SHUTOFF VALVE Russian patent published in 2007 - IPC E21B34/06 

FIELD: mining, particularly oil production industry, namely for well bottom zone sealing during different replaceable tools removal therefrom without well killing, particularly to replace inserted oil-well pumps.

SUBSTANCE: valve comprises body with circulation windows, gate with radial orifices made in gate wall and pushers installed in the orifices. Valve also has gate drive to be lowered from day surface and provided with stop cooperating with pushers in reverse drive travel. Surface cooperating with the pushers has bevel extending at maximal possible angle to drive axis, so that the angle does not result in pusher self-braking as pushers are urged to periphery. The pushers are arranged in groove zone made in the body and have lengths exceeding wall thickness. Gate drive has ledge cooperating with gate by lower edge thereof. The stop is supported by spring member, which is resilient in radial direction and may be axially displaced. Groove is made in drive so that the groove is opposite to stop. Groove depth decreases in downward direction. Groove terminates with peak defining the groove.

EFFECT: increased device reliability.

2 cl, 5 dwg