AUT-O-DOR

ELECTRICAL APPARATUS COMPRISING AN ELECTRIC MOTOR, A SET OF GEARS IN A HOUSING, A CRANK, AND A SWITCH FOR CONTROLLING THE MOTOR, SAID MACHINERY BEING ADAPTED FOR THE OPENING AND CLOSING OF DOORS, INCLUDING PUBLIC AND PRIVATE GARAGE DOORS, WAREHOUSE DOORS, FACTORY DOORS, FIRE AND POLICE STATION DOORS, AND LABORATORY DOORS