Abstract: A vibratory roller includes a vibrator operably connected to a rotatable compacting roll. The vibrator is comprised of a rotatable shaft mounted co-axially to the roll and a casing mounted on the shaft and including a chamber and an eccentric mass within the chamber the mass being transversely displaceable in the chamber. Movement of the mass within the chamber provides a variable amplitude for the vibrations induced thereby. The movement of the mass is caused by centrifugal force which urges the mass radially outwardly against a fluid storage space radially outwards of the eccentric mass in the chamber, such chamber in turn communicates through a port with a portion of the chamber radially inwards of the eccentric mass. Fluid thus flows from the radially outwards storage space through the port to the radially inwards storage space and the eccentric mass moves radially outwards until the eccentric mass closes off the port.

Abstract: A vibratory mechanism comprises a motor-driven shaft, a first mass carried by the shaft for rotation therewith, and a variable mass supported for rotation relative to the shaft whereby the angular relationship between the first mass and the variable mass can be selectively adjusted to vary the amplitude of vibration. A drive member is rotatable with the shaft. The variable mass carries a plurality of longitudinally and circumferentially spaced abutment surfaces. The drive member carries a contact face. Engagement between the contact face and the abutment surfaces occurs at different angular relationships between the first mass and the variable mass to vary the amplitude of vibration.

Abstract: A vibratory compacting roller includes a rotatable compacting roll, and a motor driven vibrator. The vibrator includes a shaft, a movable mass rotatable with the shaft and adjustable transversely thereof, and a position regulator for regulating the position of the mass to provide for a variable amplitude of vibration, the amplitude of vibration of the vibrator being lowest when the center of gravity of the mass is nearest the shaft and greatest when the center of gravity of the mass is farthest from the shaft. The position regulator comprises a spring which automatically positions the eccentric mass to the low amplitude position when the shaft is at rest, whereby minimal start-up torque is imposed upon the motor. A releaseable locking mechanism locks the mass in the low-amplitude position.