Electric ratchet wrench

An electric ratchet wrench comprising:

• a body having a first end and a second end spaced from the first end along a first axis, with the first end of the body including an inner periphery having a toothed portion, with the body including a handle adapted to be held by a user, with the handle located adjacent to the second end of the body and including a through-hole extending in a radial direction perpendicular to the first axis, with the through-hole extending in an outer periphery of the handle in a circumferential direction about the first axis;
• a driving device mounted to the first end of the body, with the driving device including a driving member, a pawl device pivotably mounted to the driving member, and a ring gear rotatably mounted around the driving member, with the driving member including an end adapted for directly or indirectly driving a fastener, with the pawl device configured to selectively mesh with the toothed portion of the body, with the ring gear rotatable relative to the driving member in a clockwise direction or a counterclockwise direction, with the ring gear including an inner toothed portion on an inner periphery thereof and an end toothed portion on an end face thereof, and with the inner toothed portion of the ring gear configured to selectively mesh with the pawl device;
• a transmission device including a transmission shaft rotatably mounted to the body;
• and a power device received in the second end of the body, with the power device including a motor, a power source and a control button, with the motor being a bidirectional motor and including a motor shaft, with the power source electrically connected to the motor for driving the motor shaft to rotate in the clockwise direction or the counterclockwise direction to thereby rotate the transmission shaft, with the control button received in the through-hole of the body and electrically connected to the motor, and with the control button operable to control rotation of the motor shaft of the motor in the clockwise direction or the counterclockwise direction, with the transmission shaft including a first end connected to the motor, with the transmission shaft further including a second end configured to switch between a meshing state meshed with the end toothed portion of the ring gear and a disengagement state disengaging from the end toothed portion of the ring gear, wherein when a resistance smaller than a torque outputted by the motor is encountered while the driving member is driving a fastener, the transmission shaft is in the meshing state and drives the ring gear to rotate, and the driving member is rotated to continuously drive the fastener, and wherein when a large resistance larger than the torque outputted by the motor is encountered at a position while the driving member is driving the fastener, the transmission shaft is in the disengagement state and causes a tooth slippage phenomenon in which the transmission shaft repeatedly engages with and disengages from the end toothed portion of the ring gear, such that the ring gear cannot be rotated, the body is permitted to be manually rotated to overcome the large resistance and to forcibly drive the fastener through the position via the driving member, and the transmission shaft reengages with the ring gear after the fastener passes through the position.