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:
Jul. 16, 1991
Filed:
Jun. 27, 1990
Aisin AW Kabushiki Kaisha, , JP;
Abstract
An automatic transmission hydraulic controller having a multiplicity of hydraulic servos for respectively controlling a multiplicity of frictional engagement elements. A hydraulic pressure to be supplied to the hydraulic servos is applied to accumulator chambers of a multiplicity of accumulators. A line pressure to be supplied to the hydraulic servos is produced by a primary regulator valve and an engine output pressure control valve is controlled by an electrical signal from a control section to produce a hydraulic pressure corresponding to the engine output. Each of at least two particular ones of the multiplicity of accumulators has a back pressure chamber formed at the rear of a piston. The pressure receiving area of this back pressure chamber and that of the corresponding accumulator chamber are substantially equal to each other. Only one of the frictional engagement elements operated by the hydraulic servos communicating with the particular accumulators is changed over from a released state to an engaged state while the other frictional engagement elements are not changed over from a released state to an engaged state, when the transmission is shifted to a predetermined speed. There is no substantial influence of a change in the line pressure upon the operating state of the other frictional engagement elements.