Patent attributes
A rotary hammer includes a motor and a spindle coupled to the motor for receiving torque from the motor. The spindle has an adjustable rotation speed. A reciprocation mechanism is operable to create a variable pressure air spring within the spindle and includes a piston configured to reciprocate within the spindle in response to receiving torque from the motor. The piston has an adjustable reciprocation frequency. A striker is selectively reciprocable within the spindle in response to reciprocation of the piston. A first transmission is transfers torque from the motor to the spindle and a second transmission is transfers torque from the motor to the reciprocation mechanism. The reciprocation frequency of the piston is adjustable independent of the rotation speed of the spindle. The rotation speed of the spindle is adjustable independent of the reciprocation frequency of the piston. At least one of the transmissions is a multi-speed transmission.
