Machine tool with an automatic tool exchanger

In a machine tool with an automatic tool exchanger having a tool spindle rotatably supported and capable of receiving a tool at one end thereof, a tool magazine for removably storing a plurality of tools, and exchange means for exchanging tools between said tool spindle and said tool magazine, the improvement comprising:

• a drive key protruding from said one end of said tool spindle and engageable, with a predetermined play in its rotational direction, with a key-way formed on each of said tools;
• a plurality of detents provided on said tool magazine in the same angular relationship with one another and respectively engageable with said key-ways of said tools, each of said detents having almost the same width as that of said drive key in the rotational direction of each tool;
• coarse indexing means for indexing said tool spindle within a predetermined angular extent after a machining operation;
• and
• fine indexing means comprising
• means provided on said tool spindle for integral rotation therewith,
• a movable cam member operably supported and being drivingly connectable with said means on said tool spindle when the same is indexed within said predetermined angular extent, said cam member being provided with a first cam segment cooperating with said means on said tool spindle for indexing said tool spindle to a predetermined angular position when a first movement of said cam member is effected and a second cam segment cooperating with said means on said tool spindle for rotating said tool spindle a little from said predetermined angular position when a second movement of said cam member is effected, and
• cam drive means connected to said cam member for generating said first movement of said cam member after said tool spindle is indexed within said angular extent by said coarse indexing means and for generating said second movement of said cam member after a fresh tool is inserted into said tool spindle by said exchange means.