Patent ID: 9272399
Filing Date: 2016-03-01
CPC Classification: B25B

Claim Text:
1. An electrical wrench, comprising: a motor, a transmission mechanism, a ratchet assembly and a controlling member wherein the motor, the transmission mechanism and the ratchet assembly are coupled to one another, wherein the transmission mechanism comprises a first transmission member and a second transmission member rotatably connected with each other, wherein the ratchet assembly comprises an eccentric shaft, a swinging member, a pawl and a ratchet, wherein the eccentric shaft is provided with a shaft projection deviating from the axis thereof, wherein the swinging member is configured to swing along with the rotation of the eccentric shaft and has an accommodating portion for accommodating the shaft projection, wherein the pawl is arranged on the swinging member and contacts ratchet teeth on the outer circumference of the ratchet, wherein the pawl is configured to drive the ratchet to rotate in a single direction along with the swinging of the swinging member, wherein the controlling member is used to control the rotation of the motor, wherein the first transmission member and the second transmission member are provided with idle travels separated from each other in the rotation direction, and wherein the controlling member comprises a detecting module for detecting whether the motor is stalled and a controlling module for controlling the motor to rotate in an opposite direction when it is detected that the motor is stalled.