Patent ID: 8622271

Claim:
A fastener driving tool comprising: a housing; a motor provided in the housing to rotate a drum; a plunger provided in the housing and configured to move up and down between a top dead center and a bottom dead center, the plunger having a blade for impacting a fastener; a spring that urges the plunger downwards and is capable of being compressed upwards; a wire member connected to the plunger and wound around the drum to move the plunger to the top dead center when the drum is driven by the motor; an energizing switch connected between a power source and the motor to control a power supply to the motor; a trigger switch that is operated by a user and is configured to turn on the energizing switch when the trigger switch is turned on; a detection switch configured to turn on after the trigger switch is turned on, and to maintain the ON state during a time period that the plunger reaches the top dead center and then returns to the bottom dead center; a control unit configured to supply electric power to the motor starting from when the trigger switch is turned on until the detection switch is turned off; and a failure detection circuit configured to stop the electric power supply to the motor when the detection switch is not turned on after the trigger switch is turned on.