| 474 / | HD | ENDLESS BELT POWER TRANSMISSION SYSTEMS OR COMPONENTS |
| 47 | DF | PULLEY WITH EXPANSIBLE RIM MEANS OR PULLEYS WITH ALTERNATELY USEABLE NESTABLE RIMS {2} |
| 49 | DF | .~ Structure for variably adjusting radius of rim section {5} |
| 52 | DF | .~.~ Including means interconnecting plural pulleys for simultaneous adjustment {1} |
| 53 | | .~.~.~ Pulleys on spaced axes |