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. 24, 1989
Filed:
Mar. 24, 1987
Aisin Seiki Kabushiki Kaisha, Kariya, JP;
Abstract
A control apparatus for an automatic transmission connected to a hydraulic control circuit having a first changeover valve for switching a main transmission mechanism having at least two speed ratios between high and low speed ratios in dependence upon at least vehicle velocity, and a second changeover valve for switching an auxiliary transmission mechanism, which is provided in addition to the main transmission mechanism and has at least two speed ratios, between high and low speed ratios at a vehicle velocity higher than a changeover velocity of the first changeover valve. The control apparatus has a third changeover valve for switching the auxiliary transmission mechanism from low to high at a vehicle velocity lower than the changeover velocity of the first changeover valve, and from high to low when the vehicle velocity rises above the changeover velocity of the first changeover valve. The third changeover valve is capable of forming an intermediate speed, such as a 1.5 or 2.5. speed, by changing over the auxiliary transmission mechanism from low to high while the main transmission mechanism is low.