HYDROMECHANICAL DOUBLE-SIDED ACTION FREEFALL WITH CONTROLLED ACTIVATION FORCE Russian patent published in 2020 - IPC E21B31/113 

FIELD: soil or rock drilling.

SUBSTANCE: invention relates to drilling equipment, namely to devices for creation of impact loads directed either upwards, or downwards, or to both sides for release of stuck part of drilling and casing strings, downhole motor, packer and other tool in well Device comprises tubular housing and hollow spindle, between which there is working fluid - oil, interconnected by movable splines, which are arranged in working fluid, impact surfaces, pistons connected to hollow spindle by threaded joints, valves limiting flow of working fluid in hydraulic chamber formed by hollow spindle, tubular case and two pistons, spring-loaded locking mechanism arranged in a cavity formed by a tubular body and a hollow spindle limited by a piston fixed at the end of the hollow spindle and piston of hydraulic chamber for locking longitudinal movement of hollow spindle relative to tubular housing. One impact surface is located outside the tubular housing, and the second impact surface is located inside the housing. To tubular housing with spring-loaded locking mechanism is connected mechanism of activation force change, consisting of hollow cylindrical coupling, tubular housing, splined hollow shaft and hollow tubular housing with end teeth engaged with cylindrical coupling. End teeth of tubular housing fix position of cylindrical coupling relative to housing, which determines length of extending nipple thread of splined hollow shaft, which, in its turn, serves as support for spring-loaded locking mechanism and determines value of force of spring contraction, fixing locking mechanism, which determines freefall activation force.

EFFECT: possibility to adjust activation force of freefall before its operation directly in conditions of drilling, which increases ease of operation, service life and reliability of freefall operation.

1 cl, 3 dwg