PURPOSE: To simplify unloading from a trolley conveyor, by disengaging a conveyed piece on a free trolley engaged with a power trolley and conveyed by it, in a separation position and moving down the separated part of the free trolley.

CONSTITUTION: The pusher 7 of a power trolley 5 is engaged between the main and auxiliary projections 11, 12 of a front free trolley 10a so that the free trolleys 10a, 10b are pulled by a power chain 6 and moved on a free rail 8. When separation unloading is effected, the main projection 11 comes into contact with a stopper 29 and the stopper is pushed in downward by the front slope of the main projection. As a result, the front free trolley 10a loses a driving forece. A conveying member 9 is stopped on a separation rail 8' and positioned and held by a lockup arm 30. When a ram 26 is protruded down, the separation rail 8' is also moved down as a conveyed piece remains secured on the rail.