Bore hole underreamer having extendible cutting arms
US6929076B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Mar 13, 2003 |
| Grant date | Aug 16, 2005 |
| Priority date | — |
| Expiry date | Jul 20, 2023 |
Classification
- Technology area (CPC E)Fixed Constructions
- CPC primaryE21B10/62
- WIPO fieldCivil engineering
- WIPO sectorOther fields
Abstract
A bore hole underreamer is provided having a hollow body with a longitudinal axis, which has an external wall, at least two cylindrical bores provided through the external wall and whose axes are transverse to the longitudinal axis. Each of the bores have a cylindrical widening arm for widening the hole, which is arranged in the bore like a hydraulic piston, so as to be able to slide therein between an active position and an inactive position. The underreamer has a locking member which can occupy a locking position in which this member locks the arms in their inactive position, and which, when it is released, can leave the locking position under a thrust from at least one of the arms subjected to the pressure capable of pushing the arm into its active position.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.