Abstract: A feeder housing is suspended from a material supply bin and has lower and upper cylindrical members with the upper member isolated from the lower member by a flexible collar which also seals the cavity formed by the members. The lower member is suspended from the upper member and has a concave bottom wall with a discharge port. A first fixed baffle next adjacent the bottom wall is a ring with shape of a segment of a toroid with angularly oriented sides having a central opening. A second conical baffle is over the central opening and is axially displaced toward the first baffle between a closed state and a material flow open state wherein material flow is normally arrested until the housing and baffles are vibrated. In a second embodiment, a single fixed baffle comprises a pair of symmetrical cones secured inverted relative to each other over a feeder housing discharge and inlet port.