Method and device in earth cutting
US4274496A · kind A · utility
6Cited by
7References
7Claims
0Family size
Assignee
Inventors
Key dates
| Filing date | Jan 23, 1980 |
| Grant date | Jun 23, 1981 |
| Priority date | — |
| Expiry date | Jan 23, 2000 |
Classification
- Technology area (CPC E)Fixed Constructions
- CPC primaryE21B10/52
- WIPO fieldCivil engineering
- WIPO sectorOther fields
Abstract
A bore head for reaming a pre-drilled hole in raise boring or for similar earth cutting operations comprising at least two sets of roller cutters. The roller cutters in the same set of cutters have the same number of rows of cutting means. The roller cutters are mounted in pairs on each side of the rotational axis of the bore head. During rotation of the bore head the cutting means move along concentric circles. In order to change the distance between two consecutive circles a roller cutter in one of the pairs of cutters is replaced by a roller cutter of the other set of cutters.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.