Hydraulically operated heavy lift system for vertically moving a string of pipe
US3949883A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jun 13, 1974 |
| Grant date | Apr 13, 1976 |
| Priority date | — |
| Expiry date | Jun 13, 1994 |
Classification
- Technology area (CPC E)Fixed Constructions
- CPC primaryE21B19/20
- WIPO fieldCivil engineering
- WIPO sectorOther fields
Abstract
A system utilizing linear hydraulic cylinders for continuously raising or lowering a pipe string. Two sets of cylinders are spaced along the length of the pipe string. The cylinders are driven reciprocally with the cylinders in one set moving out of phase with the cylinders of the second set. Each set of cylinders includes means for releasably supporting the pipe string. The supporting means are operated out of phase so that one is released while the other is supporting the pipe. Control is such that the cylinder sets alternately raise or lower the pipe by incremental amounts, providing a continuous constant motion to the pipe string.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.