Hydro-drill with circular impression
US4682660A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Dec 12, 1985 |
| Grant date | Jul 28, 1987 |
| Priority date | — |
| Expiry date | Dec 12, 2005 |
Classification
- Technology area (CPC E)Fixed Constructions
- CPC primaryE21B4/006
- WIPO fieldCivil engineering
- WIPO sectorOther fields
Abstract
The invention relates to a device for the production of circular boreholes in soil, of the type incorporating a pair of bits driven in rotation in opposite directions, the said bits being equipped with teeth or similar members for breaking up the soil. It comprises a first pair of bits (6) which are equipped with teeth, rotating in opposite directions around two parallel axes, each of these bits having the external shape of a volume of revolution the generatrix of which consists of a circular arc corresponding to the circular cross-section of the borehole which it is intended to dig, and a second pair of bits (7) situated above the first, and the bits (14a,14b) of which have the same structural characteristics as the bits of the first pair but whose axes of rotation are offset relative to the latter.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.