MULTI-SECTION PNEUMATIC IMPACT TOOL Russian patent published in 2015 - IPC E21B4/14 

FIELD: construction.

SUBSTANCE: invention relates to mining and construction, namely, to drilling equipment, and may find application in submersible and overhung drilling mechanisms. A pneumatic impact tool comprises a body with screwed-in lower and upper axle-bearings, intermediate axle-bearings placed inside the body, cylindrical cartridges between axle-bearings and a multi-piston impact tool, a drilling tool with a central blowdown channel. The inner surface of the body is made in the form of longitudinal stiffening ribs that contact tightly with external surface of cylindrical cartridges, intermediate axle-bearings and a lower axle-bearing with the possibility of their movement in the body. Insulated cavities are formed between ribs along the body, which in the lower part of the body via exhaust windows in the lower axle-bearing communicate with cavities of the exhaust tract, and axle-bearings are made with circular bores on the inner surface and rows of parallel channels that communicate a bore with one of working chambers of the section. The multi-piston impact tool has a dead axial cavity open from the side of energy carrier supply and radial channels arranged in rows along the cavity length in accordance with the number of axle bearings having circular bores on the inner surface.

EFFECT: efficiency of operation of a pneumatic impact tool increases due to increase of its impact power and resource by increasing strength of the body and number of sections with reduction of energy carrier pressure losses in a discharge tract.

5 cl, 7 dwg