Device for the controlled stabilization of tool holder shanks

A device for controlled stabilization of a tool holder shank on a respective ring nut, said tool holder shank being motorized or non-motorized, and predisposed for ER or other type fixing, the tool holder shank having a truncated conical shape and provided externally with a groove, the device comprising:

• a connecting means for connecting said ring nut to said tool holder shank, the connecting means arranged inside said ring nut and having an annular body formed of at least two shaped half-rings which include opposite protrusions projecting radially outward with respect to a central axis of the annular body, each protrusion positioned centrally on each half-ring to form a shaped prominence having an arched-convex outer profile;
• wherein the ring nut internally defines an integral, segmented first circular crown formed by opposite portions alternating with lowered areas positioned between adjacent opposite portions and through which the shaped prominences of the shaped half-rings arranged in the groove of the tool holder shank are inserted to provide a bayonet coupling with the ring nut after angular rotation of said tool holder shank;
• and
• wherein the opposite portions of the segmented first circular crown each include through-holes that are dimensioned for passage of corresponding elastic pins which firmly connect the shaped half-rings and the tool holder shank with the ring nut.