| 摘要 |
<p>A pipe gripping assembly includes, among other components, a fluid conducting swivel (30), a fluid-powered linear actuator (20) and a pipe gripping assembly (40). The linear actuator has a central rod mounted within a multi-stage, segmented barrel assembly. Each barrel segment acts as a piston, with control fluid forces being transmitted to the barrel assembly to selectively extend or retract the barrel assembly in order to engage or disengage the pipe gripping assembly. By aggregating such force, the total combined force generated by the barrel piston assemblies, the actuator assembly of the present invention can operate using pneumatic control fluid, and can operate at much lower control fluid pressures than other actuators.</p> |
