Earth drilling lubricated hydraulic shock absorber and method
US4303138A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Apr 19, 1979 |
| Grant date | Dec 1, 1981 |
| Priority date | — |
| Expiry date | Apr 19, 1999 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S277/926
- WIPO fieldCivil engineering
- WIPO sectorOther fields
Abstract
Earth drilling hydraulic shock absorber having an anvil reciprocally mounted in a casing and operatively connected with a plurality of independently operating pistons, the anvil being reciprocally mounted within the casing through a spline connection with unidirectional sealing means for equalizing pressure across the sealing means with the hydrostatic pressure in a borehole for retaining a lubricating fluid around the spline connection and to prevent abrasive matter in drilling fluid from coming in contact with the spline connection. The anvil of the shock absorber may include a reduced effective pressure area so that the anvil engages the first piston at a lower downweight.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.