Swab hoist use thereof in conveying crude oil and natural gas
US4454912A · kind A · utility
2Cited by
6References
14Claims
0Family size
Assignee
Inventors
Key dates
| Filing date | Aug 7, 1981 |
| Grant date | Jun 19, 1984 |
| Priority date | — |
| Expiry date | Aug 7, 2001 |
Classification
- Technology area (CPC E)Fixed Constructions
- CPC primaryE21B37/10
- WIPO fieldCivil engineering
- WIPO sectorOther fields
Abstract
The invention relates to a swab hoist for use in conveying crude oil and natural gas having a cable drum and a driving motor for the cable drum. It is the object of the invention to provide a swab hoist of improved properties. This is achieved according to the invention by providing a hydraulic drive for the transmission of force from the driving motor to the cable drum. The hydraulic drive consists of a hydraulic pump driven by the driving motor, a hydraulic motor connected to the cable drum and a control means, in particular a pressure-reducing means, all connected to one another by means of pressure lines.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.