TOOL SUPPORT SYNCHRONIZING SYSTEM FOR NUMERICAL CONTROL APPARATUS

A tool support synchronizing system suitable for a numerical control apparatus of a complex machine tool having multiple spindles in which work programs for a plurality of tool supports are independently and simultaneously executed and the execution of a particular block of a work program is initiated at a designated portion within the programs, in which the start of particular block is precisely synchronized. A reading device (2A, 2B) provided for each tool support reads an independent work program (1A, 1B) for its corresponding tool support. The commands of the work program are decoded (blocks 4A, 4B) from the output of the reading devices, and control circuits (6A, 6B) control the shifting of the tool support in accordance with the decoded data. Various control circuits are synchronized by a synchronizing circuit (6C) in response to the decoding of a special synchronizing command composed of a predetermined single character or symbol in the working programs.