Abstract

An electro-mechanical impact device, useful for driving nails, staples and other fastening elements. The driving member is driven by frictional engagement between a pair of counter-rotating high speed flywheels. The device has a safety provision whereby it cannot be actuated until the nose of the device is pressed against a work piece. This action also produces a movement of one of the flywheels toward the other. Actuation of the trigger moves the driving member into engagement between the counter-rotating flywheels, and these propel the driving element in a fastener driving direction. The inertia of the movable flywheel aids in efficient engagement of the flywheels with the driving member, and the movable flywheel is provided with a leaf spring permitting it to yield so that the driving member can pass between the flywheels while maintaining frictional engagement between the flywheels and the driving member. The driver is connected to an elastic member, so that when the tool is lifted from the work, the movable flywheel is moved away from the fixed flywheel, and the elastic member then retracts the driving member between the flywheels to a position out of contact therewith. The two flywheels are driven in synchronism by a single electric motor.