Modular bi-directional hydraulic jar with rotating capability
US6712134B2 · kind B2 · utility
Assignee
Inventor
Key dates
| Filing date | Feb 12, 2002 |
| Grant date | Mar 30, 2004 |
| Priority date | — |
| Expiry date | Feb 12, 2022 |
Classification
- Technology area (CPC E)Fixed Constructions
- CPC primaryE21B31/113
- WIPO fieldCivil engineering
- WIPO sectorOther fields
Abstract
A bi-directional jar with bit turning capability jars down when weight is set down on the tool and pressure is built up on a piston to move the body up while compressing a spring. When spring force opens the valve in the piston, the housing comes down striking an anvil as the flow rushes through the piston before the valve recluses for another cycle. The valve member features a hydraulic brake to slow its movement after the valve is forced open. Clutching action comes from an angled spline acting through a spirally cut cylinder, which reduces in diameter to engage the bit to turn. A single spring acts on a pair of pistons for bi-directional jarring. Modularity allows rapid conversion to uni-directional operation.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.