| 摘要 |
A pneumatic actuator (1) intended to control the rotation of the activating shaft of a shutoff valve is described. The actuator comprises a box- shaped body (2), which can be fed with compressed air, two opposing pistons (6,7) housed in the box- shaped body, translatable in opposite directions in response to the force exerted by the compressed air, between a position of maximum mutual distance and a position of minimum mutual distance, a drive shaft (5) which can be coupled to the activating shaft of the valve shutter, and a kinematic system connecting the pistons to the drive shaft. The actuator comprises at least one substantially wedge-shaped limit element (8), interposed between the pistons and movable in a plurality of stationary positions to define the corresponding positions of minimum mutual distance of the pistons, that is to adjust the end-position. |
