Abstract: A power tool including a motor, a first battery pack, a second battery pack, a first switching element coupled between the first battery pack and the motor, a second switching element coupled between the second battery pack and the motor, and controller coupled to the first switching element and the second switching element. The controller includes a first pulse-width modulation (PWM) output coupled to the first switching element and a first PWM signal to selectively close the first switching element. The controller further includes a second PWM output coupled to the second switching element and a second PWM signal to selectively close the second switching element.

Abstract: A power tool includes a housing, an output shaft supported by the housing for rotation about an axis, a battery terminal selectively operable to receive a DC power supply from a battery, and a receptacle selectively operable to receive an AC power supply from an AC power source. The power tool further includes a motor operable in a first power mode, in response to receipt of the DC power supply, to rotatably drive the output shaft, and also operable in a second power mode, in response to receipt of the AC power supply, to rotatably drive the output shaft. The power tool also includes a mechanical interlock movable between a first position in which the interlock inhibits the flow of the AC power supply to the motor and a second position in which the interlock inhibits the flow of the DC power supply to the motor.

Abstract: A power tool including a motor, a first battery pack, a second battery pack, a first switching element coupled between the first battery pack and the motor, a second switching element coupled between the second battery pack and the motor, and controller coupled to the first switching element and the second switching element. The controller includes a first pulse-width modulation (PWM) output coupled to the first switching element and a first PWM signal to selectively close the first switching element. The controller further includes a second PWM output coupled to the second switching element and a second PWM signal to selectively close the second switching element.

Abstract: A direct current fastening device and related control methods. The fastening device is powered by a direct current power source and includes a variety of safety and control features that allow the fastening device to be safety operated without, for example, a mechanical safety linkage or assembly between a trigger and a fastener firing portion (e.g., a nose switch) that prohibits the operation of the fastening device. Rather, the fastening device described herein employs a controller, a variety of switches, and monitoring techniques to ensure the safe and reliable operation of the fastening device. The configuration of the controller, for example, replaces the mechanical linkages and assemblies between the trigger and the fastener firing portion (e.g., a nose switch) that are ubiquitous safety features for such fastening devices.

Abstract: An electrical implement having a bypass mechanism for controlling a variable speed motor is disclosed. The implement includes a tool, a variable speed electrical motor activatable for driving the tool, a housing supporting the motor and tool, and a control knob for controlling the speed of the motor. The control mechanism includes an on/off switch and a variable speed control circuit. The variable speed control circuit includes a variable resistance rheostat and bypass switch. The control knob controls whether the bypass switch causes current to bypass the rheostat to operate the motor at a predetermined speed or else whether the resistance in the rheostat is variable to change the speed of the motor. The control mechanism includes a cantilevered beam engageable by the control knob to operate the bypass switch. The cantilevered beam is sufficiently flexible to allow for large deflections while placing only limited force across the bypass switch.

Abstract: A recharging system for a battery operated tool such as a lawn mower. A slidable cover is used which is movable between an open position and a closed position. The slidable cover alternately exposes a receptacle adapted to receive a removable fuse key and an electrical connector adapted to receive an electrical power cord. The receptacle and the electrical connector are longitudinally aligned with the cover so that for the cover to move to the open position and expose the electrical connector, the fuse key must be removed. The receptacle is electrically connected in series with an activation switch, the battery and the electric motor to form a motor circuit. When the fuse key is removed to expose the electrical connector, the motor circuit is broken which prevents the electric motor from being activated whether or not the activation switch is engaged.