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:
Aug. 15, 1989
Filed:
Feb. 19, 1987
Katsumi Kouno, Susono, JP;
Susumu Okawa, Aichi, JP;
Masami Sugaya, Susono, JP;
Yoshinobu Soga, Susono, JP;
Toyota Jidosha Kabushiki Kaisha, Aichi, JP;
Abstract
A hydraulic control system for a continuously variable transmission for an automotive vehicle, the transmission having a first and a second variable-diameter pulley provided on respective first and second shafts, a belt connecting the first and second pulleys, and a first and a second hydraulic cylinder for changing effective diameters of the first and second pulleys. The control system includes a first pressure regulating valve for regulating the pressure of a fluid delivered from a pressure source, and thereby establishing a first line pressure, a shift-control valve for applying the first line pressure to one of the first and second cylinders, while simultaneously permitting a flow of the fluid from the other cylinder, thereby changing the effective diameters of the first and second pulleys, and a second pressure regulating valve for regulating the pressure of a discharge flow of the fluid flowing from the above-indicated other cylinder through the shift-control valve, and thereby establishing a second line pressure lower than the first line pressure.