| 摘要 |
<p>A gripper mechanism for downhole tool is disclosed that includes a linkage mechanism and a flexible toe disposed over the linkage mechanism. In operation, an axial force generated by a power section of the gripper expands the linkage mechanism, which applies a radial expansion force to the flexible toe. For certain expansion diameters, the expansion force can be primarily transmitted to the toe from a roller-ramp interface expanding the linkage. For other expansion diameters, the expansion force can be primarily transmitted to the toe by expansion of the linkage in a three-bar linkage configuration. For other expansion diameters, the expansion force can be primarily transmitted to the toe by expansion of the linkage in a four-bar linkage configuration. Thus, the gripper can provide a desired expansion force over a large range of expansion diameters.</p> |
