A belt conveyor having clutch-driven flights for extremely low-torque operation. The flights have pivot members that rotate about an axis over a limited range of angles. A clutch mechanism includes a spring pushing a clutch wheel against a pivot member. The clutch wheel is arranged to rotate as the conveyor belt advances. Frictional contact between the rotating wheel and the pivot member imparts a moment on the flight to raise it to an extended position. When the flight is encumbered even by a light load, the low-torque mechanism automatically slips to prevent the flight from rising to the extended position.