Abstract: A drive spindle is provided with an electric motor, an output shaft of which defines a tool-bearing spindle rotatable about a longitudinal axis, and with a cooling device for the electric motor; the cooling device having an impeller mounted for rotation about the longitudinal axis of the spindle so as to generate a substantially helical airflow coaxial of the spindle itself, and a static deflector for directing the airflow from the impeller towards the electric motor along a direction substantially parallel to the longitudinal axis of the spindle.

Abstract: In a drive spindle an electric motor has an output shaft which defines a spindle able to receive an associated tool and associated with an attachment device movable between a position in which it locks the tool on the spindle and a release position; the operative conditions both of the spindle and of the attachment device being detectable by means of a single monitoring optical sensor.

Abstract: An electric chuck constituted by an electric motor coupled to a chuck in which the rotating tool is engaged; the electric motor being provided with a cooling device for the rotor located within the interior of the casing of the electric motor; the cooling device being constituted by an annular heat sink fitted to the shaft of the rotor in contact with the armature of the rotor, and a calibrated nozzle for directing a jet of air over the annular heat sink; the chuck being provided with a release device for the rotating tool operated pneumatically and controlled by a source of air under pressure, and the said calibrated nozzle being connected to this source of air under pressure.