Abstract: A two-stage miniature electrohydraulic servovalve including an electromagnetic positioner having a flexure tube mounted drive arm secured to and movable with an armature movable in accordance with a combined magnetic field resulting from both permanent magnets and an electrical signal fed to electromagnetic coils, a four-way hydraulic valve main valve stage including a valve body having a sleeve mounted therein with two annular, internal, axially spaced apart metering grooves, a metering spool having five lands alternating with four metering grooves positioned within the sleeve for controlled axial movement with respect to the sleeve, and end caps positioned over the ends of the sleeve and a jet pipe pilot stage including a jet pipe member secured to the end of the drive arm having a jet pipe nozzle aligned with the drive arm and a hydraulic fluid feeder passage which passage is disposed at right angles to the plane of movement of the drive arm, a resiliently mounted counterbalance positioned on the drive arm

Abstract: Laminated plate cylindrical receiver plug assembly structure having rectangular cross section passages therein which extend axially of the plug assembly through one end thereof on opposite sides of a very narrow divider plate and radially out of the plug assembly on opposite sides of the divider plate from the side on which the axially extending portion of the passages are on is produced by producing a plurality of separate plates having axially and/or transversely extending openings in one end thereof in rectangular form, coating every other one of the plates with brazing material, placing the rectangular plates in side by side surface engagement with the openings therein in alignment to form rectangular cross section axially and radially extending passages through the plug assembly and subjecting them to brazing temperature and pressure and then machining the ends of the brazed together rectangular plates having the openings therein into a cylindrical form and cutting off the other end of the plates.