Ameridrives Amerigear couplings and Ameriflex diaphragm couplings are utilized on helicopters, crew boats & ferries, cargo ships. Ameridisc high performance disc couplings are often used on helicopter drivetrains. Americardan® 5000 and 3000 Series universal joints used on the propulsion shafts of many types of marine vessels including crew boats, ferries, and cargo ships.