Method and apparatus for changing tools

A method of operating a machining apparatus having:

• a frame;
• a magazine holding a plurality of tools;
• a loader capable of moving the tools between the magazine and a primary transfer position;
• a chuck on the frame, adapted to hold a workpiece, and rotatable on the frame about a workpiece axis;
• a drive spindle for rotating the chuck about the workpiece axis;
• first and second tool holders each displaceable relative to one another horizontally and vertically on the frame;
• and
• a transfer arm carrying a grab,
• the method comprising the steps of sequentially:
• a) supporting each of the tool holders for movement into and out of a respective secondary transfer position at which the arm can transfer a tool to or from the respective tool holder;
• b) removing one of the tools from the magazine with the loader and moving the one tool by the loader into the primary transfer position;
• c) transferring the one tool in the primary transfer position to the grab of the transfer arm;
• d) pivoting the arm to move the one tool in the grab from the primary transfer position into one of the secondary transfer positions;
• and
• e) transferring the tool at the one secondary transfer position from the grab to the respective holder.