US Patent 7971886 Steering for towed implements

An implement includes a caster wheel pivotally attached to the implement to support the implement for movement. A steering link is engaged with the caster wheel, and an actuator is operative to move the steering link from a neutral position to a controlling position. When the steering link is in the neutral position, the caster wheel can pivot about the caster axis through a 360 degree pivot range. When the steering link is moved to the controlling position, the caster wheel is oriented to roll toward a first side of the implement.