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A downhole tool includes inner and outer telescoping cylindrical members. The inner cylindrical member has a cylindrical indexing sleeve disposed thereabout. A groove having a semi-circular cross section is disposed in a cylindrical outer surface of the indexing sleeve. Connected to the outer cylind

A downhole tool includes inner and outer telescoping cylindrical members. The inner cylindrical member has a cylindrical indexing sleeve disposed thereabout. A groove having a semi-circular cross section is disposed in a cylindrical outer surface of the indexing sleeve. Connected to the outer cylindrical member is an apparatus for holding a spherical ball so that approximately one-half the ball is engaged with the semi-circular cross section groove and the other of the ball is disposed within a radial bore in the outer cylindrical member. Relative movement between the inner and outer cylindrical members is defined by engagement of the spherical ball with the groove. The spherical ball is biased toward the groove by a compression spring or a displaceable fluid under pressure.

대표청구항 ▼

In a lug and slot assembly for guiding a relative movement between first and second telescoping tubular members of a downhole tool, the improvement comprising: said slot having a semicircular cross section; said lug being a spherical ball approximately one-half of which is received in said slot; and

In a lug and slot assembly for guiding a relative movement between first and second telescoping tubular members of a downhole tool, the improvement comprising: said slot having a semicircular cross section; said lug being a spherical ball approximately one-half of which is received in said slot; and biasing means for resiliently biasing said ball toward said slot, said biasing means including a displaceable fluid under pressure.