| 摘要 |
<p>A valve actuator is described which employs a hollow housing fabricated from a stamped metal. Located within the housing is a rotatable spindle which spindle is associated with a traveling nut which nut travels along the spindle as the spindle is rotated. The traveling nut has pivotally secured thereto a pivot nut which pivot nut rides in a slot formed in the top portion of a pivot arm. The pivot arm is associated with an aperture to accommodate a valve shaft and pivotally moves when the spindle is rotated due to the movement of the traveling nut along the spindle. The rotation of the pivot arm rotates the valve shaft to thereby open or close an associated valve in a given number of turns as required by the particular system characteristics. Associated with the pivot arm is a switch activator which activator will operate an electrical switch for a given movement of the pivot arm during valve operation. The rotatable spindle is also equipped with an internal (protected) shear pin arrangement, that prevents abuse of the actuator.</p> |
