Quick-change system for a tool holder

A quick-change system for a tool holder, said quick-change system comprising:

• a receiving fixture defining a rotational axis and configured for attachment to a tool machine, said receiving fixture having a hollow-cylindrical extension;
• a tool holder attachable releasably to said hollow-cylindrical extension of said receiving fixture;
• a switching sleeve held displaceably on said hollow-cylindrical extension, said switching sleeve being spring-loaded into a locking position;
• first balls being held in said hollow-cylindrical extension;
• second balls being held in said hollow-cylindrical extension axially and angularly offset to said first balls;
• a cylindrical holding portion provided on said tool holder and having a substantially star-shaped end face on a side facing said receiving fixture, said substantially star-shaped end face comprising a plurality of outer points arranged in regular angular intervals defining a plurality of adjacent pairs of points;
• a plurality of longitudinal grooves provided on said cylindrical holding portion, said longitudinal grooves cooperating with said first balls for securing said tool holder fixed against rotation relative to said receiving fixture;
• a plurality of first depressions, each of said first depressions being defined between one adjacent pair of points, said first depressions being configured for receiving and guiding said first balls into said longitudinal grooves upon inserting said cylindrical holding portion of said tool holder into said hollow-cylindrical extension;
• a plurality of second depressions provided on said cylindrical holding portion and cooperating with said second balls for fixing said tool holder in an axial direction;
• and
• a plurality of third depressions provided on said switching sleeve, each of said third depressions being assigned to one of said second balls, said third depressions allowing a radial movement of said second balls in an outward direction upon axial movement of said switching sleeve enabling alignment of said third depressions with said second balls;
• wherein said points of said end face are configured for angularly aligning said longitudinal grooves on said tool holder with said first balls solely upon axial insertion of said cylindrical holding portion into said hollow-cylindrical extension;
• and
• wherein each of said first depressions is configured substantially in the shape of a spherical segment for partially receiving one of said first balls.