摘要 |
<p>In general, a motorized valve actuator includes an electric drive motor having a rotatable shaft for providing an actuating torque. An output member is provided for operating a valve to be coupled thereto and a gear member is adapted to be mounted intermediate the shaft and the output member and in a first position or in a second position. The gear member includes first means for driving coupling of the motor shaft and the output member when the gear member is mounted in the first position and second means for decoupling the output member from the shaft when the gear member is mounted in the second position. In the latter position, the gear member permits the output member to be driven by a source of power external to the actuator.</p> |