Earth boring drill bit

Claim 1

A DRILLING BIT OF THE DRAG BIT TYPE ADAPTED TO BE ROTATED ABOUT ITS LONGITUDINAL AXIS, THE BIT COMPRISING: A BODY, A PLURALITY OF WINGS SUPPORTED BY THE BODY, EACH WING EXTENDING RADIALLY BEYOND THE BODY TO PROVIDE A HOLEGAUGING FACE IN THE FORM OF A PORTION OF A CYLINDRICAL SURFACE THAT SUBTENDS A SUBSTANTIAL CIRCUMFERENTIAL ARC, EACH WING ALSO EXTENDING AXIALLY AHEAD OF THE BODY TO PROVIDE AN END DRILLING FACE IN THE FORM GENERALLY OF A SECTOR OF AN ANNULUS, AND EACH WING ALSO HAVING AN EXTENDED FORWARD FACE OF GENERALLY PLANAR FORM, A LAYER OF HARD ALLOY MATERIAL SECURED TO EACH FORWARD FACE TO PROVIDE HARD CUTTING EDGES AT THE JUNCTIONS OF THAT FACE WITH THE GAUGING AND DRILLING FACES, AND CEMENTED TUNGSTEN CARBIDE INSERTS EMBEDDED IN EACH WING BEHIND THE FORWARD FACE WITH PORTIONS OF THE INSERTS EXPOSED ON THE GAUGING AND DRILLING FACES FOR LIMITING WEAR OF THE WING MATERIAL SUPPORTING THE CUTTING EDGES OF THE HARD ALLOY MATERIAL ON THE FORWARD FACE AND FOR SUPPLEMENTING THE CUTTING ACTION OF THOSE EDGES.