Motor valve having differential pressure feedback

Claim 1

A HYDRAULIC SERVO VALVE HAVING FEEDBACK, COMPRISING: A VALVE BODY, A SOURCE OF FLUID UNDER PRESSURE; PILOTVALVE MEANS IN SAID VALVE BODY INCLUDING AT LEAST ONE VARIABLE PRESSURE CHAMBER COUPLED TO SAID SOURCE OF FLUID UNDER PRESSURE, SAID VARIABLE PRESSURE CHAMBER HAVING A NOZZLE OPENING COUPLING SAID VARIABLE PRESSURE CHAMBER TO A LOW PRESSURE CHAMBER, THE FLUID UNDER PRESSURE IN SAID NOZZLE PRODUCING A FLUID JET-STREAM IN THE LOW PRESSURE CHAMBER ALONG AN AXIS, A MOVABLE MEMBER WITH AT LEAST ONE PLANAR FACE RECIPROCATABLY MOUNTED IN SAID LOW PRESSURE CHAMBER AND PROJECTING INTO THE FLUID JET STREAM TO RESTRICT THE EFFECTIVE NOZZLE OPENING AND VARY THE PRESSURE IN SAID VARIABLE PRESSURE CHAMBER IN ACCORDANCE WITH AN INPUT SIGNAL, THE PLANAR FACE OF THE MOVABLE MEMBER FORMING A CONSTANT ANGLE WITH THE AXIS OF SAID FLUID JET STREAM INDEPENDENT OF THE POSITION OF THE MOVABLE MEMBER; CONTROL, VALVE MEANS IN SAID VALVE BODY AND COUPLED TO SAID VARIABLE PRESSURE CHAMBER, SAID CONTROL VALVE MEANS HAVING FIRST AND SECOND OUTPUT CONTROL OUTLETS, SAID CONTROL VALVE MEANS BEING ADAPTED TO CONTROL THE APPLICATION OF FLUID UNDER PRESSURE THROUGH SAID OUTLETS IN ACCORDANCE WITH VARIATIONS IN PRESSURE IN SAID VARIABLE PRESSURE CHAMBER; AN OUTPUT ACTUATOR MEANS COUPLED TO SAID OUTLETS; A DIFFERENTIAL PRESSURE EXISTING BETWEEN SAID OUTLETS AND ACROSS SAID ACTUATOR MEANS; FEEDBACK-PRESSURE MEANS COUPLING THE DIFFERENTIAL PRESSURE DEVELOPED ACROSS SAID OUTLETS AND ACTUATOR MEANS, AND SAID MOVABLE MEMBER TO VARY THE POSITION OF SAID MOVABLE MEMBER IN ACCORDANCE WITH SAID DIFFERENTIAL PRESSURE AND PROVIDE SAID FEEDBACK.