SUBMERSIBLE PNEUMATIC HAMMER Russian patent published in 2019 - IPC E21B4/14 

FIELD: soil or rock drilling.

SUBSTANCE: invention relates to drilling equipment and is used in borehole drilling by rotary-percussion method. Submersible pneumatic hammer includes body with boring in front part, hammer with head and shank, connected by neck, sleeve enveloping hammer shank and forming end face of end stroke chamber, a split bushing enveloping the hammer neck with formation between it and the shank end between it and the hammer head of annular chambers of idle and working stroke, respectively, the latter of which by means of channel and window in sleeve is permanently connected to end chamber of working stroke, feeding channel in sleeve, constantly communicated with annular chamber of idle stroke, drilling bit with channels installed in front part of housing with formation between it and end face of hammer cavity constantly connected with atmosphere by channels in drilling bit. In the head of the hammer there is an annular groove connected to the annular working stroke chamber and having longitudinal surfaces of smaller and larger diameters, which are connected by a surface with a conical transition to a longitudinal surface of a smaller diameter. At the end of the hammer there are channels with an output to the specified surface with a conical transition, at that on the longitudinal surface of the smaller diameter with interference there installed is an elastic ring forming a gap with the longitudinal surface of the larger diameter.

EFFECT: increase of impact power due to increased stroke of the hammer under pressure.

1 cl, 1 dwg