IMPACT TOOL BATTERY PACK WITH ACOUSTICALLY-TRIGGERED TIMED IMPACT SHUTOFF

摘要

An electrically powered impact tool has a removably mountable battery pack which includes an acoustic detection circuit for detecting sounds generated by the impact mechanism in use and, in response to such detection, starts an adjustable time period, at the end of which a relay is actuated for disconnecting the battery of the battery pack from the tool motor for a predetermined time period. This serves as a torque-limiting mechanism where the tool is a torque-applying tool. The time period is adjustable by a dial on the battery pack housing and the control circuitry may be selectively powered through a switch on the battery pack housing.