| 123 / | HD | INTERNAL-COMBUSTION ENGINES | 
| 52.1 | DF | MULTIPLE CYLINDER {7} | 
| 56.1 | DF | .~ Having rotary output shaft parallel to cylinders {2} | 
| 56.2 | DF | .~.~ Cam on rotary output shaft {4} | 
| 56.3 | DF | .~.~.~ Swash plate type {3} | 
| 56.5 |  | .~.~.~.~ Motion converting means between two banks of cylinders |