WEAR SUB Russian patent published in 2010 - IPC E21B17/06 

FIELD: gas-and-oil industry.

SUBSTANCE: wear sub consists of case with installed therein shank, lower sub connecting shank with bottomhole motor and upper sub connected to case. Also the latter is coupled with the shank by means of pins arranged parallel to case axis. Bronze rings are installed on upper and lower flanges of the lug formed on external surface of the shank. Slots receiving said pins are made on external surface of the case and the lower sub; the pins are prevented from falling out with a bushing equipped with a lock fixing its position relative to the lower sub.

EFFECT: increased reliability of sub design ensuring repeated switching for resuming operation cycle.

4 cl, 2 dwg