摘要 |
An indexing mechanism is disclosed that can put a tool in a variety of positions while downhole in the face of .eta.high static and dynamic loads. In the preferred application, the mechanism controls a movable sleeve on a downhole choke. It contains an indexing feature comprising a pin movable in a series of slots. A piston restrained to move longitudinally engages and rotates an index sleeve to allow the pin to advance into the next J-slot track. A separate lug on the piston engages a radial face on the index sleeve to take the shock load and position the choke instead of allowing the pin to load against the closed end of the slot.
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