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:
Feb. 02, 1988
Filed:
Oct. 04, 1985
Toyota Jidosha Kabushiki Kaisha, Toyota, JP;
Abstract
In a shift control system of an automatic transmission, wherein the shift control system includes a first and a second transmissions capable of automatically switching speeds separately of one another, and the first and the second transmissions are shifted simultaneously or alternately, to thereby achieve multi-speed shifts, there is provided a system for starting and completing changes in rpm for the shift of rotary members of the second transmission during the operation of changes in rpm for the shift of rotary members of the first transmission, particularly when the first transmission is high gear shifted and the second transmission is shifted simultaneously, whereby the automatic transmission as a whole is up shifted, so that the shift characteristics can be maintained satisfactorily. In this case, an acting force of a frictionally engaging device during the operation of shift of the transmission is maintained at a predetermined value for a predetermined period of time so as to prevent a neutral portion on the intermediate portion of a series of torque transmitting system from occurring instantaneously to fluctuate an output torque.