the seal gland boss thus breaking the sealing contact and venting the excess pressure without significant loss or further contamination of the bearing lubricant with harmful fluids and abrasives.

Abstract: A method and apparatus is disclosed for monitoring the gage diameter of a rock bit which utilizes electronic sensing principles. The use of electronic sensing devices provides continuous measurement of the rock bit gage through remote monitoring equipment. The sensing devices monitor the gage of the rock bit during the electron beam welding process to assure that the gage of the rock bit remains within tolerance.

Abstract: A sweep pickup for a large diameter drill bit is disclosed. The drill bit includes a main bit body having a plurality of roller cutters rotatively mounted thereon. Drilling fluid is pumped down the annulus of the well bore, across the face of the bit and up a central passage located within the bit. A sweep pickup is connected to the central passage and includes a lower inlet having a semicylindrical chamber mounted adjacent the trailing side thereof. A flexible wiper blade is located on the leading edge of the sweep pickup tube adjacent the inlet and is adapted to contact the base of the well bore in order to agitate and project the drilled cuttings into the flow of the drilling fluid. The wiper blade also functions to block the fluid flow to the inlet of the sweep pickup from the leading side thereof, thereby creating a unidirectional fluid flow to the inlet of the sweep pickup from the trailing side thereof.