Tracing milling machine

A tracing milling machine including a machine body, a vertical spindle head supporting therein a rotatable spindle to which a cutting tool is removably attached, a tracer portion having a displaceable tracer for tracing a model and a tracer head capable of issuing a signal that indicates the amount of displacement of the tracer, a movable work table on which the model and a workpiece to be machined into a product corresponding to the model are fixedly mounted, respectively, and a tracing milling machine controller for controlling a servo movement of the work table in a vertical and a horizontal direction upon being supplied with tracing commands and with the displacement amount signals of the tracer, wherein an improvement comprises a combination of:

• means for issuing information that indicates the vertical and horizontal positions of said work table;
• a tracing command controller for generating said tracing commands from selected tracing operation inputs and said position information, said tracing command controller being connected to said tracing milling machine controller and said position information issuing means;
• an automatic tool changing means having a tool magazine for storing therein a plurality of cutting tools and a tool changing operating means for effecting the replacement of a cutting tool attached to said spindle by another cutting tool stored in said tool magazine at each tool changing time, said automatic tool changing means being attached to said machine body;
• means for generating a signal indicating each of said tool changing times from said displacement amount signal issued by said tracer head, and;
• a tool changing controller controlling the starting of a tool replacement operation of said automatic tool changing means in response to said tool changing time signal of said signal generating means.