Vibration responsive system for stopping motor driven machines

Claim 1

APPARATUS RESPONSIVE TO MECHANICAL MACHINE TOOL VIBRATIONS FOR CONTINUOUSLY CONTROLLING THE OPERATION OF AN INITIALLY STARTED CYCLICALLY OPERABLE MACHINE TOOL GENERATING A PATTERN OF MECHANICAL VIBRATIONS CORRESPONDING WITH A CYCLE OF OPERATION, SAID APPARATUS COMPRISING: FIXED MECHANICAL-ELECTRICAL TRANSDUCING MEANS ARRANGED IN ADJACENCY WITH SAID MACHINE TOOL TO SENSE SAID VIBRATIONS AND PRODUCE AN ELECTRICAL OUTPUT INDICATIVE THEREOF; TIME DELAY MEANS RECEIVING SAID OUTPUT AND DELAYING A PORTION OF SAID OUTPUT CORRESPONDING WITH ONE MACHINE CYCLE; CIRCUIT MEANS FOR COMPARING THE INSTANT OUTPUT OF SAID TRANSDUCING MEANS WITH THE DELAYED OUTPUT SIGNAL OF SAID TIME DELAY MEANS TO YIELD AN ERROR SIGNAL REPRESENTATIVE OF THE DEVIATION IN THE VIBRATIONAL PATTERN OF THE INSTANTLY OCCURRING MACHINE CYCLE FROM THE VIBRATIONAL PATTERN OF THE MACHINE CYCLE THE SIGNAL OF WHICH HAS BEEN STORED IN SAID TIME DELAY MEANS; AND MEANS RESPONSIVE TO SAID ERROR SIGNAL FOR TERMINATING OPERATION OF SAID MACHINE TOOL WHEN THE MAGNITUDE OF SAID ERROR SIGNAL EXCEEDS A PREDETERMINED VALUE CORRESPONDING WITH THE MAXIMUM ALLOWABLE DEVIATION IN SAID VIBRATIONAL PATTERNS.