Method and apparatus for directional boring under mixed conditions
US6390207B2 · kind B2 · utility
Assignees
Inventors
Key dates
| Filing date | Sep 20, 2001 |
| Grant date | May 21, 2002 |
| Priority date | — |
| Expiry date | Sep 20, 2021 |
Classification
- Technology area (CPC E)Fixed Constructions
- CPC primaryE21B47/02
- WIPO fieldCivil engineering
- WIPO sectorOther fields
Abstract
A drill head for an apparatus for directional boring according to the invention includes a bit, a holder for a device for detecting angular orientation of the bit, and a hammer including a striker for delivering impacts to the bit, wherein the bit assembly, holder and hammer are connected head to tail with the bit at a front end. The bit of the invention has a frontwardly facing main cutting surface having a plurality of main cutting teeth disposed thereon and a gage tower extending radially outwardly from the main cutting surface, which gage tower has at least one frontwardly facing gage cutting tooth thereon suitable for cutting over an angle defined by less than a full rotation of the bit. The device for detecting angular orientation is in a predetermined alignment with the gage tower so that it determines the orientation of the gage tower relative to the axis of rotation of the drill head. A starter rod may be used to connect the holder to the string, and the hammer generally follows immediately behind the bit, so that order of components from front to rear is bit, hammer, holder and starter rod. In one preferred embodiment, the main cutting surface is substantially flat and ci…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.