Direct-operated servo valve, fluid pressure servo mechanism and control method for the direct-operated servo valve

Patent 5040569 Issued on August 20, 1991. Estimated Expiration Date:

February 13, 2010. Estimated Expiration Date is calculated based on simple USPTO term provisions. It does not account for terminal disclaimers, term adjustments, failure to pay maintenance fees, or other factors which might affect the term of a patent.

Abstract Claims Description Full Text

Patent References

Rotary valve
Patent #: 4735233
Issued on: 04/05/1988
Inventor: Nogami , et al.

Electronic valve actuator
Patent #: 4845416
Issued on: 07/04/1989
Inventor: Scholl , et al.

Electrohydraulic servovalve for the control of a hydraulic actuator, in particular in servomechanisms controlling the flight of aircraft Patent #: 4858650
Issued on: 08/22/1989
Inventor: Devaud , et al.

Inventors

Assignee

Hitachi, Ltd.

Application

No. 479519 filed on 02/13/1990

US Classes:

137/625.65, Motor-operated137/625.21, Rotary valve251/129.04, Remote or follow-up control system for electrical actuator251/129.13With speed or braking control

Examiners

Primary: Cohan, Alan

Attorney, Agent or Firm

Antonelli, Terry, Stout & Kraus

Foreign Patent References

63-53972 JP. 04/13/1988

International Class

F16K 031/04

Foreign Application Priority Data

1989-03-13 JP

Abstract

A direct-operated servo valve which exhibits stable damping characteristics. The servo valve is characterized in that a viscous fluid is charged in the gap between a stator and a movable element. The velocity of a valve member is detected and a feed back the velocity signal is obtained by this detection so as to enable a damping of the motion of the valve member.