| 摘要 |
A bi-directional jar with bit turning capability is disclosed. To jar down, 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 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.
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