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:
May. 12, 1992
Filed:
Jan. 31, 1990
Applicant:
Inventors:
Assignee:
Nissan Motor Co., Ltd., Yokohama, JP;
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
B60K / ;
U.S. Cl.
CPC ...
74866 ; 74867 ;
Abstract
A downshift quality control for a predetermined downshift involving engagement of a predetermined hydraulically operated friction element, i.e., a low clutch, is disclosed. A hydraulic fluid supply circuit communicates with the low clutch and includes a variable flow restrictor, i.e., an orifice and a timing valve. The timing valve is operated by a solenoid under control of a control unit. The control unit monitors a speed ratio of a revolution speed of an internal combustion engine to a revolution speed of an output member of an automatic transmission and energizes or deenergizes the solenoid to shift the timing valve to a position where a passage bypassing the orifice is opened.