Rotary harrows

A rotary harrow comprising a frame and coupling means on said frame for attachment to a prime mover, a plurality of soil working members rotatably mounted on shafts journalled on said frame and driving means connected to rotate said soil working members, said shafts and soil working members extending in a row transverse to the normal direction of travel of the harrow, said soil working members each comprising a support rotatable on a generally vertical shaft and each support being connected to at least one tine that has a lower soil working portion depending downwardly from said support to contact the ground and trace a general circular path through the soil, screening means mounted on the cultivator and said screening means having an inclined surface that extends across the working width of said row in front of said supports, said screening means terminating above the soil working portion and being positioned to protect said supports, the upper portions of the tines and their support connections from damage by debris encountered in and on the soil during operation while leaving the lower soil working portions of the tines exposed to work the soil, said screening means being a protective roller having a curved surface that faces said supports and said curved surface normally being positioned closely adjacent those supports, said roller being elongated and freely rotatable about its longitudinal axis.