QUICK DISENGAGING VALVE ACTUATOR

摘要

TITLE QUICK DISENGAGING VALVE ACTUATOR An actuator is provided which is respondable to control fluid pressure for moving an operative means of a valve between open and closed positions. The actuator comprises a housing having a cylindrical bore defined therethrough. A shaft is carried in the housing and is engagable with the operative means. Piston means are carried by one of the shaft and the housing and are sealingly slidable along the other of the shaft and the housing and longitudinally movable within the cylindrical bore. Fluid chamber means are companionly associated with the piston for yielding a differential force across the piston means upon variation of fluid control pressure within the actuator. The shaft is selectively shiftable longitudinally in a first direction to move the operative means to one of open and closed positions by variation in fluid control pressure, and is shiftable to a second direction to move the operative means to the other of the open and closed positions upon subsequent variation in fluid control pressure. One of the shaft and operative means has slotted means thereon for transverse receipt of a companion engagement means on the other of the shaft and the operative means whereby the operative means and the shaft are thereafter in substantial longitudinal engagement. The shaft and the operative means are disengageable by relative transverse shifting of the shaft and the operative means to remove the actuator from the valve.