US Patent 11174962 Pneumatic servo valve with adjustable drive unit

A servo valve for an actuator comprises a housing, a sleeve provided within the housing comprising an axis (A) and having a plurality of metering holes for communication with a cavity within. A metering rod extends within the cavity for metering flow of pneumatic fluid through the metering holes. The metering rod is coupled to a drive unit for axial movement within the cavity, the drive unit comprising a drive unit housing, a solenoid and an adjustable core. The adjustable core comprises a threaded first portion having a thread and a second portion. The thread of the first portion engages a thread extending through the drive unit housing for adjustment of the relative position of the adjustable core with respect to the solenoid.