WASHOVER UNITY OF DRILLING BIT (VERSIONS) Russian patent published in 2009 - IPC E21B10/18 

FIELD: mining.

SUBSTANCE: invention relates to washover units of rock-destruction tools. Unit includes a nozzle, an insert with stepped inner surface for nozzle, which is located between housing and nozzle, and a sealing element installed between socket bottom and nozzle upper edge; all these parts are fixed in eccentric socket of said housing by means of retainer. Retainer is installed through radial channels in said housing and insert. Side surface of socket is provided with a closed longitudinal groove from the side of insert, which is connected with radial channel in said housing. Height and width of this groove exceed diameter of rod retainer. This retainer is installed in longitudinal groove and can move in the direction parallel to the nozzle axis under the force of compressed sealing element. According to another option, the unit is equipped with a rod retainer. Housing and hub are provided with radial channels for rod retainer. Side surface of socket is provided with closed longitudinal groove, which is matched with radial channel in the housing. Height and width of said longitudinal groove exceed diameter of rod retainer, which is rigidly connected with hub and installed in such a manner as to be able to move in this longitudinal groove of housing in the direction, which is parallel to the nozzle axis.

EFFECT: improved reliability of washover unit operating.

2 cl, 4 dwg