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U.S. Department of Energy
Office of Scientific and Technical Information

Tubular spring slip joint and jar

Patent ·
OSTI ID:5252803
The present invention comprises a pressure balanced tubular spring slip-joint and jar including a generally tubular outer housing having longitudinal slot means in the wall thereof, and a hammer area of increased wall thickness at one end thereof, within which housing slidably extends a jar mandrel means having first and second longitudinally spaced enlarged diameter anvil areas, at least one fastener tapped into one of those anvil areas, the heads of said fastener protruding into said slot means. Both said housing and said mandrel means possesses axial bores therethrough, which are placed in communication via the bore of a tubular spring within the housing, whereby during extension and contraction of the slip-joint and jar means of the present invention the area within said axial bores and said spring bore is of a constant volume. The invention may be employed to provide force impulses in either longitudinal direction, said tubular spring aiding the application of those impulses when said housing and said mandrel means move relatively toward each other. By proper selection of spring length and use of a coiled spring having spaced coils, the present invention may also be employed as a bi-directional shock absorber.
Assignee:
Halliburton Company
Patent Number(s):
US 4512424
OSTI ID:
5252803
Country of Publication:
United States
Language:
English