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:
Aug. 27, 1991
Filed:
Aug. 25, 1989
Applicant:
Inventors:
Chitoshi Morishige, Hiroshima, JP;
Tomoo Sawasaki, Hiroshima, JP;
Assignee:
Mazda Motor Corporation, Hiroshima, JP;
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
B60K / ;
U.S. Cl.
CPC ...
74866 ; 74844 ; 74867 ;
Abstract
A hydraulic control system for controlling a transmission of an automotive vehicle has a hydraulic pump driven by an engine to deliver a line pressure and a regulator valve for regulating the line pressure according to a pilot pressure applied thereto. To change the pilot pressure so as to regulate the line pressure to a desired pressure, a duty solenoid valve is operated at a proper duty rate with a steady signal. The steady signal for operating the duty solenoid valve at the desired duty rate is provided at a frequency which is changed according to operating conditions of the automotive vehicle.