Patent ID: 6929437

Claim:
Spindle ( 1 ), having a longitudinal axis and a body, for machining at high rotational speeds, comprising a tool-holding taper collet ( 2 ) with radial slits ( 2 r ) that is kept closed to clamp a tool ( 3 ) by pressing the collet axially against a seat ( 4 ) of complementary shape by the reaction force (F) of precompressed elastic means ( 6 ) interposed between the tool-holding collet ( 2 ) and the body ( 1 s ) of the spindle ( 1 ), and is opened by moving the collet axially away from said seat ( 4 ) by applying an axial force (S) to the collet to further compress said precompressed elastic means ( 6 ), which spindle is characterized in that said elastic means are a sleeve ( 6 ) of elastic material housed coaxially between the inside wall of a cavity ( 1 e ) formed in said body ( 1 s ) of the spindle ( 1 ) and a shaped collar ( 7 ) of epoxy resin applied coaxially around the outer surface of a free end ( 8 m ) of an extension ( 8 ) of the tool-holding collet ( 2 ).