COOLED MANDREL OF ROTARY MILL AND METHOD OF ITS COOLING Russian patent published in 2015 - IPC B21B25/04 

FIELD: machine building.

SUBSTANCE: cooled mandrel of rotary piercer includes snout, work cone and calibrating area, internal cavity, and through radial channels at snout area. At area of work cone at distance from end of the snout area maximum 0.4 of mandrel length the reverse ridge is made with height 1÷42% of mandrel diameter creating on the surface of the work cone a ring groove. In place of crossing the work cone surface with reverse ridge along the perimeter of the mandrel the through radial channels are made, their entrances are oriented in the direction of the calibrating area.

EFFECT: increased wear resistance of the cooled mandrel, quality of internal surface of sleeves, and reduced overpressure in the cooling system and mandrel.

1 dwg, 1 tbl