| 摘要 |
A system for varying the vibration generating force of a rotating eccentric weight (22) comprises a second weight (28) movable from a position on the same side of the axis of rotation as the eccentric weight to a second position on the opposite side of the axis of rotation, the movement being linear and radially across said axis of rotation. A coil spring (27) may be employed to move the movable weight toward the second position initially, in compression, and later to resist additional movement in said direction, in tension, so as to provide basically a linear system for varying the vibrational force. The second weight may advantageously be mounted on a piston 29 in a cylinder 23, and movement of the second weight, against centrifugal forces, effected by applying fluid pressure to the piston. <IMAGE> |
