Title: Self-monitoring dual-spool servovalve

Abstract: An improved electrohydraulic servovalve has first and second valve spools mounted for independent sliding movement relative to a body in response to a common command signal. The valve has a first drive mechanism operatively arranged to cause a desired motion of one valve spool in response to the command signal, and has a second drive mechanism operatively arranged to cause a desired simultaneous similar motion of the other valve spool in response to the command signal. The improvement comprises a differential position sensing mechanism arranged to sense the relative positions of the two valve spools and operative to produce an output related to the difference therebetween, and an indicating device supplied with such output and operative to indicate substantially dissimilar relative positions of the spools.

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Inventors: Garnjost, Kenneth D. (Orchard Park, NY)
Ballard, John S. (South Wales, NY)

Application Number: 06/155550
Filing Date: 1980-06-02
Publication_date: 1982-07-13
Assignee: MOOG INC

Primary Class(es): 137/554 91/31, 137/596.160, 91/510, 91/363A, 91/437
Other Classes: F15B20/00; F15B13/043; F15B20/00
US Patent Ref:

3139109	June, 1964	Ruchser	137/596.16	Valve control system
3270623	September, 1966	Garnjost et al.	Fluid powered servomechanism of a redundant, monitor type
3338138	August, 1967	Wood	Redundant control system
3338139	August, 1967	Wood	Redundant control system
3554084	January, 1971	Rasmussen et al.	91/509	REDUNDANT FORCE SUMMING SERVO UNIT
3937254	February, 1976	Stahle	137/596.16	Device for monitoring control elements
4009642	March, 1977	Vanderlaan	913/63A	Differential pressure sensing valve

Other Refs: GB673372GB673375GB937487GB1221451GB1341290SU663932

June, 1952
June, 1952
September, 1963
February, 1971
December, 1973
May, 1979	137/596.16

Other References: W. J. Thayer, Technical Bulletin 127, Redundant Electrohydraulic Controls, Published May, 1976 by Moog, Inc.

Primary Examiner: Michalsky, Gerald A.
Assistant Examiner:
Attorney: Sommer & Sommer

Claims:

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