| 摘要 |
1394211 Valves LONE STAR INDUSTRIES Inc 1 Aug 1972 [9 Aug 1971] 35887/72 Heading F2V A fast valve operator for rotating a valve shaft (14) (Fig. 1, not shown) through 90 degrees to effect opening or closing of the valve (10) comprises a shaft 20 coaxial with and flexibly coupled to the shaft (14), a driven sprocket 38 and idler 46 coupled by a sprocket chain 40 the ends of which are adjustably secured to a piston rod 86 so that movement of the rod in either direction causes rotation of the shaft 20. The piston is "cocked" in the "closed" position of the valve by a trigger 102 preventing clockwise rotation of the sprocket 38. To operate the trigger fluid pressure is applied to a piston/ cylinder arrangement 110 which causes a striker 120 to move into the path of the trigger and release the sprocket. To "cock" the piston, fluid pressure is applied to the piston via conduit 74 whilst the trigger locks the sprocket 38. Once released the piston moves leftwards to open the valve (10) and is slowed towards the end of its movement by a dashpot effect of the piston rod 86 entering a bore in an end plate 63 of the cylinder 62. The valve operator is reset by applying fluid pressure via conduit 72. An alternative form of trigger comprises a core (124) rotatably fixed to shaft 20 (Figs. 5 and 6, not shown) and a spring (144) attached to a cage (138) and urged into engagement with the surface of the cone by a spring (148). Movement of the shaft 20 in one direction causes the spring (144) to wrap around the surface more tightly and hold the piston "cocked". Release is effected by applying a current to solenoid (150) to retract the cage (138). In another form the piston is held fluidically (Fig. 7, not shown) and release is effected by energizing a number of solenoid valves (164, 172, 176, 186). The sprocket (240) (Figs. 8 and 9, not shown) may be in continuous loop and the trigger 102 may be provided with a roller bearing catch (200). |
