Shock absorber for well drilling pipe
US4133516A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Jul 29, 1977 |
| Grant date | Jan 9, 1979 |
| Priority date | — |
| Expiry date | Jul 29, 1997 |
Classification
- Technology area (CPC E)Fixed Constructions
- CPC primaryE21B17/07
- WIPO fieldCivil engineering
- WIPO sectorOther fields
Abstract
A shock absorber assembly has an outer body connectible at one end in a well drill string and an inner body connectible at one end in the well drilling string, with the bodies telescopically coengaged. Between the bodies is an annular space, filled with hydraulic fluid and containing a pressure equalizing annular piston. Stacked sets of dished-spring washers are disposed in coengaged frictional relation to form parallel-acting columns in the annular space between the two bodies. The equalizing piston is exposed to the pressure of drilling fluid inside the inner body, in one form, and outside the outer body, in another form. Another equalizing piston defines between the bodies a fluid filled chamber containing torque transmitting means for causing the bodies to rotate as a unit during drilling operations while allowing telescopic extension and retraction of the bodies. Telescoping of the bodies causes fluid transfer through restricted passages to dampen the telescopic motion.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.