HYDRAULIC BILATERAL DRILLING JAR Russian patent published in 2012 - IPC E21B31/113 

FIELD: machine building.

SUBSTANCE: device includes tubular housing and hollow mandrel. Housing and mandrel consist of parts. Mandrel includes the first piston, hammers arranged between anvil projections, the second piston, two restricting mechanisms forming the chamber filled with working fluid for interaction of fluid with fluid chamber in the form of a belt of increased diameter of hollow mandrel; the first and the second annular valves; central piston with annular seals. At least one valve unit is installed in each annular valve. Central piston is formed with annular shoulder of increased diameter of mandrel and arranged in working fluid chamber formed with inner diameter of hollow housing, the first and the second annular valves and mandrel. The first valve unit restricts the working fluid flow from the chamber formed with central piston, inner diameter of the housing, the first annular valve and mandrel to the chamber formed with the first piston, inner diameter of the housing, the first annular valve and hollow mandrel.

EFFECT: increasing service life and improving reliability, operating efficiency, and preventing sudden activation.

5 cl, 8 dwg