Drilling and hole enlargement device
US7757787B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Jan 31, 2007 |
| Grant date | Jul 20, 2010 |
| Priority date | — |
| Expiry date | Jan 31, 2027 |
Classification
- Technology area (CPC E)Fixed Constructions
- CPC primaryE21B21/10
- WIPO fieldCivil engineering
- WIPO sectorOther fields
Abstract
An expandable drilling apparatus includes a main body comprising a central bore and at least one axial recess configured to receive an arm assembly operable between a retracted position and an extended position, a biasing member to urge the arm assembly into the retracted position, a drive position configured to thrust the arm assembly into the extended position when in communication with drilling fluids in the central bore, a selector piston translatable between an open position and a closed position, wherein the selector piston is thrust into the open position when a pressure of the drilling fluids exceeds an activation value, wherein the drilling fluids are in communication with the drive piston when the selector piston is in the open position, and a selector spring configured to thrust the selector piston into the closed position when the pressure of the drilling fluids falls below a reset value.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.