OVERFLOW DRILL BALL VALVE Russian patent published in 2018 - IPC E21B34/10 E21B21/10 

FIELD: soil or rock drilling.

SUBSTANCE: invention relates to overflow devices of a drill string with a screw downhole motor. Valve consists of cylinder case with stepped hole and radial (overflow) hole. There can be several overflow holes. Holder in form of a segment is installed, for example, in the stepped hole of the case. Cartridge is made of a cylindrical cavity in which a saddle, a ball, a conical return spring located below the seat, a cylindrical pusher, installed between the ball and the conical spring are installed. One end of the conical spring with a smaller diameter is mounted on a centering projection formed on the bottom of the pusher, and the other end of the spring with a large diameter is mounted with support on the bottom of the cage. Longitudinal centering ribs are formed on the outer surface of the upper part of the cylindrical pusher, forming longitudinal channels for the flow of liquid with the inner surface of the saddle. Saddle is installed in a stepped hole of the cylindrical cavity and clamped by a limiter made in the form of a cage, which is installed in the cage, for example, using a threaded connection. Threaded radial hole coaxial to the radial hole of the case for flow of liquid is made in the holder. Screw with filtering holes and a hole for flow of liquid is screwed into the holder through the radial hole of the case. Screw maintains the holder in radial and axial directions.

EFFECT: technical result is improvement of reliability and service life of the valve.

2 cl, 3 dwg