Patent ID: 6786236
Filing Date: 2004-09-07
Classification: F15B,Y10T

Abstract:
An electrohydraulic servo valve, comprising:a first stage servo unit having a drive assembly adapted to move a forked clevis member from a null position to alternatively open and close first and second nozzle orifices such that when the first nozzle orifice is open flow is permitted between a pressure port and a control port and when the second nozzle orifice is open flow is permitted between the control port and a return port; and a second stage valve unit having a sliding valve member and having an inlet port in communication with the first stage control port, a flow port and a pressure port, wherein flow from the second stage pressure port to the flow port is controlled by the sliding valve member; whereby the clevis member and the sliding valve member are linked by a feedback spring such that movement of the sliding valve member imparts a feedback force to the feedback spring to return the clevis member to the null position such that movement of the sliding valve member is proportional to an input signal to the drive assembly.