Abstract: A tool breakage detecting apparatus is provided with a preset counter to be preset with a predetermined value. The content of the counter is subtracted one by one each time either one of a tool and a workpiece to be machined is moved a unit distance toward the other thereof from a cutting movement start position being spaced a predetermined distance from the other thereof. If the content of the counter is reduced an amount corresponding to a distance larger than the predetermined distance, tool breakage is detected.

Abstract: An index device for indexing a rotatable magazine, having a plurality of tool holding devices which store a variety of tools and are addressed in a numerical order, to a predetermined tool change position for a tool exchange operation. A check signal is generated each time a specific tool holding device having an address of a predetermined binary coded state is indexed to the tool change position. A memory device stores a binary coded number of a tool holding device indexed at the tool change position. An abnormality is checked in accordance with a check signal and a content of the memory device.

Abstract: Machine tool apparatus for handling routine pallets and priority pallets with loading and unloading stations comprising a plurality of machine tools for performing machining operations on a workpiece mounted on a pallet; main conveyer means for carrying a pallet in one direction, buffer conveyer means for storing a pallet to be loaded onto a machine tool; return conveyer means for returning a pallet to an unloading station; pallet transfer means for moving a pallet among the conveyer means, stations and machine tools; and central control means for controlling the machine tools and the conveyer means; the pallet transfer means being responsive to the central control means for carrying a priority pallet from the main conveyer means to one of the machine tools and being responsive to the central control means for moving a routine pallet from main conveyer means to the buffer conveyer means and from the buffer conveyer means to one of the machine tools only when the machine tool on which the routine pallet is to