Wellhead retrieval tool assembly
US5474124A · kind A · utility
10Cited by
9References
7Claims
0Family size
Inventors
Key dates
| Filing date | Aug 26, 1994 |
| Grant date | Dec 12, 1995 |
| Priority date | — |
| Expiry date | Aug 26, 2014 |
Classification
- Technology area (CPC E)Fixed Constructions
- CPC primaryE21B31/20
- WIPO fieldCivil engineering
- WIPO sectorOther fields
Abstract
A wellhead retrieval tool assembly for retrieving a check valve has a spear formed as a solid ring at the bottom with free fingers extending upward. The fingers are resilient and have protrusions adapted to engage a retrieval groove in the check valve. A wedge ring is provided on the tool body to positively lock the fingers in radially outward engagement with the retrieval groove. The wedge ring is fixed to the body by a shear pin so that upon a predetermined axial force the pin shears and releases the wedge allowing withdrawal of the tool assembly.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.