SUBMERSIBLE PNEUMATIC IMPACT TOOL Russian patent published in 2018 - IPC E21B4/14 

FIELD: construction; mining.

SUBSTANCE: invention relates to mining and construction – to drilling equipment, is used for drilling wells by the rotary-shock method. Submersible pneumatic impact tool includes a body, a hammer having a head and a shank connected by a neck, a front sleeve covering the head of the hammer and having longitudinal openings, a rear sleeve surrounding the shank of the hammer and forming the end chamber of the working stroke with its end face, a slotted sleeve that surrounds the neck of the hammer forming between it and the shank, between it and the head of the hammer, respectively, annular chambers of the idle and the working stroke, the latter of which, through a channel and an opening in the rear sleeve, is permanently connected to the end chamber of the working stroke, a feeding channel in the rear sleeve continuously communicated with the annular idle stroke chamber, a drill bit with channels installed in the front part of the body to form a cavity between it and the end face of the hammer permanently connected to the atmosphere by channels in the drill bit and with the longitudinal openings in the front sleeve. In the inner cavity of the front sleeve a step of a smaller diameter is made in its rear part, and a groove is provided on the outside of the front sleeve in the zone of this step, which is open to the annular chamber of the working stroke and connected by channels with the longitudinal openings of the front sleeve. In the said groove, an elastic ring is provided forming a gap with the inner wall of the body.

EFFECT: it is possible to increase the impact power by increasing the stroke of the hammer under pressure by reducing its resistance to the movement and reducing the effect of leakages between the end face, the annular chambers of the working stroke and the annular chamber of the idle stroke.

1 cl, 1 dwg