A double ended drill bit having two sets of cones mounted back to back in a cone holder with means for rotating the cone holder about a horizontal axis to expose the second bit for drilling after the teeth on the cones on the first have become worn. Such apparatus includes means for moving the drill bit assembly out of a housing and rotating the drill bit assemblies so as to expose the unworn bit for use in drilling the well.

In a diamond bit having mud channels formed in the face thereof, a single row of diamonds is arranged along each mud channel. The diamonds are positioned so that the scraping edge of each diamond is between two perpendicularly arranged planes of the diamond and so that one of these planes lies in the wall of the mud channel.

An improved drill bit tooth having a leading tooth face, i.e., the face first contacting the formation being cut, substantially parallel with the axis of rotation of the drill bit cone. The trailing face of the tooth is convexly shaped to act as a fulcrum. This tooth configuration allows the tooth to get under and lift a chip from the formation being cut, rather than sliding it to the side.

A drill bit including at least one roller cutter rotatively mounted on a journal which is supported by bushings between two legs of a saddle support to retain the journal in its position between the legs during drilling.

A diamond bit, the diamonds in the sidewall thereof being set in a blunt position in a direction radial to the central axis of the bit as well as in a cutting position in a direction tangential to a helical line passing through the cutting tip of the diamond and having a central axis coinciding with the central axis of the bit.

A rotary drill bit having a plurality of journal-mounted rotating cutters, jet passageways through which drilling fluid is discharged between the cutters and check valves disposed in the passageways to permit drilling fluid to flow therethrough to the cutters and to prevent flow in reverse direction therethrough into the interior of the bit.

A rotary drill bit design of the type adaptable to rotary diamond-drilling bits or the like having a drilling face crossed by a number of fluid passageways to provide drilling lands on which cutting elements, such as diamonds, are mounted employs a construction wherein the matrix portion of each drilling land defines a wedgelike volume open in the direction of bit rotation with respect to the drilling surface or gage surface defined by the exposed portions of the cutting elements upon rotation o...

Rock bit for drilling holes in the earth's crust which can be connected to driving means and being provided with supports or rock bit legs in which rotatable cutting elements or cutter cones are journalled, wherein a rock bit support comprises a removable part to which the bearing outer race ring is connected, the support part being a regularly shaped spatial body having edges which, in the assembled position, are situated in boundary planes of the support or rock bit leg.

A drill bit comprising a body suspended in a well bore by an electrical cable which transmits power to a motor secured to the body and eccentric cam member rotated by the drive shaft of the motor and engagable with a plurality of reciprocal drill pins whereby the pins are sequentially impinged against the sidewalls and bottom of the well bore for producing a drilling operation.

A rotary drill bit having a plurality of journal-mounted rotating cutters and jet passageways through which drilling fluid is discharged between the cutters is provided with removable nozzles for air or other drilling fluid. The nozzles are provided with a peripheral groove and secured in place in said passageways by the divided ends of a bifurcated retaining pin.