Abstract: A bottom-hole feeding mechanism comprising: a cylinder (1), a screw spindle (2) engaging with the cylinder (1) by means of a non-stopping splined screw pair (3), a first piston (6) received within the cylinder (1) and coupled with the screw spindle (2) and a hollow rod (8), an axial spindle (4) arranged along the cylinder (1) axis and engaging the cylinder (1) by means of an axial splined pair (5), a second piston (7) rigidly coupled with the axial spindle (4) and engaging the inner surface of the cylinder (1) and the outer surface of the hollow rod (8), wherein the hollow rod (8), the first piston (6), the second piston (7) and the cylinder (1) form a closed chamber (9) comprising a throttle (10), hydraulic channels (11) on the body of a valve (21), and a float (12).

Abstract: The present invention relates to hydraulic jars which include a jar body; a spindle axially movable within the jar body and coupled to the jar body by means of a helical splined coupling; the spindle being connectable to a pipe string and the stuck object; a cylinder concentrically placed within the jar body with a radial gap, and having chambers for filling with a work fluid, the chambers being separated by a piston and fluidly connected by a channel, wherein the channel is provided by a back valve. The piston is axially movable within the cylinder, and is connectable to the spindle by means of a tractive rod, and to the body by means of a compensative rod. The piston is further provided with elastic split compression rings having initial gaps equal or close to zero.