US Patent 7462145 Machine tool

A machine tool is described, in particular a grinding machine, with a tool storage device. The tool storage device contains an outer magazine wheel (34) and an inner magazine wheel (58), which are independently concentrically rotatable in a controlled manner. The outer magazine wheel (34) preferably holds grinding tools (56), while the inner magazine wheel (58) preferably holds grinding wheel protectors (68). The grinding tool (56) and the grinding wheel protector (68) are removed from the tool storage device and are returned to the latter by the tool spindle (30). The grinding tools (56) and grinding wheel protectors (68) can be exchanged independently in arbitrary combinations and possibly also simultaneously.