| 摘要 |
A novel rope tension damper device (60) is adapted to be installed, for example, on the deck of a ship (10) at a location between the winch (40) that controls the effective length of the rope and the fairlead (70) that guides the rope so that it does not snag or tangle as it is wound and unwound from the winch. The device comprises a co-planar of sheaves (102, 108) respectively mounted at opposite ends of a rotatable arm (110). The two sheaves are oriented with their respective rotational axes parallel to the rotational axis of the arm such that with the rope entering the device tangential to a point on the periphery of the first sheave (102) and exiting from the device tangential to a second point on the periphery of the second sheave (108), and with the arms longitudinal axis (3) more or less perpendicular to the orientation of the rope as it enters and exits from the device prior to the application of any tension, the rope within the device will be guided by the two sheaves into a generally S-shaped configuration which will be gradually distorted into a relatively straight configuration as the tension in the rope applies a torque couple to the arm and thereby causes it to rotate to an orientation more parallel to that of the rope outside the device. Preferably, a pair of such elastomeric torsional members (126, 128) are provided, one on either side of the rotatable arm (110) and concentric with its rotational axis. Shearing forces within the elastomer serve to generate a counter-torque or the rotating inner arm, thereby causing a variable damping force to be applied to the rope as the arm and sheave assembly is rotated from its zero load position. In accordance with a preferred embodiment of the invention, each torsion spring in a pair of hollow elastomeric cylinders (170, 172) coaxially nested about the arm's rotational axis, with a first end of the outer cylinder (172) being fixedly connected to a first end of inner cylinder (170) such that when one of the respective second ends is attached to the arm and the other of the respective second ends is attached to the outerframe (176), the torque generated by the inner elastomeric cylinder and the torque generated by the outer elastomeric cylinder are combined. |
