Abstract: This invention discloses a rolling cone drilling bit comprising a plurality of conical roller cutters having hard metal cutting elements thereon and being so positioned relative to each other that their rotational axes are offset from the rotational axis of the drill bit, and a drilling fluid nozzle system for directing a pressurized fluid stream across certain of the cutting elements and thereafter against the formation generally at the bottom of the well bore so that when the drill bit is used in its most advantageous areas, such as the soft, medium-soft and plastic formations, the nozzle system prevents "balling up" of the cutters and greatly increases the drilling efficiency of the bit.

Abstract: A rotary drill bit comprising a bit body adapted to be secured to a drill string and to receive drilling fluid under pressure therefrom, the body having a plurality of nozzles for exit of the drilling fluid, and a plurality of depending legs at its lower end. The bit further includes a plurality of roller cutters, one for each leg, each cutter comprising a generally conical cutter body rotatably mounted on the respective leg, and a plurality of cutting elements thereon. The cutter body at its conical surface is formed of a material resistant to erosion by high drilling fluid which may impinge it.

Abstract: A rotary drill bit for drilling a well bore comprising a bit body adapted to be detachably secured to a drill string and receive drilling fluid under pressure therefrom and having a plurality of depending legs and a nozzle system for exit of drilling fluid from the bit body. The drill bit further comprises a plurality of roller cutters, each cutter having a generally conical roller cutter body rotatably mounted on one of the legs and a plurality of cutting elements on the cutter body.

Abstract: A rotary drill bit comprising a bit body having a chamber therein adapted to receive drilling fluid under pressure, a plurality of nozzles in communication with the chamber for exit of the drilling fluid, and a plurality of depending legs at its lower end, each having a bearing journal. The bit further includes a plurality of roller cutters, one for each leg, each cutter comprising a generally conical cutter body rotatably mounted on the bearing journal of the respective leg, and a plurality of cutting elements thereon. Each nozzle has an orifice in a position below the top of an adjacent roller cutter but above the central axis of the respective bearing journal at its inner end with respect to the bit body.

Abstract: A rolling cutter drill bit is disclosed having an improved thrust face bearing structure which utilizes alternating segments of at least two different bearing metals. The composite thrust face bearing structure disclosed has a first metal selected for a low temperature operation, and at least one additional metal selected for high temperature operation.