Floating cushion sub
US4759738A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Jun 3, 1985 |
| Grant date | Jul 26, 1988 |
| Priority date | — |
| Expiry date | Jun 3, 2005 |
Classification
- Technology area (CPC E)Fixed Constructions
- CPC primaryE21B3/02
- WIPO fieldCivil engineering
- WIPO sectorOther fields
Abstract
A floating cushion connection member is operable between a power head and a drill string member. A first cap member is mounted about the periphery of a piston. A washpipe extends from within the bore of the piston to a mounting area in a second cap member. A body member connects the first and second cap members. A spline member in the form of drive pins located between the body member and the piston rotate the piston with the body member and second cap member and allow the piston to move axially relative to the body member and the second cap member. The washpipe has limited angular movement within the second cap member and the piston. Cushion members are provided between the second cap member and the piston and the piston and the first cap member, respectively.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.