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:
Mar. 12, 1991
Filed:
Apr. 25, 1989
Applicant:
Inventors:
Fumiaki Baba, Hiroshima, JP;
Jyujiro Oda, Hiroshima, JP;
Assignee:
Mazda Motor Corporation, Hiroshima, JP;
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
B60K / ;
U.S. Cl.
CPC ...
74844 ; 192 / ;
Abstract
In an automatic transmission, a hydraulic pressure control valve produces hydraulic pressure according to a pilot pressure fed thereto. A duty solenoid valve controls the pilot pressure. An oil temperature sensor detects the temperature of the hydraulic oil and a driving period changing circuit changes the driving period of the duty solenoid valve according to the temperature of the hydraulic oil so that the driving period is long when the temperature of the hydraulic oil is low and short when the temperature of the hydraulic oil is high.