23 PARTS OF AUTOMOTIVE-VEHICLE AND AIRCRAFT MOTORS AS WELL AS ALL OTHER TYPES OF MOTORS (EXCEPT ELECTRIC MOTORS)-NAMELY, PISTONS, CYLINDERS, CYLINDER BUSHINGS, VALVES, VALVE-SEAT RINGS, VALVE CONES, VALVE PISTONS AND VALVE GUIDES; PRESSURE LUBRICATORS FOR AUTOMOTIVE VEHICLES; HYDRAULIC AND AIR-PRESSURE DEVICES-NAMELY, COMPRESSORS, PUMPS, AND PRESSURE RESERVOIRS; HYDRAULIC SYSTEMS FOR FARM TRACTORS; CAR JACKS, TIRE PUMPS; HYDROSTATIC AND HYDRODYNAMIC CLUTCHES FOR AUTOMOTIVE VEHICLES AND HYDRAULIC CONTROL VALVES THEREFOR; AGRICULTURAL AND INDUSTRIAL WHEEL AND TRACK TRACTORS, POWER SHOVELS, AND HARVESTERS