MECHANICAL JAR Russian patent published in 2006 - IPC E21B31/107 

FIELD: underground well repair, particularly means adapted remove equipment stuck at well face.

SUBSTANCE: device comprises body and spindle associated with working string and with equipment to be freed from well. The body and spindle are secured with each other by means of shear pin so that axial pay is created between striking surfaces thereof. The body and the spindle are connected with each other by screw pair. Friction member having high rest friction coefficient is located between thrust surfaces of the body and the spindle.

EFFECT: extended functional capabilities and increased efficiency.

4 dwg