US Patent 7213479 Vibratory mechanism and vibratory roller

A vibratory mechanism includes vibratory shafts, which are stored within a roll and are arranged symmetrically across a rotation axis of the roll, fixed eccentric weights fixed to respective vibratory shafts, rotatable eccentric weights rotatably attached to respective vibratory shafts, a rotation controller controlling a range of movement of the rotatable eccentric weights, and an eccentric moment controller which changes an eccentric moment around the vibratory shaft depending on the rotation direction of the vibratory shafts, whereby the vibration state of the roll is switchable between standard vibration and horizontal vibration.