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:
Apr. 15, 2003
Filed:
Mar. 14, 2001
Yoshikazu Miyagawa, Fuji, JP;
Satoshi Sakakibara, Fuji, JP;
Jatco Transtechnology Ltd., , JP;
Abstract
A CVT has primary and secondary pulleys, and a control unit for controlling the transmission ratio by controlling the line pressure applied to the first and secondary pulleys. The control unit calculates a standard step position of a step motor corresponding to the target transmission ratio and provides a command signal representative of the difference between the standard step position and the current position of the step motor. A shift control valve actuated by the step motor controls the pressure to be applied to the primary pulley. The control unit compares the actual transmission ratio with the target transmission ratio, and if the shift is not completed, the control unit commands an additional step number. Unless the shift to the HI side is accomplished when the additional step number reaches the threshold value, the line pressure is increased to achieve the shift.