Abstract: A shutter mechanism for an electrical receptacle includes two shutter members each of which has a cam surface under one blade slot of the receptacle face and a blocking member under the other blade slot. One of the blade slots is T-shaped to admit either a blade parallel with the first blade or a blade perpendicular thereto. The blocking member under that slot is split along the plane of the perpendicular blade forming a gap which is separable when that kind of blade is inserted. To prevent separation until two blades are simultaneously inserted, the separable portions have projections which are held together by arms of the other shutter member. The apparatus is usable with a plug also having a grounding blade.

Abstract: A safe electrical receptacle has internal switches to connect the power source to female connector elements when plug blades are inserted through openings in the receptacle cover. A blade inserted through one opening closes the switch to energize the female element behind the other opening. Slidable switch operators are disposed between the receptacle housing cover and the female elements and are moved laterally to close the switches before the plug blades engage the female elements.