[ COMBINED ELECTRIC AND MACHINERY PLANTS PLACED ON TRAMWAY CARS-, namely, ELECTRIC CONTROLLERS, ROLLER AND BOW COLLECTORS, ELECTRIC COUPLING SWITCHES AND GEARING, SOLENOID RAIL BRAKES, ELECTRIC SWITCHES FOR LOW AND HIGH TENSION FOR SMALL AND LARGE OUTPUTS, EXCESS CURRENT SWITCHES, METAL AND LIQUID RESISTANCES FOR ELECTRIC PLANTS, VOLTAGE CUT-OUTS AND EXCESS CURRENT CUT-OUTS, ELECTRIC WELDING AND RIVETING FRAMES, MAGNET WHEELS, MAGNET HOUSINGS, ELECTRIC ROTORS, POLES AND INDUCTOR RINGS, AND WITH THE EXCEPTION OF USE FOR PURPOSE OF AUTOMOTIVE VEHICLES THE FOLLOWING ] ELECTRIC [ GENERATORS AND ] MOTORS [, MOTOR STARTERS, GENERATOR FRAMES, AND MOTOR HOUSINGS ]