John W Rollins

US Patent:

45568324, Dec 3, 1985

Filed:

Mar 8, 1984

Appl. No.:

6/587669

Inventors:

John P. Rollins - Lancaster SC

Assignee:

Duff-Norton Company, Inc. - Charlotte NC

International Classification:

H02P 108
G05D 300

US Classification:

318467

Abstract:

Apparatus for electrically controlling actuation and deactuation of a hydraulic fluid directional control valve between centered, forwardly-moved and reversely-moved positions thereof includes a reversible electric motor whose drive train is connected to the valve control member for forward and reverse rotation thereof and an arrangement of two forward and two reverse electric circuits between an electrical source and the motor, two manual switches each in associated forward and reverse circuits, four limit switches positioned each in one circuit, and cams mounted on the motor drive train to open and close the limit switches in relation to the rotational disposition of the drive train to provide for manual actuation by the manual switches of selected forward and reverse rotation of the motor drive train and valve control member, for automatic deactuation of the electric motor by the limit switches at each of the two predetermined rotated dispositions of the valve member, for selective holding of the valve member at its operative rotated dispositions by continued manual engagement of the manual switches, for automatically actuating the electric motor cooperatively by the manual and limit switches upon release of the manual switches for opposite return rotation of the drive train and valve control member, and for automatically deactuating the electric motor by the limit switches upon return of the drive train and valve control member to their original centered disposition.