ANNULAR REVERSING DRILL TOOL Russian patent published in 2009 - IPC B23B51/04 

FIELD: mechanics.

SUBSTANCE: drill tool includes hollow body with a wall and chip clearance grooves and cutting teeth. For increasing the processing capacity and life of drill tool due to improvement of chip flow and balancing of cutting forces, body is made of zigzag-shaped annular profile in the form of alternating protrusions and cavities on both sides of the wall, which form external and internal chip clearance grooves at cross points of which there located are cutting teeth with opposite cutting faces, the front surfaces of which face the side of adjacent groove. Rear surface of cutting faces can be stepped and made in the form of margin along arc of circle and projection behind it.

EFFECT: increasing the processing capacity and life of drill tool.

2 cl, 4 dwg