Patent ID: 7588389

Claim:
A vibratory roller unit adapted for use on a lawn mower of a type having a power means for raising and lowering a lift bar; said vibratory roller unit comprising a framework adapted for attachment to the lift bar, a transversely extending drum rotatably mounted in the framework, said drum liftable in and out of contact with the ground by the lift bar and when in contact following the ground and a shaft driven by the power means and rotatably mounted within the framework, said shaft having a fixed inboard eccentric weight and an outboard eccentric weight, said outboard eccentric weight rotatable about the shaft with respect to the fixed inboard eccentric weight, said inboard and outboard eccentric weights being cylindrical with an off longitudinal centerline throughbore for the shaft, whereby the inboard and outboard eccentric weights are capable of applying a centrifugal force which is transmitted to the drum and applied to the ground under the drum as the drum rolls across the ground, said centrifugal force varying in amplitude between a maximum and minimum depending upon the rotatable position of the outboard eccentric weight with respect to the fixed inboard eccentric weight.