Acoustic tool break detection system and method
Patent 4642617 Issued on February 10, 1987. Estimated Expiration Date: 
December 21, 2004. Estimated Expiration Date is calculated based on simple USPTO term provisions. It does not account for terminal disclaimers, term adjustments, failure to pay maintenance fees, or other factors which might affect the term of a patent.
December 21, 2004. Estimated Expiration Date is calculated based on simple USPTO term provisions. It does not account for terminal disclaimers, term adjustments, failure to pay maintenance fees, or other factors which might affect the term of a patent.Patent References 3793627 3841149 3842663 Apparatus for the detection of vibration in rotating machinery Apparatus for detecting damages of cutting tools Apparatus for monitoring tool life Patent #: 4563897 InventorsApplicationNo. 06/685005 filed on 12/21/1984US Classes:340/680, Machine tool340/683, Vibration700/175, Condition of tool or workpiece (e.g., tolerance, tool wear)73/104, SURFACE AND CUTTING EDGE TESTING73/660Rotating machinery or deviceExaminersPrimary: Rowland, James L.Assistant: Hofsass, Jeffery Attorney, Agent or FirmInternational ClassesB23Q 17/09 (20060101)G01H 1/00 (20060101) G05B 19/4065 (20060101) G05B 19/406 (20060101) AbstractSubstantial cutting condition changes that occur gradually, as opposed to the more usual sudden large change, are detected by setting upper and lower cutting noise mean level thresholds. When the mean cutting noise exceeds the upper threshold or stays below the lower threshold for a preset number of signal samples, a tool break alarm is generated. Techniques are given to reduce false alarms at the start and end of the cut and on runout on initial rough surface cuts. The system comprises an accelerometer or other sensor whose signal is preprocessed to attenuate lower frequency machinery noise and detect the signal energy in a band below 100 KHz, then sampled, and the digitized signal samples analyzed by pattern recognition logic. | |
