Pressure balanced double porting servo valve

Claim 1

A FLAT VALVE CONSTRUCTION COMPRISING A VALVE BLOCK HAVING A FIRST FLAT VALVE FACE, A VALVE HEAD RIGIDLY SECURED IN SPACED RELATION TO SAID VALVE BLOCK AND PRESENTING A SECOND FLAT VALVE FACE, RECTANGULARLY SHAPED CONTROL CHAMBERS FORMED IN SAID FIRST FLAT VALVE FACE AND CORRESPONDING CONTROL CHAMBERS FORMED IN SAID SECOND FLAT VALVE FACE IN ALIGNMENT WITH SAID CONTROL CHAMBERS IN SAID FIRST FLAT VALVE FACE, A VALVE PLATE HAVING OPPOSITE SYMMETRICALLY ARRANGED THIRD AND FOURTH FLAT VALVE FACES EACH FORMED BY A PAIR OF RECTANGULAR SHAPED LANDS ALIGNED WITH SAID CONTROL CHAMBERS WHEN THE VALVE IS IN A NULL POSITION, A PAIR OF LEAF SPRINGS SECURED TO OPPOSITE ENDS OF SAID VALVE PLATE AND TO OPPOSITE SIES OF SAID VALVE BLOCK TO SUPPORT SAID VALVE PLATE BETWEEN SAID VALVE BLOCK AND SAID VALVE HEAD IN CLOSELY SPACED FRICTION FREE RELATION TO SAID FIRST AND SECOND FLAT VALVE FACES THEREOF AND TO PERMIT RECTILINEAR MOVEMENT OF SAID VALVE PLATE IN OPPOSITE DIRECTIONS ALONG A LINE THROUGH SAID LANDS FOR CONTROLLING FLUID FLOW THROUGH SAID VALVE, PASSAGE MEANS THROUGH SAID VALVE PLATE INTERCONNECTING OPPOSITE FACE PORTIONS THEREOF; SAID VALVE BLOCK COMPRISING AN ASSEMBLY OF PARALLEL SECTIONS NORMAL TO SAID VALVE PLATE, BOLT MEANS PARALLEL WITH SAID VALVE FACES SECURING SAID SECTIONS TOGETHER SO THAT THEIR ENDS DEFINING PORTIONS OF SAID FIRST VALVE FACE ARE COPLANAR, MEANS INTEGRALLY JOINING ADJACENT SAID SECTIONS TOGETHER ALONG ABUTTING SIDE EDGES THEREOF; SAID SECTIONS INCLUDING A PAIR OF END SECTIONS, A PAIR OF CONTROL SECTIONS EACH ADJACENT ONE OF SAID END SECTIONS, AND A CENTRAL SECTION BETWEEN SAID CONTROL SECTIONS; SAID CENTRAL SECTION HAVING A PASSAGE EXTENDING THERETHROUGH FOR SUPPLYING PRESSURE FLUID TO PRESSURE CHAMBERS FORMED BETWEEN SAID LANDS IN SAID VALVE PLATE AND SAID CENTRAL SECTION ALSO HAVING A WIDTH GAUGED TO THE SPACING BETWEEN SAID LANDS SO THAT OPPOSITE FACE OF SAID CENTRAL SECTION PROVIDE SHARPLY DEFINED SQUARE EDGES IN THE FIRST VALVE FACE; SAID CONTROL SECTIONS EACH COMPRISING A PAIR OF SPACER MEMBERS SPACED APART IN THE PLANE OF ITS OWN SECTION AND HAVING A WIDTH EQUAL TO THE WIDTH OF ONE OF SAID LANDS TO SPACE THE END SECTIONS FROM THE CENTRAL SECTION SO THAT FLAT VERTICAL SURFACES OF SAID END SECTIONS AND CENTER SECTION DEFINE WALLS OF SAID CONTROL CHAMBER AND ALSO PROVIDE SHARPLY DEFINED EDGES IN THE FIRST VALVE FACE WHICH COOPERATE WITH THE EDGES OF THE LANDS TO DEFINE FLOW CONTROL ORIFICES.