US Patent 7896098 Power tools

Power tools are taught that may include, for example, means for detecting impact sounds generated, e.g. by a hammer strikes an anvil or by oil pulse from an oil unit. The detecting means may include a receiver (30) adapted to selectively convert sound within a narrow frequency range into electric signals. Preferably, the impact sounds fall within the narrow frequency range of the receiver (30). A processor 38 may be utilized to control the motor (22) in order to stop the rotation of the hammer when a pre-determined number of impact sounds has been detected by the detecting means. In addition or in the alternative, various means for setting various operating conditions are taught, including dials 34, sound sensors 30, keypads and remote control devices 250. Further, means for performing maintenance condition status checks are taught.