Impact tool control method and apparatus and impact tool using the same
AssigneeMagna-Lastic Device, Inc.
InventorsDavid W. Cripe, Christopher Jones
Life of this patent
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Abstract
An impact tool control method and apparatus and an impact tool using the same. Pulses of torque applied to a fastener by the impact tool are measured. The duration and magnitude of the torque pulse are subtracted from a torque signal and the resulting difference is integrated over time to obtain a fastener angular velocity signal. The angular velocity signal is integrated over time to obtain a displacement signal which can be converted to a torque signal. The impact tool can be controlled based on the value of the torque signal.
Claims21
A method for determining torque applied to a fastener comprising the steps of:
- beginning a fastener tightening sequence;
- applying torque pulses to the fastener during the fastener tightening sequence;
- measuring the values of amplitude and duration of each torque pulse applied to the fastener during the fastener tightening sequence;
- measuring the duration between the torque pulses;
- processing the amplitude and duration of the torque pulses to obtain the total torque applied to the fastener during the fastener tightening sequence;
- and
- terminating the fastener tightening sequence, wherein the processing step comprises;
- generating a torque pulse signal based on the torque pulses;
- subtracting a torque signal from the torque pulse signal to generate a difference signal;
- and
- integrating the difference signal to obtain a fastener angular velocity signal.
An impact tool comprising:
- a body;
- an output shaft adapted to be coupled to a fastener;
- means for applying torque pulses to said output shaft during a fastener tightening sequence;
- a torque transducer coupled to said output shaft;
- and
- means for monitoring the entire tightening sequence and processing the output of the torque transducer to obtain torque on the fastener, wherein the means for processing comprises,
- means for generating a torque pulse signal based on the output of the torque transducer;
- means for subtracting a torque signal from the torque impulse signal to generate a difference signal;
- and
- means for integrating the difference signal to obtain a fastener angular velocity signal.
Dependencies are inferred from the claim text.