Patent ID: 6082472
Filing Date: 2000-07-04
Classification: E02D,E21B

Abstract:
Earth displacement drill comprising a drill tube which can be driven to execute a rotary movement and a boring tip connected thereto for rotation therewith, wherein the boring tip has a cylindrical part with a circumference thereof and which adjoins the drill tube and has at least two helical strips which are arranged at the circumference and which climb upwardly at an angle, and wherein the boring tip also has a tapering part having a periphery thereof and located beneath the cylindrical part and having at least two arched surfaces which extend towards the periphery, wherein substantially flat helical surfaces including the helical strips are provided and the arched surfaces have lower edges which adjoin the flat helical surfaces in a substantially step-free manner, the cylindrical part including a lower edge thereof with the helical surfaces extending continuously to the lower edge of cylindrical part and to the upper edge of adjacent arched surfaces with each of the flat helical surfaces forming a step with the adjacent arched surface, as viewed opposite to the direction of rotation.