The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Jan. 15, 1991
Filed:
Feb. 01, 1989
Plato J Leeson, Rockford, IL (US);
John W Wardle, Roscoe, IL (US);
Woodward Governor Company, Rockford, L;
Abstract
A time division multiplexed (TDM) hydraulic control system having a plurality of channels, each channel having a servo actuator. Electrical demand signals are arranged in TDM sequence and applied to a single multiplexed pilot valve so that the pilot valve produces a plurality of hydraulic signals. Commutator means are associated with the pilot valve for distributing the hydraulic signals to the associated channels. In order to achieve useful output flow rates in the channels, each channel includes a second stage valve which integrates the hydraulic signals for its channel to produce an output flow rate which is a function of the integrated signal. The flow rates are continuously produced (as compared to the multiplexed output signals) and are coupled to actuators in the channels for controllably adjusting the position thereof. Feedback means associated with the actuators includes rate feedback for stabilizing the multiplexed control loops.