Swivel joint for reverse circulation drill
US4326736A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Apr 14, 1980 |
| Grant date | Apr 27, 1982 |
| Priority date | — |
| Expiry date | Apr 14, 2000 |
Classification
- Technology area (CPC E)Fixed Constructions
- CPC primaryE21B21/02
- WIPO fieldCivil engineering
- WIPO sectorOther fields
Abstract
A swivel joint to be located at the upper end of a drill string in reverse circulation drills to support loads occurring on the drill string, the swivel joint including a fixed outer housing, a center housing rotatably mounted in the outer housing through bearings, a hollow inner housing vertically slidably fitted in the center housing, and an upper lid fixedly mounted on the outer housing to close the inner and center housings, the inner housing having at the upper and lower ends thereof flanged projections extending toward the center housing to restrict the range of the vertical sliding movement of the inner housing and being, after imposition and release of a downward thrust, slid upward within a range defined by a spacing between the flanged projection at the lower end of the inner housing and the lower end of the center housing subject to an upward thrust acting thereon, thereby preventing transmission of the upward thrust to the outer housing.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.