| 摘要 |
A vibratory hammer/extractor for use with elongated pilings and the like extended into the earth includes a clamping assembly for releasing and securing the hammer to an upper end portion of a piling extended into the ground. A vibratory exciter is mounted on the clamping assembly for generating vibratory forces to be imparted to the piling while clamped tightly, and a suspension device is provided for supporting the exciter and isolating the vibration thereof from a hammer supporting element such as a flexible cable extending downwardly from the boom of a crane. The vibratory exciter includes a hollow gear case having a lower end wall secured to the clamping assembly and at least one pair of eccentric weights mounted on shafts for rotation about an axis transversely of the clamped piling for imparting vibratory forces to the piling as the eccentrics are driven in rotation. Each eccentric comprises a unitary body of dense material such as steel plate having a generally circular periphery and coaxially mounted to rotate with a supporting shaft. Each eccentric body is formed with an enlarged opening or slot on one side of the shaft between a central shaft hub and an outer rim adjacent the periphery. The removal of material to form the slot creates an eccentric center of gravity on the opposite side of the shaft away from the slot. The exciter includes a rotary power unit such as a hydraulic motor mounted on the gear case for rotating a drive shaft carrying one of the eccentrics and the other eccentric is driven by intermeshing toothed engagement with the one eccentric to rotate in an opposite direction.
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