EJECTOR SYSTEM OF DRILLING Russian patent published in 2011 - IPC B23B51/06 

FIELD: machine building.

SUBSTANCE: here is disclosed drilling head for tubular shank end having internal diametre and thread. The drilling head consists of an axial case with a channel passing through the first end. Thread near the first end corresponds to thread on the shank end and facilitates channel equalising relative to internal diametre of the shank end. An orifice in the head passes from external surface of the case to the channel. Next to the second end there also two set off surfaces passing in axial direction and approximately parallel. The head is equipped with an inserted cutting plate secured between set off surfaces. Also, the cutting plate has the first surface at least partially contacting one set off surface and second surface at least partially contacting another set off surface, one or several cutting edges adjacent to the first surface, second surface or both surfaces and the cutting edge adjacent to one or several cutting edges.

EFFECT: development of drilling head with replaceable plate for orifices to 19 mm in diametre.

18 cl, 7 dwg