| 摘要 |
<p>A valve actuator, for example a mechanism for imparting motion to a blast furnace evacuation valve, includes a force generator which. is coupled to the valve member by a displacement mechanism including a pivotal lever and a pivot arm. The pivotal lever has a pair of angularly related arms with the free end: of one arm being coupled to the force generator and the free end of the second arm being coupled to a point on the pivot arm intermediate the ends thereof by a connecting rod or rods. The pivot arm is connected to the valve member and the connecting rod or rods are articulated to both the pivot arm and to the second lever arm which may be telescoping.</p> |
