| 摘要 |
In a hydraulic piston actuator the supply of working fluid is governed by at least one servo valve of the three-gate type, the spring-loaded valve body of which is activated by a thermowire adapted normally to hold the valve body in a position to close-off the supply of fluid. One end of the thermowire is connected to a compensating device, goverened by the movement of the actuator piston in such a manner that thermal movements are partly counteracted. The servo valve may actuate a maximum switch, and a time relay will, after a predetermined period of time put the fluid pump out of action, and connect both sides of a double acting actuator with a return flow tank. |
