Patent ID: 7806205

Claim:
An earth drilling device comprising: a rotary drive coupled to a drilling head by a shaft; a pipe along which the shaft at least partially extends including a first end for connection to a vacuum source and a second end beyond which the drilling head at least partially extends; and the drilling head comprises a scraper hoop which is rotated by the rotary drive to contact and dislodge earth without a cutting liquid and including at least two radial sections which are connected to the shaft and radially extend outward from the shaft and only partially cover an inner cross section of the second end, at least two axially oriented surface sections which are respectively connected to a different one of the at least two radial sections which, upon rotation of the drilling head, glide in contact with an inner wall of the pipe or an inner wall of a coaxial sleeve connected to the second end and at least two axially projecting sections which respectively are connected to a different one of the axially oriented surface sections which extend beyond the pipe or the sleeve to contact and dislodge the earth.