ELEVATOR Russian patent published in 2011 - IPC E21B19/06 

FIELD: gas-and-oil producing industry.

SUBSTANCE: elevator consists of case with cantilevers and of flap with locking device pivotally connected to case with axle. Also, the case of the elevator and cantilever correspond to a split structure. In the case of the elevator there are made two orifices for transient seat of cantilevers into the case, they are secured with bolt connections and additionally fixed with a pin.

EFFECT: increased reliability of device operation due to reduced bending moment during elevator operation facilitating partial transfer of loads from cantilevers to case.

2 cl, 6 dwg