Quick-change chuck

A quick-change chuck, comprising a shank sleeve arranged to be driven by a machine spindle and having an axis and a free annular end face;

• a locking sleeve arranged to hold a tool and inserted in the shank sleeve to rotate therewith, the locking sleeve having a forward end;
• a locking nut screwed on the forward end of the locking sleeve and having an annular face which can bear axially against the free annular end face of the shank sleeve, the locking nut having an abutment face and an annular groove with internal inclined flanks;
• a ball sleeve axially fitted on the shank sleeve and connected with the latter, the ball sleeve having a distal end and an annular extension piece at the distal end, the annular extension piece having one end forming an axial stop against which the locking nut can abut with the abutment face thereof, the annular extension piece having an annular face which can bear axially against the free annular end face of the shank sleeve, the ball sleeve having radial bores;
• locking balls held radially movable in the extension piece of the ball sleeve and engageable radially in the annular groove of the locking nut between the inclined flanks of the latter;
• a control sleeve axially displacably held on the ball sleeve and having an end section which is axially adjacent to the locking balls and has an inner receiving part and a substantially frustoconically converging ramp face by means of which the locking balls engage, on axial displacement of the control sleeve into its locking position, radially into the annular groove of the locking nut, while the locking balls in the case of contrary axial displacement of the control sleeve into its release position, emerge radially from the annular groove liberating the locking nut with the locking sleeve, and can enter said receiving part of said control sleeve, said control sleeve having an inner wall;
• a spring located between the control sleeve and the ball sleeve and urging the former relative to the latter;
• a detent device arranged between the control sleeve and the ball sleeve so that the control sleeve is automatically detained in relation to the ball sleeve in its axial release position against self-effected dropping back into the locking position under the action of the spring, the detent device on introduction of the locking sleeve by means of external axial pressure upon the control sleeve can be overridden with subsequent automatic axial displacement of the control sleeve under the action of the spring into its locking position, the detent device including a detent shoulder and a detent recess provided in said control sleeve, and detent members which are radially movably held in the radial bores of the ball sleeve and in the locking position of said control sleeve are pressed by the inner wall of the control sleeve inward against the action of the spring, and in the release position of the control sleeve are firstly overrun by the detent shoulder of the control sleeve and engage under the action of the spring radially behind the detent shoulder into the detent recess of the control sleeve, the ball sleeve having in the region of the detent balls an end oblique annular surface of frustoconical configuration with direction of taper towards the annular extension piece, the oblique annular surface extending into the axial zone of the radial bores of the ball sleeve in such manner that the detent balls in the locking position of the control sleeve protrude radially beyond the oblique annular surface.

A quick-change chuck, comprising a shank sleeve arranged to be driven by a machine spindle and having an axis and a free annular end face;

• a locking sleeve arranged to hold a tool and inserted in the shank sleeve to rotate therewith, the locking sleeve having a forward end;
• a locking nut screwed on the forward end of the locking sleeve and having an annular face which can bear axially against the free annular end face of the shank sleeve, the locking nut having an abutment face and an annular groove with internal inclined flanks;
• a ball sleeve axially fitted on the shank sleeve and connected with the latter, the ball sleeve having a distal end and an annular extension piece at the distal end, the annular extension piece having one end forming an axial stop against which the locking nut can abut with the abutment face thereof, the annular extension piece having an annular face which can bear axially against the free annular end face of the shank sleeve;
• locking balls held radially movable in the extension piece of the ball sleeve and engageable radially in the annular groove of the locking nut between the inclined flanks of the latter;
• a control sleeve axially displacably held on the ball sleeve and having an end section which is axially adjacent to the locking balls and has an inner receiving part and a substantially frusto-conically converging ramp face by means of which the locking balls engage, on axial displacement of the control sleeve into its locking position, radially into the annular groove of the locking nut, while the locking balls in the case of contrary axial displacement of the control sleeve into its release position, emerge radially from the annular groove liberating the locking nut with the locking sleeve and can enter the receiving part of the control sleeve;
• a spring located between the control sleeve and the ball sleeve and urging the former relative to the latter;
• a detent device arranged between the control sleeve and the ball sleeve so that the control sleeve is automatically detained in relation to the ball sleeve in its axial release position against self-effected dropping back into the locking position under the action of the spring, the detent device on introduction of the locking sleeve by means of external axial pressure upon the control sleeve can be overridden with subsequent automatic axial displacement of the control sleeve under the action of the spring into its locking position, the end section of the control sleeve having an end step which protrudes into the axial displacement path of the locking nut and has an end face forming the first stop face, the locking nut having an axial annular surface facing toward the end face of the end step of the control sleeve and forming the second stop face;
• and means for displacing the control sleeve from its release position into its locking position, the stop faces being arranged so that upon the introduction of the locking sleeve with the locking nut the second stop face of the locking nut abuts against the first stop face of the control sleeve and displaces the latter in an axial direction from its release position into its locking position so as to form the displacing means.