Electric stapler

摘要

An electrically powered stapler is disclosed having a sliding blade for driving staples which is reciprocated by a lever and crank mechanism driven by an electric motor through a torque increasing gear train. Jamming of the stapler is prevented by mounting the lever's fulcrum on a plunger which is releasably retained to a fixed support by a flexible collar. The plunger has an enlarged head, and the collar has a plurality of flexible fingers which grip the plunger behind the head to retain the plunger to the collar. The plunger can be disengaged from the collar by the application of a predetermined force directed away from the plunger, such as occurs on the fulcrum during a jammed condition when the blade cannot drive a staple and is stalled. The pivot point of the lever then shifts to the blade end of the lever and the plunger is reciprocated by the lever instead of the blade, allowing the motor and other components to cycle through their full range of motion without stalling. The plunger is reengaged into the collar automatically as the plunger is reciprocated and the stapler is again ready to staple.