A rotary feeder has a valvular rotor rotating on an axis in a cylindrical cavity. A plurality of rigid, free-floating blades project from a hub of the rotor to delimit several material-receiving pockets circumferentially distributed over the hub. The inner edges of the blades rest in axial recesses in the hub and are supported by fixed projections extending outwardly from the hub along the trailing side of the blades. The recesses permit limited angular movement of the blades relative to the hub. The blades have widths from the hub to the periphery of the cylindrical cavity greater than corresponding radii through the inner edges of the blades at the hub, whereby the blades are angularly inclined relative to such radii. Top portions of the blades are applied to peripheral wall portions of the cylindrical cavity. The recesses, the fixed projections, and peripheral wall portions of the cylindrical cavity cooperate to hold the blades in position. The fixed projections carry means for urging the blades toward the corresponding radii. The blades are biased or periodically adjusted angularly toward the mentioned corresponding radii during wear of the outer portions and the peripheral wall portions to maintain worn top portions of the blades applied to the peripheral wall portions of the cylindrical cavity.