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. 03, 1992
Filed:
Mar. 30, 1990
Shigeki Goto, Aichi, JP;
Yoshitami Saitou, Aichi, JP;
Aisin Seiki Kabushiki Kaisha, Aichi, JP;
Abstract
A hydraulic control apparatus for an automatic transmission has friction elements for performing a downshift by releasing one friction engaging element and engaging another. The apparatus includes duty control valves connected to the friction engaging elements, duty solenoid valves connected to oil lines for supplying pilot hydraulic pressure to the duty control valves, and control means. In a case where a release duty signal is outputted to one duty solenoid valve to control the pilot hydraulic pressure to thereby release the one friction engaging element, and downshift is a power-on downshift, the control means raises the duty ratio of the other duty solenoid valve to a predetermined valve to raise engaging hydraulic pressure supplied to the other friction element when rotational speed of the transmission input shaft is greater than a difference between the product of output shaft rotational speed and low-side gear ratio and a rotational speed commensurate with a delay in engine speed upturn.