| 摘要 |
The invention relates to a valve with a pneumatic drive system, having a spring-loaded displaceable piston arranged in a cylinder housing and having a piston rod which is arranged on the piston and which is in engagement with a valve stem, at the end of which a gasket is arranged on a gasket seat in the manner of a valve. Valves of this type are known per se, high sealing forces being necessary in order to close the valve seat, along with drive systems of correspondingly large dimensions for the piston rod and valve stem. However, the greatest force is only ever required at the moment of closing of the valve seat, whereas only minor forces are needed for the remaining stroke, so that disadvantageously costly and complicated mechanical drive systems are employed, even though these are required only in the closing region of the valve. The object on which the invention is based is to employ a drive system of substantially smaller dimensions in the closing region of the valve, along with equally high sealing forces. To achieve the object, the invention provides for arranging a lever-transmitting member between the piston and the valve stem, a lower closing force generated by the piston being converted via the lever-transmitting member into a higher valve-closing force.
|
