WELL BORE PLUGGING DEVICE Russian patent published in 2007 - IPC E21B34/06 

FIELD: downhole equipment, particularly one used with flow string in well pumping to perform underground well repair without killing thereof.

SUBSTANCE: device comprises body with sealing member and central channel having seat. Device also has valve made as counterweight and provided with fixer, which retains the valve in closed position. The valve is installed on body to close central channel. Device includes socket member with openings connected to seat and adapted to receive valve made as cam with conical seating surface and longitudinal slot. Inserted in the slot is lever provided with spherical end, which cooperates with counterweight made as connection pipe. The counterweight may automatically interact with cam on lever rotation through any angle. Device may be provided with retaining means, which automatically cooperates with valve cam. Device also has stop mechanism made as fork member. Lower end of fork member is shaped as truncated cone and interacts with stop, which may slide in radial direction.

EFFECT: increased stability and reliability of device installation in well bore, improved sealing ability of valve, which plugs well bore during underground repair thereof without reservoir killing.

3 cl, 2 dwg