198 / | HD | CONVEYORS: POWER-DRIVEN |
523 | DF | CONVEYOR SYSTEM HAVING A GRAVITY CONVEYOR SECTION {11} |
540 | DF | .~ Gravity discharge material holder is source of supply, discharging by gravity to power-driven section {6} |
543 | DF | .~.~ With at least one more successive power-driven section {2} |
544 | .~.~.~ Of the apron belt type |