Drill bit with single cutting head

Claim 1

A rotary drill for drilling a well in the surface of the earth, said drill comprising: (a) a drill bit including an upper portion for connection to a drill string, duct means including a fluid outlet into the well for carrying fluid to extract detritus and clean the bottom of the well and receiving means; (b) a solid cutting head comprising a conical head portion and a unitary stem portion with no internal passages therein, said conical head portion including holes therein and cutting elements inserted in said holes, said stem portion being received in said receiving means of said drill bit, wherein said stem and said receiving means include holding means for rotatably holding said cutting head in said drill bit; (c) bearing means between said drill bit and said conical head, said bearing means being fixed relative to said drill bit and to said conical head for preventing movement between bearing surfaces of the bearing means which contact the drill bit and conical head and the drill bit and conical head, but allowing said conical head to rotate relative to said drill bit; (d) a lubrication system, independent of said duct means, interconnected between said drill bit and said cutting head said lubricating system including a stabilizer means for equalizing the pressure in the lubricating system with the pressure in the bore hole surrounding the bit.