HYDRAULIC KEY FOR STARTING SCREW OF DRILLING COLUMN Russian patent published in 2010 - IPC E21B19/16 

FIELD: gas-and-oil industry.

SUBSTANCE: hydraulic key for starting screw of drilling column consists of two successively installed sections: first one hinged on bracket of drill tower and second one with fixed jaw, of movable jaw, of rocking arm, of hydro-cylinders for supply, lock, and start and of limit switch installed between bracket and first section. The first section has a slot wherein a centre pin of the second section enters. One lever of the rocking arm is pivotally connected to the movable jaw, its central part is connected to the second section, while the lock hydro-cylinder is positioned on the second lever of the rocking arm coupling it with the second section. The hydro-cylinder of supply is arranged on the drill tower and the first section; the hydro-cylinder of start is positioned on the first and second sections. Also the hydraulic key is equipped with an additional limit switch installed between the first and the second sections. Axis of the hydro-cylinder of start forms angle 45÷90° with a straight line passing through contact points of the jaw of the second section with the drilling column; also points of fixture of the hydro-cylinder of start on the first section and points of fixture of the first section on the bracket coincide.

EFFECT: increased reliability and automatic control of hydraulic key operation.

2 cl, 1 dwg