23 SINGLE AND MULTIPLE DRUM HOISTS AND DRUMS THEREFOR FOR EMPLOYMENT IN THE FIELD OF COMMERCIAL ACTIVITY, COMMONLY KNOWN AS THE CRANE,HOIST, AND DERRICK FIELD, COMPRISING THE MANUFACTURE, SALE, AND DISTRIBUTION OF CRANES, WINCHES, DERRICKS, HOISTING EQUIPMENT, AND MATERIAL HANDLING EQUIPMENT ADAPTED FOR USE IN CONSTRUCTION PROJECTS, INDUSTRIAL PLANT OPERATION, AND LOADING CARGO FROM AND TO COMMON CARRIERS