Abstract: A granular material spreader is adapted for towing behind a yard tractor. A frame upports an inverted cone which is sized to contain a supply of granular material for distribution. The bin sweep rod is carried adjacent to the inside surface of the cone, and turns a drive spring. The drive spring drives a helix, which rotates about the bin sweep rod, driving the granular material toward the narrow base of the cone. Should the helix become jammed, the drive spring snaps past the helix, rather than risk damage by forcing its movement. A bin sweep drive wheel is also driven by the revolution of the bin sweep. Movement of the wheel against the an upper portion of the outside surface of the cone moves the bin sweep rod and helix in a circular path about the inside surface of the cone. A valve at the base of the cone allows granular material to drop into a housing which defines slots about portions of its perimeter.

Abstract: A spreader for granular material such as sand comprises a trailer adapted to be pulled behind a vehicle such as a tractor or other utility vehicle. A frusto-conical bin forms a hopper for a granular material to be dispensed and directs the material into a spreader housing where the material is impelled outwardly through a discharge opening by a rotating impeller. The impeller and an orbital rotating bin sweep arm are driven by coaxial drive shafts via a belt and pulley mechanism. A frictional tire engages the upper rim of the bin and propels the sweep arm in an orbital path. The material discharge rate and discharge pattern are controllable by a slide gate and interchangeable cover plates which vary the size of the discharge opening. The impeller and bin sweep assembly may be driven by an internal motor or from the towing vehicle by a power take-off drive.