Insulating shutter mechanism for bus bars

A control center for distributing electric power from a power supply source to power-consuming devices, comprising a cabinet having a frame providing a compartment on the front side of the cabinet, a plurality of vertical, horizontally spaced, bus bars in said cabinet, a barrier of electrically insulative material covering the bus bars, the barrier having spaced contact-receiving openings for each bus bar so that terminal contacts of a circuit interrupter may be inserted into the openings when a circuit interrupter is placed in the cabinet, shutter means for closing the openings when the circuit interrupter is withdrawn from the bus bars, said means including a planar shutter extending across the spaced openings and having spaced apertures;

• the planar shutter being slidable between aligned and unaligned positions of the openings and apertures which positions correspond to installed and removed positions of the circuit interrupter, shutter-opening means comprising an elongated rod rotatable about its axis and having an outturned portion operatively connected to said shutter, and the shutter-opening means also comprising an outwardly inclined cam segment extending into the path of travel of the circuit interrupter so that the rod is rotated to move the shutter to the aligned position when the circuit interrupter is installed.