Patents Assigned to NF Circuit Design Block Co., Ltd.
  • Device for detecting tool abnormality
    Patent number: 4478538
    Abstract: When a drill is overloaded, while cutting a hole in a workpiece, a torque limiter disconnects the drill from a main spindle. As the drill is disconnected from the main spindle, the torque limiter generates high-level elastic waves. The elastic waves are converted by a transducer into a voltage signal. The level of the voltage signal is compared with a threshold value.
    Type: Grant
    Filed: September 28, 1982
    Date of Patent: October 23, 1984
    Assignees: Yoshiaki Kakino, NF Circuit Design Block Co., Ltd., Showa Tool Co., Ltd.
    Inventor: Yoshiaki Kakino