Expandable well drilling tool
US4693328A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jun 9, 1986 |
| Grant date | Sep 15, 1987 |
| Priority date | — |
| Expiry date | Jun 9, 2006 |
Classification
- Technology area (CPC E)Fixed Constructions
- CPC primaryE21B17/1014
- WIPO fieldCivil engineering
- WIPO sectorOther fields
Abstract
A three roller centralizer is expandable from a position with the rollers retracted to a position with the rollers extended to a larger diameter for remaining concentric in a hole being underreamed. A diagonal camming surface is fixed on the body above each such roller. An axially shiftable diagonal camming surface is mounted on a piston below each such roller. Application of hydraulic pressure on the piston squeezes the rollers outwardly toward their extended position. After the rollers are fully extended, the lower camming surface can travel further so that axially extending surfaces above and below each roller prevent collapse of the rollers toward the retracted position. Links pivotably interconnect the carrier for such a roller and the body and lower camming surface respectively for retaining the rollers. Such a link has an elongated opening so that the carrier can move along the diagonal and axially extending surfaces instead of being limited to a circular path.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.